Positioning using a single satellite in low earth orbit
System and method for determining location of a subscriber device (e.g., mobile phone) in the communication system, a satellite in low-earth orbit. The system includes a subscriber device, at least one satellite with a known position and velocity and nodal station (i.e., terrestrial base station) to communicate with the subscriber device via satellite. The method includes the determination of the parameter range, the parameter rate of change of range. The parameter range is the distance between the satellite and the subscriber apparatus. Parameter rate of change of range is a relative radial velocity between the satellite and the subscriber apparatus. Then determine the location of the subscriber unit on the Earth's surface on the basis of the parameter range, the parameter rate of change of range and known position and velocity of the satellite. Achievable technical result is the rapid determination of the location of the subscriber device using a single satellite. 3 N. and 11 C.p. f-crystals, 9 Il.
The technical field
The invention relates to Oprah is tsogo apparatus in a satellite communication system using the characteristics of communication signals.
The level of technology
Conventional satellite communication system contains at least one terrestrial base station representing a host firewall mates and hereafter referred to as the anchor base station, at least one subscriber device (e.g. mobile phone) and at least one satellite to relay communication signals between the node station and a subscriber unit. The hub station provides communication channels between the subscriber apparatus and other subscriber devices or communication systems such as terrestrial telephone system.
Was developed a number of communication systems with multistation access to transfer information among a large number of users in the system. These methods include methods to expand the range, based on multiple access with time division multiplexing (mdvr), multiple access, frequency division multiple access (FDMA equipment), multiple access, code-division multiplexing (mdcr), the principles of which are well known in the field of communications. Methods mdcr in the communication system with multiple access are disclosed in U.S. patent No. 4901307 from 13.02.1990, "communications System spread spectrum on the basis of the set is from 0 4.01.1995, "Method and apparatus for use of the transmission power in the full spectrum of the system spread spectrum communications for tracking phase, time and energy of the individual receiver", owned by the assignee of the present invention and referred to here for details.
In the above-mentioned patent documents discloses a communication system with multiple access, in which a large number of mobile or remote users of the system uses the subscriber devices to communicate with other users of the same system or other connected systems, such as the public switched telephone network (PSTN). Subscriber units communicate through the hub and satellites, using the communication signals type signal mdcr spread spectrum.
Communication satellites form beams that illuminate the spot, formed by the projection of the satellite signals at the Earth's surface. A typical diagram of radiation of the satellite in the region of the spot consists of multiple beams, located in the specified service area. Typically, each beam contains several so-called polucha (also known as channels mdcr), serving General geographical area, each of the p pre-selected pseudotumour (PN) code sequences to modulate (i.e., "expansion") of information signals in a given spectrum band prior to modulation onto a carrier signal for transmission of communication signals. Through the PN expansion of the transfer method with the extension of the spectrum, well-known in the field of communications, a signal is generated for transmission, having a much greater bandwidth than the data signal. In a straight line (i.e. a line beginning at a junction and terminating at a subscriber unit) extends PN codes and binary sequences are used to distinguish between signals transmitted to the hub station in different beams, and to distinguish between signals of multipath propagation. These PN codes are usually shared across all communication signals in a specific polluce.
In a typical system mdcr a broader spectrum of uses canalobre codes to distinguish between signals intended for a particular subscriber apparatus and transmitted to a satellite beam in a straight line. This means that for each subscriber unit in a straight line provided individual orthogonal channel through the use of individual baseband orthogonal code. Usually to implement canalobre odkodowa elements for satellite systems.
In typical communication systems mdcr a broader spectrum, such as described in U.S. patent No. 4901307, provides for the use of coherent modulation and demodulation for communications with the subscriber device in a straight line. In communication systems using this principle as a coherent phase reference for direct communication lines used high-frequency pilot signal. This means that the pilot signal, which typically does not contain information modulation, is transmitted from the hub station in the entire service area. Typically, for each beam, are used for each used frequency is transmitted one pilot signal from each nodal station. These pilot signals are shared by all subscriber units receiving signals from this junction.
Pilot signals are used by subscriber units to enter into synchronism with the system and for tracking time, frequency and phase of the other signals transmitted from the hub station. The phase information obtained by tracking the carrier pilot signal, is used as the reference phase of the carrier for coherent demodulation other system signals and signals of the graph. This method allows many signals graphics compatible with the motion tracking.
When the subscriber unit is not involved in the communication session (i.e., cannot receive or send signals graph), the hub station can send information to this particular subscriber device using the signal, known as the radio call signal. For example, when a call to the mobile phone base station notifies the mobile phone using the radio call signal. The radio call signals are also used to distribute assignments of channels of traffic, purpose of access channels and system service information.
The subscriber unit can respond to a radio call signal sending an access signal or access attempts on the return line (i.e. the line that begins in the subscriber apparatus and terminating at a junction). The signal access is also used when the subscriber unit initiates a call.
If you want to communicate with the subscriber device, the communication system may need to determine its location. The need for determining the location of a subscriber device occurs for several reasons. One of them is that the system you must choose an appropriate anchor station for Bespalov (for example, the phone company). For the service provider usually attached to specific territory in which he handles all calls from its subscribers. If you want to link with a particular subscriber device, the communication system can distribute the call to the service provider on the basis of the territory in which this subscriber unit. To determine the appropriate area, the communication system needs to know the location of the subscriber device. Such cause arises, if you want to distribute calls to service providers on the basis of political boundaries or contractual services.
An important requirement for determining the location of a satellite communication system is performance. When there is a need for establishing connection with a particular subscriber device, you need to quickly choose an anchor station which will service the subscriber device. For example, for a user of a mobile phone is unlikely to be acceptable delay lasting more than a few seconds when placing a call. In this situation, the accuracy of the positioning is less important than the need for speed. The error is below 10 km is considered valid. Echnosti, and not performance.
One known solution is used in the system of the U.S. Navy TRANSIT. In this system, the subscriber unit performs continuous measurement of the Doppler shift of the signal transmitted in the broadcast mode by satellite in low earth orbit (NOT). These measurements continue for several minutes. For a system usually requires two satellite pass, which leads to having to wait for more than 100 minutes. In addition, since the calculation of the location is performed in the subscriber unit, the satellite must transmit in broadcast mode, information about your location (so-called ephemeris). While these TRANSIT system can provide high accuracy (about one meter), the accompanying delays are unacceptable for use in a commercial satellite communications system.
Another known solution is used in systems ARGOS and SARSAT (search and rescue satellite). In this decision, the subscriber unit transmits an intermittent signal beacon receiver on the satellite, which performs a frequency measurement signal. If your companion takes more than four beacon signals from the subscriber device, he can usually identify it m is s Doppler measurements, as in the TRANSIT system.
Another known solution is used in the global satellite positioning system (GSM). Each satellite transmits a broadcast signal with a time stamp, which includes the ephemeris of the satellite. When the subscriber unit receives the signal of GSM, it measures the transmission delay relative to your own time and determines pseudodominant to the position of the transmitting satellite. In GSMA you want to use three satellites to determine two-dimensional coordinates, and four to determine three-dimensional coordinates.
One of the drawbacks of the system GSMA is that positioning requires at least three satellites. Another disadvantage is that, because the calculations are performed in the subscriber apparatus, satellites, GSM should pass in broadcast mode information of its ephemeris, and the subscriber device must have the computational resources to perform the necessary calculations.
The disadvantage of all the above solutions is that their implementation of the subscriber unit must have a separate transmitter or receiver in addition to that which is necessary for signal processing of the light is and the way". This solution uses two satellites for active positioning of the subscriber device using trilateration. Despite some advantages, this solution requires two satellites.
Thus, there is a need in a satellite-based location system that allows you to quickly determine a location using just one satellite.
