System, method and user's terminal in system of unambiguous determination of location with the use of two satellites on lo- altitude near-earth orbit

FIELD: location of objects, in particular, user's terminals, with employment of means of satellite communication system.

SUBSTANCE: the offered system has a mobile telephone set, interline integration unit, at least two satellites with known orbits, means for determination of such parameters as the distance from the user's terminals to each of the satellites and their difference. Provision is also made for means (one or both) for determination of such parameters as the radial velocity of one of the satellites relative to the user's terminal and the difference between the radial velocities of one and the other satellite relative to the user's terminals. The means for location of the user terminal in the interline integration unit is engageable with the above means. It acts on the basis of the known positions and velocities (orbits) of the satellites and the above parameters: distances of satellites from the user's terminals, radial velocities and the their differences. Estimations of the positions of the satellites are specified on the basis of processing of the results of measurements of the given parameters.

EFFECT: provided unambiguous location of the user's terminal with a high speed of response.

28 cl, 13 dwg

The technical field

The invention relates to determining the location of objects using artificial satellites and, more specifically, to a system and method for determining the location of a user terminal in a satellite communication system using measurements performed on both ends of the link.

Prior art

A typical satellite communication system contains at least one terrestrial base station (node firewall mates), at least one user terminal (e.g. mobile phone)and one or more communications satellites to relay communications signals between the host firewall mates and the user terminal. Referred to the firewall node interfacing the communication channels from the user terminal to other user terminals or communication systems, such as terrestrial telephone system.

Developed various communication systems, multiple access, designed for the transmission of information between a large number of system users. These methods include such techniques spread spectrum, multiple access with time division multiplexing (mdvr), multiple access frequency division multiple access (FDMA equipment) and multiple access code division multiplexing (mdcr), the foundations of which is well known in the art. Methods mdcr in the communication system of multiple access are disclosed in U.S. patent No. 4901307 dated February 13, 1990 on “communication System multiple access spread spectrum using satellite or terrestrial repeaters”, and in application for U.S. patent No. 08/368570 from January 4, 1995 for “Method and apparatus for using full spectral transmit power in a communication system with spread spectrum for tracking the phase and energy of the individual caller, which is assigned to the assignee of the present invention.

In the above-mentioned patent documents disclosed communication systems, multiple access, in which a large number in the General case of mobile or remote systems use user terminals to communicate with other system users or users connected systems, such as the public switched telephone network (PSTN). User terminals communicate through the firewall nodes mates and companions using communication systems mdcr spread spectrum.

Communication satellites form beams that illuminate the spot or irradiated region by sending satellite signals due to the Earth's surface. Typical chart satellite beam in this spot contains a number of beams arranged in a tentative is but a specific configuration of the work area. In a typical case, each beam contains a number of so-called sub-beams (also called channels mdcr)that fills the whole territorial area, and each uses a different frequency band.

In a typical communications system spread spectrum uses a set of pre-selected sequence of pseudo-random noise (PN) code designed to modulate (i.e. spread spectrum) of information signals in a predefined spectral range before carrying out modulation of the carrier frequency for transmission in the form of communication signals. The broadening of the spectrum due to the use of PN code representing widely known from the prior art method of transmitting spread spectrum, ensures the formation of a transmitted signal bandwidth is much greater than the bandwidth of the data signal. In a straight line (i.e. the line coming from the firewall node pair and ending at the user terminal) are used PN spread spectrum codes or binary sequences that allow discernment of the signals transmitted by node firewall mates in various rays, and the distinction signal multipath propagation. These PN codes are typically shared among all communication signals within dannoharu-beam.

In a typical system, mdcr spread spectrum used channel codes to ensure distinguish between signals intended for a specific user terminal, transmitted within a satellite beam in a straight line. I.e. the unique orthogonal channel is provided for each user terminal in a straight line through the use of unique channel orthogonal code. Usually for the implementation of channel codes are Walsh functions with a typical length of the order of 64 item code for terrestrial systems and 128 of the code elements for satellite systems.

Typical communication system mdcr spread spectrum, such as described in U.S. patent No. 4901307, involve the use of coherent modulation and demodulation for communications with the user terminals in a straight line. In communication systems that use this method. as a coherent phase support is used, the pilot carrier signal (hereinafter pilot signal). This means that the pilot signal, usually without modulation data signal transmitted by node firewall mates for the entire service area. Only one pilot signal is typically transmitted by each node firewall pairing for each beam used for each frequency. These pilot signals are shared among all users who ski terminals, receiving signals from a host firewall pair.

Pilot signals are used by user terminals to achieve initial synchronization in the system, and to provide tracking time, frequency and phase for other signals transmitted by nodes firewall pair. The phase information obtained from the escort carrier pilot signal, is used as the reference phase of the carrier frequency for the implementation of coherent demodulation other system signals or traffic signals. This method enables multiple traffic signals to share a common pilot signal as a reference phase, thereby ensuring the implementation of more efficient and effective tracking mechanism.

If the user terminal is not involved in the communication session (i.e. the user terminal cannot receive or send signals traffic), then the firewall node pair can transmit information to a specific user terminal using the signal, known as the signal search call (paging signal). For example, if a call must be placed on the particular mobile phone, the node firewall mates notifies the mobile phone using the paging signal. Peringome signals are also used for the allocation of the value assignment of traffic channels, provide access to the assigned channels and to send a service system information.

The user terminal can respond to the paging signal by the signal transmission access or attempt to access the return line (this line originating from the user terminal and terminating at the firewall node pair). The signal access is also used when the user terminal initiates the call.

When you need to exchange information with the user terminal, the system may require determining the position of the user terminal. The need for information about the location of the user terminal due to several reasons. One of them is that the system should choose the appropriate host firewall mates for providing a communication channel. One aspect of this problem is to distribute the communication line to the appropriate service provider (e.g., telephone company). The service provider in a typical case is assigned to a specific geographical area and serves all calls to users on this site. If you need to communicate with a specific user terminal, the communication system may assign this service call the service provider, based on the territory, where n is a thing the user terminal. To determine the appropriate area, the system needs information about the location of the user terminal. Similar problems arise when the call should be assigned to service providers with regard to political boundaries or in the case of services, the associated contractual obligations.

Fundamentally important in determining the location of a satellite communication system is speed. If you want to communicate with a specific user terminal, the firewall node pair, which is allocated to service to the user terminal should be chosen with high performance. For example, for a mobile user, in all probability, would have been unacceptable delay more than a few seconds when placing a call. Requirements for positioning accuracy is less important than the requirements of speed. Error less than 10 km is considered quite acceptable. In contrast, most traditional ways of positioning satellite systems make high demands on accuracy than speed requirements.

One of the known approaches used in the TRANSIT system the U.S. Navy. In this system, the user terminal performs continuous dopiero the ski measurement signal, transmitted in broadcast mode by satellite in low earth orbit. Such measurements continued for several minutes. The system usually requires two passes of the satellites, which leads to having to wait for more than 100 minutes. Furthermore, since the calculation of the location is performed by user terminal, the satellite must transmit in broadcast mode information related to its location (also called " ephemeris”). Although the TRANSIT system provides high accuracy (about one meter), the delay associated with the measurements in this system, unacceptable for use in commercial satellite communication systems.

Another traditional approach is used in systems ARGOS and SARSAT satellite system for search and rescue). In this approach, the user terminal transmits intermittent beacon signal to the receiver on the satellite, which carries out measurement of the signal frequency. If your companion takes more than four beacon signals from the user terminal, he can usually determine the location of the user terminal. Since the beacon signal is intermittent, continuous Doppler measurements, such as performed by the TRANSIT system, not implemented. In addition, the solution is ambiguous, providing the possibility of obtaining R the solutions with a certain probability on each side of the ground area (i.e. line on the earth's surface directly under the satellite trajectory).

Another traditional approach used in the global positioning (GPS). In this method, each satellite transmits in broadcast mode signal with time stamps, which includes satellite ephemeris. When the user terminal receives the signal of the GPS system, the user terminal measures the transmission delay relative to its own clock generator and determines pseudodominant to the location of the transmitting satellite. The GPS system requires the use of three satellites for two-dimensional positioning and four satellites for four-dimensional positioning.

One of the drawbacks of this method based on the use of GPS is that at least three satellites are required to determine the location. Another disadvantage of this method is that due to the calculations performed by the user terminal, the satellites of the GPS system must transmit in broadcast mode in their ephemerides, and the user terminal must have the computational resources to perform the required calculations.

One of the disadvantages of all the methods mentioned above is that the user terminal must is to have a separate transmitter or receiver, in addition to that required for processing communication signals, to use these methods.

Another conventional method is disclosed in U.S. patent No. 5126748 of 30 June 1992 on “Dual-mode satellite navigation system and method”. In this way there are two companion for the active location of the user terminal on the three sides. The disadvantage of this method is that the solution is ambiguous, providing two possible locations. Additional information needed to resolve the specified ambiguity.

Thus, there is a need in a satellite-based location system, which provides an unambiguous positioning with high performance.

The invention

The present invention provides a system and method unambiguous n high speed positioning of the user terminal (e.g. mobile phone) in a satellite communication system such as communication system that uses satellites in low-earth orbits. The system includes a user terminal, at least two satellites with known locations and known velocities and the firewall node pair (i.e. terrestrial base station) to make the ing communication with the user terminal via satellites. The method includes the steps of determining the set of parameters that describe the temporal and spatial correlation between the user terminal and the satellites. and calculate the location of the user terminal using some or all of the parameters, as well as known locations and known velocities of the satellites.

Can be used four parameters: range, rate of change of range, the difference between the distances and the difference of the speed change ranges. The parameter “distance” represents the distance between the satellite and the user terminal. The parameter “difference range” is the difference between (1) the distance between the user terminal and the first satellite and (2) the distance between the user terminal and the second satellite. Parameter rate of change of range” represents the relative radial velocity between the user terminal and the satellite. The parameter “speed difference change range” is the difference between (1) a relative radial velocity between the user terminal and the first satellite and (2) a relative radial velocity between the user terminal and the second satellite.

In the first embodiment of the invention uses the range, the difference between the distances and the difference between the SC is Rasta change ranges. In the second embodiment of the invention uses a range, the rate of change of the distance and the difference of the distances. In the third embodiment of the invention uses all four parameters. In a preferred embodiment of the invention uses an iterative weighted least squares Gauss-Newton to calculate the location of the user terminal based on the used parameters and the known locations and velocities of the satellites.

