Signal search procedure for location systems

FIELD: location.

SUBSTANCE: first search is carried out as part of the location attempt and gives the measurement data. The additional search is repealed if these data satisfy to one or more of the chosen exit criterions. Otherwise the second search is carried out.

EFFECT: increasing of the location accuracy.

10 cl, 8 dwg

 

The technical field to which the invention relates

The subject of discussion, here disclosed relates to the field of positioning and, more specifically, to the procedures of the search signals, useful in the process of locating, extracting measurements of these signals and determine the location of the object on the basis of these measurements.

The level of technology

GPS system for determining geographic location (geo-location system) is a system of orbiting satellites, which makes it possible for the receiver of the signals from these satellites to determine the location of the receiver. Each of these satellites transmits a signal, which is frequency divided with a repeating pseudo-random noise (PN) code from 1.023 elementary signals that uniquely identifies the satellite. These 1.023 elementary signal is repeated every millisecond. The signal is also modulated data bits that have a duration of 20 MS.

Figure 1 shows the use of GPS system for determining the geographical location in which the receiver 100 in a wireless communication system receives the transmission from the satellites 102a, 102b, 102, 102d, visible this receiver 100. The receiver 100 extracts the temporal dimension of four or more of these programs. The receiver 100 provides these measurements module 104 definition conventions the position determination entity, PDE), which determines the location of the receiver 100 according to these measurements. Alternatively, with this information, the receiver 100 may determine its own location.

The receiver 100 searches for a transmission from a particular satellite by comparing pseudotumor (PN) code for the satellite with the received signal. The received signal is typically a mixture of transmissions from multiple satellites visible to the receiver 100, in the presence of noise. This mapping is performed on a number of possible shifts of this PN code. Every single time shift is called a temporary hypothesis. The full set of hypotheses that are tested, is called a search window in time. This search box is also referred to as a search window in code space, since each offset points to a different point within the code sequence, which is this "code space".

Each mapping is done for the "integration time". "Integration time" is time coherent integration, multiplied by the number of coherent integrations, which are not combined coherently.

For a particular PN code, the value of the correlation (matching) is referred to as the correlation value. If there is a strong correlation between code with which the received signal was frequency distributed, and locally generated PN code, this value is the correlation is high. Correlation values associated with each hypothesis, define the correlation function. Peaks in this correlation function is determined and compared with a preset noise threshold. This threshold is chosen so that the probability of falsely detecting the transmission of the satellite was below a specified level. Measuring the relative time of receipt of the signals received from each satellite is determined by the location of an early peak, which is above the selected threshold. It should be noted that the peaks may have what is commonly referred to as side lobes. Lateral petals are vertices (or peaks lower level) on each side of this peak. Such side lobes, if any, are ignored.

There is a tradeoff between accuracy and sensitivity of the search and the amount of time required to perform this search. This compromise solution is done by setting the time coherent integration, the number of coherent integrations and the size of the search window. The larger these values are, the higher the sensitivity of the receiver 100. Higher sensitivity means better detection of weak or delayed transmission. This results in higher accuracy in the resulting estimates of location. On the other hand, if these values are greater than, that required more than a length of the additional time, to obtain the necessary temporary measure. It also increases the risk that the receiver 100 overflows, as it increases the magnitude of these values.

When it is assumed that the transmission from the satellites are strong, the search parameters should be set relatively low in order to minimize the search time. This reduces the risk that the receiver 100 is full. Satellite transmission is likely to be strong, when, for example, a subscriber station is located outside on a clear day without atmospheric or related to weather disturbances. On the other hand, when it is assumed that the transmission from the satellites are weak or detainees, the search parameters should be set relatively high in order to avoid the loss of weak or delayed signals. It should be clear that the loss of signals compromises the accuracy of the resulting estimate of the location. Satellite transmission is likely to be weak or detainees, for example, when a subscriber station is located indoors or are atmospheric or related to the weather disturbance.

As many subscriber stations are mobile, and in General cannot be known in advance, will send a strong or weak. Therefore, there is no way to determine how to set the search parameters in any specific the condition. Accordingly, it would be preferable to be able to set the search parameters in a way that ensures that weak signals will be detected, but that a strong signal can be detected quickly and without overflow of the receiver.

The invention

The method of search signals for use in determining the location of the receiver. This method begins with the first search. Measurements extracted from the results of this first search. Additional search cancel, if the measurements satisfy one or more criteria you select "exit". The location of the receiver is determined on the basis of measurements made in the first search.

If the measurements do not satisfy the criteria selected output, conduct a second search. In one application, then specify the location of the object on the basis of measurements from the second search, or a combination of the first and second searches.

In one embodiment, the first search selects the speed, rather than accuracy and sensitivity. Exit criteria are selected to ensure that measurement result from the first search, sufficient to determine the location of the object at a desired level of accuracy. The second search is cancelled if the measurements satisfy these criteria. If the measurements do not satisfy the selected criteria, then conduct a second search. This second finding highlights the precision and sensitivity than speed.

In one embodiment, the receiver searches for the signals transmitted by GPS satellites. In this embodiment, all of the GPS satellites, which looks up the receiver, determine a first set of satellites". Those satellites in the first set of satellites for which the correlation value is equal to or specified "noise threshold, determine a second set of satellites". Those satellites in the second set of satellites that have a correlation value equal to or greater than the second threshold, determine a third set of satellites". The second threshold higher than the first threshold. The fourth set contains all of the satellites in the first set, but excludes satellites from the third set.

In one embodiment, the second search is cancelled if all the satellites in the first set of satellites have a correlation value that is equal to or exceeds the second threshold. That is, the number of satellites in the third set of satellites is equal to the number of satellites in the first set of satellites.

In the second embodiment, the second search is cancelled if the metric (i.e., the ratio of signal quality), determined from the azimuthal angle of each satellite in the second set and the peak of the carrier signal-to-noise ratio for each satellite, exceeds a certain threshold.