The proposed system and method for rapid determination of the location of the subscriber device (e.g. mobile phone) using just one satellite in a satellite communication system such as communication system, a satellite in low-earth orbit. The system includes a subscriber device, at least one satellite with a known location and a known speed and junction station (i.e., terrestrial base station) to communicate with the subscriber device via satellite. The method is to determine the parameters describing the temporal and spatial correlation between the subscriber apparatus and the satellite, and determine the location of the subscriber device using these parameters and the known location and velocity of the satellite.
Two of the parameter to use is the satellite and the subscriber device.
Parameter rate of change of range is a relative radial velocity between the subscriber device and the satellite.
In a preferred embodiment of the invention for determining the location of the subscriber apparatus based on the used parameters and the known position and velocity of the satellite uses an iterative method of weighted least squares Gauss-Newton.
One advantage of the invention is that it allows you to quickly determine the location using one satellite, such as satellite, NOT.
Brief description of drawings
The invention is further explained in the description of examples with reference to the drawings, in which identical or functionally similar elements are denoted by the same reference position. In addition, the left digit of the reference position indicates the drawing, which for the first time you receive this number.
Fig.1 is a typical satellite communication system,
Fig.2 is a structural diagram of an exemplary version of the transceiver used in the subscriber unit,
Fig.3 is a structural diagram of an exemplary variant of transceiver devices used in a base station,
Fig.4 is sheared.5 - structural diagram of an exemplary variant of the tracking system frequency used in the subscriber unit,
Fig.6 is an illustration of the sub-satellite point and the projection surface of isocontours parameters range and rate of change of distance is related in this companion,
Fig.7A is a graphical representation of the frequency components of the signal measured in the subscriber device,
Fig.7B is a graphical representation of the frequency components of the signal measured at the hub station,
Fig.8 is an algorithm illustrating the operation of the preferred variant of the invention,
Fig.9 is a structural diagram illustrating an exemplary variant of the working environment in which you can use the invention.
Detailed description of preferred embodiments of the invention.
The proposed system and method to quickly determine the location of a subscriber device in a satellite communication system using a single satellite in low earth orbit (NOT). Specialists will be clear that the concept of the present invention can be used in satellite systems, in which the satellites are spinning out on NOT, if the relative movement of the satellites and subscriber Apparatebau discussed preferred variant of the invention. Despite the fact that describes a specific operation, configuration and layout, it is clear that this is done only for purposes of illustration. For professionals will be obvious, and other operations, configuration, and layout, are not beyond the scope of the present invention.
Description of the invention consists of four parts. The first part describes a typical satellite communication system. The second part describes the parameters used by the system in the way that the positioning. In the third part of the method of determining the location described in the form of physical representation. And finally, describes the implementation of the way location.
II. A typical satellite communication system
In Fig.1 depicts a typical satellite communication system 100. Satellite communication system 100 includes a hub station 102, the satellite 104 and user devices 106. Subscriber units 106 are mainly three types: stationary subscriber apparatus A, usually set in fixed facilities, mobile subscriber units V, usually installed in vehicles, and portable subscriber units S, usually portable type. The hub station 102 communicates with subscriber units 106 che is Arata 106. The transceiver 200 uses at least one antenna 210 for receiving communication signals, which are served in the analog receiver 214, where they are converted with decreasing frequency, amplified and discretized. Commonly used antenna switch 212, which allows the same antenna to perform both functions of transmission and reception function. However, some systems use a separate antenna for operation at different frequencies.
Digital communication signals from the output of the analog receiver 214 are received in the at least one digital receiver A data and at least one digital search receiver 218. You can use the additional digital receivers 216A-216N data, performed in a multidrop configuration to achieve a given level of diversity of signals, depending on the acceptable level of complexity of the block, as will be clear to experts. The receiver is made in this way is called multi-tap receiver, and each receiver 216 data is called diversion. Taps tap receiver are used not only for separation of signals, but also to receive signals from multiple satellites. In addition, you can use the advanced search receiver is on device electrically connected to the digital receivers 216A-216N data and to search the receiver 218. Control processor 220 provides, among other functions, basic signal processing, control timing, power, and switching the channel of communication or coordination, and the choice of frequencies used for the carrier signal. Another basic function of management, which often performs control processor 220 is the selection or manipulation of PN code sequences or orthogonal functions that should be used for forms processing of communication signals. Signal processing in the control processor 220 may include the definition of the parameters used in this invention. Such computations of signal parameters relating to, for example, to the relative time and frequency, may include the use of additional or separate electronic circuits to improve the efficiency or speed measurement, or improve the distribution of control processing.
The outputs of digital receivers 216A-216N data is electrically connected to a custom digital electronic circuitry 222 main band (the frequency band of the modulating signal). Custom digital electronic circuits 222 main strip include processing elements and pre which include storage elements of signals and data, such as short-term or long-term storage devices; input devices and output, such as displays, speakers, keyboard and handset; an analog-to-digital elements, vocoders and other elements of speech processing and analog signals, etc., All together they form part of the subscriber to the electronic circuits of the main bands that are well known in the field of communications. If you are using signal processing with diversity, custom digital electronic circuits 222 main strip can contain unifier explode and decoder. Some of the elements can also be controlled by control processor 220 or through communication with him.
When voice or other data are prepared as the output message or communication signal coming from the subscriber device, the user of the digital electronic circuit 222 main strip used for receiving, storing, processing and other skills to transfer the required data. Custom digital electronic circuits 222 main strip serves the data to the modulator 226 transfer running control processor 220. The signal leaving the modulator 226 transfer is fed into the controller 228 power, which provide the signal from the antenna 210 to the hub station.
The transceiver 200 may also use one or more elements of precorrection or precorrection 232 and 234. Such precorrection described in co-pending application for invention "Precorrected time and frequency for non-geostationary satellite systems" for number____(will be assigned a case of a patent attorney RA), mentioned here for information. Precorrected preferably occurs at the output of the digital controller 228 power at the fundamental frequency band. The spectral information of the main strip, which includes the adjustment of the frequency is translated to a corresponding secondary carrier frequency when increasing the conversion is performed in the amplifier 230 transmit power. Precorrection or the power correction is performed using known methods. For example, precorrection can be performed using the complex rotation signal, which is equivalent to multiplying the signal by a factor of ejtwherecalculated on the basis of known ephemeris of the satellite and the desired frequency channel. This is very useful in cases when the communication signals are treated as in-phase (I) and quadrature (Q) channels. For forms is but you can use a digital computing element to rotate the coordinates, which uses binary shifts, addition and subtraction to perform a discrete number of turns, resulting in the specified shared rotation. Such methods and hardware for their implementation are well known in the field of communications.
Alternatively, the element 234 of precorrection can be set in the transmission path at the output of amplifier 230 power transmission for the frequency of the outgoing signal. This can be implemented using known methods, such as increasing or down conversion of the signal transmission. But the frequency change of the analog output of the transmitter can be more time consuming, as always there are a number of filters used for signal conditioning, and changes on this connection can affect the filtration process. Alternatively, the element 234 of precorrection may be part of a mechanism of selection or adjustment of frequency in analog cascade 230 increases conversion and modulation in the subscriber device to use the adjusted frequency for converting the digital signal at a given transmission frequency in a single operation.
Information or data from Kim signals shared resource, can be sent in a base station using a number of known methods. For example, this information can be sent as a separate information signal or be connected to other communications prepared custom digital electronic circuits 222 main strip. Alternatively, you may enter information in the form specified bits control the modulator 226 transfer or regulator 228 power transmission under control of the control processor 220.