One of the advantages of the present invention is that it provides an unambiguous, high-speed positioning.

Another advantage of the present invention is that it provides positioning with high performance when using only two satellites.

Another advantage of the present invention is that it provides positioning with high performance without requiring transmission from the satellites to the user terminal information about their ephemeris for use in determining the location.

Another advantage of the present invention is that it provides positioning with high performance in the communication system without requiring polzovateley the x terminal determine your location.

Brief description of drawings

The characteristics and advantages of the present invention are explained in the following detailed description, illustrated by the drawings, in which identical reference positions denoted by identical or functionally similar elements. The left digit of the reference position indicates the number of the drawing on which this reference position appeared for the first time.

Figure 1 - representation of typical satellite communication system;

figure 2 - block diagram of an example implementation of a transceiver for use in a user terminal;

figure 3 - block diagram of the transmission device and the reception for use in the host firewall mates.

4 is a block diagram of the circuit of the provisional tracking for use in a user terminal;

5 is a block diagram of the contour tracking speed for use in the user terminal;

6 is an image of the sub-satellite point for the two satellites and the projection on the earth's surface isocontours parameter range, the difference between distance and difference of speed change ranges relating to satellites;

7 illustrates the case where the parameter is the rate of change of distance can not resolve the singularity GTS (geometric factor affecting accuracy), presents a method of positioning using only parameters [daln] the STI and the difference ranges;

Fig image ground truth points for the two satellites and the projection on the earth's surface isocontours parameter range, the difference between distance and rate of change of ranges related to satellites;

figa is a graphical representation of frequency components of the signal measured in the user terminal;

FIGU is a graphical representation of frequency components of the signal measured in the firewall node pair;

figure 10-12 is a flowchart of sequences of operations according to the preferred options for implementation of the present invention and

Fig is a block diagram illustrating a computer environment, which can be accomplished the present invention.

Detailed description of preferred embodiments of the invention

1. Introduction

The present invention relates to a system and method to uniquely identify the location of a user terminal in a satellite communication system using at least two satellites in low-earth orbits. As will be clear to experts in the art, the principle of the present invention can be applied to satellite systems, in which the satellites are moving and not in low-earth orbits, if the relative movement between the satellite and the user terminal dostatochno, to provide a measure of the rate of change of range, as described below.

Below are described in detail preferred embodiments of the present invention. Although describes specific steps, configurations and devices, however, specialists in the art it should be clear that this is done only for illustrative purposes. For a specialist in the relevant field of technology it is clear that can be used and other stages, other configurations and devices without changing the nature and scope of the invention.

The present invention will be described in four sections. First will be described a typical satellite communication system. Secondly, it describes the parameters. used in methods of positioning in the system. Thirdly, it describes the actual methods of positioning on the basis of their physical representations. And finally, describes the implementation of these ways of positioning.

2. A typical satellite communication system

Figure 1 illustrates a typical satellite communication system 100. The satellite communication system 100 includes a host firewall pair 102. satellites A and B and user terminals 106. User terminals 106 are usually of three types: fixed user terminals A, which in a typical case, is embedded in the fixed structure; a mobile user is the cue terminals V, which in a typical case installed in the vehicle, and portable user terminals S, which in a typical case are portable. The firewall node pair 102 communicates with the user terminal 106 via satellites A and B.

An example implementation of the transceiver 200 for use in a user terminal 106 shown in figure 2. The transceiver 200 uses at least one antenna 210 for receiving communication signals that are transmitted to the analog receiver 214, where they are converted with decreasing frequency, amplified and converted into digital form. To run a single antenna functions such as reception and transmission using duplexer 212. However, some systems use separate antennas for the opportunity to work at different frequencies.

Digital communication signals from the output of the analog receiver 214 are served by at least one digital data receiver A and digital search receiver 218. You can use the additional digital data receivers 216B-216N in a configuration known as multi-tap receiver, to ensure the required levels spaced signal processing, depending on the acceptable level of complexity of the units, as is obvious to experts in the field of technology. The receiver is made in so the second configuration, is called multi-tap receiver, each digital data receiver 216 (A-N) is called a “challenge”.

Taps tap receiver are used not only to ensure explode signal, and for receiving signals from multiple satellites. Therefore, the user terminal implementing the method for determining location using two satellites corresponding to the invention should be used at any given time at least two digital data receiver 216A-216N for receiving signals from two satellites. In addition, the second search receiver 218 or more of such receivers can be used to provide a signal is detected with high performance, or one or more receivers can be used together to solve this problem.

At least one control processor 220 of the user terminal is electrically connected to digital data receivers 216A-216N and with the search receiver 218. Control processor 220 provides, among other functions, basic signal processing, control and synchronization, power and procedure for switching the channel of communication or coordination and selection of the frequency to be used as load-bearing signals. Another major function of management, frequently executed control processor 220 is breeding is whether manipulation pseudocumene code sequences or orthogonal functions, intended for use in the processing of communication signals. The signal processing implemented by the control processor 220 may include a definition of the parameters used in the present invention. Such computations of signal parameters, such as relative time or frequency, may include the use of additional or separate specialized schemes to improve the efficiency or speed measurements or to improve the distribution of processing resources, providing management.

Outputs digital data receivers 216A-216N are electrically connected with custom circuits 222 digital signal processing baseband in the user terminal. Custom schema 222 digital signal processing baseband contain elements of processing and presentation to be used for forwarding information to the user terminal from the user terminal. This means that the elements storing signals or data, such as operational or long-term digital memory; the water device or output, such as display screens, speakers, keypad and handset; etc. form an integral part of custom circuits signal processing baseband, well known in the art. If the COI is processing box is used with distributed signals, the custom schema 222 digital signal processing baseband can include a block of combining signals with diversity and decoder. Some of these elements may operate under control of a control processor 220 or when exchanging information with him.

When speech or other data signal is generated as an output message or communication signal, originating from a user terminal, the user circuit 222 digital signal processing baseband used for receiving, storing, processing and other skills necessary data for transmission. Custom schema 222 digital signal processing baseband give these data to the modulator 226 transfer, operating under control of a control processor 220. The output signal of the modulator transmission 226 is transmitted to the control unit with a capacity of 228, which provides control of the output power of the transmit power amplifier 230 for transmitting the output signal via the antenna 210 to the host firewall pair.

The transceiver 200 may also use one or more elements of the pre-correction 232 and 234. The work of such items prior to the correction described in co-filed patent application of the same applicant on a Temporary and preliminary frequency is orecchio for systems using non-geostationary satellites” (case number a patent attorney RA). Preferably, the pre-correction is performed on the output of the digital control unit with a capacity of 228 frequency baseband. The spectral information of the baseband, which includes frequency, is converted to the corresponding Central frequency conversion process with increasing frequency, are performed in the transmit power amplifier 230. Prior correction or adjustment of the frequency is performed using well known methods. For example. pre-correction can be performed by rotating the phase of the complex signal, which is equivalent to multiplying the signal by a multiplier of e^jωtwhere ω is calculated based on the known satellite ephemeris and the desired channel frequency. Very useful is the processing of communication signals using in-phase (I) and quadrature (Q) channels. Devices direct digital synthesis can be used to generate products such rotation phase. As an option, can be used in digital computing element to rotate the coordinates, which uses a binary shift operations. summation and subtraction to perform a sequence of discrete turns, with that which can be obtained required a full turn. Such methods and implement their hardware well known in the art.

As a possible variant, the element of pre-coding 234 may be included in the transmission path at the output of amplifier 230 transmit power to set the frequency of the outgoing signal. This can be implemented using well-known operations such as transformation with increasing and decreasing frequency of the transmitted signal. However, the frequency change of the analog output of the transmitter may be more difficult, so as to obtain the desired waveform is often used a number of filters, and change the connection sequence can interfere with the filtering process. As a variant, the element 234 preliminary correction can be part of the mechanism of the frequency selection or control for cascade (230) analog-to-digital conversion and modulation of the user terminal, so that accordingly the converted frequency is used to convert the digital signal to the desired transmit frequency using a single stage of processing.

Information or data relating to one or more measured parameters for received communication signals, or signals of one or more shared resources, can be transmitted to the host firewall's supra is possible using various methods, known in the art. For example, information can be transmitted in a separate information signal or added to other communications prepared custom circuits 222 digital signal processing baseband. Alternatively, information can be entered in the form of predefined bits of the control modulator 226 transfer or control unit 228 delivered power under control of a control processor 220.

Digital data receivers 216A-N and search receivers 218 contain elements of the correlation signal processing to implement the demodulation and tracking specific signals. Search receivers 218 are used to search for pilot signals or other powerful signals with a relatively constant characteristic, while digital data receivers 216A-N are used for tracking pilot signals or for demodulation of signals associated with the detected pilot signals. Therefore, the output signals of these blocks can be controlled to obtain information used to calculate parameters used in the present invention. Information measurements performed user terminal 106 over the received communication signals or signals of the shared resources may be transferred to the firewall node pair is of using different methods known in the art. For example, information can be transmitted as a separate signal data, or it can be added to other messages generated custom circuits 222 digital signal processing baseband. Digital data receivers 216 (A-N) also use elements of the tracking frequency, which can be driven so as to produce the control processor 220 information about the current frequency and time for demodulating signals. This is discussed below with reference to figure 4 and 5.

Control processor 220 uses the information to determine the extent to which received signals are shifted relative to the expected frequency based on the frequency of the local oscillator and converting the same bandwidth as necessary. This and other information related to the shifts of the frequency error and Doppler shift, can be saved in one or more memory elements 236 errors and Doppler shifts, if necessary. This information can be used by the control processor 220 for setting the operating frequency or may be transferred to the host firewall mates using different communication signals.

At least one element 238 time reference is used for generating and storing historical information, such as Dana and time with the current, to support the determination of the positions of the satellite. Time can be saved and updated periodically. Time may also be periodically sent to the host firewall pair. In addition, the current time is saved each time the user enters an inactive mode, i.e. when it shuts down. This time value is used in conjunction with on-time to determine various parameters of the signal, time-dependent, and changes the location of the user terminal.

