Method for finding satellite signals in multi-channel receiver for signals of satellite radio-navigational systems

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.

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The invention relates to the field of navigation and can be used in the receivers of signals from satellite navigation systems (SNS), are used to determine position coordinates of the user and the current time according to the satellite signals SRNS GLONASS, GPS and the like.

Definition of coordinate and time information in the signal receivers GPSr is based on reception of signals emitted by satellites GPSr, and processing parameters: frequencies of the received signals and delays relative to the local time scale. For a reliable determination of the position coordinates of the user and the current time necessary simultaneous stable reception of signals from several satellites, the number of which shall be not less than the number of simultaneously defined orthogonal parameters, which is usually four or more. Typically, the number of actually received signals GPSr within their working areas is much higher (see, for example, [1] - Uasable. Satellite navigation and its applications / M: Eco-Trends, 2003, C-14, fig.1.2, p.32-33, 2.1), that allows to successfully solve a wide variety of tasks coordinate and time support.

Known multi-channel receivers GPSr working on signals SRNS GLONASS and GPS, are described in patents: [2] - EN No. 2146378 (C1), G01S 5/14, 10.03.2000; [3] - EN No. 2167431 (C2), G01S 5/4, 27.01.2001; [4] - EN No. 2178894 (C1), G01S 5/14, 27.01.2002; [5] - EP No. 1052786 (A1), G01S 1/00, G01S 5/14, H04B 7/185, 15.11.2000.

The generalized block diagram of these receivers consists of a block of radio frequency conversion unit multi-correlation processing and computer-related peripherals - display panel and control panel. The RF unit conversion performs selective reception and amplification of signals in a given frequency band split signals systems (GLONASS, GPS), the conversion of the carrier frequency signal with decreasing frequency, and then converting the signals into digital form. To perform these functions block radio frequency conversion includes analog filters, amplifiers, frequency converters (analog mixers), analog-to-digital converters (discriminatory), as well as the shaper of clock and heterodyne signals. The evaluator and the unit multichannel correlation processing jointly complex operations on selection of the useful signal from noise and interference, dividing them into components related to different satellites, the extraction of these components of the navigation parameters and service data, the conversion in the output accordingly to customer's requirements and the output of results on the display panel or in the other four the e, need to the consumer. The transmitter consists of a processor, the local guardian of the timeline, and memory device comprising non-volatile memory for storing programs and constant values and memory to store intermediate results of calculations. Block multichannel correlation processing consists of N channels, each of which is capable of processing the signal of any satellite. All channels are connected, on the one hand, with the output of the radio frequency conversion, and on the other, via the bus for the exchange of data with the evaluator. All blocks are synchronized clock signals. In the receiver [2]÷[5] the clock signal generated in the RF unit conversion, as the reference signal may be either a signal of its own crystal oscillator or external reference signal, for example, derived from the standard frequency and time.

The channels of the multi-unit correlation processing at the receiver [2]÷[5] performed in the model scheme presented in [2, 4], [3, 3], [4, 3], [5, 6], which consists of the switch signal systems (GLONASS or GPS), a control register, a digital controlled oscillator carrier, digital mixers in-phase and quadrature channels of the processing blocks of the digital demodulators, cumulative units-phase and kV is tatarovo channel processing, and digital controlled code generator, generator reference code and a programmable delay line. The basic procedures performed in each of the channels of the multi-unit signal processing receivers [2]÷[5], is the correlation of a signal from the output of the switch signal systems, with a copy of the desired signal and accumulate the correlation results in a cumulative blocks within a certain time interval. Typically, this interval is one millisecond, which corresponds to the length of the pseudorandom code sequence (SRP) of the reference C/a code SRNS GPS and GLONASS. This correlation is performed by multiplying the digital samples of the input signal generated inside the channel, a local copy of the desired signal, i.e. a copy of the signal of the selected satellite GPSr. The circuit loops tracking delay of the reference code and the frequency of the signal is done using a calculator. The computer reads information from the storage, processes it using the appropriate software and generates the control signals for the digital generator carrier and code, closing the loop tracking.