In the third embodiment, realized is I second search cancelled if the number of satellites in the second set is equal to or exceeds the specified threshold.

In the fourth embodiment, the second search cancel, if the ratio of the peak carrier signal to noise for each measurement in the second set is equal to or exceeds the specified threshold.

The fifth option exercise combines two or more of the four previously mentioned embodiments.

Brief description of drawings

The components in the figures are not necessarily reduced to a certain scale. Rather, the emphasis is on the demonstration of the principles of the disclosed subject matter. In the figures the same reference position indicate identical parts.

Figure 1 - chart system GPS geo-location.

Figure 2 - block diagram of the operational sequence of the method to search for signals useful in determining the location of the object, according to one variant of implementation of the disclosed subject matter.

Figure 3 - block diagram of the operational sequence of the method to search for signals useful in determining the location of the object in accordance with a second embodiment disclosed subject matter.

Figure 4 shows an example of the polygon formed by the measurements retrieved from the initial search, where the area of this polygon shows the quality of these is of Sereni.

Figa-5B contain a flowchart of the operational sequence of the method to search for signals useful in determining the location of the object in accordance with another embodiment disclosed subject matter.

6 is a block diagram of a system to search for signals useful in determining the location of the object in accordance with one embodiment disclosed subject matter.

7 is a block diagram of a subscriber station in a wireless communication system that includes a system of Fig.6.

Detailed description

As used here, it is assumed that terms such as "almost" and "essentially", and will allow some leeway in mathematical precision to account for tolerances which are acceptable in this activity. Accordingly, any deviation up or down from the value modified by the terms "almost" or "essentially"in the region of from 1% to 20%should be considered as being clearly within the scope of this specified value.

Moreover, as used here, the term "software" includes instructions used to direct a programmable device to perform some function. Accordingly, the software includes, for example, such things as source code, object code, binary is the first code, built-in programs, macros, microcommand, or any combination of two or more of the above.

Moreover, the term "memory" refers to any processor-readable storage media includes, but is not limited to this, RAM, ROM, EPROM, PROM, EEPROM, disk, floppy disk, magnetic drum, hard disk, CD-ROM, DVD, or the like, or any combination of two or more of the above, which can store the software.

The term "processor" refers to any device that is able to execute the software. Accordingly, the processor includes a General or special purpose microprocessor, finite state machine (finite state machine), a controller, a computer, a digital signal processor (DSP), or similar.

The term partner means navigation satellites such as GPS satellites.

Figure 2 is a block diagram of the operational sequence of the method to search for signals useful in determining the location of the object in accordance with one embodiment disclosed subject matter. This method begins with step 200, which includes conducting a first search as part of attempts to determine the location. From step 200, the method proceeds to step 202. At step 202 measurements are extracted from the search results.

From step 202, the method proceeds to step 204. Step 204 determines UD is vitoret whether measurement, the result from the first search, one or more selected criteria "exit". If these measurements satisfy one or more selected criteria output, an additional search within the above-mentioned attempts positioning is canceled. If these measurements do not satisfy one or more selected criteria output, at step 206. Step 206 performs a second search for signals useful in determining the location of this object.

The second variant of the method to search for signals useful in determining the location of the object shown in figure 3. In this embodiment, the method begins with step 302, which contains a search of transmissions from satellites in the first set. This finding highlights the speed, rather than accuracy and sensitivity.

In one example, in which the object is a subscriber station in a wireless communication system, the PDE provides subscriber stations facilitate the detection information acquisition assistance information, AAI), showing satellites, which likely signals that the subscriber station can receive. The satellites transmit signals that can be received by the receiver, usually referred to as "satellites in view" or "satellites that are visible". These satellites form the first set of satellites. In the second example, the information AAI is not available. therefore, the first set of satellites consists of all satellites in the GPS system for determining geographic location. In the third example, the subscriber station has access to the latest "almanac". The almanac is the information transmitted by the GPS satellite, for example, which shows the location and orbit of the satellites in this GPS together. In addition, the subscriber station has access to close to the rate of time and a rough knowledge of its own location. In this almanac, time and rough knowledge of the location of the subscriber station predicts what satellites for it to be visible. These satellites form the first set of satellites in this example.

From step 302, the method proceeds to step 304. At step 304 measurements are extracted from the search results. In one example, these measurements contain the signal-to-noise ratio (signal to noise ratio, SNR) and code phase (time) for each of the distinct peaks of the correlation values. Lateral petals, if any, are ignored.

Step 306 is followed by step 304. At step 304 SNR measurement from the first search are compared with the first noise threshold. The first noise threshold is set to a level that ensures that the probability of false alarm below a specified level. The satellites, which are greater than the first noise threshold, form the second set of satellites.

From step 306 with the persons goes to step 308. At step 308 SNR measurement is compared with a second threshold. The second threshold higher than the first. Satellites that exceed the second threshold, generate a third set of satellites. The fourth set of satellites is defined as all the satellites in the first set of satellites, but excluding satellites from the second set of satellites. Accordingly, the fourth set of satellites includes all the satellites of the first group of satellites from which signals are taken at the level below the second threshold.

Stage 310 is followed by step 308. At step 310 dimensions examined to determine if they satisfy one or more criteria exit. Exit criteria are chosen in such a way as to ensure that the quality of these measurements are sufficient to determine the location of the object with the desired level of accuracy. If these measurements satisfy one or more of these selected criteria output, an additional search is cancelled. If these measurements do not satisfy one or more selected criteria output, at step 312.

At step 312 is executed a second search. This second finding highlights the precision and sensitivity, rather than speed, and thus uses a longer integration time in the process of correlation (matching), resulting in a longer time positioning. The second search is he the only satellites in the fourth set of satellites. As soon as the second search is performed, at step 314. At step 314, the measurement signals received from the satellites in the fourth set, extracted from the search results. Then the method ends.