In addition, the memory elements 240, 242 can be used to store specific information about the parameters that will be discussed in more detail below. For example, the memory element 240 may store the measurement data of the user terminal, made in connection with such option, as the rate of change of range, for example, the difference in relative frequency shifts between the two incoming signals. The memory element 242 can be used to store measurement data of the user terminal, made in connection with such option, as the difference in distance, for example the difference in time of arrival of two signals. This memory elements use patterns and schemes well known in the art, and can be performed as separate items or as a large joint structure in which a specified informatiekunde thus, to be able to search and retrieve.

As shown in figure 2, the local oscillator 250 is used as a reference source for the analog receiver 214 to implement down-convert the incoming signal in the frequency band of the modulating signals at the desired frequency. It can be implemented using several intermediate stages of conversion, if this is desirable, as long as the signal will not appear in the desired frequency band of the modulating signals. The local oscillator 250 is also used as a support for the analog transmitter 230 for the implementation of the enhancing conversion of the signal from the frequency band of the modulating signal at the desired carrier frequency for transmission over the reverse link, as well as a frequency standard or support for the scheme clocking 252. The clocking scheme 252 generates clock signals for the various stages or elements of the processing in the user terminal 200, such as schemes of temporary tracking correlators in digital receivers A-N and 218, the modulator 226 transfer element 238 time reference and control processor 220. The clocking scheme 252 may be configured to generate delays to ensure lag or timing relative to clock signals or clock signals, that is p and processor management. This means that a temporary tracking can be adjusted to a predefined value. Can also be applied codes delayed or ahead of a relatively “normal” clocking in a typical case, one or several periods of the sequence of code elements that PN codes or elements that make up these codes could be used with different clocking, if necessary.

Possible implementation of the device 300 to transmit and receive use in the firewall node pair 102 are presented in figure 3. The host portion of the network 102 mates presented in figure 3, contains one or more analog receivers 314 associated with the antenna 310, intended for reception of communication signals, which are then converted with decreasing frequency, amplified and converted into digital form using a variety of schemes well known in the art. In some communication systems may use multiple antennas 310. Digitized signals from the analog receiver 314 are fed to the input of at least one module 324 digital receivers.

Each module 324 digital receivers corresponds to the elements of the signal processing used for the management of information exchange between the host firewall pair 102 and one user terminal 10, although some modification of the considered variants known in the art. One analog receiver 314 may provide input signals for multiple modules 324 digital receivers, and a certain number of such modules typically used in the nodes of network 102 mates with all satellite-rays and possible signals of the receive diversity mode to be processed at any given time. Each module 324 digital receivers contains one or more digital data receivers 316 and search receivers 318. Search receiver 318 in General searches for signals on appropriate modes of receive diversity, other than pilot signals, and multiple receivers can be used in parallel to increase the speed of search. In the communication system, the set of digital data receivers A-316N are used for diversity reception of signals.

The output signals of the digital data receivers 316 served on the device that contains the processing elements 322 in the frequency band of the modulating signals is well known in the art and are not discussed in more detail. Option processing device in the frequency band of the modulating signal includes blocks combining signals received with diversity, and decoders, for combining signals INR is luchevogo distribution into a single output signal for each user. Option processing device in the frequency band of the modulating signal also includes diagrams of interfaces to provide output data, supplied in a typical case, a digital switch or network. Various other known elements, such as vocoders, data modems, the switching elements of the digital data and the memory can be included in the device 322 processing in the frequency band of the modulating signals. These elements provide control sending data signals to one or more communication module 334.

The signals transmitted to the user terminals 106, served on one or more communication module 334. Typical firewall node pair uses a number of communication module 334 to allow for the simultaneous maintenance of multiple user terminals 106 and simultaneously for multiple satellites and beams. The number of communication module 334, used by host firewall pair 102, is determined by factors well known in the art, including system complexity, number of satellites simultaneously in view, the throughput of users, the degree explode when receiving, etc.

Each transmission module 334 includes a modulator transmission 326, which modulates a broader spectrum of transmitted data. The output of the modulator 326 associated with cyfrowy the control unit 328 power transmission, which controls the transmission power of the outgoing digital signal. The digital control unit 328 power transmission in the General case uses the minimum power level in order to reduce mutual interference and efficient allocation of resources, but can also use the appropriate power levels, if necessary, compensate for the attenuation in the transmission path and other characteristics of the transmission path. Generator 332 PN signal is used in the modulator transmission 326 for spread spectrum signals. This code generator can form a functional part of one or more control processors or memory elements used in the firewall node pair 102.

The output signal of the digital control unit 328 the transmit power is supplied to the adder 336, where it is summed with output signals from other control units transmit power. These output signals represent the signals intended for transmission to other user terminals 106 on the same frequency and within the same beam as the output signals of the control unit 328 power transmission. The output signal of the adder 336 is applied to the analog transmitter 338 for digital to analog conversion, conversion to the desired radio frequency (RF) carrier, subsequent amplification, filtering and filing one or more antennas 340 for transmission to the user terminal 106. Antenna 310 and 340 may be the same antennas, depending on the complexity and configuration of the communication system.

At least one control processor 320 firewall node pair is electrically connected to the modules 324 receivers, communication module 334, and a processing circuit 322 in the frequency band of the modulating signals. These blocks can be physically separated from one another. Control processor 320 provides commands and control signals to implement functions such as signal processing, generating signals, power control, the control procedure for switching communication channels, combining diversity signals and interfacing systems. In addition, control processor 320 distributes codes PSH signals spread spectrum, orthogonal code sequence, and a separate transmitters and receivers or modules for use in information exchange with users. In addition, control processor 320 may be used to calculate parameters and implementing the positioning method corresponding to the present invention.

Control processor 320 also controls the generation of the pilot signal and its power, sync, paging channel signals and their supply to the control unit 328 power transmission. Channel pilot signal submitted is just a signal, not modulated data, and can use the duplicate permanent structure or permanent structure of the frame. I.e. orthogonal function used for formation of the channel pilot signal, in the General case has a constant value, such as all “1” or all “0”or a well-known repeating structure of alternating “1” and “0”.

Although control processor 320 may be electrically connected directly to the module elements, such as transmission module 334 or the receiving module 324, each module in the General case contains specific module processor, such as processor transmission 330 or the processor receiving 321, which controls the elements of this module. Thus, in the preferred embodiment, control processor 320 is electrically connected to processor transfer 330 and processor receiving 321, as shown in figure 3, and can manage a large number of modules and other resources more efficiently. The processor of the transmission 330 controls the generation of the signal power for the pilot signal, signals, paging signals, the signals of the channels of traffic, and supply them to the control unit with a capacity of 328. The processor receiving 321 controls the search, PN codes of the spread spectrum signals for demodulation and control of the received power. The processor 321 may be used when determining the parameters, the IP is alzhemed in this way, corresponding to the invention, or can be used to detect and transmit information received from a user terminal associated with such parameters, thus reducing the computational load control processor 320.

For the implementation of embodiments of the present invention can be used one or more blocks of the pre-correction or items pre-equalization 342 and 344. Preferably the element correction 342 is used to set the frequency of the digital output signal of the digital control unit 328 power on the frequency band of the modulating signals. As in the user terminal, the spectral information of the frequency band of the modulating signals, including frequency setting, is converted to the corresponding Central frequency in the process of increasing the conversion performed in the analog transmitter 338. Pre-equalization is performed using methods known in the art, such as the rotation phase of the complex signal, described above, and the angle of rotation is determined from the known satellite ephemeris and the desired channel frequency. As in the user terminal, can be used other ways of rotating the phase of the signal and the corresponding hardware and without the application of the essence and scope of the present invention.

In addition to the pre-equalization may be desirable to perform a preliminary temporary correction to change the relative synchronization signals or PN codes. This is done by setting the generation and synchronization codes or settings synchronization with other signals, when the signal is generated in the frequency band of the modulating signal before issuing its control unit with a capacity of 328. For example, the control unit 320 may determine when the codes are generated, their relative synchronization and superimposed on the signals, and when the signals affect the modulator transmission 326 and transferred to different satellites using control unit with a capacity of 328. However, the known elements or circuits preliminary frequency correction, in the form of separate blocks, similar to the elements of the pre-correction 342, 344, and parts of these blocks can be used without application of the elements of the preliminary frequency correction or addition to it.

Figure 3 element correction 342 is shown as included in the transmission path before the adder 336. This allows individual control of each signal of the user terminal. However, you may have a single item prior to correction, if the pre-correction is performed after the adder 336, as user terminals share the same transmitting path from the node firewall mates to the satellite.

As a possible variant, the element correction 342 may be included in the transmission path at the output of the analog transmitter 338 to set the frequency of the outgoing signal using well-known methods. However, the frequency change of the analog output of the transmitter may be more difficult and may interfere with the procedures of filtering signals. Alternatively, the output frequency analog transmitter 338 can be configured directly using the control processor 320 to provide a shifted output frequency that is offset from the normal Central frequency.

The magnitude of the frequency correction applied to the outgoing signal based on the well-known Doppler shift between the firewall node pair and each satellite, through which communication is effected. The amount of shift required to compensate for the Doppler shift of the satellite can be calculated control processor 320 using well-known data of the orbital position of the satellite. These data may be buffered in one or more storage devices 346, such as lookup tables or memory elements, and then extract what I can from them. These data can be obtained from other data sources, if this is desirable. The memory elements 346 can be performed on various well-known circuits, such as a mass storage device with random access (NVR), a persistent storage device (ROM), or magnetic memory elements. This information is used to implement Doppler settings for each satellite used by the firewall node pair at a specific point in time.

As shown in figure 3, the block reference time and frequency (BWC) 348 provides the reference signal frequency for the analog receiver 314. The universal time signal from the GPS receiver may be used in some applications. It can also be used for a number of stages of frequency conversion. BWC 348 also provides the reference signal for the analog transmitter 338. BWC 348 also provides signals to other stages or elements of the processing device transmitting and receiving node 300 firewall mates, such as correlators in digital receivers 316-N and 318, the modulator transmission 326, control processor 320. BWC 348 is also the possibility of introducing a delay or advance a certain value in the signals relative timing or clock signals, under control of a processor. Possible measurement C is chronic illustrated in figure 4, which presents the contour of the provisional tracking 400 to the user terminal. This type of contours of the provisional tracking in the prior art define the term Tau Dither, as is known in the art. According to figure 4, the incoming communication signals from the analog receiver in a typical case is discretized with increased sampling frequency and then entered in the decimation filter 402. The decimation filter 402 operates with the pre-selected frequency and constant, in order to transmit only certain samples for the subsequent stages of the receiver.