The procedure of tracking signals precedes the initial stage of the search procedure and detection signals from satellites, which can work at this time.

On the SC signal is being implemented by the two parameters : the frequency and character of the SRP reference code. The set of all positions of the search frequency and the character of the SRP reference code defines the scope of the search. The position shift of the frequency search is performed through discrete frequency changes of the output signals of the digital controlled oscillator carrier. Changing positions of the search characters SRP reference code is carried out by discrete changes the delay of the reference code in the programmable delay line. The procedure for finding the satellite signal is a sequential search of all the frequency-time positions of the search and comparison of the accumulated results of the correlation processing with a given detection threshold. In the receiver [2]÷[5] this threshold is set based on the given probabilities passes and false alarms for low level signals. According to research specific time-frequency positions, the decision about the absence or presence of the satellite signal at the given position.

Data source to search for satellite signals, which should work, since the receiver power is a priori information about the location of the receiving antenna of the receiver, a priori information about the current time, as well as information on current satellites GPSr and their location in space. The use of a priori what information speeds up the search signals and accordingly obtain a navigation solution. A priori information is adjusted periodically based on the service information extracted from the received signals. In addition, in the process of tracking signals is the current refinement and update of the a priori data on the calculation results of the current coordinates of the satellite in orbit, for example, using the method described in [6] - US No. 6567712 (B1), G01C 21/12, 20.05.2003.

During breaks in operation of the receiver is required to resume the time information stored in the local guardian of the timeline of the transmitter, and the position of satellites in orbits in his memory. However, increasing the length of the interruption, this information is aging, the reliability of the stored data is reduced, which creates a problem for the resumption of the receiver.

In the particular case, have limited scope, the problem of choice of working satellites enabling the receiver to the work can be removed at the expense informational support from a base station associated with the radio receiver and provided with means for its own formation ephemeris data, data about the numbers of visible satellites and the Doppler frequency shift, as well as data about the approximate location of the receiver, see, for example, [7] - US No. 6480557 (B1), H04B 1/10, 12.11.2002; [8] - US No. 6690323 (B1), G01S 5/02, H04B 7/185, 10.02.2004.

In the General case when no prior is reliable data to select operating satellites the receiver with his inclusion starts with blind scan signals. The purpose of a blind search in the absence of fresh data to gain the necessary number of satellites, the signals which are accepted at this time in the location of the receiver. In a blind scan review of elementary areas of uncertainty by regular or random scan, where under uncertainty refers to the list of satellites included in GPSr, and ranges for the frequency and the delay within which the signals from these satellites can be received. Generalized method of blind search satellite signals GPSr described in [9] Network satellite navigation system / Usershave, Ali, Nevanac and other edited Wasserchemie. - M.: Radio and communication, 1993, s-124.

Blind search satellite signals starts with the search signal of the first satellite of the search list that contains the symbols of all the satellites GPSr, and continues until a sufficient for navigation measurements of the amount of detected signals. Search for the satellite signal is performed in accordance with standard procedure, the implementation of which for each possible position of the search range solved the famous problem of detecting - decision about the presence or absence of the position signal. Upon detection of the satellite signal, if the total is the number of signals is not enough to solve the navigation task, select the next satellite from the search list (and so on, to obtain a sufficient number of signals). The same thing (select the next satellite from the remaining list) occurs when the satellite signal is not detected. This is the case, for example, in the case where the satellite is below the horizon or shading his signal any interfering object.

This way the blind search can be performed in single-channel or multi-channel receiver, performed according to the type of the receivers described in [2]÷[5]. In the second case multi-channel receiver provides the opportunity to begin a blind search simultaneous search n≤N first signals from the search list, where N is the number of channels multi-channel receiver, determined by the number of channels of the multi-unit correlation processing. Simultaneous search n signals increases the probability of detection in the first step of finding at least one, and often a greater number of signals available at the point of reception. Due to this, search in a multi-channel receiver accelerated (compared to single-channel receiver) on average proportional to the number of channels used, and, in addition, when the detection signals of the respective channels can go directly to their processing and extraction of navigation parameters. This type of search is implemented, in private the tee, 12-channel receiver "eTrex" GARMIN, see [10] - eTrex.series specifications. - GARMIN International, USA, 2000 (Advertising materials GARMIN, USA), on the screen which visually displays all the sequences specified selection of satellites and the results of their signals.

