CN102087361B - Method and device for acquiring satellite navigation signal - Google Patents
Method and device for acquiring satellite navigation signal Download PDFInfo
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- CN102087361B CN102087361B CN 200910241405 CN200910241405A CN102087361B CN 102087361 B CN102087361 B CN 102087361B CN 200910241405 CN200910241405 CN 200910241405 CN 200910241405 A CN200910241405 A CN 200910241405A CN 102087361 B CN102087361 B CN 102087361B
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Abstract
The invention discloses a method and device for acquiring a satellite navigation signal, belonging to the technical field of communication. The method comprises the following steps of: acquiring an in-phase component and a quadrature component, wherein the in-phase component contains a C/A code; respectively carrying out correlation operation on the acquired in-phase component containing the C/A code, and the quadrature component with a local C/A code; carrying out FFT (Fast Fourier Transform) on obtained correction operation results; carrying out differential coherent accumulation on the FFT results; judging according to the results of the differential coherent accumulation, wherein if the results are larger than a threshold value, the satellite signal is successfully acquired, or else, the satellite signal is failed to acquire. The method solves the problem that navigation signals with high symbol hopping ratio cannot be integrated and accumulated for a long time; and the differential coherent accumulation method is adopted, thus the signal to noise ratio is increased and the satellite signals are successfully acquired.
Description
Technical field
The present invention relates to communication technical field, particularly a kind of catching method of satellite navigation signals and device.
Background technology
Capture technique is the key component during GPS (Global Positioning System, GPS) receiver signal is processed.The quality of its catching method is one of main standard of evaluation receiver.
Two kinds of high sensitivity GPS signal acquisition methods commonly used are coherent integration and non-coherent integration.Wherein, coherent integration refers to the correlation of the reception C/A coded signal of different cycles and local C/A coded signal is carried out the correspondence stack, can offset more noise, strengthen signal, improves signal to noise ratio (S/N ratio).But the length of coherent integration is subject to the restriction of Doppler shift and navigation data bits saltus step.For gps signal, every 20ms is once data bit saltus step just, if therefore will there be loss the coherent integration time above the 20ms energy, can reduce signal to noise ratio (S/N ratio) on the contrary.And non-coherent integration is to add up after the correlated results delivery with per cycle again, and noise intensity also added up accordingly when signal intensity superposeed like this, so that the raising of signal to noise ratio (S/N ratio) is not obvious.
Therefore the scheme for the sensitivity first-selection that improves receiver is to increase as far as possible the coherent accumulation time, but because navigation signal modulation navigation data, the coherent accumulation time is subject to the restriction of data bit saltus step, therefore how under the condition without any supplementary, to avoid the data bit saltus step that coherent accumulation is exerted an influence, become the focus of high sensitive receiver research, now widely used is multiple data position circular correlation (Circular Correlation with Multiple Data Bits, CCMDB) acquisition algorithm (as shown in Figure 1).Wherein, in each coherent integration interval, estimate the most reliable data bit combination; Then, before coherent accumulation is merged into noncoherent accumulation, utilize it to remove the symbols influence of data bit.The combination of supposing every kind of data bit is that probability equates that the average equivalent point time under the worst case is shown in formula (1):
Wherein,
Be equivalent point time, N
tFor the number of times of integration, ε for number of times, the T of saltus step occur
IBe total integral time, owing to only search for N
bThe integration loss that individual edge causes is shown in formula (2):
Therefore with regard to the C/A code of GPS, work as N
bBe 4 o'clock, carry it into formula (1) and formula (2), finally can calculate the integration loss is 10%.But for the very high navigation signal of symbol hop rate, N
bSelection can be subject to certain restrictions, so the integration of said method loss will become large.
The inventor finds in realizing process of the present invention, there is following shortcoming at least in prior art: for the very high navigation signal of symbol hop rate, it is cumulative to carry out long integration, can't improve preferably signal to noise ratio (S/N ratio), can not realize preferably catching weak signal.
Summary of the invention
In order to prolong the cumulative time of integration, improve the signal to noise ratio (S/N ratio) that receives signal, realize the success of weak signal is caught, the embodiment of the invention provides a kind of catching method of satellite navigation signals, and described technical scheme is as follows:
On the one hand, the embodiment of the invention provides a kind of catching method of satellite navigation signals, and described method comprises:
Acquisition comprises in-phase component and the quadrature component of C/A code;
The C/A code in-phase component and the quadrature component that obtain are carried out related operation with local C/A code respectively;
Result to related operation carries out the FFT conversion;
It is cumulative that the result of FFT conversion is carried out differential coherence;
The result cumulative according to differential coherence adjudicates, if greater than then capturing satellite signal success of threshold value; Otherwise capturing satellite signal failure;
Wherein, described C/A code in-phase component and quadrature component with acquisition specifically comprises with the step that local C/A code carries out related operation respectively:
Steps A: the receive data of 2L millisecond is carried out segmentation take 2 milliseconds as unit;
Step B: obtain the replica code of the local L millisecond that produces, behind the replica code of each millisecond, add 1 millisecond zero;
Step C: the data that obtain among the receive data in the steps A and the step B are carried out related operation, obtain the data of the 1st millisecond of correspondence of each section behind the related operation;
Step D: judge that whether the data of absolute value maximum in the data of the 1st millisecond of correspondence of described each section are less than 0, if carry out the sign inversion correction less than 0; Otherwise execution in step E;
Step e: with the corresponding addition of 1 millisecond of data of L section, with the 1 millisecond of data output that obtains after the addition.
Whether the data of absolute value maximum are less than 0, if specifically comprise less than 0 step of carrying out the sign inversion correction: each numerical value in this segment data is taken advantage of-1 in the data of described the 1st millisecond of correspondence judging described each section.