Thinned sample is transmitted to the Union element 404, in a typical case, the multiplier, for Association with the corresponding PN code of the spread spectrum produced by a generator or source 406 PN code. to accomplish the compression of the signal. The compressed signal is supplied to the Union element 408, where it is combined with the corresponding functions W_ideveloped by the generator or source 410 to retrieve the data. Functions orthogonal code correspond to those used to create channels of communication signal. In the General case for implementing this procedure uses the pilot signals or paging signals, although they may be used and other powerful signals. The orthogonal code is a code used to generate the pilot is ignal or paging signal, as is well known in the art. Alternatively, spread spectrum codes or orthogonal codes can be combined together and then combined with the sample at any stage of processing, as is known in the technique.

The temporary path tracking can use the scheme “lead/lag”, as described in U.S. patent No. 4901307, as mentioned above. This approach measures the degree of overlapping clocking the incoming signals and digital receivers 216 using samples of the incoming data stream is shifted relative to the nominal time of the code element. This offset is plus or minus half the repetition period of the elements of the PN code, and consequently is lagging and leading.

If the timing of these data, positive or negative shift differs from clocking peaks nominal compressed incoming signal in a symmetric manner, the difference between the values of the samples with delay and advance equal to zero. This means that the value obtained by forming the difference between the trailing and leading signals, zero if the offset half of the code element centered on “timely” clocking the received signal. If the relative timing used by the receivers 216, does exactly Taktarov is their received signal, and is leading relative to the incoming data signal, the difference between the retarded and advanced samples generates an adjustment signal, which has a positive value. On the other hand, when the clocking signal is delayed, then the difference between the retarded and advanced samples generates an adjustment signal, which has a negative value. Obviously, if desired, you can use inverse or other value.

To implement this method, the output signal of the thinning filter is controlled so as to appear on half of the code element earlier than the nominal value used for the demodulation of signals. Then the output signal of the decimation filter is compressed and decoded, and the resulting data are accumulated over a pre-selected interval (in a typical case, during the period character) in the memory 414. The accumulated character data provide values of energy of character signal, which are squared in element 416 squaring to obtain a non-negative value for “ahead” signal.

Another set of samples is accumulated and summed or integrated over the next pre-selected period using the drive 414. However, during this period a set of elementinstance 412 is used to delay submission of PN and orthogonal code by one period of the sequence of code elements. This has the same effect as changing the clocking of samples or thinning, with the formation of the “retarded” copy compressed and decoded data. These compressed and decoded data are stored on the pre-selected time period in the memory 414. If necessary, you can use the additional elements and storage devices. The accumulated character data are squared in element 416 squaring. The resulting quadratic ahead and lagging values are subtracted from each other or are compared to obtain the difference-ahead-delayed clocking element 418. This difference is filtered using a filter 420 clocking to generate a signal 422 lead-lag. The contour of the provisional tracking continues to implement alternating between using nesuderinama and delayed codes for the formation of the lead-lag characters that are used to update or generate a signal 422 lead-lag. This continues up until clocking receiver is not installed in its original state, that corresponds to the translation of the receiver in the inactive state or in a state tracking for a new signal that is clear to a person skilled in this field, those who Nicky.

The initial and current control constant for the process of thinning and delay codes are provided by such schemes as the circuit 424 of the control clock. Circuit 424 control clock determines the timing of sampling with filter thinning 402. At the same time expanding the range by using the PN code, and generating the orthogonal code are controlled by signals from circuit 424 of the control clock. This clocking is sometimes called the inclusion of the PN signal, because it involves the use of codes. May also be used in the initialization signal or the signal of the synchronization period. Clocking selected with schema 424 control constant. adjusts signal timing/delay 422 in response to the output signal of a closed loop clocking. In General clocking is ahead at an interval of time equal to the period the item code, e.g., 1/8 of the length of the code, if you use a discretization with increased 8 times frequency, for receiving the input signal prior to decimation. The use of such a clocking mechanism and lead/lag is well known in the technique.

The amount by which each allotment digital receiver adjusts its timing to synchronize or align with the input signal, is used to determine the relative is alergic time of signal arrival. This is easily done by tracking the full value of time changes (lead/lag)used closed circuit 400. The memory 426 may be used to accumulate and summarize each signal lead/lag or commands at pre-selected time interval. It gives a complete or total value of the changes required to align the clocking of the incoming signal and the receiver. It is the mixing signal from the local user terminal or clocking receiver. If the clocking of the user terminal is relatively close to the clock node firewall mates or synchronized, it can provide a measure of the delay experienced by the signal during its propagation between the firewall node pair and a user terminal that allows you to calculate the distance. Unfortunately, many factors, such as the inaccuracy or drift of the lo frequency, prevent such direct calculations.

However, setting the clocking of the two digital receivers 216 can be used to retrieve the value of the relative time difference of arrival of signals. Here each digital receiver receives the signal from the satellite A or B, and define the settings clocking requires tracking signal. the adjusting clocking can be issued either directly to the control processor or a specialized computing element, forming the difference between these two values. This difference shows the relative difference in time of arrival of two signals in the user terminal, and the obtained value can be passed to the firewall node pair.

As mentioned above, these data can be transferred to the host firewall mates as part of other messages or as special signals containing information about the time. Data can be stored in transient memory elements for subsequent shipment and use. Information may also be issued or to be remembered with some “time stamp reflecting the time of its receipt, so the firewall node pair has the exact temporal relation to the data and has the ability to more accurately determine the location of the user terminal. However, the accuracy desirable in communication systems, as mentioned above, is not a very stringent requirement. If information is transferred within a short interval of time after its receipt, the timestamp is not of much use. In General, data is transferred within a few frames of data from the time of their measurement, and if there are problems with the shipment, the data are generated again before shipment, therefore expire not more than a few frames. However ispolzovaniem label provides more flexibility in data transmission and the ability to re-send signal or set of signals regardless of the actual time. Otherwise, the system can use fixed intervals (slots) clocking and requests transmission of messages, if timestamps are used to provide the desired level of precision.

This process is similar to signals received by the firewall node pair, except that there is no detection of the pilot signal and the orthogonal codes in General are associated with signals of the access attempts. One of the advantages for the host firewall pairing is that clocking can be used as an absolute time reference. This means that the firewall node pair has a precise system timing, as mentioned above, and can accurately determine the difference in application time vocational schools or orthogonal codes concerning his own time. This allows the firewall node pair to determine the exact values of the transmission times or distances from the state of the PN codes used for each receiver or diversion. These transfer times or distances can be used to define the parameters of the range or rate of change of range in accordance with the present invention. Therefore, the information for each outlet can be processed separately and does not require a join using element 428, to whom it was addressed above.

Possible measurement frequency is illustrated in figure 5, which shows a circuit 500 tracking frequency, intended for use in the user terminal. These frequency measurement can be used to determine the rate of measuring the distance and velocity difference measurement ranges in accordance with the present invention. As shown in figure 5, the communication signals from the analog receiver serves to block rotation 502. Block rotation 502 operates at a pre-selected, but custom phase to eliminate errors in frequency or offsets in the digital samples received from the analog receiver digital receiver or removal.

When using signals mdcr sample can be transferred to one or more members of the Association 504, in a typical case, the multiplier, for Association with the corresponding PN code of the spread spectrum issued by one or more generators or sources 506, to retrieve the data. These PN codes spread spectrum and orthogonal codes can be combined with the signal either separately or together on one stage. If you are using traffic channels for frequency tuning, the item fast Hadamard transform (BIA) can be used instead of the block Association 504 and code generator 506. This method is disclosed in Z. the turnout in U.S. patent No. 08/625431 on “Monitoring frequency for modulation orthogonal Walsh functions”, assigned to the assignee of the present invention.

The signals from the rotation phase, compressed and decoded, accumulate on the symbol interval in the memory 514 for receiving character data, and the results are given on the element generating the cross-product of vectors or generator 518. At the same time, each character is given by delay element 516 on one character, which introduces a delay of one symbol period before the transmission symbol generator 518 cross-product.

Generator 518 cross-product forms the cross product of the vectors between this symbol and the previous symbol to determine the change in phase between the characters. This provides a measure of the error in the rotation phase is entered in the input signal. The output signal generator 518 cross-product is given as an estimate of the error in the frequency or ratio settings on the unit turn 502 and phase generator 506 of the code.

Management testirovanie for compression and decompression is provided by schemes such as the control circuit 524 constant, as mentioned above. Such timing may be provided in the form of the output signal of the clocking circuit as described above.

The amount by which each allotment or digital receiver adjusts its phase to ensure alignment with the input signal is scrap, used to determine the relative offset of the frequency of incoming signals. I.e. the amount by which the phase of block rotation phase must be configured to eliminate the residual error in the configuration of the signal indicates the amount by which the frequency of the incoming signal is shifted relative to the expected or local reference frequency for the user terminal.

Because the communication system operates within a fixed set of frequency bands for communication signals, the receivers known Central or nominal carrier frequencies to be used. However, as a result of Doppler shifts and other effects, which can be minimum, the incoming signal will not have exactly the expected center frequency. The configuration described above, determine the offset, which can be used to determine the Doppler shifts and the actual frequency of the incoming signal.

This is easily done by tracking the full magnitude of the changes implemented by the circuit 500 tracking frequency. The memory 522 can be used to accumulate the phase changes from estimates of the error signals or commands on a pre-selected interval. This gives full or the resulting magnitude of the change required to align the frequencies of the incoming signal and the receiver, and is the offset the frequency of the signal relative to the local user terminal or frequency receiver, converted to the appropriate frequency band.

As mentioned above, these data can be transmitted to the host firewall mates as part of other messages or as special signals containing information about the frequency. Data can be stored in transient memory for subsequent shipment and can also be supplied with a certain timestamp. However, this is generally not required because data is sent in multiple frames of data from the time of their measurement and can be regenerated if necessary. Otherwise, the system can use fixed intervals clocking and requests transmission of messages, if timestamps are used to provide the desired level of precision.