Digital receivers 216A-N data and the search receiver 218 is made with elements of the correlation signals for demodulation and tracking of special signals. Search receiver 218 is used to search for pilot signals or other signals of high power with a relatively stable form, and receivers 216A-N data are used to track the pilot signal or the demodulation of the signals associated with the detected pilot signals. Consequently, it is possible to control the output signals of these units to ensure that the information used to calculate the parameters according to the invention. Information about the measurements performed by the subscriber unit 106 on the received communication signals or the signals of the shared resource, you can send the separate data signal or attach to other messages custom digital electronic circuits 222 main strip. The receivers 216(A-N) data are also used elements of the tracking frequency that can be controlled to obtain current information about the frequency and time management processor 220 in relation demodulating signals. This aspect is discussed further with reference to Fig.4 and 5.
Control processor 220 uses this information to determine the extent to which the received signals are shifted relative to the expected frequency based on the frequency of the local oscillator when scaling it in the same frequency band. If necessary, this and other information related to the shifts of the frequency error and Doppler shift, can be stored in one or more elements 236 of memory errors/Doppler shift. This information can be used in the control processor 220 to adjust its operating frequency or can be passed into the hub station using different communication signals.
For the formation and storage of historical information, such as date and time of day, allowing to determine the position of the satellite is used, at least one element 238 time standard. This time you can remember and PEMA remembered every time when the subscriber unit is in off mode, i.e., "off". It is time together with time "enable" is used to define different time-dependent signal parameters and changes in the location of the subscriber device.
In addition, for storing special information about the parameters, discussed in more detail below, it is possible to use elements 240 and 242 memory. For example, the element memory 240 may store the measurements made in the subscriber apparatus and a related parameter is the rate of change of range, for example, changes in the relative frequency shifts between the two incoming signals. Element 242 you can use the memory to store measurements performed by the subscriber device and related to the parameter difference range, such as time difference of arrival of two signals. In these memory elements are used in construction and circuitry are well known in the field of communications, and they can be made as separate elements or as a larger unified construction in which this information is saved with the ability to control for subsequent retrieval.
As shown in Fig.2, the local oscillator 250 or generator frequency reference is used in the AC at a given frequency. If desired, it can also be used in many intermediate operations conversion to until the signal reaches the set frequency base band. As shown in the drawing, the oscillator 250 is also used as a reference in analog transmitter 230 to increase conversions from the main strip on a given carrier frequency for transmission in the reverse link, and as a standard or reference frequency for the circuit 252 clocking. Circuit 252 clocking generates clock signals for the other stages or processing elements in the subscriber apparatus 200, for example, schemes for tracking correlators in digital receivers 216A-N and 218, the modulator 226 transfer element 238 time standard and control processor 220. Circuit 252 clocking can also be performed with the possibility of creating delays in order to delay or advance relative to the clocking of the clock signal under control of the processor. Thus, the monitoring time can be adjusted to the specified value. It also allows you to use codes that should be ahead of "normal" clocking or be left behind, usually on one or several periods of the element signal, so that it will apply iant transceivers 300, used in a base station 102. Part of the hub station 102 shown in Fig.3, has one or more analog receivers 314, connected to the antenna 310, for receiving communication signals, which are then converted with decreasing frequency, amplified, and is discretized using various known digital circuits. In some communication systems use multiple antennas 310. Discrete output signal of the analog receiver 314 are fed to the input of at least a digital receiver module 324, shown by the dashed lines.
Each digital receiver module 324 corresponds to the elements of the signal processing used to manage communication between a hub station 102 and one subscriber device 106, although there are other options. One analog receiver 314 can apply input signals to multiple digital receiver modules 324, and usually at the nodal stations 102 uses several such modules to ensure processing of all rays satellites and possible diversity signals at any point in time. Each digital receiver module 324 has one or more digital receivers 316 data and search receivers 318. Search receiver 318 basically searches relevant to reimburse more search blocks. When implemented in a communication system for receiving signals with the division uses a variety of digital receivers 316.
The output signals of the digital receivers 316 data submitted in the following elements 322 of the processing in the main band, which is known in the field of communications and is not shown in detail. Option processing device in the main strip contains combiners explode and decoders for combining signals of multipath propagation in a one output signal to the subscriber. The processing device in the main strip also contains the interface circuit to ensure that the output is usually for a digital switch or network. Some elements 322 of the processing in the main zone can be implemented as a number of other known elements, such as vocoders, modems, data and digital components switching and data storage, but is not limited to. These items are used for control or direction of transmission of data signals in one or more transmitting modules 334.
Each signal to be transmitted in the subscriber units 106, electrically served in one or more transmitting modules 334. A typical base station uses several transmitting modules 334, carstvo transmitting modules 334, used in a base station 102, is determined by known factors, including the complexity of the system, number of satellites, usually located in the field of view, subscriber bandwidth, the selected degree explode, etc.
Each transmitting module 334 includes a modulator 326 transmission, which modulates a broader spectrum of data to transmit and has an output electrically connected with the digital controller 328 transmit power, which adjusts the transmit power used for the outgoing digital signal. Digital controller 328 power transmission uses the minimum power level to reduce interference and resource allocation and the corresponding power levels, when it is required to compensate for the attenuation on the transmission path and other characteristics of the transmission path. PSH generator 332 is used by the modulator 326 for transmission expansion signals. This code generation can be a functional part of one or more control processors or memory elements used in a base station 102.
The output signal of the regulator 328 transmit power is supplied to the adder 336, where it is summed with the output signals from the other control circuits of power. This weekend Gnal controller 328 transmit power. The output signal of the adder 336 is supplied to an analog transmitter 338 for digital to analog conversion, conversion to the corresponding carrier frequency, subsequent amplification, filtering and filing one or more antennas 340 for radiation in the direction of subscriber units 106. Antenna 310 and 340 may be the same antennas, depending on the complexity and configuration of this communication system.
At least one control processor 320 junction electrically connected to the reception module 324, transmitting modules 334 and the electronic processing circuit 322 in the base band. These blocks can be physically separated. Control processor 320 provides command and control signals to implement, but is not limited to, functions such as signal processing, the formation of the clock signal, power control, switching control of the communication channels, the signal integration explode and interfacing systems. In addition, control processor 320 assigns extending PN codes, an orthogonal code sequence and specific transmitters and receivers or modules for use in customer communications. Control processor 320 can also be used to wichester 320 also controls the formation and power of pilot channel signals, signals and signals of the radio call, as well as their relationship with the regulator 328 transmit power. The pilot channel signal is simply a signal that is not modulated with data, and can use multiple, permanent or combination fixed frame structure. This means that the orthogonal function used for formation of the channel, the pilot signal has an essentially constant value, for example, all 1 or all 0, or a known combination of alternating 1 and 0.
Although control processor 320 may be directly electrically connected with the elements of some module, for example, the transmitting module 334 or receiving module 324, each module typically contains a dedicated processor, such as the transmitting processor 330 or the receiving processor 321, managing elements of this module. In a preferred embodiment of the invention, control processor 320 is electrically connected with the transmitting processor 330 and the receiver processor 321, as shown in Fig.3. Thus, a single control processor 320 can more effectively manage the operations of a large number of modules and resources. The transmitting processor 330 controls the formation and power of the pilot signals, signals, signals PR 321 controls the search, extending PN codes for demodulation and control of the received power. The CPU 321 can also be used to define the parameters of the signals used in the proposed method, or it can detect and transmit the data acquired from the subscriber apparatus with respect to such parameters, thereby reducing the load on the control processor 320.