In one application, the location of the object is determined based on the measurements from the first search, if he is only executed search. If both of the search, the location of the object is determined on the basis of measurements from the second search, or a combination of the first and second search. In one example, where you meet both of the search, the location of the object is determined on the basis of measurements for satellites in the third set, the result from the first search, and measurements for satellites in the fourth set, the result from the second search.

In one configuration, these measurements are provided to the device, such as a module location (position determining entity, PDE), which estimates the location of the object on the basis of these measurements. Alternatively, these measurements object evaluates its own location.

In one embodiment, the second search is aborted if the number of satellites in the third set equal to the number of satellites in the first set, showing that all the satellites that were searched, satisfy the second threshold.

In the second embodiment is constructed mnogo linic dimensional associated with the satellites in the second set. For each of these satellites is formed by the vector from the satellite azimuth angle and peak of the carrier signal-to-noise ratio. The orientation of this vector is determined based on the azimuthal angle (i.e., the angle of elevation from the horizon into the sky) satellite. The magnitude of this vector is based on the ratio of the peak carrier signal to noise. These vectors are in some coordinate system. The endpoints of these vectors are connected to one another to define a certain polygon. In this embodiment, the second search is aborted if the area of this polygon is equal to or greater than a threshold. It should be understood that the greater the change in azimuth, the larger the area of this polygon. In addition, the stronger is the signal, the larger the area of this polygon. Therefore, it is clear that many of the satellites that are distributed across the sky and who have strong signals will result in a polygon with the largest area.

Figure 4 shows an example of the polygon defined by the five vectors 400a, 400b, 400c, 400d and 400e. Each of these vectors represents or corresponds to the dimension. More specifically, the angle between the vector and the vertical axis is the azimuthal angle for the satellite, and velocimetro vector is the ratio of the peak carrier signal to noise. The endpoints of these vectors are identified by using the reference position 402a, 402b, 402c, 402d and 402e. A polygon that is defined by these endpoints, identified by using the reference position 406. The area of this polygon, which is determined using known techniques, is used in the above comparison.

In the third embodiment, the second search is aborted if the number of satellites in the second set is equal to or exceeds a certain threshold.

In the fourth embodiment, the ratio of the peak carrier signal-to-noise ratio for each of the satellites in the second set is formed. The second search is aborted if this amount is equal to or exceeds a preset threshold.

Figa-5B contain a flowchart of the sequence of operations, showing the example of the method according to disclose the subject of the search for signals useful in determining the location of the object.

In this example, the user selects one of the three available choices, and each determines the compromise between time, location and accuracy/sensitivity. The first option provides the best time of positioning. The second option provides the following the best time of positioning, but also gives Lou the high precision and sensitivity, than the first option. The third option provides the best accuracy and sensitivity, but the worst time of the positioning of these three.

The method begins with step 502, which contains the search and location of transmission from the satellites in the first set. In this phase, the shallow search. A shallow search is defined here as one that highlights the speed, rather than accuracy and sensitivity. In one example, the search parameters for shallow search determine when full integration is set to 80 MS, time coherent integration is equal to 20 MS and the number of coherent integrations that are not coherently combined, is equal to 4.

From step 502, the method proceeds to step 504. At step 504 measurements are extracted from the search results. In one example, these measurements contain the ratio of the peak carrier signal to noise and time shift code for each of the distinguishable peaks.

Step 506 is followed by step 504. At step 506, the measurement is compared with a preset noise threshold. Those satellites, where the ratio of the peak carrier signal to noise exceeds the predefined noise threshold, form the second set.

In one example, this noise threshold depends on the search parameters. For shallow search, the noise threshold is set by 25.0 dB-Hz. For intermediate search, which will be discussed in relation to this the surface 518 and 522, this noise threshold is set to 18.1 dB-Hz. For deep search, which will be discussed in relation to step 524, this noise threshold is set by 14.0 dB-Hz.

Step 508 is followed by step 506. At step 508, the measurement is compared with a second threshold. The second threshold higher than the first. The third set is defined as those satellites in the first set, which satisfies the second threshold. The fourth set is defined as those satellites in the first set, but excluding S.

In one example, the second threshold varies with the choice of time positioning against the accuracy/sensitivity selected by the user. In one configuration, the second threshold for the first, second and third choices respectively set 29.4 dB-Hz, 32,4 dB-Hz and. The latter shows an installation that is so great that the second threshold is never satisfied.

Stage 510 is followed by step 508. At step 510, |S|, the number of satellites in the third set compared to |NTHE|, number of satellites in the first set. If |S| is equal to |NTHE|, showing that all satellites, escauriaza at step 502, satisfy the second threshold, the method ends. If not, the method proceeds to step 512.

At step 512 the polygon described earlier in relation to figure 4, is formed of measurements for satellites in the second set is e, and is determined by the area A of the polygon.

Step 514 is followed by step 512. At step 514, the area of A polygon is compared with a threshold area of AT. In addition, |N|, the number of satellites in the second set is compared with the threshold NIT. If the area A exceeds ATor |N| exceeds Nthe method ends. Otherwise, the method continues at step 516 on figv.

In one example, the threshold area of ATand the threshold number Nchange threshold time positioning against the accuracy/sensitivity selected by the user. In one configuration, the threshold area of ATfor the first, second and third choices respectively set on 4×10, 6×10and. The latter shows an installation that is so great that this threshold is never satisfied. In addition, the threshold number of NITfor the first, second and third choices respectively set on 4, 5 and. Again, the latter shows an installation that is so great that this threshold is never satisfied.

At step 516, |N|, the number of satellites in the second set is compared with a second threshold number of Nthe . If |N| is bounded by NEexecutes step 518. Otherwise, the method continues at step 520.

In one example, the second threshold number of NEvaries with the choice of time positioning against the accuracy/sensitivity selected by the user. In one configuration, the value of N for the first, second and third choices respectively set at 5, 5 and. The latter shows a setting that is so great that this threshold is never satisfied.