3. Available options

In a preferred embodiment, the present invention uses a combination of four parameters: range, rate of change of range, the difference between the distances and the rate of change of the difference of the distances. These parameters describe the spatial and temporal correlation between the user terminal 106 and satellites A and B. These parameters, their measurement and application are described below.

Figure 6, 7 and 8 presents projections on the surface of isocontours representing these parameters. Isocontour parameter represents a curve. with the uniting all points having the same parameter value. Figure 6 and 7 shows the sub-satellite point A and B two satellites A and B respectively (i.e. the point on the Earth's surface directly below the satellite) and the projection on the surface of isocontours range, the difference between distance and rate of change of the difference of distances related to satellites A and B. Two axes - x axis A and y axis V, calibrated in thousands of kilometers, are presented to illustrate the approximate scale. On Fig presents the sub-satellite point A and B two satellites A and B respectively, and a projection on the surface of isocontours range, the difference between distance and rate of change of the difference of distances related to satellites A and B.

Range

The parameter range is the distance between the satellite and the user terminal. In a preferred embodiment, the range represents the distance R between satellite 104 to the user terminal 106. The projection of ISO-R-contour on the surface of the Earth describes a circle whose centre is under the appropriate satellite, as shown in phantom lines 604 figure 6. In a preferred embodiment, the distance R is determined by measuring the delay of the bilateral distribution (TDR) signal transmitted from the satellite 104 to Elizavetinskaya terminal 106 and back to the same satellite 104. Then R is obtained by dividing STR by 2 to obtain the one-way delay distribution and multiplying the result by the speed of light, representing the speed of signal propagation. Alternatively, SDR is used as a parameter range.

In a preferred embodiment of the present invention of SDR is measured as follows. First, the signal containing a known PN sequence or code spread spectrum transmitted by node firewall pair 102. The signal is relayed to the user terminal 106 satellite 104. The user terminal 106 pereizuchit signal, either directly or with a known delay. Pereizlucheniya the signal is relayed back to the host network 102 mates with the same satellite 104. The firewall node pair 102 then compares the state of the PN sequence in a received signal with the state of the local PN sequence. The difference between these two States is then used to determine the total delay of the bilateral distribution, which includes a known delay between the host firewall pair 102 and the satellite 104. These delays are known, since the distance between the satellites 104 and the host firewall pair 102 is supported by the firewall node pair 102, as is known in the art. Visit is of the known delay of the full delay bilateral distribution, you can get the value of SDR. Using the known satellite ephemeris, a known delay between the host firewall pair 102 and the satellite 104 can be calculated in various ways well known in the art.

In an alternative embodiment, R is obtained by measuring a “hybrid” delay bilateral distribution of the signal transmitted from the satellite A to the user terminal 106 and back to the second satellite W. In this embodiment, however, the one-way delay of signal propagation can not be simply determined by dividing by 2 “hybrid” delay bilateral signal propagation. Because the measurement involves two satellites requires some information about their relative position. In a preferred embodiment of the present invention, this information is determined from a parameter defined as the difference of the ranges discussed below. To a person skilled in the art should be obvious that this information can be obtained from other dimensions and other parameters. After finding the one-way delay of signal propagation for satellite 104, the distance R is determined by multiplying the one-way delay of signal propagation at the speed of light.

In a preferred embodiment of the present invention gibr is DNA delay bilateral distribution of the signal is measured as follows. First, the signal containing the used PN sequence is transmitted by the host firewall pair 102. The signal is relayed to the user terminal 106 of the first satellite A. The user terminal 106 pereizuchit this signal either immediately or with a known delay. Pereizlucheniya the signal is relayed back to the host network 102 mates with a second satellite W. Then the firewall node pair 102 compares the state of the PN sequence in a received signal with the state of the local PN sequence. The difference in conditions is then used to determine the full hybrid delay bilateral signal propagation based on the known repetition rate of the code elements. Subtraction of known delays between the host firewall pair 102 and the first satellite A and between the firewall node pair 102 and the second satellite V of full hybrid delay bilateral distribution of the signal allows to obtain hybrid delay bilateral distribution of the signal.

For specialists in the art it should be clear that to obtain R, you can use other ways without changing the nature and scope of the present invention.

In a preferred embodiment of the present invention, the delay of the bilateral distribution of si is Nala can be measured in the process of the call, and when the connection of the call. If the measurement is made when establishing the call connection, the measured signal is typically transmitted from a host firewall pair 102 to the user terminal 106 as part of a paging signal is relayed from the user terminal 106 to the host firewall pair 102 in the form of a signal access - If the measurement is made in the call, then the measured signal is typically transmitted from a host firewall pair 102 to the user terminal 106 and back as part of the traffic signals. To a person skilled in the art it is clear that the measured signal may be a signal of another type or may be included in the other signals, if necessary, without changing the nature and scope of the present invention.

The difference ranges

Parameter defined as the difference of the distances is the distance between the user terminal 106 and the two satellites A and B. In a preferred embodiment of the present invention the difference between the ranges is the difference dR between (1) the distance between the specific user terminal 106 and the first satellite A and (2) the distance between the specific user terminal 106 and the second satellite W. Projection from-dR-contours on poverkhnostyami describes a set of hyperbole, as shown by the dotted lines 606 figure 6, and dR=0 is a path in a straight line. In a preferred embodiment of the present invention, the difference of the distances dR is defined as follows. First, the firewall node pair 102 transmits two signals. The first signal is transmitted via the first satellite A to the user terminal 106 and the second signal is transmitted via the second satellite B to the user terminal 106. In a preferred embodiment of the present invention the first and second signals are pre-adjusted time, as described above with reference to figure 3, the firewall node pair 102, so that they pereklokayutsia the first and second satellites A and B essentially simultaneously.

Secondly, the user terminal 106 determines the delay difference between (1) the time at which the user terminal 106 has received the signal from the first satellite and (2) the time at which the user terminal 106 has received the signal from the second satellite. This difference in the delays hereinafter referred to as Δ t. Thirdly, the user terminal 106 transmits a message Δ t to the firewall node pair 102. Finally, the firewall node pair 102 determines from dR Δ t. For specialists in the art it should be clear that to get a dR can is to use other ways without changing the nature and scope of the present invention.

In an alternative embodiment of the present invention Δ t is used as parameter, defined as the difference of ranges.

In a preferred embodiment of the present invention the first and second signals are pilot signals. To a person skilled in the art it is clear that can be used for any other signal without changing the nature and scope of the present invention.

In a preferred embodiment of the present invention the first and second signals are pre-adjusted, as explained above with reference to figure 3, the firewall node pair 102 before transmitting to ensure synchronization of the PN code signals (including relevant shifts of the PN codes for the sub-rays), when they pereklokayutsia satellites A and B, and the user terminal 106 determines Δ t by comparing the States of the PN codes in the two received signals. In an alternative embodiment of the present invention the first and second signals are not pre-adjusted time, but the difference in time of reemission between the first and second signals are eliminated to the firewall node pair 102 after receiving signals. To a person skilled in the art it is clear that can be used other ways of pre-correction is La compensate for the difference in the lengths of the paths between the host network 102 mates and companions A and B.

The rate of change of range

Parameter defined as the rate of change of range, represents the relative radial velocity between the user terminal and the satellite. In a preferred embodiment of the present invention the rate of change of the range represents the relative radial velocitybetween the user terminal 106 and the satellite 104. In an alternative embodiment of the present invention, the speed change range is the Doppler shift RTDop in the signals transmitted between the user terminal 106 and the satellite 104. it can be calculated by multiplying RTDop at the speed of light and dividing by the Central carrier frequency. The projection of ISO-D-contours on the surface of the Earth describes a set of curves like hyperbole, symmetric with respect to the velocity vector of the corresponding satellite, as shown in solid lines 804 on Fig. Contour RTDop=0, passing through the subsatellite point A satellite A, is a straight line.

In a preferred embodiment of the present invention R is determined using two frequency measurements, one of which is held in the user terminal 106, and the other node firewall zobrazenie, in the following way. The user terminal 106 measures the frequency of a signal received from a host firewall mates 102 via satellite 104, and reports this frequency in the firewall node pair 102. The firewall node pair 102 measures the frequency of the signal received from the user terminal 106 via the same satellite 104. Thus, in the node network 102 mates with the results of the two frequency measurements. In a preferred embodiment, the frequencies are related to the frequency of the local oscillator. The real frequency is then obtained, as described above. This method is disclosed in co-filed application “Determination of frequency shifts in the communication system” (patent attorney docket RA) of the same applicant.

These measurements can be represented by two equations with two unknowns: the relative radial velocityand normalized shift f_off/f₀lo user terminal. This pair of equations can be solved relatively specified unknownand f_off/f₀that gives the results of measurements that are useful in other aspects of the operations of the satellite communications system, as it is obvious to experts in the field of technology.

Conclusion these two equations are represented graphically on figa and 9B. The piano is GA graphically presents the components of the frequency, measured in the user terminal 106. On FIGU graphically presents the components of the frequency measured in the firewall node pair 102.

- relative radial velocity between satellite 104 and the user terminal 106

C is the speed of propagation (speed of light)

f_F- nominal frequency straight line

f_R- nominal frequency return line connection

f₀is the nominal frequency of the local oscillator of a user terminal 106

f_offthe offset from the lo frequency of the user terminal 106

f_off/f₀the normalized frequency offset of the local oscillator of a user terminal 106

In accordance with figa frequency, measured in the user terminal 106, is defined as follows:

In accordance with figv frequency, measured in firewall node pair 102, is defined as follows:

By adding and subtracting (1) and (2) obtain the frequency offset and relative radial velocity in the following form:

To a person skilled in the art it is clear that can be used other ways to getwithout the modify the nature and scope of the invention.