A similar method of simultaneous parallel search signals for multiple satellites in a multi-channel signal receiver GPSr, in which a search signal for each satellite is a sequential view of possible values of the delay and Doppler frequency offset signal and comparison of search results with a threshold, described in [11] is a global satellite navigation system GLONASS / Vasoline, Ciesinski, Uguru and other edited Vinaria, Ahipara, Vasoline. - M.: IPGR, 1998, p.74-78, figure 6.1. p.á192-193.

Way to find satellite signals in a multi-channel signal receiver GPSr described in [11], is adopted as a prototype.

Prototype method consists in the following. Choose from satellites on the search list in accordance with the number of channels used in a parallel search. In each of the channels are searching appointed from a list of signal, using the standard operations of search and detection signal, i.e., for each possible position of the search range to solve the problem of detecting - decision analicia or absence in this position signal. If any channel signal is not detected, then choose the next satellite from the remaining list and repeat the search operation and the detection signal to obtain sufficient (for the implementation of navigation measurements) number of detected signals.

When searching using quadrature components I and Q signal converted in the channel block multichannel correlation processing, and the detection signal in the unit cell search is carried out in accordance with the algorithm simple quadrature detector (I2+Q2)≥h, where h is a threshold selected from a given probability of correct detection.

The disadvantage of the prototype method is that when searching for each channel its own signal operations at individual signal obtained by a sufficiently large. The first search result signal (a signal or not) appears only when the procedure completes, any channel or signal is detected either by the decision of his absence. In the absence of signal in the channel you want a great time checking all of the search range; if the signal duration of a search is determined by the time to reach the position at which the signal is located.

Obviously, the search time for the desired number of signals depends on the cost is the time to detection of each signal present in the air, as well as viewing the entire search range of each of the signals, the choice of which proved unsuccessful. If the results of the first stage multichannel blind search failed to get the right amount of working signals, the inevitable second phase of the search, but go to it it is possible only after the liberation of channels that were busy searching for the missing signals.

There are cases where the time taken to receive the first reference coordinates, it is desirable to reduce in any mode of operation of the equipment, including when performing this blind scan signals.

The problem to which the invention is directed, is to develop a method of blind searches signals in a multi-channel signal receiver GPSr, providing a reduction in the average search time required for the navigation of the measurement signals SRNS.

The essence of the invention is that the way to find satellite signals in a multi-channel signal receiver GPSr, namely, that search for satellite signals included in the search list, to get enough for navigation measurements of the amount of detected signals, unlike the prototype, the first in the search list include arbitrary sequence of three satellites, providing maximum covered the e surface of the Earth, and subsequent satellites include in the search list in the order determined by the maximum sum of the average distances from each of them to all satellites in the search list closer to its beginning, search for the signals of each check of the satellite, since the first satellite from the list of search simultaneously all the free channels of the receiver with the distribution of the search range between channels, the search for satellite signals perform consistently on the search list to the first detection signal and the search signal subsequent satellites remaining in the list search is carried out in the manner determined by the maximum difference between the sum of the average distances selected for verification satellite from all previous proven satellites with undetected signals and the sum of the average distances of the satellites from all previous proven satellites with the detected signals. In the particular case of the method first in the search list include three satellites, the sum of the average distances between which the maximum.

Thus, unlike the prototype method, in the present method the search sequence of the signals of the satellites is subject to the following rule: the search begins from satellites, providing maximum coverage of the surface of the Earth, continues the user is receiving them with the remote satellites, and so on until the first positive result, then the search sequence is determined by the degree of closeness selected for validation of the satellite to proven satellites signals are detected, and the distance from the proven satellites, the signals are not detected. This search sequence, coupled with the fact that the search signal of each check is being implemented simultaneously by all the free channels of the receiver with the distribution of the search range between channels, provides a reduction in the average search time required for the navigation of the measurement signals SRNS.