At step 518 is performed intermediate search for satellites in the fourth set. Smart search is defined as one that highlights the precision and sensitivity than speed, but does so in less than a deep search. From step 518, the method proceeds to step 526.

In one example, the intermediate search is characterized by full integration equal to 880 MS, time coherent integration is equal to 20 MS and the number of coherent integrations that are not coherently combined, equal to 44. It should be understood that these values are only provided as examples of values that can be used, and should not be assumed that they have any special value.

At step 520 the estimated time required to perform a deep search for satellites in the fourth set is. This time is compared with the maximum time available. If the estimate exceeds the maximum time, showing that there is insufficient time to undertake a thorough search, the method proceeds to step 522. Otherwise, the method continues at step 524.

In one example, the temporary estimation based on reviews of quality services. In the second example, which includes the search initiated by the PDE module or limited to a mobile device, such as one that starts when you call 911 subscriber station in the system, consistent with IS-801, the maximum time is the quality value of the preferred answer (Preferred Response Quality, PRQ), defined by the PDE module. In the third example, for a search initiated by a mobile device, such as one that includes finding a web-based geography, initiated by a subscriber station, this is the maximum time is assigned to this subscriber station.

At step 522 is performed intermediate search for satellites in the fourth set. This intermediate search was described previously in connection with step 518. From step 522, the method proceeds to step 526.

At step 524 runs deep search for satellites in the fourth set. Deep search is defined as one that highlights the precision and sensitivity than speed, and does so to a greater extent than the intermediate search.

In one example, a deep search is characterized by full integration equal to 1760 MS, time coherent integration is 80 MS and the number of coherent integrations that are not coherently combined, equal to 22. These values should be understood as provided as examples and should not be construed as having any particular value.

In one configuration, as time coherent integration exceeds a time period of 20 MS, for which the data bit is modulated in the satellite signal, the coherent integration in a deep search is performed with the support of sensitivity from PDE to compute the phase changes that occur inside the 80 MS time coherent integration.

From step 524, the method proceeds to step 526. At step 526 retrieves measurements for satellites in the fourth set. The method then ends.

Variant implementation of the system 600 to search for signals useful in determining the location of the object shown in Fig.6. As shown, the system 600 includes a processor 602, memory 604, and the correlator 606.

The correlator 606 is configured to produce the correlation function of the signals provided by the receiver (not shown). The correlator 606 provides the correlation function processor 602, either directly or through the memory 604. The correlator 606 may literality hardware, software, or a combination of hardware and software.

The memory 604 of the material implements a number of software instructions to perform any of the methods in the 2, 3 or 5A-5B, or any of the embodiments, implementations, or examples herein described or suggested.

The processor 602 is configured to refer to the software instructions, and execute software instructions, material by the memory 604. Through execution of these instructions, the processor 602 sends the correlator 606 to perform the first search for signals useful in determining the location of the object. Then, the controller 602 retrieves measurements from the resulting correlation function, provided by the correlator 606. Then the processor determines whether these extracted measuring one or more selected criteria exit. If so, the processor 602 completes the search. If not, the processor 602 sends the correlator 606 to perform a second search for signals useful in determining the location of the object.

An implementation option of the subscriber station 700 in a wireless communication system is shown in Fig.7. This particular subscriber station 700 is configured to perform or to include system 600 of 6.

Radio transceiver 706 is configured to modulate remodel is stimulated (baseband) information such as speech or data, RF carrier, and demodulate a modulated RF carrier to obtain the demodulated information.

The antenna 710 is configured to transmit the modulated RF carrier through a wireless communication channel and receive modulated RF carrier through a wireless communication channel.

The processor 708 demodulated data (Baseband processor) is configured to provide baseband information from the processor 602 to the transceiver 706 for transmission through a wireless communication channel. The processor 602, in turn, receives the demodulated information from the input device within the user interface 716. The processor 708 demodulated data also configured to provide baseband information from the transceiver 706 to the processor 602. The processor 602, in turn, provides this demodulated information to the output device within the user interface 716.

The user interface 716 contains many devices for input or output user information such as voice or data. Device, usually contained inside the user interface includes a keyboard, display screen, microphone and loudspeaker.

GPS receiver 712 is configured to receive and demodulate the GPS satellite transmission and p is dostavljati this demodulated information to correlator 606.

The correlator 606 is configured to output GPS correlation functions from information provided by the GPS receiver 712. For a given PN code correlator 606 produces a correlation function defined over the area of temporary shifts of code that define the search window. Each individual correlation (matching) is performed in accordance with defined coherent and non-coherent integration parameter.

The correlator 606 also configured to output related to the administration of the correlation function of the information relating to the control signals provided to it by the transceiver 706. The subscriber station 700 uses this information to obtain wireless communication services.

Channel decoder 720 is configured to decode the channel symbols, provided by the processor 708 demodulated data into underlying source bits. In one example, in which the channel symbols are surtace encoded symbols, the channel decoder is a Viterbi decoder (Viterbi decoder). In the second example, in which the channel symbols are serial or parallel concatenation of the convolutional codes, the channel decoder 720 is turbodecoding.

The memory 604 is configured to include program instructions that carry out is their any way of figure 2, 3, 5A-5B, or any of the embodiments, implementations, or examples out there that have been described or suggested.

The processor 602 is configured to refer to the software instructions, and execute these program instructions. Through execution of these program instructions, the processor 602 analyzes the GPS correlation function, provided by the correlator 606, retrieves the dimensions of the peaks there, and determines whether the location of the subscriber station 700 to be determined on the basis of these measurements, or whether you want the search to determine the location of this object.

The processor 602 is also configured to determine a root mean square error (RMSE)associated with each of these dimensions. These measurements and RMSE error values are provided to the PDE module (not shown). PDE weighs each of these dimensions, based on the inversion of its corresponding RMSE values, and then estimates the location of the subscriber station 700 based on these weighted measurements. Alternatively, the subscriber station 700 determines its own location for this information.