In an alternative embodiment,get a hybrid method using two satellites A and B. In this embodiment, the user terminal 106 measures the frequency of a signal received from a host firewall mates 102 via the first satellite A, and transmits a message about this frequency in the firewall node pair 102. The firewall node pair 102 measures the frequency of the signal received from the user terminal 106 via a second satellite W. Thus, in the firewall node pair 102 there are two measurements of the frequency and, therefore, there are two equations that must be solved. However, in this embodiment, there are three unknowns: the relative radial velocity of the first satellite A, the relative radial velocity of the second satellite V and normalized offset lo t_off/f₀. Thus, to solve the system of equations formore information is needed. In a preferred embodiment of the invention, this information can be obtained through the parameter defined as the difference of the speed change ranges. To a person skilled in the art it should be clear that this information can also be obtained using other parameters and measurements. So what Braz, this option provides the work in accordance with the invention, even when the same satellite 104 may not be used for signals from the forward and reverse links. This situation may occur, for example due to sudden blockage, deterioration in signal quality, etc.

In a preferred embodiment of the invention, the frequency measurement can be made both in the call and connect the call. If the measurement is made when establishing the call connection, the signal measured in the user terminal 106 is bendingover signal, and the signal measured in the firewall node pair 102 is the signal access. If the measurement is made during the call, the signals measured in the user terminal 106 and the host firewall pair 102, are signals of the graph. To a person skilled in the art it is clear that can be used signals of a different type without changing the nature and scope of the present invention.

The difference between the speed change ranges

The difference between the speed change ranges (also known as the difference between the Doppler shifts) is a parameter described by the difference between (1) the rate of change of range between the user terminal 106 and the first satellite television with flat screen is A and (2) the rate of change of range between the user terminal 106 and the second satellite W. In a preferred embodiment, the difference of the speed change range is the differencebetween (1) a relative radial velocity between the specific user terminal 106 and the first satellite A and (2) a relative radial velocity between the user terminal 106 and the second satellite W.

In an alternative embodiment of the present invention, the difference of the speed change range is the difference Δ f, measured in the user terminal 106, between the frequency of the signal received from a host firewall mates 102 via the first satellite A, and the frequency of the signal received from a host firewall mates 102 via a second satellite W. The differenceassociated with the difference Δ f as follows:can be obtained by multiplying the Δ f at the speed of light and dividing by the Central carrier frequency.

The projection of ISO-Δ f-contours on the surface of the Earth describes a set of curves, as shown in solid lines 608 figure 6.

In a preferred embodiment of the present invention DK is defined as follows. First, the firewall node pair 102 transmits two signals. The first signal is transmitted via the first satellite A to polzovateli the th terminal 106, and the second signal is transmitted via the second satellite B to the user terminal 106. In a preferred embodiment of the present invention the frequency of the first and second signals are pre-adjusted in the firewall node pair 102, so that they pereklokayutsia the first and second satellites A and B essentially on the same frequency.

Secondly, the user terminal 106 determines the difference between (1) the frequency of the signal received from the first satellite, and (2) the frequency of the signal received from the second satellite. This frequency difference hereinafter referred to as Δ f. Finally the user terminal 106 determinesby multiplying Δ f at the speed of light and dividing the result by the Central carrier frequency of the first and second signals. For specialists in the art it should be clear that to obtainyou can use other ways without changing the nature and scope of the present invention.

In a preferred embodiment of the present invention, the first signal is pre-adjusted in the firewall node pair 102 before passing by adjusting the signal frequency to compensate for Doppler shift, caused by the known relative movement between the first satellite A and firewall node with the voltage 102, and the second signal is pre-adjusted in the same way. In an alternative embodiment, none of the signals is not adjusted according to the frequency. Specialist in the art it should be clear that other means of correction can be used to compensate for the motion of satellites A and B.

In a preferred embodiment of the present invention the first and second signals are pilot signals. To a person skilled in the art it is clear that can be used for any other signal without changing the nature and scope of the present invention.

4. Ways of positioning

The parameters described above may be used in at least three different combinations to determine the location of user terminal 106. These three positioning method described below. For explanation of the present invention, the physical representation of parameters characterized by the contours of constant values of the parameters (isocontours), designed on the surface of the Earth.

In the first embodiment of the present invention, the positioning is based on the distance difference range and differential speed change ranges. Figure 6 presents isocontour these parameters. Figure 6 the range denoted by R, the difference ranges - dR, the difference between the SC is Rasta change ranges - Δ f. Figure 6 one ISO-R-contour depicts strapontin line and marked 604; it forms a circle, representing the range of 2750 km between the user terminal 106 and the satellite A. Subsatellite point 614 satellites 104 are connected to the base line 612. Any ISO-R-path will cross the base line 612 at an angle of 90° . Figure 6 also presents the family of ISO-dR-paths are shown by dashed lines 606. Each ISO-dR-path is a hyperbola. connecting all points having the same value of dR, and crosses the base line 612 at an angle of 90° . Figure 6 contour dR is scaled in thousands of miles. Path d=0 is a normal bisector of the base line 612. Path d=+0,5 located directly to the right of the contour dR=0, connects all points for which the distance to the satellite A exceeds the range to the satellite W 500 km

The method of positioning using only range and differential ranges typical of two problems. The first problem is related to the ambiguity of the situation. For example, consider the case when R=2750 km and dR=+500 km According to Fig.6, the contour R=2750 km crosses the contour dR=+500 km in two points - Suite 610a and V. Without additional information it is impossible to determine whether the user's terminal point Suite 610a or V. Consequently, this solution is not odnoznachnym.

The second problem is known as the “geometric factor affecting accuracy” (GTS). The ambiguity associated with GTS, occurs when a small error in the parameter causes a large error in determining the position. Because the contours of R and dR cross the base line 612 at an angle of 90° they can be tangential or nearly tangential. Therefore, a small error in any of these parameters can lead to large error location. Without additional information about the location positioning based on the distance and difference of distances will lead to ambiguity associated with the GTS.

Use the appropriate third parameter can solve both the above problems for most cases. According to Fig.6, the parameter Δ f characterizing a difference between the speed change range, shown as a family of curves indicated by the position 608, shown in solid lines, programmirovanie in kHz. The shape of the curves Δ f is a function of the relative velocity of the satellites A and B. The velocity vectors of the satellites A and B marked positions A and B and represented as arrows, passing along the trajectory. The region of maximum Δ f is near the top of section 6, where subtracti satellites A and B.

According to the SNO 6, outlines Δ f almost perpendicular to the contours of R and dR. For this reason, the parameter Δ f differential speed change ranges provides the resolution of ambiguity positioning and eliminates the problem GTS. For example, the Suite 610a point lies on the path Δ f=20 kHz, while the point B lies approximately on the contour Δ f=84 kHz. Because point Suite 610a and V clearly distinguishable by their values Δ f, Δ f differential speed change ranges provides the resolution of ambiguity positioning. For the same reason parameter Δ f differential speed change ranges provides a solution to the problem GTS. the differential speed change ranges can also solve these problems, as it should be clear to a person skilled in this technical field.

Figure 7 presents the case when setting the velocity difference of the changes of the distances does not provide a solution to the problem GTS in the positioning method using only the range and difference of distances. In this case the velocity vector (and thus the trajectory and subtract) one of the two satellites A and B, observed by the user terminal 106, almost parallel. This geometry leads to the fact that the contours Δ f near the user terminal 106 converge and are almost the computers is correctly circuits R and dR near point 712 on the base line 612. Since all three contours are almost parallel near the user terminal 106, then there is a singularity GOS. Singularity GOS can be resolved by replacing the parameter that is defined through the difference of the speed change ranges, the parameter defined through the change speed ranges, as shown below.

Figure 10 presents a flowchart of the sequence of operations according to the first variant embodiment of the invention. Define one or more parameters of range, as described above, and presents a step 1002. Define one or more parameters of the difference of the ranges as described above and represented by step 1004. Define one or more parameters of the differential speed change ranges as described above and presents a step 1008. Then the position of the user terminal on the Earth's surface is determined using well-known positions and velocities of the satellites, as well as range, the difference between distance and difference of speed change ranges. as represented by step 1010 and described below.

In the second embodiment of the present invention, the positioning is based on the use of distance, difference, distance and speed change ranges. On Fig presents case corresponding to Fig.7, but hard-Δ f-to the contour of replaced by ISO-D-circuit, measured relative to the satellite A, as shown in solid lines 804. ISO-RTDop-outline-like hyperbole and symmetric with respect to the velocity vector of the satellite A. Each RTDop-loop connects the point on the Earth's surface having the same Doppler shift relative to the satellite A. ISO-RTDop-circuit graduated in kHz, and the circuit RTDop=0 passes through the subsatellite point A satellite A. Thus, the observer, who is on the path RTDop=0, satellite A will be presented as not moving neither to the observer, or the observer.

Figure 11 presents a flowchart of the sequence of operations according to the second variant embodiment of the invention. Define one or more parameters of range, as described above, and presents a step 1102. Define one or more parameters of the difference of the ranges as described above and presents a step 1104. Define one or more parameters of the speed change ranges as described above and presents step 1106 Then the position of the user terminal on the Earth's surface is determined using well-known positions and velocities of the satellites, as well as range, the difference between distance and rate of change of range, as represented by step 1110 and described below.

As follows from Fig, parameter RTDop speed change is of the range can reduce the problem of singularity GTS, inherent in the method of positioning using only range and differential ranges. However, in rare cases, only one parameter is the rate of change of distance is insufficient to resolve the singularity GTS. In such cases, the singularity GTS can be resolved with the use of all four parameters. Thus, in the third embodiment of the present invention, the positioning is based on the distance difference range, the rate of change of distance and difference of speed change ranges. Specialist in the art it should be clear that a further increase in accuracy can be achieved by using more than one value of each parameter in any of the options described above.

On Fig presents a flowchart of the sequence of operations according to this third variant embodiment of the invention. Define one or more parameters of range, as described above, and presents a step 1202. Define one or more parameters of the difference of the ranges as described above and presents a step 1204. Define one or more parameters of the speed change ranges as described above and presents step 1206. Define one or more parameters of the differential speed change ranges, as describe what about the above and presents step 1208. Then the position of the user terminal on the Earth's surface is determined using well-known positions and velocities of the satellites, as well as range, the difference ranges, the rate of change of distance and difference of speed change ranges, as represented by step 1210 and described below.

5. Performing positioning

Before a detailed description of the implementation of positioning, it is useful first to consider the environment in which can be the positioning method corresponding to the invention. On Fig presents a block diagram illustrating an environment that represents the computer system 1300, which may be part of the control processor 220 and/or control processor 320. Computer system 1300 includes one or more processors, such as processor 1304. The processor 1304 is connected to the communication bus 1306. Various embodiments of the described in terms of this is taken for an example of a computer system. To a person skilled in the art it should be clear how to implement the positioning method corresponding to the invention using other computer systems, computer architectures, finite state machine hardware, conversion tables and the like, and combinations of these tools.