The essence of the proposed method and the possibility of its implementation are explained with illustrative materials presented in figures 1, 2 and 3

which figure 1 presents a generalized structural diagram of a multiband receiver signals GPSr that implements the proposed method;

figure 2 is a generalized block diagram of one channel of the multi-unit correlation processing in a multi-channel signal receiver GPSr;

figure 3 - block diagram of the algorithm, explaining the sequence of operations of the proposed method.

The generalized block diagram of a multichannel receiver GPSr (figure 1) consists of interconnected unit 1 radio frequency conversion unit 2 lot is anal correlation processing, consisting of N channels 3 (31, 32, ..., 3N), each of which is capable of processing the signal of any satellite transmitter 4 and block 5 peripheral devices.

Unit 5 peripheral devices designed for manual input of control commands and data and display the output. The unit 5 peripheral devices include, for example, a control panel and a display panel (not shown in figure 1).

Unit 1 RF conversion is intended for the selective reception and amplification of signals in a given frequency band split signals systems (GLONASS, GPS), conversion of the carrier frequency signal with a lower frequency and then convert the signals into digital form suitable for processing in block 2. In block 1 of the radio-frequency transformation also generates clock signals (Fň), which synchronizes the operation of all the blocks of the receiver. In this case, the block 1 of the radio-frequency conversion can be performed in accordance with known scheme presented in [2, 3].

The transmitter 4 is used to implement operations associated with computing, formation required for operation of the receiver internal commands, storing control programs and data, formation of the output data, including the data displayed on the display panel and block 5 peripheral devices. The transmitter 4 is composed of a processor, the local guardian of the timeline, and memory device comprising non-volatile memory for storing programs and constant values and memory to store the intermediate results of calculations (not shown in figure 1).

Unit 2 multichannel correlation processing is designed to perform together with the computer 4 complex operations for search and detection of signals from satellites, in which the useful signal from noise and interference and split them into components related to different satellites, as well as complex operations associated with subsequent tracking of detected signals and the extraction of the navigation data and service information. When the search signal of one satellite used several channels 3-free tracking, and when the tracking is one, the one that was first detected signal of the satellite.

In this case, each of the channels 3 (31, 32, ..., 3Nunit 2 multichannel correlation processing is performed in accordance with known scheme presented in [2, 4]. The composition of this scheme are (see figure 2) switch 6 switch signal systems (GLONASS or GPS), the register 7 control, digital controlled oscillator 8 carrier, digital mixers 9 of the 10 in-phase and quadrature channels of processing, blocks 11 and 12 digital demodulators in-phase and quadrature channels of processing, consisting of digital demodulators 111, 112and 121, 122cumulative blocks 13 and 14 in-phase and quadrature channels of processing, consisting of the drives 131, 132and 141, 142and digital controlled code generator 15 generator 16 reference code and a programmable delay line 17.

Signal inputs digital demodulators 111and 112are interconnected and form a signal input unit 11, the digital outputs of the demodulators 111and 112form the outputs of the block 11 and the reference inputs digital demodulators 111and 112form a supporting unit 11. Signal inputs digital demodulators 121and 122are interconnected and form a signal input unit 12, the digital outputs of the demodulators 121and 122form the outputs of the block 12 and the reference input of the digital demodulator 121and 122form a supporting unit 12.

The outputs of the drives 131and 132form output unit 13, the signal inputs of the drives 131and 132form a signal input unit 13, and connected between a clock input drives 131and 132form a clock input unit 13. The outputs of the drives 141and 142form the outputs of the block 14, Ignalina inputs drives 14 1and 142form a signal input unit 14, and connected between a clock input drives 141and 142form a clock input unit 14.