While described different implementation, implementation, and examples, specialists in the art will recognize that additional embodiments of, implementation of, and examples that have not been explicitly disclosed, are of voteobama of the claimed invention. In particular, the possible options for implementation, where the invention is applied to extract measurements are useful in determining the location of the object from the transmission base station, or combinations of transmission base stations and GPS satellites. Therefore, this invention should not be limited, except as by the attached claims.

1. Way to search for signals useful in determining the location of the object, namely, that

perform a first search for signals useful in determining the location of the object as part of attempts to determine the location,

moreover, this first search includes a search of the satellites in the first set;

retrieve one or more measurements of the received search results;

determine whether these measurements to one or more selected criteria;

cancel an additional search within this attempts to determine the location, if the measurements satisfy one or more selected criteria; and

perform a second search for signals useful in determining the location of the object if the measurements do not satisfy one or more selected criteria, output, and those satellites in the first set, the signals which satisfy a given first noise threshold, formed the comfort of the second set, those satellites in the first set, the signals which satisfy the second noise threshold, form the third set, the satellites in the first set, but excluding the third set, form the fourth set and the second search is cancelled if the number of satellites in the third set equal to the number of satellites in the first set.

2. The method according to claim 1, in which measurements from the satellites in the second set define a polygon, and the second search cancel, if the area of this polygon is equal to or exceeds a preset threshold.

3. The method according to claim 2, in which the second search is cancelled if the number of satellites in the second set is equal to or exceeds a preset threshold.

4. Way to search for signals useful in determining the location of the object, namely, that

perform a first search for signals useful in determining the location of the object as part of attempts to determine the location,

moreover, this first search includes a search of the satellites in the first set;

retrieve one or more dimensions of the obtained search results, and these dimensions contain the ratio of the peak carrier signal to noise and phase code for each distinct peaks;

determine whether these measurements to one or more selected criteria;

cancel additional search frame is x this attempt positioning, if the measurements satisfy one or more selected criteria; and

perform a second search for signals useful in determining the location of the object, if the measurements do not satisfy one or more selected criteria, output, and those satellites in the first set, the signals which satisfy a given first noise threshold, form the second set, those satellites in the first set, the signals which satisfy the second noise threshold, form the third set, the satellites in the first set, but excluding the third set, form a fourth set, and summarize the ratio of the peak carrier signal to noise for each of these measurements in the second set and the second search cancel, if this amount is equal to or exceeds a preset threshold.

5. Way to search for signals useful in determining the location of the object, namely, that

perform a first search for signals useful in determining the location of the object, as part of attempts to determine the location, and the first search includes a search of the satellites in the first set;

retrieve one or more measurements of the received search results;

determine whether these measurements to one or more selected criteria;

cancel an additional search in the region is mcah this attempt positioning, if the measurements satisfy one or more selected criteria; and

perform a second search for signals useful in determining the location of the object if the measurements do not satisfy one or more selected criteria, output, and those satellites in the first set, the signals which satisfy a given first noise threshold, form the second set, those satellites in the first set, the signals which satisfy the second noise threshold, form the third set, the satellites in the first set, but excluding the third set, form the fourth set and the second search limit these satellites in the fourth set.

6. Machine-readable storage medium storing a sequence of program instructions, execution of which by a processor enables the method to search for signals useful in determining the location of the object, namely, that

perform a first search for signals useful in determining the location of the object, as part of attempts positioning;

retrieve one or more measurements of the received search results;

determine whether these measurements to one or more selected criteria;

cancel advanced search within this attempt positioning, e is whether the measurements satisfy one or more selected criteria; and

perform a second search for signals useful in determining the location of the object when the dimension of the first search does not satisfy one or more selected criteria, output, and this first search includes a search of the satellites in the first set, while those satellites in the first set, the signals which satisfy a given first noise threshold, form the second set, those satellites in the first set, the signals which satisfy the second noise threshold, form the third set, and satellites in the first set, but excluding satellites of the third set, form the fourth set and the second search is cancelled if the number of satellites in the third set equal to the number of satellites in the first set.

7. Machine-readable storage medium according to claim 6, and measurements for satellites in the second set define a polygon, and the second search cancel, if the area of this polygon is equal to or exceeds a preset threshold.

8. Machine-readable storage medium of claim 6, where the second search is cancelled if the number of measurements in the second set is equal to or exceeds a preset threshold.

9. Machine-readable storage medium of claim 6, where the ratio of the peak carrier signal to noise summarize for each dimension in the second set and the second search cancel, if this sum is as equal to or exceeds a preset threshold.

10. Machine-readable storage medium of claim 6, where the second search is limited to satellites in the fourth set.



 

Same patents:

FIELD: wireless communication.

SUBSTANCE: device and method for wireless communication system with segment of direct/ascending communication line and segment of return/ascending communication line are allocated within bandwidth limits. Exactly network service area is separated for numerous areas. Allocation of direct/ascending communication line segment and return/ascending communication line segment is subject to transposition in numerous areas. Device and method can be realized within wireless multipath system.

EFFECT: improved transmission capacity of communication line.

26 cl, 17 dwg

FIELD: radio communication systems involving use of satellites.

SUBSTANCE: system for regional satellite communications and for servicing transportation corridors consists of a ground-based segment and space segment, which includes a spacecraft, fitted with controllable receiving-transmitting phased antenna array, capable of generation of multi-beam polar pattern with individual control of position of each beam, where one of the beams of polar pattern is constantly directed at servicing zone with gateway station, output of which is connected to dispatching center.

EFFECT: provision of personal mobile communications to users, increased level of interference protection in communication channels, protection from unsanctioned access to channels for management and control of transportation and loads, simplified system for orientation and stabilization of spacecraft position, reduced flow of working substance of propulsion system of spacecraft, reduced economical costs of deployment and operation of system.