Computer system 1300 with whom holds the main memory 1308, preferably NVR, and may also include an auxiliary memory 1310. Auxiliary memory 1310 may include, for example, the drive 1312 on hard drives and/or drive 1314 on a removable memory, such as a drive on floppy disks, on magnetic tape, on optical disks, etc. Drive 1314 on a removable memory reads and/or writes to a removable memory block 1318 well known manner. Removable memory block 1318 represents a floppy disk, magnetic tape, optical disk, etc. Removable memory block 1318 includes a computer storage medium on which is stored a computer program and/or data.

In alternative embodiments, the auxiliary memory 1310 may include other similar means for loading computer programs or other commands to the computer system 1300. Such means may include a removable memory unit 1322 and interface 1320. Examples of such means may be cartridges software and interface to the cartridge (for example, as in video games), circuit Board memory (e.g., electrically erasable programmable read-only memory EEPROM or EPROM) with the corresponding socket and the other circuit blocks of memory 1322 and interfaces 1320, which provide transfer programs and data from the removable memory block 1322 to the computer system 1300.

Computer system 1300 may also include all the I communication interface 1324. The communications interface 1324 provides the ability to transfer programs and data between the computer system 1300 and the external devices through a communication channel 1326. Examples of communications interface 1324 can include a modem, a network interface (such as Ethernet card), a communications port, etc. Programs and data sent over the communications interface 1324, have the form of signals which can be electronic, electromagnetic, optical or other types of signals, with the possibility of reception by the communications interface 1324 through a communication channel 1326.

Implementing the positioning method in accordance with the present invention is described on the example in this sample computing environment. This description is provided only for the convenience of understanding. It is not envisaged that the operation of the positioning method. corresponding to the invention should be limited to the above example. In fact, the specialist in the art it should be clear how to implement the invention in alternative computing environment.

In one of the embodiments of the present invention the location of the user terminal 106 is determined by implementing the positioning method described below in example computer system 1300. The specialist in this area of the technology should be clear, that positioning can be performed using the finite state machine hardware, conversion tables, etc. without changing the nature and scope of the present invention.

Formed M× 1 vector of parameters, denoted by z, consisting of M parameters used to determine the location. The vector z can include one or more of the parameters described above. As is known in the technique, the parameters are nonlinear functions of 2-dimensional vector x location of the user terminal having the form

where the Superscript “T” indicates the transpose of a matrix or vector in accordance with a ratio of

where M× 1 vector z represents the error of the measurements, h is a nonlinear function that describes the ratio between the measured parameters and the position of a user terminal 106. I.e. h is a function of the positions and velocities of the satellites A and B. In an alternative embodiment, the vector x location of the user terminal can be defined by the three Cartesian coordinates, not by latitude and longitude, as shown below in equation (7):

According to Gauss's method of linearization M× To the partial derivative matrix H is armywide to determine the location of user terminal 106, where K is the number of unknown location, and the matrix element (m, k) is the partial derivative of the m-th dimension with respect to the k-th parameter of the location given for this position X. for Example, if the vector location describes the latitude and longitude, as in equation (5), equal To 2, and the elements in the k=1 column matrix N describe the partial derivatives relative to the latitude of the user terminal 106, and the elements in the k=2 column matrix N describe the partial derivatives relative to the longitude of the user terminal 106. If the vector location specified in Cartesian coordinates (K=3), then k=(1, 2, 3) columns of the matrix N are coordinates (x, y, z), respectively. If you are using Cartesian coordinates, it uses an additional equation to specify the squares of the coordinates equal to the square of the radius of the Earth. The relationship between x and H is defined as follows:

Iterative weighted least squares is used to determine the unknown parameters of the location. In a preferred embodiment of the invention uses a weighted Gauss-Newton described in H.W.Sorenson, Parameter Estimation - Principles and Problems, New York, Marcel Dekker, 1980. The iterative equation is specified as follows:

where and- assess the current and next positions, respectively, a W - M× M matrix of weights. The index i represents the iteration number, and i=0 represents the first iteration. Matrices or vectors based on the estimated location, indicated by the upper index_^”. Reference point, i.e. the last known location of the user terminal is selected as the initial estimate of the location. If there is no last known location of the user terminal, it can be used in any position, for example, the position of the node firewall pair 102.

The partial derivative matrix, which is determined when the current estimate of the location, defined as

and the ratio is expected parameters, no errors, defined using the current estimate of the location. The iteration ends when the difference betweenanddecreases below a predefined threshold. The threshold is determined by the system developers and/or operators with regard to the accuracy of the system, as is known in the art. For example, the threshold may be based on the accuracy of the code element in the measurements and on the repetition rate of the code elements.

The elements of the M× M is atrice weights W provide an opportunity to consider the influence of specific parameters on the assessment location when there are more parameters than are unknown. In a preferred embodiment, the weight matrix W is a diagonal matrix whose elements reflect the relative accuracy with which can be determined for each item. Thus, the element values are set based on the known accuracy of the measurement system, as is obvious to a person skilled in the art. Therefore, the parameter, based on a very precise measurement, is more important than the parameter that cannot be measured with the same accuracy. The elements of the weights matrix are initialized to predefined values, but can be dynamically adjusted. Optimum accuracy is achieved if the weight matrix is chosen as the inverse of the covariance matrix of measurement errors.

If measurement errors are mutually independent with zero mean and variance:

then W is a diagonal matrix withas its diagonal elements. With this choice of W, the variance of the k-th element of vector x estimate of the location is determined in the form

Finally, the combined theoretical error location horizontally, expressed in units of distance, is defined as follows:

where R_E- the radius of the Earth.

Usually, if you have selected the correct weight matrix in accordance with the dispersion error, the iteration may converge to a local minimum in accordance with the mirroring of the true solution on the opposite side of the base line 612. You can define the neighborhood of another solution with the first solution by displaying it relative to the base line 612. A new cycle of iterations required to locate the exact second solution. As soon as the two possible solutions, still need to find that which is true. This is done by comparing the calculated frequencies in accordance with each solution with the measured frequencies.

The following describes the best way that ensures a more direct convergence of the iterations to the correct solution. This method is called “adaptation weights matrix”. As an example, when the frequency measurements are the variance of the errors in excess of timing, frequency measurements are given lower weights in well-formed matrix of weights. However, as indicated above, this may lead to convergence of mirror solutions. Thus, the original matrix of weights (control weight matrix) is chosen at random, to give more weight to frequency measurements (in the above example), is it “correct” result, based on the variances of the errors. This ensures that the iteration can be reduced to the true solution, and not to the mirror solution. After a fixed predefined number of iterations (usually a small number) or after have reached a state of near convergence (as determined by measurement of the difference betweenand), switches to the correct (optimal) the weight matrix W described above. This last step ensures that the resulting ultimately the error in this solution is the minimum possible. The above method can be generalized to change weights matrix more than once.

In a preferred embodiment of the invention, the positioning method uses a flattened ellipsoidal model of the Earth's surface. In an alternative embodiment, the method of positioning initially uses flattened ellipsoidal model of the Earth's surface, such as Earth model WGS-84. If the values of x converge in such a way that the difference betweenandbecomes smaller than a predetermined threshold, a detailed digital model of the Earth is replaced by the smoothed model, and iterations continue to come up until the time the ity between andwill not be less than the second predefined threshold. Thus, any errors due to the raised position of the user terminal 106, reduced. In an alternative embodiment, a detailed digital model of the Earth is replaced after a predetermined number of iterations. The threshold values for the distances and the number of iterations described above are determined in accordance with various factors, as is obvious to a person skilled in this technical field.

In an alternative embodiment, it is possible to estimate the height above the Earth's surface. Additional fictitious dimension - the distance from the center of the Earth, which is considered in connection with the use of Cartesian coordinates, should not be treated as a real dimension. In connection with the error σ_hand the corresponding weightwill ensure a smooth transition from two-dimensional to three-dimensional positioning positioning, which is also estimated height above the Earth's surface corresponding to smooth the model. Adding an unknown height can be similarly implemented in polar coordinates (latitude, longitude, altitude). In this case, is added fictitious height measurement.

The error associated with fictionalization, determines the degree to which the assessment of height can fluctuate on the estimated height values. If the error increases, the weight associated with this dimension is reduced, and the procedure of positioning becomes more three-dimensional positioning. The lack of additional introduction of unknown height is that it causes a higher sensitivity in unknown locations horizontally errors actual measurements. Therefore, it is preferable to assign a big mistake (light weight) fictitious height measurement only in those areas where the height changes rapidly in the function of the horizontal distance and topographic map cannot be effectively used.

5. Conclusions

Although the above described various embodiments of the present invention, it should be borne in mind that they are presented only for example, but do not provide for any restrictions. For specialists in the art it should be clear that it can be made various changes in form and detail without changing the nature and scope of the invention. Thus, the claimed invention is not limited to the above-described embodiments, but should be determined in accordance with the claims.

1. The system for determining the location the Oia for satellite communication systems, contains the user terminal, at least two satellites with known locations and known velocities, the firewall node pair for communication with the user terminal through the above-mentioned satellites, the means defining the parameter range that represents the distance between one of these satellites and the user terminal, the means of determining a parameter difference ranges, representing the difference between the distance between one of the satellites and the user terminal and the distance between another satellite and the user terminal, at least one of the following means: means for determining the parameter of the speed change range, which represents the radial velocity of one of the satellites relative to the user terminal, means for determining the parameter of the differential speed change ranges, representing the difference between the radial velocities of both satellites relative to the user terminal, means for determining the location of the user terminal in the firewall node pair based on known locations and velocities of the satellites, parameter range, the parameter difference ranges and at least one of the specified parameter SK is growing even more changes in the range and setting the velocity difference change ranges.

2. The system according to claim 1, in which the above setting range is determined by the propagation delay of the signal, and the system further comprises means for measuring the propagation delay of the signal in the firewall node pair in the transmission of the above-mentioned signal from the host firewall mates to the user terminal through one of the satellites and relay signal from the user terminal to the firewall node pair through one of the satellites.