The signal inputs of the switch 6, forming a signal input channel 3, associated with the signal outputs (outputs signals of GLONASS and GPS) unit 1 RF conversion. Signal inputs digital mixers 9 and 10 are connected with the output of the switch 6, and the reference inputs are connected respectively with the first and second outputs of the digital controlled oscillator 8 of the carrier. Signal input terminals 11 and 12 of the digital demodulators are connected respectively to the outputs of the digital mixers 9 and 10, and their outputs are connected to the corresponding inputs of the cumulative units 13 and 14. The outputs of the cumulative units 13 and 14 are connected via the bus data exchange with the computer 4. The output of the digital controlled oscillator 15 code associated with the signal generator input 16 of the reference code, the output of which is connected with the signal input of the programmable delay line 17. The outputs of the controllable delay lines 17 are connected with the corresponding reference inputs of the blocks 11 and 12 digital demodulators (reference inputs digital demodulators 111, 112, 121, 122). The first output of controllable delay line 17, which is formed by the "exact" ("p") a copy of the reference code associated with the reference input is mi digital demodulators 11 1and 121and the second output of controllable delay line 17, which is formed by "biased" (d) a copy of the reference code, coupled to the reference inputs of the digital demodulators 112and 122. The control input of the programmable delay line 17 is connected with the first output register 7 control, the second output of which is connected with control inputs of the switch 6 and the generator 16 reference code. Digital controlled oscillator carrier 8, the register 7 control, digital controlled code generator 15 generator 16 reference code connected via the bus data exchange with the computer 4. Clock inputs of the digital controlled oscillator 8 carrier, cumulative units 13 and 14, the programmable delay lines 17, digital controlled code generator 15 is connected with a clock input of channel 3 is connected to the output of clock signals (Fň) unit 1 RF conversion.

Blind search satellite signals in accordance with the inventive method is carried out in a multi-channel signal receiver GPSr on the following algorithm (figure 3).

First, create a list of search in which the first to include an arbitrary sequence of three satellites, providing maximum coverage of the Earth's surface, and subsequent satellites include in the search list in the order determined by the maximum sum of the average distances from kadogos them to all the satellites, located in the search list closer to its beginning (figure 3, blocks 18, 19). In the particular case of first in the search list include three satellites, the sum of the average distance between them is maximal. Create a list of search tools calculator 4, the storage of the list of search carried out in his memory. Because in a blind search no a priori information about the current time, system status and visibility of the satellites in the point whose coordinates need to determine to list search using the average distance between the satellites, obtained by averaging over the period of treatment. As the primary information from which to form medium distances, can be used, for example, data obtained on the basis of theoretically known or once accepted almanac, and with the inclusions of the receiver, these data can be updated for use in subsequent searches.

Then search for satellite signals according to the search list sequentially, starting with the first on the list of the satellite, to the first detection signal (figure 3, blocks 20, 21).

The search signal check the satellite takes place simultaneously all the free channels 3 with the distribution of the search range between the channels 3. The channel in which the signal is received, check the satellite is transferred to the tracking mode C is detected by the signal, the remaining channels are transferred to the search signals of these satellites. When the first detection signal selection rule subsequent satellites are changing with the advent of new information in the search history - found signals. Now the search signals subsequent satellites remaining in the list search is carried out in the manner determined by the maximum difference between the sum of the average distances selected for validation of the satellite from all previous proven satellites with undetected signals and the sum of the average distances of the satellites from all previous proven satellites with the detected signal, i.e. searching for the satellite signals, the most remote from the satellites with undetected signals and maximally close to the satellites with the detected signals (figure 3, blocks 22, 23).

Search in this order continue to obtain sufficient for the implementation of the navigation measurement signals (figure 3, block 24).

Searching satellite signals implemented in the present method are well-known operations, carried out in a similar multi-channel receivers [2]÷[5], [7], [8].