3 cl, 8 dwg

FIELD: radio communication networks, in particular, methods and devices for controlling transmission power.

SUBSTANCE: in accordance to the method, power of transmission through direct communication line to a client terminal in composition of a radio communication system, which contains a set of rays, is controlled by means of determining baseline power level, Pbaseline, on basis of accepted effective signal to noise ratio (SNR) in control channel; marginal value of power, Pmargin, is determined on basis of detected sensitivity to interferences; and correction of power level, Pcorrection, is determined on basis of determined packet error coefficient (PER); and Ptransmit is set on basis of Pbaseline, Pmargin and Pcorrection. For example, Ptransmit may be set to power level which is essentially equal to a total of Pbaseline, Pmargin and Pcorrection. Each component, Pbaseline, Pmargin and Pcorrection, may be determined by means of independently acting check connection circuits or processes.

EFFECT: weakening of interferences with simultaneously economized transmission power, in particular in composition of systems with limited energy potentials.

3 cl, 8 dwg

FIELD: radio-navigation, possible use in signal receivers of satellite radio-navigation systems used to determine client location and current time from signals of GLONASS, GPS, and similar radio-navigation systems.

SUBSTANCE: in the method satellite signals included in search list are found, until number of detected signals, which is sufficient for navigation measurements, is produced. In first positions of the search list three satellites are included in arbitrary order which ensure maximal coverage of Earth surface. Further satellites are included into search list in order which is determined by maximal sum of average distances between each one of them and all satellites positioned in the list closer to the beginning. The search for signals of each checked satellite is performed simultaneously using all free channels of receiver with distribution of search range between the channels. Satellite signal search is performed serially based on aforementioned list, starting from first one in the list, until first detection of signal. The search for signals of further satellites remaining in aforementioned list is performed in order determined by maximal difference between the sum of average distances between the satellite selected for check and all earlier checked satellites with undetected signals and the sum of average distances between that satellite and all earlier checked satellites with detected signals.

EFFECT: creation of method for blind finding of signals in multi-channel receiver of satellite radio-navigation signals, ensuring reduction of average search time required to solve navigational problem of the number of satellite radio-navigation system signals.

2 cl, 3 dwg

FIELD: satellite systems.

SUBSTANCE: system and method are claimed for detecting errors of temporal displacement in a satellite system, on basis of Doppler displacement and speed of Doppler displacement alteration. In accordance to the invention, user terminal determines first and second time displacements, respectively related to first and second satellite beams from respectively first and second satellites. Further, user terminal determines Doppler displacement and speed of Doppler displacement alteration, related to first and second satellite beams. Temporal displacement is estimated on basis of measured Doppler displacement and speed of Doppler displacement alteration and then compared to time displacement, determined by the user terminal. If the result of comparison does not match a specific threshold, beam identification error is stated.

EFFECT: ensured identification of satellite beams.

6 cl, 12 dwg, 1 tbl

FIELD: system for two-sided wireless communications, in particular, system for two-sided wireless communications, which provides capability for direct communication between terminals and mediated communication between terminals through the other terminal.

SUBSTANCE: wireless communication system contains portable communication devices, capable of setting up direct communication between terminals and mediated communication between terminals through another terminal, without using a stationary base station. Portable communication device, used as a terminal, has capability for functioning as a router for other communication devices in system when maintaining a separate direct connection to another portable communication device. After registration, registered device begins communication process by finding other devices.

EFFECT: increased efficiency.

3 cl, 22 dwg

FIELD: wireless communications, possible use for realizing communications with systems of both satellite and ground communications.

SUBSTANCE: multi-mode receiver-transmitter for wireless communication device contains first transmission channel for generation of first radio frequency transmission signal, compatible with first communication system, first receiving channel for receiving first radio frequency receipt signal from first communication system, second receipt channel for receiving second radio frequency receipt signal from satellite positioning system and used for determining position of wireless communication device, where aforementioned first and second receipt channels jointly use common receiving route.

EFFECT: combined capacity for ground and/or satellite communication in mobile receiver-transmitter with possible position detection and minimized power consumption.

5 cl, 9 dwg

FIELD: space engineering; operation of spacecraft flying in orbit of artificial earth satellite, but for geostationary orbit, which are stabilized by rotation along vertical axis, as well as ground reception points.

SUBSTANCE: system used for realization of this method includes emergency object transmitter, onboard equipment of spacecraft and ground equipment of reception point. Onboard equipment of spacecraft includes horizon sensor, receiving antenna, comparison unit, receiver, Doppler frequency meter, blocking oscillator, two AND gates, two rectifiers, pulse generator, pulse counter, switching circuit, magnetic memory, transmitter, transmitting antenna, modulating code shaper, RF generator and power amplifier. Ground equipment of reception point includes receiving antenna, RF amplifier, two mixers, standard frequency unit, phase doubler, three narrow-band filters, phase scale-of-two circuit, phase detector, Doppler frequency meter, computer and recording unit. Proposed method consists in search of such space position of space object by receiving antenna when Doppler frequency of received signal is equal to zero. Measurement at this moment of angle between mechanical axle of receiving antenna and horizon axis is carried out referring to onboard receiving unit.

EFFECT: extended functional capabilities; enhanced accuracy of determination of spacecraft orbit elements; reduction of time required for search of emergency object.

5 dwg

FIELD: controlling power consumed by space grouping of satellites as they pass shadow sections of orbits.