To implement embodiments of the invention can use one or more precorrection or elements 342 and 344 of precorrection frequency. It is preferable to use precorrector 342 to adjust the frequency of the digital output signal of the digital controller 328 power at the fundamental frequency band. As in the subscriber device, the spectral information of the main strip, including the correction frequency is converted to the corresponding secondary carrier frequency while increasing conversion performed in the analog transmitter 338. Precorrection frequency is carried out using known methods, for example, the above-described integrated turn signal, in which the rotation angle is calculated based on the known ephemeris of the satellite and of a given frequency channel. As in the subscriber device, you can use the
If desired, in addition to precorrection frequency to perform precorrection time to change the relative clocking signals or PN codes. This is typically implemented by correcting the generation and clocking code or clocking another parameter signal when the signal is formed in the main zone and prior to its issuance by the regulator 328 power. For example, the controller 320 can determine when the codes are generated, and their relative timing and application of the signals, and when the signals are processed by a modulator 326 transmission or transmitted by different satellites regulator 328 power. But at desire it is possible to use known elements or scheme precorrection time, part blocks or separate units (not shown), similar elements 342 and 344.
In Fig.3 precorrector 342 is shown as located in the transmission path before the adder 336. This enables you to optionally carry out a separate control for each subscriber unit. However, you can use one element of precorrection when precorrected is performed after the adder 336, because subscriber devices share the same transmission path from the hub station to the SPU the new transmitter 338 for correcting the frequency of the outgoing signal using well-known methods. However, the frequency change of the analog output of the transmitter can be more time consuming and affect the processes of filtering of the signal. Alternatively, the output frequency analog transmitter 338 can be adjusted directly control processor 320 to provide the output frequency shifted relative to the normal average carrier frequency.
The magnitude of the frequency entered in the outgoing signal based on the well-known Doppler shift between the hub station and each satellite, through which communication is effected. The amount of shift required to account for the Doppler shift of the satellite can be calculated by a host process 320 using known data of the orbital position of the satellite. These data can be stored in one or more elements 346 memory, such as reference tables or memory elements, and retrieved from them. If desired, this data can also be obtained from other data sources. The memory elements can be implemented using a number of known devices, such as ROM and NVR or magnetic storage devices. This information is used to determine the correction of the Doppler shift for each satellite used is Aly reference frequency in the analog receiver 314. In some applications, you can use the signal of a single time (S) from the receiver GSMA as part of this process. If desired, it can also be used in many intermediate operations transformation. BWC 348 also serves as the standard for analog transmitter 338. It also provides clock signals to other stages or elements of the processing in the transceiver device 300 a junction, for example, correlators in digital receivers 316-N and 318, the modulator 326 transmission and control processor 320. If desired BWC 348 can also be done with the possibility of a delay or timing relative clocking signals under control of a processor to the specified values.
In Fig.4 shows a possible embodiment of the measuring clocking representing the system 400 of tracking time for the subscriber device. This type of tracking system known as the system Tau Dieter. In Fig.4 communication signals received from the analog receiver, usually quantized with excessive frequency, and then introduced into thinner 402. Thinner 402 operates with a constant speed and constant to pass in subsequent stages of the receiver only is Yedinaya with relevant system extends PSH codes coming from the PN generator or source 406, for the convolution of the signal. Folded signal in a unifying element 408, where it is combined with a corresponding orthogonal code functions Wiproduced by the code generator or source 410, if used, to obtain the data. Orthogonal code functions are functions used to create channels of communication signals. Normally, this process uses the pilot signals and the signals of the radio call, although you can use other signals to high power. Therefore, the orthogonal code is essentially the code used to generate the pilot signal or radio call signal, known in the field of communications. Alternatively, you can combine extender PN codes with orthogonal codes, and then combine them with samples in a single operation in a known manner.
As a scheme for tracking time, you can use the scheme "lead/lag", is described in U.S. patent No. 4901307 mentioned above. In this solution, the degree to which the clocking of the incoming signals and digital receivers is the same or consistent, measured by sampling the incoming data stream when the shift of otroitement PN code and is called "lag" or "ahead".
If clocking data from a plus or minus offset symmetrically different from clocking nominal peaks collapsed incoming signals, the difference between sample values of the lag and lead is equal to zero. This means that the value obtained by forming the difference between the trailing and leading signals, tends to zero when the shift by half element centered in the area of timely clocking the received signal. If the relative timing used by the receivers 216, does not provide accurate tracking time of a received signal and ahead of the incoming signal, then the difference between the signal delay and signal timing gives the correction signal with a positive value. If the clock signal is too slow, this difference gives the correction signal with a negative value. It is clear that if desired, you can also use the back or another dependency.
To implement this method, the output signal of the thinner control so that he appeared on the floor element earlier than normal demodulation signals. Then the output signal of the thinner roll and decode, and the obtained data accumulate over C is rerout energy symbols, which squares in element 416 squaring to obtain non-negative values for advanced signal.
With accumulating register 414 is accumulated and summed or integrated, another group of samples for subsequent pre-selected period of time. But in this period to delay submission of PN and orthogonal codes to a single period of the element signal, a set of elements 412 delay. This gives the same effect as changing the clocking of samples, or thinning, providing a delayed version of the thumbnail and the decoded data. Minimized and the decoded data are accumulated for a given period in nakaplivaya register 414. Optionally, you can use additional elements and memory devices. Accumulated delayed data symbol squares in element 416 squaring. Received leading and lagging squared values or subtracted from each other, or are compared to obtain the required differential clocking delay/advance element 418. This difference is filtered in the filter 420 clocking for receive signal 422 lead/lag. Tracking system premenapause characters used to update or generate values of the signal 422 lead/lag. This procedure continues until until clocking receiver is not installed in its original state, for example, when the receiver is turned off or transferred to the new tracking signal, as will be clear to the experts.
The control current source and constant for the process of thinning and delay codes are provided by a special electronic circuit, for example circuit 424 of the control clock. This means that the circuit 424 control clock determines the time-sampling of thinner 402. At the same time, the formation extends PN code and the orthogonal code is also under the control of signals from the circuit 424 of the control clock. This clocking is sometimes referred to as the enable signal supply PN code, as it allows the use of codes. You can also use the initialization signal or the signal clocking the EPOCH. Clocking selected circuit 424 of the control clock is adjusted signal 422 lead/lag in response to the output signal of the clocking scheme. Usually this time is ahead of time, the components of any dominace, for accumulation of the input signal prior to decimation. The use of such mechanisms clocking and lag and lead are well known in the field of communications.
To determine the relative delay time of signal arrival is used, the amount by which each allotment or digital receiver adjusts its timing to synchronize or harmonize with the input signal. This is easily accomplished by tracking the total change in time (lead/lag) used in the system 400 clocking. Cumulative register 426 can be used for accumulation and summation of each signal or team lead/lag for a selected period of time. Thus, it is possible to obtain the total value of the change required to align the incoming signal with the clock of the receiver. It represents a shift of the signal relative to the local clocking subscriber apparatus or receiver. If clocking subscriber device relatively close to clocking the hub, or synchronized with it, it can give a measure of the delay experienced by the signal as it passes between the hub station and the subscriber apparatus that allows Vici drift of the local oscillator.
As noted above, these data can be sent in a junction station as part of other messages or as special signals time. Data can be stored in the elements of short-term memory for subsequent transfer and use. This can also transmit or maintain any form of "time stamp reflecting the time of data collection, so that the hub station has a precise time dependence for the data and can more accurately determine the location of the subscriber device. But as mentioned above, the accuracy requirements of communication systems are not very hard. If information is transferred quickly enough after its collection, the affixation timestamp does not bring great benefits. Usually the data is sent in multiple frames of data after their measurements and, if you are having problems with the transmission, the data is generated again before they are transmitted, they are delayed for a few frames. However, timestamps increase the flexibility of data transmission and re-transmission of signals or groups of signals, regardless of the actual time. Otherwise, if to maintain a given level of accuracy in the system does not use timestamps, process is used for both signals, take junction, except that the pilot signal is not detected, and orthogonal codes to be mainly associated with signals access attempts. One advantage to the hub, is that time can be considered as a standard of absolute time. That is, the hub station has a precise system time, as described above, and can accurately determine the time difference for the application of PSH or orthogonal codes regarding its own time. This allows the hub to determine the exact propagation time or distance from the state of PN codes used in each receiver or challenge. The propagation time or distance can be used to determine the parameter range according to the invention. Therefore, the information for each outlet can be processed separately, as this is useful in some applications, and there is no need to combine it with the item 428, as described earlier.