3. The system according to claim 1, in which the said parameter is the difference of the distances is determined by the difference between the delays of signal propagation, and the system further comprises means for measuring the difference of the delays in the user terminal between the first signal received from a host firewall mates through one of the satellites and the second signal received from a host firewall mates through another satellite.

4. The system according to claim 3, which provides a pre-correction time at least one of the two mentioned signals to compensate for delays associated with the difference of the distances from the firewall node pair to one of the satellites and from the firewall node pair to another satellite.

5. The system according to claim 3, in which the host firewall mates made enabling configuration of the differential delay compensation is alergic, related to the difference of the distances from the firewall node pair to one and to the other satellites.

6. The system according to claim 1, in which the parameter rate of change of range is determined by the frequencies of the first and second signals, the system further comprises first means for measuring the frequency in the user terminal, designed to measure the frequency of the first signal received from a host firewall mates through one of the satellites, means in the user terminal for transmission of the measurement result of the specified frequency of the first signal in the firewall node pair, and the second means for frequency measurement tool firewall pairing, designed to measure the frequency of the second signal received from the user terminal through one of the satellites.

7. The system according to claim 1, in which the parameter is the velocity difference of the changes of the distances is determined by the frequency difference, and the system further comprises a user terminal means for measuring the frequency difference of the first signal received from a host firewall mates through one of the satellites, and the second signal received from a host firewall mates through another satellite.

8. The system according to claim 7, which provides a preliminary adjustment of the frequency of at least one of the two pack is mentioned signals to compensate for the Doppler shift, due to the difference between the radial velocities of both satellites with respect to the host firewall pair.

9. The system according to claim 7, in which the host firewall pairing is made for configuration of the difference frequency to compensate for Doppler shifts due to the radial velocities of both satellites with respect to the host firewall pair.

10. The method of determining the location of a user terminal in a location system comprising a user terminal, at least two satellites with known locations and known velocities and the firewall node pair for communication with the user terminal through the above-mentioned satellites, including the step of determining the parameter range that represents the distance between one of the satellites and the user terminal, the step of determining a parameter difference ranges representing the difference between the distances of one and the other satellites from the user terminal, the step of determining at least one of the following parameters: parameter rate of change of range, which represents the radial velocity of one of the satellites relative to the user terminal parameter differential speed change ranges, not only who found a difference of radial velocities of both satellites relative to the user terminal, the step of determining the position of the user terminal on the Earth's surface based on the known locations and known velocities of the satellites, as well as the specified parameter range, the parameter rate of change of range and at least one of the mentioned parameters, the difference between distance and difference of speed change ranges.

11. The method according to claim 10, in which the said parameter range is determined by the propagation delay of the signal so that the phase parameter definition range further includes the step of measuring the firewall node pair propagation delay of the signal from this node to the user terminal through one of the satellites and relay signal from the user terminal to the firewall node pair through one of the satellites.

12. The method according to claim 10, in which the said parameter is the difference of the distances determined by the difference of propagation delays of the signal so that the phase parameter definition difference ranges further includes the step of measuring in the user terminal of the differential delay between the first signal received from a host firewall mates through one of the satellites and the second signal received from a host firewall mates through another satellite.

13. The method according to item 12, in which at least one of these two signals before artelino Refine over time to compensate for delays associated with the difference between the distances of one and the other satellites from a host firewall pair.

14. The method according to item 12, in which the host firewall mates adjust the difference of the delays to compensate for delays associated with the difference between the distances of one and the other satellites from a host firewall pair.

15. The method according to claim 10, in which when determining the parameter of the speed change range detection phase this parameter further includes the step of measuring in the user terminal frequency of the first signal received from a host firewall mates through one of the satellites, the phase transfer of result frequency of measurement of the first signal in the firewall node pair, the step of transmitting the second signal from the user terminal to the firewall node pair through one of the satellites and the measurement stage in the firewall node pair frequency of the second signal received from the user terminal through one of the satellites, and the specified parameter is the rate of change of range is a result of measuring the frequency of the first and second signals.

16. The method according to claim 10, in which when the determination parameter is the velocity difference of the changes of the distances of the detection phase this parameter includes the step of transmitting the first signal from the host firewall mates to the user of the term is in through one of the satellites and transmitting the second signal from the host firewall mates to the user terminal via another satellite, and the measurement stage in the user terminal frequency difference of the first signal and the second signal.

17. The method according to clause 16, in which at least one of these two signals is pre-adjusted in frequency to compensate for Doppler shift, caused by the difference of radial velocities of both satellites with respect to the host firewall pair.

18. The method according to clause 16, in which the host firewall mates configures the difference frequency to compensate for Doppler shifts due to the difference of radial velocities of both satellites with respect to the host firewall pair.

19. The user terminal location system containing at least two satellites with known locations and known velocities and the firewall node pair for communication with the user terminal through these satellites, which includes means for relaying the first signal received from a host firewall mates through one of the satellites, means for determining a parameter difference ranges representing the difference between the distances of one and the other satellites from the user terminal, and at least one of the following means: a means for determining the parameter of the velocity difference changed the I range, representing the difference between the radial velocities of both satellites relative to the user terminal, means for measuring the frequency of a second signal transmitted by the host firewall mates through another satellite for the transmission of the result of the frequency measurement in the firewall node pair and transmitting the third signal to the host firewall mates through another satellite, providing the possibility of determining the position of the user terminal on the Earth's surface based on the specified relayed the first signal parameter is the difference of the distances of known locations and known velocities of the satellites, as well as at least one of the mentioned parameter differential speed change ranges, the measurement frequency and the transmitted third signal.

20. System location for a satellite communications system that contains the user terminal, at least two satellites with known locations and known velocities, the firewall node pair for communication with the user terminal through the above-mentioned satellites, the means defining the parameter range that represents the distance between one of these satellites and the user terminal, means for determining the parameter of the spacing and distances, representing the difference between the distance between one of the satellites and the user terminal and the distance between another satellite and the user terminal, means for determining the parameter of the speed change range, which represents the radial velocity of one of the satellites relative to the user terminal, means for determining the parameter of the differential speed change ranges, representing the difference between the radial velocities of both satellites relative to the user terminal, means for determining the location of the user terminal in the firewall node pair based on known locations and velocities of the satellites, these parameters range and rate of change of distance, difference of the distance and difference of speed change ranges.

21. System location for a satellite communications system that contains the user terminal, at least two satellites with known locations and known velocities, the firewall node pair for communication with the user terminal through the above-mentioned satellites, the means defining the parameter range that represents the distance between one of these satellites and the user is skim terminal, the means of determining a parameter difference ranges, representing the difference between the distance between one of the satellites and the user terminal and the distance between another satellite and the user terminal, means for determining the parameter of the differential speed change ranges, representing the difference between the radial velocities of both satellites relative to the user terminal, means for determining the location of the user terminal in the firewall node pair based on known locations and velocities of the satellites specified parameter range, the difference between distance and difference of speed change ranges.

22. System location for a satellite communications system that contains the user terminal, at least two satellites with known locations and known velocities, the firewall node pair for communication with the user terminal through the above-mentioned satellites, the means defining the parameter range that represents the distance between one of these satellites and the user terminal, the means of determining a parameter difference ranges, representing the difference between the distance between one of the satellites and the user is Kim terminal and the distance between another satellite and the user terminal, means for determining the parameter of the speed change range, which represents the radial velocity of one of the satellites relative to the user terminal, means for determining the location of the user terminal in the firewall node pair based on known locations and velocities of the satellites specified parameter range, the rate of change of distance and difference of ranges.

23. System location for a satellite communications system that contains the user terminal, at least two satellites with known locations and known velocities, the firewall node pair for communication with the user terminal through the above-mentioned satellites, the means defining the parameter range that represents the distance between one of these satellites and the user terminal, the means of determining a parameter difference ranges, representing the difference between the distance between one of the satellites and the user terminal and the distance between another satellite and the user terminal, at least one of the following means: means for determining the parameter of the speed change range, which represents the radial the speed of one of the satellites relative to the user is defined terminal, means for determining the parameter of the differential speed change ranges, representing the difference between the radial velocities of both satellites relative to the user terminal, means for determining the location of the user terminal in the firewall node pair based on known locations and velocities of the satellites, parameter range, the parameter difference ranges and at least one of the specified parameter rate of change of range and setting the velocity difference change ranges, but such means of positioning includes means for generating M×1 vector z containing the above-mentioned parameters, where M is the number of defined parameters, means for generating vector location x that defines the initial reference point, means to generate a matrix of N partial derivatives containing information about the locations and velocities of these satellites and models describing the shape of the Earth, and the relationship between x and H is

means for generating M×M weight matrix W to account for the influence of individual parameters and tool for the iterative solution of the equation

where and- assess the current and next locations of the satellites, respectively,- vector current estimates of the above parameters; i - the number of the iteration, and the iterations are carried out until such time as the difference betweenanddrops below the first predetermined threshold.

24. The system according to item 23, in which the said means for positioning further includes a tool that uses a simplified model of the Earth as long as the difference betweenandwill not fall below the second predetermined threshold, and then using accurate numerical model of the Earth.

25. The system according to item 23, which referred to the weight matrix W is a matrix, inverse of the covariance matrix of measurement errors.

26. The system according to item 23, in which the said means for positioning further includes a tool that uses the first weight matrix W₁for the first n predefined iterations, and then the second weight matrix W₂that is a matrix, inverse of the covariance matrix of measurement errors, with the first weight matrix W₁assigns a weight parameters near the STI change range and differential speed change ranges greater than the parameters of distance and difference of ranges, and assign weights vary stronger than in the case of matrix W₂.

27. The system according to item 23, in which the said means for positioning further includes a tool that uses a simplified model of the Earth for the first n predefined iterations, and after them the exact numerical model of the Earth.

28. The system according to item 23, in which the said means for positioning further includes a tool that uses the first weight matrix W₁as long as the difference betweenanddrops below a third predetermined threshold, and thereafter the second weight matrix W₂that is a matrix, inverse of the covariance matrix of measurement errors, with the first weight matrix W₁assigns a weight parameters the rate of change of range and velocity difference of the changes of distances greater than the dimensions of distance and difference of ranges, and assign weights vary stronger than in the case of matrix W₂.