In General the procedure for finding the satellite signal in a separate channel 3i includes the following standard steps. At the beginning of the search process computer 4 on the basis of the list of POI is ka and a given distribution of the search range between channels 3, sets the initial frequency-time position search in the channel 3i, i.e. sets the carrier frequency for the digital controlled oscillator 8 carrier frequency code for the digital controlled oscillator 15 of the code and the position of the "exact" ("p") and "offset" (d) copies of the reference C/a code SRNS GLONASS or GPS using register 7 control. In accordance with the command transmitter 4, issued in register 7 control switch 6 connects at its output the signals needed GLONASS or GPS. The signal received at the signal inputs of the digital mixers 9 and 10, the reference inputs are received quadrature signals ("SIN" and "COS") reference frequency with the respective outputs of the digital controlled oscillator 8 of the carrier. Digital controlled oscillator 8 carrier provides the formation of a quadrature intermediate frequency signals of a given character SRNS GLONASS, binary code which is issued by the computer 4, or intermediate frequency signals SRNS GPS. Digital mixers 9 and 10 provide the selection signals given letters SRNS GLONASS or satellite signals SRNS GPS and transfer spectra of these signals in the baseband frequency to the zero frequency). With the digital outputs of the mixers 9 and 10, the signals are sent to the signal input terminals 11 and 12 of the digital demodulators. On the reference inputs of the blocks 11 and 12 digital demodulators lane with the first and second outputs of the programmable delay lines 17 act accordingly "exact" ("p") and "offset" (d) a copy of the reference C/a code SRNS GLONASS or GPS. Blocks 11 and 12 digital demodulators using part of them digital demodulators 111, 112and 121, 122perform a correlation of the received signals with the "exact" ("p") and "offset" (d) copies of the reference C/a code SRNS GLONASS or GPS. Programmable delay line 17 operates on the signals from the output of the generator 16 reference code that generates the reference pseudo-random C/a codes of the satellites SRNS GLONASS or GPS. Required for operation of the generator 16, the clock signal frequency of 1.023 MHz for GPS or 0,511 MHz for GLONASS served on its signal input from the output of the digital controlled oscillator 15 of the code. The choice of the type produced by a pseudorandom code sequence and the values of the clock frequency of the reference code is carried out by commands of the transmitter 4, received via the bus interchange on the generators 15 and 16. The correlation results are accumulated in the cumulative blocks 13 and 14 in the respective drives 131, 132and 141, 142namely, the drive 131accumulates the in-phase component correlation exact copy of the signal (Ip), the drive 132accumulates the in-phase component correlation shifted copies of the signal (Id), the drive 141accumulates quadrature component correlation exact copy of the signal (Qp), and the drive 142accumulates quadrature to mponent correlation shifted copies of the signal (Qd). Accumulation period equal to the period of reference C/a code, i.e. a 1 msec. Accumulated in the accumulators 131, 132, 141, 142data (Ip, Qp, Id, Qd) periodically read by the computer 4, which are implemented algorithms for signal detection, for example, as in the prototype, the algorithm is simple quadrature detector [I2p(d)+Q2p(d)]≥h, where h is a threshold selected from a given probability of correct detection. If the comparison reveals a threshold is exceeded, then a decision is made about the detection signal at a given time-frequency position of the search. Following is the confirmation procedure, at the end of which the decision on termination or continuation of the procedure searches for the following positions search. The position shift of the frequency search is performed through discrete frequency changes of the output signals of the digital controlled oscillator 8 of the carrier. Changing positions of the search characters SRP reference code is carried out by discrete changes the delay of the reference code in the programmable delay line 17.

If a decision is made about the detection signal in the channel 3i, the search procedure of the signal in this channel and other channels involved in the search signal of the satellite, is terminated. The channel 3i proceeds to process the ur tracking a detected signal, and the remaining channels, freed from the search signal of the satellite, redirect to search for the next satellite signal from the search list.

If after processing all set for the channel 3i positions of the search signal in the channel 3i is not detected, the transmitter 4 to reroute the channel to search for the next satellite signal from the search list.

Thus, using the proposed method is blind search satellite signals in multichannel receiver GPSr. In comparison with the prototype of the proposed method has the following features: sequential search for satellite signals concentrates the resources of the receiver on the search before it is completed a decision that is in your search history, and is used to increase the detection probability at the next stage of the search; the search for the satellite signal all the free channels of the receiver reduces the time for the satellite signal in proportion to the number used when searching for channels and reduces the time for forming the next events in the history of the search signals; using information about the average distances between the satellites GPSr and real history search reduces the probability of assignment to search for satellites, the signals of which to take in the current session it is unrealistic. The combination of these features leads to) is the average duration of a blind search.

Of the above, it follows that the claimed invention is technically feasible and solves the problem by devising the method of blind searches signals in a multi-channel signal receiver GPSr, providing a reduction in the average search time required for the navigation of the measurement signals SRNS.