In Fig.5 shows one embodiment of the measurement frequency, which is a common type of diagram 500 tracking frequency to the subscriber apparatus. These frequency measurement can be used to determine the rate of change gave 502. The rotator 502 operates at a predetermined, but adjustable phase to remove residual frequency errors or shifts of the digital samples received from the analog receiver digital receiver or removal.
When using signals mdcr sample can be transferred in one or more combiners 504, typically the multiplier, for Association with the corresponding system extends PN codes generated by the one or more code generators or sources 506, to retrieve the data. Such widening PN codes or orthogonal codes can be combined with the signal separately or together in a single operation. If the frequency used channels of traffic, then you could use a fast Hadamard transform (BIA) instead of the multiplexer 504 and code generator 506. This method is described in application for U.S. patent 08/625481 on "Monitoring frequency for orthogonal Walsh modulation," owned by the assignee of this invention and are mentioned here for information.
The signals obtained after the rotation, coagulation and decoding, accumulated during the period character in nakaplivaya register 514 to obtain the symbol data, and the results are given in the item or gain symbol, which creates a delay for the period of one symbol before transmission symbol generator 518 vector product.
Generator 518 cross product produces a vector product between the specified symbol and the previous symbol, to determine the change in phase between these characters. This gives a measure of the error in the rotation phase, included in the input signal. The output signal generator 518 vector product served as the estimation error of the frequency or the correction factor in the rotator 502 and a code generator 506.
Managing clocking to the processes of convolution decoding is provided with electronic circuits, such as circuit 524 control clock described above. This timing can be provided as an output signal of the system clocking described above.
To determine the relative shifts of the frequency of incoming signals is used, the amount by which each allotment or digital receiver adjusts its phase to align with the input signal. This means that the value should be adjusted phase rotator to remove residual errors in the coordination signal, means the amount by which sdinet.
As the communication system operates in fixed sets of frequency bands for communication signals, the receivers know what the average or nominal carrier frequencies should be used. But as a result of Doppler shifts and other effects, which can be minimum, the incoming signal will not be at the expected average frequency of the carrier. The above adjustments to determine the offset that should be used to determine the Doppler shifts and the actual frequency of the incoming signal.
This can easily be done by tracking the total amount of change applied by the system 500 tracking frequency. Cumulative register 522 can be used for simple accumulation phase change of the error estimates, signals or commands for a specified period. This gives the full magnitude of the changes necessary to harmonize frequencies of the incoming signal and the receiver, and represents the frequency shift of the signal relative to the local frequency of the subscriber apparatus or receiver, scaled to the appropriate frequency band.
As before, these data are sent to the hub station as part of other messages or as special signals information about the frequency. These data can be saved and". But this is not necessary, as the data is sent in multiple frames of data after measurements and can be formed again in case of any problems. If timestamps are not used to maintain a given level of accuracy, the system probably uses fixed time intervals and the requirement to provide messages.
III. Operating parameters
In a preferred embodiment of the invention uses two parameters: the range and rate of change of distance. These parameters describe the spatial and temporal correlation between the subscriber device 106 and the satellite 104. Further details on these parameters, their measurement and use.
In Fig.6 shows the projection of isocontours representing these parameters, on the surface of the Earth. Isocontour parameter represents a curve connecting all points having the same value for this parameter. In Fig.6 shows the sub-satellite point 614 (i.e., the point on earth's surface directly below the satellite) and the projection on the surface of iocontrol parameters range and rate of change of distance is related to the satellite 104. To illustrate the approximate scale of esposti represents the distance between the satellite and the subscriber apparatus. In a preferred embodiment of the invention, the parameter range is the distance R between satellite 104 and user device 106. Projection isocontour R on the surface of the Earth describes a circle with center under the appropriate satellite, as shown by point 604 in Fig.4. In a preferred embodiment of the invention R is obtained by measuring the latency dual pass (DCP) of the signal transmitted from the satellite 104 to the subscriber device 106 and back to the same satellite 104. Then define R by dividing the zdp two to get the delay to one side, and multiply the result by the speed of light, which is a speed signal. Alternatively, DCP is used as a parameter range.
In a preferred embodiment of the invention the zdp is measured in the following way. First, the hub station 102 transmits a signal containing a known current PN sequence or extend the code. This signal is relayed to the subscriber device 106 satellite 104. Subscriber device 106 again transmits this signal immediately or after a known delay. The retransmitted signal is relayed back to the hub station 102 in the same satellite 104. Then the hub station 102 compares the state P the fact is used to determine the overall latency by double passage, which includes a known delay between the node station 102 and the satellite 104. These delays are known, since the distance between satellite 104 and the hub station 102 is retained hub station 102 in a known manner. Subtract the known delay from the total delay in the double passage gives the zdp. Using known ephemerides of the satellites, calculates a known delay between the node station 102 and the satellite 104 in a known manner.
Specialists will be clear that to obtain R can be used in other ways without going beyond the scope of the invention.
In a preferred embodiment of the invention the delay when you double pass can be measured during a call or during a connection. If the measurement is performed during connection establishment, the measured signal is usually passed from the hub 102 to the subscriber device 106 as part of the radio call signal and re-transmit to the subscriber unit 106 in the hub station 102 as part of the signal access. If the measurement is done during a call, the measured signal is usually passed from the hub 102 to the subscriber device 106 and back as part of the traffic signals. Specialists will be clear that the measured signal is bretania.
The rate of change of range
Parameter rate of change of range is a relative radial velocity between the subscriber device 106 and the satellite 104. In a preferred embodiment of the invention, the parameter rate of change of range is the relative radial velocitybetween the subscriber device 106 and the satellite 104. In an alternative embodiment of the invention the parameter rate of change of range is the Doppler shift Sdprop in the signals transmitted between the subscriber device 106 and the satellite 104.can be calculated by multiplying Sdprop at the speed of light and dividing by the average carrier frequency. Projection isocontours Sdprop on the Earth's surface is described by a set hyperpolarizing curves that are symmetric with respect to the vector 616 speed corresponding to the satellite, as shown by point 606 in Fig.6. Contour Sdprop=0, which passes through the sub-satellite point 614 satellite 104, describes a straight line.
In a preferred embodiment of the inventiondetermined by performing two measurements (one in the subscriber device 106 and one in the hub station 102) following the reports this frequency in a base station 102. The hub station 102 measures the frequency of the signal received from the subscriber device 106 via the same satellite 104. Now in the hub station 102 has two dimensions. In the preferred embodiment, these frequencies are measured relative to the frequency of the local oscillator. You can then get the actual frequency, as will be described below. This method is described in co-pending application of the same applicant for the invention of "Definition of frequency shifts in communication systems" (case a patent attorney RA), which is mentioned here for details.
These measurements can be represented by two equations with two unknowns: the relative radial velocityand normalized shift f0ff/f0lo subscriber unit 106. This pair of equations can be solved for the two unknown afterbut also f0ff/f0that is a dimension that is useful in other aspects of satellite communication systems, as will be obvious to the experts.
The solution of these two equations is illustrated graphically in Fig.7A and 7B. Fig.7A provides a graphical representation of the components of the frequency measured in the subscriber unit 106. Fig.7a/85/857574.gif" border="0">- relative radial velocity between satellite 104 and user device 106,
S - speed (speed of light),
fF- nominal frequency straight line
fRis the nominal frequency of the reverse link,
f0ffis the nominal frequency of the local oscillator subscriber device 106,
f0ff/f0the normalized frequency shift of the local oscillator subscriber device 106.