SUBSTANCE: proposed method includes evaluation of power consumed by each of airborne retransmitters installed on satellites, as well as disconnection of airborne retransmitters as soon as satellites enter shadow sections of orbits and their reconnection upon exit therefrom. In addition, time taken by each satellite to pass mentioned section, power consumed by each retransmitter, and total power consumed by retransmitters of each satellite at given section are evaluated before each satellite enters respective shadow section of orbit. Balance between power accumulated in each satellite and power consumed in shadow section of orbit is found. Satellites having time-intersecting shadow sections are grouped with those having positive and negative balance of power consumption as well as with satellites whose input power is balanced. Alternate satellites residing on illuminated sections of orbits are determined for negative-balance subgroup. Operating retransmitters are switched over to alternate satellites before each satellite subgroup starts passing shadow section to provide for balancing or positive balance of input power. In case of negative input power balance, power that can be borrowed from alternate satellites is evaluated and mentioned retransmitters are connected to them. Then alternate satellites are found in positive-balance satellite subgroup using above-described method.

EFFECT: enhanced reliability of communications.

1 cl, 3 dwg

FIELD: radio navigation aids, applicable in digital correlators of receivers of satellite radio navigation system (SPNS) signals, in particular, in digital correlators of receivers of the SPNS GLONASS (Russia) and GPS (USA) signals.

SUBSTANCE: the legitimate signal in the digital correlator is detected by the hardware, which makes it possible to relieve the load of the processor and use its released resources for solution of additional problems. The digital correlator has a commutator of the SPNS signals, processor, digital mixers, digital controllable carrier-frequency oscillator, units of digital demodulators, accumulating units, programmed delay line, control register, digital controllable code generator, reference code generator and a signal detector. The signal detector is made in the form of a square-law detector realizing the algorithm of computation of five points of the Fourier sixteen point discrete transformation with additional zeroes in the interval of one period of the, c/a code with a subsequent computation of the modules of the transformation results and their incoherent summation and comparison with a variable threshold, whose value is set up depending on the noise power and the number of the incoherent readout. The signal detector has a controller, multiplexer, complex mixer, coherent summation unit, module computation unit, incoherent summation unit, noise power estimation unit, signal presence estimation unit and a unit for determination of the frequency-time coordinates of the global maximum.

EFFECT: provided acceleration of the search and detection of signals.

2 cl, 6 dwg

FIELD: devices used in satellite radio navigation.

SUBSTANCE: the claimed method uses the operation of linear interpolation of two adjacent numbered readouts of the input signal embracing the forecast moment of the next change of the code symbol, the obtained value of the interpolated ordinate is normalized to the estimate of the useful signal amplitude, multiplied by the Gaussian prior probability, and an error signal is obtained according to the criterion of the maximum of the posterior probability density.

EFFECT: enhanced accuracy of tracking of delay of range finder code fronts of navigational satellite signals with the aid of a theoretically optimal delay discriminator insensitive to the multipath propagation in a digital receiver, multiprogram one inclusive, as well as eliminated uncertainty in the method of interpolation of numbered ordinates of the mixture of the signal with noise by the moment of the forecast delay, eliminated uncertainty in the method of formation of the delay from the prehistory to the current moment of estimation.

2 cl

FIELD: real time scale navigation with the goal of detecting position of mobile device.

SUBSTANCE: in the invention, radio-signals of three different carrier frequencies are used, transmitted by satellites. Method includes a stage for determining indeterminacy of carrier frequency phase of "especially wide phase track", stage for estimating indeterminacy of phase of "wide phase track" and stage for resolving phase indeterminacy of one of frequencies. Additional stage includes utilizing ionosphere corrections in real time scale during third stage, where these ionosphere corrections are based on continuously updated ionosphere model of aforementioned ionosphere layer, computed by stationary ground-based support station, combined with geodesic data, computed by the so-called leading stationary ground-based support station.

EFFECT: ensured capability for precise navigation at distances exceeding 100 kilometers from supporting satellite communication stations.

2 cl, 17 dwg, 6 tbl

FIELD: radio-navigation, possible use in signal receivers of satellite radio-navigation systems used to determine client location and current time from signals of GLONASS, GPS, and similar radio-navigation systems.

SUBSTANCE: in the method satellite signals included in search list are found, until number of detected signals, which is sufficient for navigation measurements, is produced. In first positions of the search list three satellites are included in arbitrary order which ensure maximal coverage of Earth surface. Further satellites are included into search list in order which is determined by maximal sum of average distances between each one of them and all satellites positioned in the list closer to the beginning. The search for signals of each checked satellite is performed simultaneously using all free channels of receiver with distribution of search range between the channels. Satellite signal search is performed serially based on aforementioned list, starting from first one in the list, until first detection of signal. The search for signals of further satellites remaining in aforementioned list is performed in order determined by maximal difference between the sum of average distances between the satellite selected for check and all earlier checked satellites with undetected signals and the sum of average distances between that satellite and all earlier checked satellites with detected signals.

EFFECT: creation of method for blind finding of signals in multi-channel receiver of satellite radio-navigation signals, ensuring reduction of average search time required to solve navigational problem of the number of satellite radio-navigation system signals.

2 cl, 3 dwg

FIELD: submarine, marine terrestrial and close-to-ground navigation, in particular type GPS and GLONASS systems.

SUBSTANCE: at a time instant, that is unknown for the receiver, a signal is synchronously radiated by several radiators with known co-ordinates. The radiated signals are received by the receiver, the signal speed square is measured in the current navigation session, the Cartesian co-ordinates of the receiver are computed according to the moments of reception of the radiated signal and the measured signal speed square.

EFFECT: enhanced precision of location of the signal receiver.

2 dwg

FIELD: radio navigation aids, applicable in digital correlators of receivers of satellite radio navigation system (SPNS) signals, in particular, in digital correlators of receivers of the SPNS GLONASS (Russia) and GPS (USA) signals.