Sources of information

1. Wasallowed. Satellite navigation and its applications / M: Eco-Trends, 2003, C-14, fig.1.2, p.32-33, 2.1.

2. RU # 2146378 (C1), G01S 5/14, publ. 10.03.2000.

3. RU # 2167431 (C2), G01S 5/14, publ. 27.01.2001.

4. RU # 2178894 (C1), G01S 5/14, publ. 27.01.2002.

5. EP No. 1052786 (A1), G01S 1/00, G01S 5/14, H04B 7/185, publ. 15.11.2000.

6. US No. 6567712 (B1), G01C 21/12, publ. 20.05.2003.

7. US No. 6480557 (B1), H04B 1/10, publ. 12.11.2002.

8. US No. 6690323 (B1), G01S 5/02, H04B 7/185, publ. 10.02.2004.

9. Network satellite navigation system / Usershave, Ali, Nevanac and other edited Wasserchemie. - M.: Radio and communication, 1993, s-124.

10. eTrex.series specifications. - GARMIN International, USA, 2000 (Advertising materials GARMIN, USA).

11. Global satellite navigation system GLONASS / Vasoline, Ciesinski, Uguru and other edited Vinaria, Ahipara, Vasoline. - M.: IPGR, 1998, p.74-78, figure 6.1. p.á192-193.

1. Way to find satellite signals in multichannel receiver of signals of satellite radio navigation system which ensures that the search signal is fishing satellites, included in the search list, to get enough for navigation measurements of the amount of detected signals, characterized in that the first in the search list include arbitrary sequence of three satellites, providing maximum coverage of the Earth's surface, and subsequent satellites include in the search list in the order determined by the maximum sum of the average distances from each of them to all satellites in the search list closer to its beginning, search for the signals of each check of the satellite, since the first satellite from the list of search simultaneously all the free channels of the receiver with the distribution of the search range between channels, the search for satellite signals perform consistently on the search list to the first detection signal and the search signal subsequent satellites remaining in the list search is carried out in the manner determined by the maximum difference between the sum of the average distances selected for validation of the satellite from all previous proven satellites with undetected signals and the sum of the average distances of the satellites from all previous proven satellites with the detected signals.

2. The method according to claim 1, characterized in that the first in the search list include three satellites, the sum of the average distances mezhdumorie maximum.



 

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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: engineering of radio-systems for exchanging data, possible use for interference-protected information exchange between mobile airborne objects and ground complexes in "air to air" and "air to ground" channels.

SUBSTANCE: in accordance to the invention, in the device at transmitting side antenna polar pattern is induced onto polar pattern of receiving side antenna, relaying route is selected, current position and parameters of all airborne objects is determined for current time moment, extrapolation location points are computed for corresponding airborne objects during communication session being planned, mutual targeting of polar patterns of antennas of ground complex and the first (in the order of service) airborne object, second airborne object, etc., is performed, the objects being tracked during movement, data exchange is performed between corresponding objects of the system. After receipt confirmation is received, the procedure is repeated for second airborne object, etc. In ground complex and airborne objects picked for retransmission, operations of mutual targeting of polar pattern centers of UHF range antennas to appropriate objects and operations of tracking them during movement are performed.

EFFECT: increased interference protection and speed of transfer.

1 dwg

FIELD: communication systems, possible use for radio relaying of radio-television signals.

SUBSTANCE: in the method for aiming transmitting antenna of repeater at client station, which method includes aiming of receiving antenna of repeater at signal source by its rotation on basis of azimuth and elevation angle until signal capture, and then precise aiming of receiving antenna with usage of program aiming with correction by the signal being received, and also transmitting antenna of repeater is aimed at client station using calculated azimuth and elevation angle, before aiming of receiving antenna at signal source the antenna is turned along azimuth for an angle up to one hundred eighty degrees and for no less than three different azimuth angles, values of repeater error are measured relatively to horizon plane using angle sensor installed on the azimuth axis of receiving antenna. After that receiving antenna is turned along azimuth until signal capture, during that simultaneously in accordance with found parameters elevation angle of receiving antenna is changed, then in the mode of precise aiming of receiving antenna at signal source azimuth is successively increased and decreased by equal angles, both signal values read in these positions are used for more precise detection of signal source position azimuth. Then receiving antenna is turned along azimuth for angle corresponding to client station angle, and then receiving antenna is turned along azimuth for one hundred eighty degrees, in both positions repeater error relatively to horizon plane is measured by means of angle sensor. After that transmitting antenna is aimed at client station using computed azimuth and elevation angle, during azimuth aiming, precise position of signal source is used, and during elevation aiming, precise value of repeater error relatively to horizon plane is used.