As shown in Fig.7A, the frequency, measured in the subscriber unit 106, is defined as
As shown in Fig.7B, the frequency, measured in a base station 102, is defined as
Addition and subtraction (1) and (2) gives the frequency shift and the relative radial velocity according to the dependencies
Specialists will be clear that it is possible to use other methods for determiningwithout going beyond the scope of the invention.
In a preferred embodiment of the invention the frequency measurements can be made during a call or during a connection. If the signal is radio call, and the signal measured at the hub station 102 is the signal access. If the measurement is made during a call, the signals measured in the subscriber unit 106 and the hub are traffic signals. Specialists will be clear that it is possible to use other signals, without going beyond the scope of the invention.
IV. The method of positioning
The above two parameters can be used to determine the location of user device 106. To facilitate understanding of the invention, the physical representation of parameters shown as secondary options projected onto the surface of the Earth.
In a preferred embodiment of the invention, the location is determined on the basis of the parameters of the range and rate of change of range. In Fig.6 parameter range is R, and the parameter rate of change of range is Sdprop. It also shows one isocontour R, denoted as 604, which forms a circle, representing the range of 2000 km between the subscriber device 106 and the satellite 104.
In Fig.6 shows a family of isocontours Sdprop, in General, the position 606. Isocontour Sdprop have the kind of hyperbole and are located symmetrically with respect to the vector 616 velocity of the satellite is led shift relative to the satellite 104. Isocontour Sdprop graduated in kHz, the circuit Sdprop = 0 passes through the underlying point 614 satellite 104.
This method of positioning has two drawbacks. The first is the ambiguity of the location. For example, consider the case in which R=2000 km, and Sdprop = +30 kHz. As can be seen in Fig.6, the contour R=2000 km crosses the path Sdprop = +30 kHz in two points Suite 610a and V. Without additional information it is impossible to determine whether the subscriber unit 106 in the Suite 610a point or point V. Therefore, this decision is ambiguous.
The second drawback is the so-called "geometric attenuation accuracy (GOTH), which occurs when a small error in the measurements leads to a large error in the determination of location. When the outline of the range and rate of change of range touch or almost touch each other, as shown at point C in Fig.6, a small error in any parameter will result in a large error of the positioning. Without additional information about the location method location only in terms of range and speed change range can be exposed to GOTH.
These problems can be solved by mininterno information. This information can be obtained by additional measurements or other parameters, for example what is the beam of the satellite is used. One such method is described in co-pending application of the same applicant for the invention "the decision of the ambiguous location determination using spot satellite number (not assigned, the case of a patent attorney PD456). Secondly, these problems can be solved if you start with some qualitative assessment of the location of the subscriber device 106, such as his or her last known location.
In Fig.8 shows an algorithm illustrating the operation of the preferred variant of the invention. One or more parameters range are determined as described above and shown in step 802. One or more parameters of the speed change range is determined as described above and shown in step 806. Then determine the location of the subscriber unit on the Earth's surface on the basis of well-known positions and velocities of the satellite and parameters of range and speed change range, as shown in step 810 and described below.
V. Implementation of the positioning
Before proceeding to a detailed description of the definition metallogeny way location. In Fig.9 shows a structural diagram illustrating such an apparatus. This apparatus is a computing system 900, which may be part of the control processor 220 and/or control processor 320. Computer system 900 includes one or more processors, such as processor 904. The processor 904 is connected to an adjoining bus 906. Different options are described with reference to this exemplary computer system. After reading the description of the invention, a specialist in the field of communications will be able to understand how to implement the method of positioning according to the invention using other computer systems, architecture, hardware, reference tables, etc., and their various combinations.
Computer system 900 includes primary storage device 908, preferably, the storage device with random access (NVR), and may also include secondary storage device 910. The secondary storage device 910 may be, for example, the drive 912 on hard drives and/or removable storage drive 914, such as a flash drive, floppy disk, tape drive, optical drive, etc. Removable nakopitelny element represents a floppy disk, magnetic tape, optical disk, etc., it is Clear that the removable cumulative element 918 contains a suitable computer storage medium with stored programs and/or data.
In alternative embodiments, the secondary storage device 910 may include other similar means to load in the computer system 900 programs or other commands. Such means can be, for example, a removable cumulative element 922 and interface 920. For example, you can use the cartridge with the program and cassette interface (as in video game devices), a memory on a removable chip (e.g., EPROM, or PROM) and associated socket, and other removable cumulative elements 922 and interfaces 920, which allow you to transfer programs and data from the removable cumulative element 922 in the computing system 900.
Computer system 900 may also include a communication interface 924. Communication interface 924 allows you to transfer programs and data between computer system 900 and the external devices tract 926 communication. Examples of communication interface may be a modem, a network interface (such as Ethernet card), a communications port, etc., Programs and data sent over with, is the quiet can make communication interface 924 on route 926 connection.
In further describes the implementation of the method of determining the location with reference to this exemplary variant of the equipment. However, this is done only for convenience of description. This does not mean that one method of positioning according to the invention can be implemented in the exemplary apparatus. In fact, after reading the following description, a specialist in the field of communications will be able to understand how to implement the proposed method of determining the location of alternative hardware.
In one embodiment of the present invention the location of the subscriber unit 106 determines by performing the following method in a computing system 900. It is clear that the method of positioning can be implemented in a state machine, reference tables, or so on, without going beyond the scope of the invention.
According to a preferred variant of the invention is constructed vector M×1 parameters, denoted as z, which consists of M parameters used in determining location. The z vector may include one or more of each of the parameters described above. As you know, this
where the subscript T means the transpose of a matrix or vector, according to
where the vector v to M×1 represents measurement error, a h is a nonlinear function that describes the dependence between the measured parameters and the location of the subscriber unit 106, h is also a function of the positions and velocities of the satellites A and B. Alternatively, the vector x location of the subscriber device can be defined by the three Cartesian coordinates, not by latitude and longitude, as shown in equation (7).
According to Gaussian linearization method, to determine the location of the subscriber unit 106 is constructed the partial derivative matrix H for M×K, where K is the number of unknown location, and in which the element (m, k) is a private derivative of m-dimension relative to the k-parameter location defined in the specified location x. For example, if the vector location describes the latitude and longitude as in equation (5), K=2, the elements in column k=1 matrix N describe the partial derivatives relative to the latitude of the subscriber unit 106, and the elements in column k=2 describe private coordinates (K=3), the columns k=(1, 2, 3) in the matrix H, respectively, related to the coordinates (x, y, z). When using Cartesian coordinates is used an additional equation to indicate that the sum of the squares of the coordinates equal to the square of the radius of the Earth. The relationship between x and H is defined as
To determine the unknown parameters of location, use an iterative method is weighted least squares. In a preferred embodiment of the invention uses a weighted Gauss-Newton described by H. W. Sorenson, Parameter Estimation - Principles and Problems", New York, Marcel Dekker, 1980. The iterative equation is obtained from the dependency:
where- assess the current and next location, respectively, and W is the weight matrix of M×M the Index i represents the iteration number, and i=0 represents the first iteration. Matrices or vectors based on the estimated location, marked by the upper index "". As an initial estimate of the location selected some reference point, for example, the last known location of the subscriber unit 106. If the last location �ata/85/857587.gif" border="0">
is a private derivative matrix, a specific assessment of your current location, and
are the expected parameters without error, defined by evaluating your current location. The iteration ends when the difference betweenfalls below a predetermined threshold. This threshold is determined by the designers and/or operators of the system based on the accuracy of the system using known methods. For example, the threshold may be based on the accuracy of the signal elements in the measurement and transmission speed of the signal elements.