SUBSTANCE: the legitimate signal in the digital correlator is detected by the hardware, which makes it possible to relieve the load of the processor and use its released resources for solution of additional problems. The digital correlator has a commutator of the SPNS signals, processor, digital mixers, digital controllable carrier-frequency oscillator, units of digital demodulators, accumulating units, programmed delay line, control register, digital controllable code generator, reference code generator and a signal detector. The signal detector is made in the form of a square-law detector realizing the algorithm of computation of five points of the Fourier sixteen point discrete transformation with additional zeroes in the interval of one period of the, c/a code with a subsequent computation of the modules of the transformation results and their incoherent summation and comparison with a variable threshold, whose value is set up depending on the noise power and the number of the incoherent readout. The signal detector has a controller, multiplexer, complex mixer, coherent summation unit, module computation unit, incoherent summation unit, noise power estimation unit, signal presence estimation unit and a unit for determination of the frequency-time coordinates of the global maximum.

EFFECT: provided acceleration of the search and detection of signals.

2 cl, 6 dwg

FIELD: aviation engineering.

SUBSTANCE: device has on-ground automated system for controlling air traffic made in a special way, interrogation unit and re-translator mounted on air vehicles and made in a special manner as well. Autonomous duplication is used for measuring distance between flying vehicles.

EFFECT: widened functional abilities.

6 dwg

FIELD: radio communication.

SUBSTANCE: in accordance with the invention, the device for radio communication provides for getting of first time base (for example, getting of the code time shift) from the signal received from the transmitter on the ground. The predetermined shift based at least on the delay of propagation of received signal is applied to the first time base for obtaining of the second time base. For example, the second time base may be equalized with the time base of the satellite system of position finding (for example, GPS NAVSTAR).

EFFECT: synchronizing signal is generated, with has a time code shift based on the second time base.

6 cl, 12 dwg

FIELD: satellite radio navigation, geodesy, communication, applicable for independent instantaneous determination by users of the values of location co-ordinates, velocity vector components of the antenna phase centers of the user equipment, angular orientation in space and bearing.

SUBSTANCE: the method differs from the known one by the fact that the navigational information on the position of the antenna phase centers of ground radio beacons, information for introduction of frequency and time corrections are recorded in storages of the user navigational equipment at its manufacture, that the navigational equipment installed on satellites receives navigational radio signals from two and more ground radio beacons, and the user navigational equipment receives retransmitted signals from two satellites.

EFFECT: high precision of navigational determinations is determined by the use of phase measurements of the range increments according to the carrier frequencies of radio signals retransmitted by satellites.

3 dwg, 1 tbl

FIELD: the invention refers to navigational technique and may be used at designing complex navigational systems.

SUBSTANCE: an integrated satellite inertial-navigational system has a radioset connected through an amplifier with an antenna whose outputs are connected to a computer of the position of navigational satellites and whose inputs are connected with the block of initial installation of the almanac of data about satellites' orbits. The outputs of this computer are connected with the inputs of the block of separation of radio transmitting satellites. The outputs of this block are connected with the first group of inputs of the block of separation of a working constellation of satellites whose outputs are connected with inputs of the block of computation of a user's position. The system has also a meter of projections of absolute angle speed and a meter of projections of the vector of seeming acceleration which are correspondingly connected through a corrector of an angle speed and a corrector of seeming acceleration with the first group of inputs of the computer of navigational parameters whose outputs are connected with the first group of the outputs of the system. The system also includes a computer of initial data which is connected with three groups of inputs correspondingly to the outputs of the meter of projections of absolute angle speed and the meter of projections of a vector of seeming acceleration and to the outputs of a block of integration of information and also to the outputs of the block of computation of a user's position. At that part of the outputs of the computer of initial data are connected to the inputs of the computer of navigational parameters and all outputs are connected to the first group of the inputs of the block of integration of information whose second group of inputs is connected with the outputs of the corrector of an angle speed and the corrector of seeming acceleration, and the third group of inputs is connected to the outputs of the block of computation of a user's position. One group of the outputs of the block of integration of information is connected to the second group of the inputs of the block of selection of a working constellation of satellites, the other group of the outputs are directly connected to the second group of the outputs of the system, the third group of the outputs are connected to the inputs of the corrector of seeming acceleration and the fourth group of the outputs are connected with the inputs of the corrector of an angle speed and the second group of the inputs of the computer of initial data.

EFFECT: increases autonomous of the system, expands composition of forming signals, increases accuracy.

4 dwg

FIELD: railway transport.

SUBSTANCE: proposed repair team warning device contains "n" navigational satellites, dispatcher station consisting of receiving antenna, satellite signals receiver, computing unit to determine corrections to radio navigational parameter for signals from each navigational satellite, modulator, transmitter, transmitting antenna and computer of standard values of radio navigational parameters, movable object installed on locomotive and consisting of satellite signals receiving antenna, satellite signals receiver, computing unit for determining location of movable object, first receiving antenna, first receiver, first demodulator, matching unit, modulator, transmitter, transmitting antenna, second receiving antenna, second receiver and second demodulator, and warming device consisting of receiving antenna, receiver, demodulator, computing unit for determining distance between movable object, warning device, modulator, transmitter, transmitting antenna, satellite signals receiving antenna, satellite signals receiver and control unit.

EFFECT: improved safety of track maintenance and repair teams in wide zone of operation.

6 dwg

FIELD: the invention refers to radio technique means of determination of a direction, location, measuring of distance and speed with using of spaced antennas and measuring of a phase shift or time lag of taking from them signals.

SUBSTANCE: the proposed mode of determination of coordinates of an unknown transmitter is based on the transmitter's emitting of a tracing signal to the satellite, on receiving of signals of an unknown transmitter and legimite transmitters which coordinates are known, on forming a file of clusters, on selection of the best clusters out of which virtual bases are formed for calculating coordinates of legimite and unknown transmitters according to the coordinates of legimite transmitters and the results of calculation of their coordinates one can calculate mistakes of measuring which are taken into account at calculating the coordinates of the unknown transmitter.

EFFECT: increases accuracy of determination of coordinates of an unknown transmitter in the system of a satellite communication with a relay station on a geostationary satellite.

2 dwg, 1 tbl

Up!