EFFECT: increased precision of aiming of transmitting antenna of repeater, prevented usage of additional equipment for aiming the transmitting antenna, simplified operation.

4 dwg

Satellite relay // 2306671

FIELD: radio engineering, possible use for relaying signals in satellite communication systems with multi-access.

SUBSTANCE: relay contains N receiving channels, each one of which includes a receiving antenna, input amplifier, matching device, detector, threshold device, and also common blocks: activity analysis block, commutator, transmitter and transmitting antenna.

EFFECT: increased efficiency of usage of throughput of P-ALOHA protocol due to realization of servicing discipline, making it possible to block packets received via other beams when mono-channel is busy.

7 dwg, 1 ann

FIELD: space engineering; spacecraft flying in earth artificial satellite orbit, but for geostationary orbit stabilized by rotation along vertical axis.

SUBSTANCE: system used for realization of this method includes spacecraft case, infra-red horizon pulse sensor, receiving antenna, comparison unit, receiver, Doppler frequency meter, biased blocking oscillator, two AND gates, two rectifiers, pulse generator, pulse counter, switching circuit, magnetic storage, transmitter, transmitting antenna, onboard timing device, onboard master oscillator and emergency object transmitter. Doppler frequency meter includes 90-deg phase shifter, two mixers, two difference frequency amplifiers, 180-deg phase inverter, two AND gates and reversible counter. Frequency of received oscillations is preliminarily reduced in two processing channels.

EFFECT: enhanced accuracy of determination of coordinates due to accurate measurement of minor magnitudes of Doppler frequency and recording its zero magnitude.

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: radio engineering, applicable in receivers of signals of satellite radio navigational systems.

SUBSTANCE: the micromodule has a group of elements of the channel of the first frequency conversion signals, group of elements of the first channel of the second frequency conversion of signals, group of elements of signal condition of clock and heterodyne frequencies and a group of elements of the second channel of the second frequency conversion signals.

EFFECT: produced returned micromodule, providing simultaneous conversion of signals of standard accuracy of two systems within frequency ranges.

4 dwg

FIELD: aeronautical engineering; determination of aircraft-to-aircraft distance.

SUBSTANCE: aircraft-to-aircraft distance is determined by the following formula: where position of first of first aircraft is defined by azimuth α1, slant range d1, altitude h1 and position of second aircraft is determined by azimuth α2, slant range d2 and altitude h2. Proposed device includes aircraft azimuth indicators (1,4), flying altitude indicators (2,5), indicator of slant range to aircraft (3,6), adders (7, 14, 15, 19), multiplication units (8-12, 16, 18), cosine calculation unit 913), square root calculation units (17-20) and indicator (21).

EFFECT: avoidance of collision of aircraft; enhanced safety of flight due to determination of true aircraft-to-aircraft distance with altitude taken into account.

2 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

FIELD: radio engineering, possible use in radio control systems.

SUBSTANCE: in accordance to the invention, in each measurement period received radio signals are transformed to spatial spectrum, values of which with weights proportional to calculated weakening of transmitter radio-signals during expansion towards mobile direction-finder are accumulated during the whole time of direction-finder movement and normalized by average quadratic value of weights with production of averaged spatial spectrum. Position of the transmitter is determined on basis of maximum of averaged spatial spectrum.

EFFECT: expanded area of working zone by 20%, increased resistance to interference in case of multi-beam expansion of radio-waves under conditions of a city and increased precision of transmitter position detection up to 40%.

4 dwg

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