The elements of the weight matrix W for M×M are the means, emphasizing the influence of specific parameters on the estimated locationif the parameter is greater than the unknown. In a preferred embodiment, the weight matrix W is a diagonal matrix whose elements reflect the relative accuracy with which you can define each parameter. Therefore, the element values are set based on the known accuracy of the measurement system, as will be clear to experts. Therefore, the parameter, based on a very accurate measurement, predesired on pre-determined 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 independent from each other and have zero mean and variances
then W is a diagonal matrix withas the diagonal elements.
With this choice of W, the variance of K-th element of the estimated vector x location is defined as
And finally, the total theoretical error horizontal location in units of distance is defined as
where re- the radius of the Earth.
In a preferred embodiment, the method of determining the location, use a smooth ellipsoidal model of the earth's surface. Alternatively, the proposed method of determining the location of the first uses a smooth ellipsoidal model of the earth's surface, such as the model WGS-84. When the values of x converge to such an extent that the difference betweenless than the specified parageusia until while the x values will not converge to such an extent that the difference betweenis less than the second predetermined threshold distance. Thus smoothed out any errors introduced by the rise of the subscriber unit 106. In an alternative embodiment, a detailed digital model of the Earth's surface is substituted after a specified number of iterations. The above thresholds on the distance and number of iterations are determined according to various factors, as will be clear to the experts.
Although the above-described different embodiments of the invention, it is clear that they have been presented only as examples and are not restrictive. For specialists in the relevant field of technology will be apparent various changes in form and detail, without going beyond the scope of the invention. Therefore, the invention is not limited to any of the above-described exemplary variants of its implementation, and is defined only by the attached claims and equivalents.
1. The system for determining the location of the subscriber device for a satellite communication system containing subscribers is referred to the subscriber unit through the said satellite, means for determining the parameter range, means for determining the parameter of the speed change range, and the above-mentioned parameter rate of change of range is a measure of the frequency of the first signal and the second signal is provided in said subscriber apparatus of the first means of frequency measurement for frequency measurement of the first signal received from the hub station via the above-mentioned satellite, provided in said subscriber unit means to make a measurement result of the frequency of the first signal in the above-mentioned junction station and provided in the hub, the second means of frequency measurement for frequency measurement of the second signal received with said subscriber unit through the said satellite, and provided in said hub, means for determining the location of the subscriber unit on the Earth's surface on the basis of the known position and velocity, parameter range, the parameter rate of change of range.
2. System location under item 1, characterized in that the above setting range is the distance between the satellite and the subscriber device.
3 is a delay when you double the signal, transmitted from the satellite to the subscriber apparatus and back to the same satellite, the system further comprises provided in said hub, means for measuring the latency of the double passage of the signal transmitted from the mentioned junction in said subscriber apparatus via satellite and retransmitted with said subscriber apparatus in the above-mentioned junction station through the mentioned satellite.
4. System location under item 1, characterized in that said parameter is the rate of change of distance is a relative radial velocity between the satellite and the subscriber device.
5. System location under item 1, characterized in that it further comprises means for dividing the frequency of the first signal at the nominal frequency of the first signal to obtain the first relationship, means for dividing the frequency of the second signal at the nominal frequency of the second signal to obtain a second relation, and means for multiplying the sum of the first and second relations at half the speed of light to obtain the above-mentioned parameter rate of change of range.
6. System location bonniem and known speed, junction station to communicate with said subscriber unit through the said satellite, means for determining the parameter range, means for determining the parameter of the rate of change of distance and provided in said hub, means for determining the location of the subscriber unit on the Earth's surface on the basis of the known position and velocity, parameter range, the parameter rate of change of range, and the said means for positioning includes means for forming a vector z of size M×1, containing the above-mentioned parameters, where M is the number of defined parameters, the means for forming a vector x location representing the original reference point, means for forming a private derivative matrix H containing information relating to the known position and velocity of said satellite and model of the Earth, describing the shape of the Earth, and the correlation between x and H is defined as
the means for forming the weight matrix W of size M×M, to emphasize the influence of specific parameters, and the tool is 599.gif" border="0">are respectively the estimates of the current and the next position, a i represents the iteration number, as long as the difference betweenwill not be reduced below the first predetermined threshold, T is the transpose symbol.
7. System location on p. 6, characterized in that the said means for determining the location includes a tool for assessing the current and the next position of the subscriber handsetwhen using smooth ellipsoidal model of the earth surface as long as the difference betweenwill not decrease below the second predetermined threshold, and then use detailed digital models of the earth's surface.
8. System location on p. 6, characterized in that the said weight matrix W is the inverse of the covariance matrix of measurement errors.
9. System location on p. 6, characterized in that the said means of positioning further comprises means for evaluating the current and the next subscriber unitwhen using smooth ellipsoidal model of the earth is displacement, where n is a predetermined number.
10. The method of determining the location of a subscriber unit in a communication system containing subscriber device, a satellite with a known position and known speed and junction station for communication with the subscriber apparatus via satellite, namely, that (a) determine the parameter range relative to the satellite, (b) defines the rate of change in distance relative to the satellite, and (c) determine the location of the subscriber unit on the Earth's surface on the basis of the known position and velocity, the above parameter range, the parameter rate of change of range, and step (b) additional (i) measured in the subscriber unit to the frequency of the first signal received from the hub station via the satellite, (ii) send the measurement result of the frequency of the first signal in a base station, (iii) transmit the second signal with the subscriber device in the hub station via satellite, and (iv) measured in the hub, the frequency of the second signal received from the subscriber terminal via the satellite, and the above-mentioned parameter rate of change of range is a referred measure the frequency of the first and second signals.
11. The way p is onatski device.
12. The method according to p. 10, characterized in that the parameter range is a delay when you double the signal, and step (a) additionally (i) measured in junction delay when you double the signal transmitted from the hub station in the subscriber apparatus via satellite and retransmitted to the subscriber device in the hub station via satellite.
13. The method according to p. 10, characterized in that said parameter is the rate of change of distance is a relative radial velocity between the satellite and the subscriber device.
14. The method of determining the location under item 10, characterized in that it further carry out the division of the frequency of the first signal at the nominal frequency of the first signal to obtain the first relationship, the division of the frequency of the second signal at the nominal frequency of the second signal to obtain a second relationship, and the multiplication of the sum of the first and second relations at half the speed of light to obtain the above-mentioned parameter rate of change of range.
FIELD: radio engineering, in particular, passive radio control systems.
SUBSTANCE: the method consists in measurement of the direction to the source of radio-frequency radiations, estimation of relative time delay with a subsequent computation of the coordinates of the source of radio-frequency radiations as a point of intersection of the line of direction to the source and the hyperbolis line of the position, all the measurements are taken at one receiving point, the relative time delay is determined by estimation of the discrepancy of the time of signal arrival from the source relative to the reference time scale formed on the basis of estimation of time structure of the signal source, whose position is supposed to be known, and the coordinates of the source of radio-frequency radiations are computed as the point of intersection of the line of direction to the source and the hyperbolic line of the position determined on the basis of comparison of the estimations of the discrepancy of the time of arrival of signals in time from the sources with the known and estimated location functioning in a single system of synchronization by digital (discrete) types of signals.
EFFECT: provided determination of the coordinates of the sources of USW-SHF radio-frequency radiation ranges using digital (discrete) types of signals from one point of radio control.
FIELD: radio navigation systems.
SUBSTANCE: device can be used for nearer navigation. Device has aerial, aerial switch, reference frequency receiver, information receiver, and transmitter, control unit, unit for calculation of original coordinates of object moving along route, alarm signal source. Coordinates can be calculated in case of closer re-translator fails due to the fact that radio navigation transmitter-receiver acts as temporal re-translator.
EFFECT: improved efficiency of operation.
FIELD: technological processes.
SUBSTANCE: measurements of pseudoranges are done between spacecraft-consumer and navigation spacecrafts of working constellation with number of at least two, at that in the moments of these measurements absence, spacecraft-consumer condition vector is predicted basing on the last obtained position estimation, and in the moments of measurements availability, in order to determine position of spacecraft, the multi-channel sequential Kalman filter is used for non-linear models of movement and measurement, which allows to determine position of spacecraft-consumer basing on measurements of pseudoranges between spacecraft-consumer and navigation spacecrafts of working constellation with number of at least two.
EFFECT: improves accuracy and simplifies determination of spacecraft-consumer condition vector.
FIELD: instrument making.
SUBSTANCE: proposed method of determining location of radio-frequency radiation source (RRS) relates to passive radio control systems. This method comprises preliminary delivery of three cartridges into supposed RRS location. Note here that aforesaid delivery is carried out by launching three carriers, each carrying one cartridge comprising navigation receiver and transceiver. The latter comprises panoramic receiver and signal parametre transmitter. After retention in soil, navigation receiver and transceiver are automatically, or by "start" signal, actuated simultaneously. The navigation receiver signals allow determining coordinates of the location of each carrier. Every transceiver incorporating aforesaid panoramic receiver searches RRS signals in preset frequency range. RRS signal detected, it is digitised and transmitted by transceiver, via repeater satellite, to radio control station for RRS location to be determined relative to navigation receiver coordinates.
EFFECT: higher accuracy of locating RRS signals in hard-to-reach areas.
FIELD: radio engineering.
SUBSTANCE: reference coordinate model of route - available motion trajectory is presented in system of orthogonal geocentric coordinates combined with global navigation satellite system. Coordinates of points in reference coordinate model are expressed in the form of three stationing functions, distance is measured from at least one satellite of global navigation satellite system to mobile object, based on which, equation of sphere is composed, and joint solution of three stationing functions and equation of sphere is used to identify coordinates and stationing of mobile object, and speed and acceleration of mobile object motion is defined as the first and second derivatives of stationing in time by differential scheme of the first and second order.
EFFECT: expanded field of application and improved accuracy of satellite navigation by detection of mobile object coordinates by linear crossbearing of its satellite receiver that moves along available trajectory of motion.
FIELD: radio engineering, communication.
SUBSTANCE: method comprises preliminary delivery to the presumed area of location of the radio-frequency source a plurality of sensors (not less than four), structurally mounted on multicopter-type unmanned aerial vehicles (UAV) of the "mini" category. Each UAV sensor comprises a navigation-time unit, a nondirectional antenna, a panoramic receiver and a transceiver. A medium-class unmanned or manned aerial vehicle (relay aerial vehicle) is used as a means of delivering and maintaining UAV sensors, as well as for relaying coordinate information coming from said sensors, and transmitting control commands from a ground-based control and processing station. After delivering to the presumed area of location of radio-frequency sources, the UAV sensors are distributed in space based on commands from the ground-based control and processing station. A set of UAV sensors and relay aerial vehicles is formed in space by a multi-position radio monitoring system. The method employs the property of multicopters to assume a fixed state in space, which lowers the system dynamic factor and enables to form an analogue to ground-based receiving stations in the air (one of which is central, located at minimal distance from the relay aerial vehicle, and the rest being peripheral) of a difference-range-finding system. Based on signals from the navigation-time unit, coordinates of each UAV sensor in space are determined and then high-precision referenced with their own coordinate system of the difference-range-finding system and a single time. To this end, information on coordinates of peripheral UAV sensors in the formed difference-range-finding system is transmitted to the central UAV sensor. Each UAV sensor, having a panoramic receiver, searches for radio-frequency source signals in a given frequency range. Upon detection of a radio-frequency source signal, said signal is digitised and transmitted by the transmitter of the transceiver to the central UAV sensor. Based on incoming data, the central UAV sensor determines the location of the radio-frequency source.
EFFECT: high accuracy of locating a radio-frequency source operating in a hard-to-access location.
FIELD: physics, navigation.
SUBSTANCE: invention relates to passive radio monitoring systems and can be used in radio-frequency source positioning systems. The technical result achieved is shorter time for identifying the location of a radio-frequency source with a limited region in space. The method includes performing space- and time-synchronous direction-finding of a radio-frequency source followed by correction processing of the stream of signals from each direction-finder to detect signals from radio-frequency sources whose coordinates belong to a predetermined scanned region in space.
EFFECT: space-time synchronisation is carried out by simultaneously forming the directional pattern of the direction-finders, the direction of the maximum of which is oriented towards the geometric centre of the scanned element of the region for spatial monitoring of radio-frequency sources.
FIELD: radio engineering, communication.
SUBSTANCE: reference, analytically calculated phase lines are formed and saved for various values of delays with the step Δτ without impact of additive Gaussian noise; by means of two synchronously operating analogue-digital converters the analogue casual signal x(t) noised by Gaussian additive noise and its copy y(t) = x(t-τ3) delayed for the period τ3 are digitized; the mutual spectral density (mutual Fourier spectrum) of the signals x(t) and y(t) is calculated; the phase line of mutual spectral density (mutual phase Fourier spectrum) of the signals x(t) and y(t) is calculated. Using the degree of similarity of the calculated phase line of mutual spectral density with one of reference phase lines of the mutual phase spectrum the final decision on the value of mutual delay of these signals is made.
EFFECT: improvement of accuracy of measurement of mutual delay of random signals in conditions of additive Gaussian noise and expansion of arsenal of control methods.
FIELD: radio engineering, communication.
SUBSTANCE: invention can be used in systems for locating radio-frequency sources. The method of determining coordinates of a radio-frequency source comprises delivering, in the presumed area of the location of a radio-frequency source, direction-finding elements taking into account mutual arrangement thereof on the area and forming a goniometric location system. The goniometric location system is formed by delivering direction-finding stations taking into account spatial requirements of the goniometric system base, consisting of at least two measurement elements which estimate the phase of the received signal. Each carrier is fitted with means for performing the search, detection and determination of parameters of radio-frequency source signals, radio navigation determination of coordinates and data transceiving. One direction-finding station is formed by launching at least two carriers at given delivery coordinates in the area of the location of a radio-frequency source. After mounting into the ground and putting into the working condition using means for the radio navigation determination of coordinates, coordinates of the means for performing the search, detection and determination of parameters of radio-frequency source signals are determined, the values of which are transmitted to a reference radio control station. The means for performing the search, detection and determination of parameters of each direction-finding station perform the frequency search of radio-frequency source signals and measure the phase value upon detection thereof. The phase and frequency values of the received signal of the means for performing the search, detection and determination of parameters of radio-frequency source signals are transmitted to the reference radio control station, where, based on the received data, coordinates of the radio-frequency source relative to the coordinates of the points of delivery of the direction-finding station elements are determined.
EFFECT: high accuracy of determining coordinates of radio-frequency sources located in a hard-to-reach area.
FIELD: radio engineering, communication.
SUBSTANCE: method employs a multi-position system comprising at least two spaced-apart signal processing and receiving stations (SPRS) and a radio-frequency source spatial parameter determining station (SPDS) linked thereto. The SPRS each comprise three receiving channels (points) randomly arranged relative to each other, each performing the estimation of the phase of the received wave. The SPRS have coordinate referencing of each receiving channel (point) in a Cartesian coordinate system. The values of the coordinates of the receiving points (channels) and the estimate values of the phase of arrival of a wave in each channel are sent to the SPDS which, using the measured phase values of the radio-frequency source, construct phase planes of the received field with each SPRS, and coordinates of the radio-frequency source are determined from coordinates of the middle of the minimum section connecting straight normal lines to the said phase planes.
EFFECT: eliminating limitations on the mutual spatial arrangement of receiving channels of direction-finding stations.