Described result to the FFT conversion carries out the cumulative step of differential coherence and specifically comprises:
The n time quadrature component, in-phase component are carried out differential coherence with the n-1 time quadrature component, in-phase component respectively to add up.
The described result who adds up according to differential coherence adjudicates, if greater than then capturing satellite signal success of threshold value; Otherwise also comprise after the step of capturing satellite signal failure:
If greater than threshold value then after the capturing satellite signal success, with code phase and the carrier frequency output of C/A code; Correspondingly,
If then after the lock-on signal failure, adjust phase place, the carrier frequency of local code less than predetermined threshold value, re-start search.
On the one hand, the embodiment of the invention provides a kind of acquisition equipment of satellite navigation signals again, and described device comprises:
Obtain module, described acquisition module is used for obtaining to comprise in-phase component and the quadrature component of C/A code;
Computing module, described computing module are used for C/A code in-phase component and quadrature component that described acquisition module obtains are carried out related operation with local C/A code respectively;
FFT conversion module, described FFT conversion module are used for the result of related operation is carried out the FFT conversion;
Differential coherence accumulator module, described differential coherence accumulator module are used for that the result after the conversion of described FFT conversion module is carried out differential coherence and add up;
Judging module, described judging module are used for adjudicating according to the cumulative result of differential coherence, if greater than then capturing satellite signal success of threshold value; Otherwise capturing satellite signal failure;
Wherein, described computing module specifically comprises:
Segmenting unit, described segmenting unit are used for the receive data of 2L millisecond is carried out segmentation take 2 milliseconds as unit;
Adding device, described adding device is used for obtaining the replica code of the local L millisecond that produces, and adds 1 millisecond zero behind the replica code of each millisecond;
Acquiring unit, described acquiring unit are used for the data that obtain in the receive data of described segmenting unit and the described adding device are carried out related operation, obtain the data of the 1st millisecond of correspondence of each section behind the related operation;
Whether the data of the data absolute value maximum of the 1st millisecond of correspondence of each section that judging unit, described judging unit are used for judging that described acquiring unit obtains are less than 0, if carry out the sign inversion correction less than 0; Otherwise carry out the first output unit;
The first output unit, described the first output unit are used for the corresponding addition of 1 millisecond of data of L section, with the 1 millisecond of data output that obtains after the addition.
Described judging unit also comprises: computation subunit, described computation subunit are used for each numerical value of this segment data is taken advantage of-1.
Described differential coherence accumulator module is used for that specifically the n time quadrature component, in-phase component are carried out differential coherence with the n-1 time quadrature component, in-phase component respectively and adds up.
Described judging module specifically comprises:
Decision unit, described decision unit are used for adjudicating according to the cumulative result of differential coherence, if then represent the capturing satellite signal success greater than threshold value; Otherwise expression capturing satellite signal failure;
The second output unit, described the second output unit are used for the code phase of C/A code and carrier frequency output; Adjustment unit, described adjustment unit is used for adjusting phase place, the carrier frequency of local code.
The beneficial effect of the technical scheme that the embodiment of the invention provides is:
In-phase component by increasing the C/A code and quadrature component are carried out respectively related operation with local C/A code time, result to related operation carries out the FFT conversion, it is cumulative that the result of FFT conversion has been carried out differential coherence, and the method for adjudicating according to the cumulative result of differential coherence, solved for the very high navigation signal of symbol hop rate, can not carry out the cumulative problem of long integration, and the method that has adopted differential coherence to add up, improved signal to noise ratio (S/N ratio), realized that the success of satellite-signal is caught.
Description of drawings
In order to be illustrated more clearly in the embodiment of the invention or technical scheme of the prior art, the below will do to introduce simply to the accompanying drawing of required use in embodiment or the description of the Prior Art, apparently, accompanying drawing in the following describes only is some embodiments of the present invention, for those of ordinary skills, under the prerequisite of not paying creative work, can also obtain according to these accompanying drawings other accompanying drawing.
Fig. 1 is the synoptic diagram of the catching method of a kind of satellite navigation signals of providing of prior art;
Fig. 2 is the synoptic diagram of the catching method of a kind of satellite navigation signals of providing of the embodiment of the invention 1;
Fig. 3 is the process flow diagram of the catching method of a kind of satellite navigation signals of providing of the embodiment of the invention 1;
Fig. 4 is the synoptic diagram of the Related Computational Methods that provides of the embodiment of the invention 1;
Fig. 5 is the process flow diagram of the Related Computational Methods that provides of the embodiment of the invention 1;
Fig. 6 is the process flow diagram of the acquisition equipment of a kind of satellite navigation signals of providing of the embodiment of the invention 2.
Embodiment
For making the purpose, technical solutions and advantages of the present invention clearer, embodiment of the present invention is described further in detail below in conjunction with accompanying drawing.
Referring to Fig. 2 and Fig. 3, the method that the embodiment of the invention provides a kind of satellite navigation signals to catch, idiographic flow sees for details hereinafter to be described:
Step 101: the simulating signal that the GPS receiver receives is carried out down coversion, obtain intermediate-freuqncy signal.
Wherein, the simulating signal that receives of GPS receiver comprises: carrier signal, text, C/A code.For example: the simulating signal that the GPS receiver receives is 16MHz, through down-converted, obtains the intermediate-freuqncy signal of 4MHz.
Step 102: the intermediate-freuqncy signal that step 101 is obtained is converted into digital intermediate frequency signal through A/D converter.
Step 103: take the frequency of digital intermediate frequency signal as carrier frequency, digital intermediate frequency signal is multiplied each other with in-phase component, the quadrature component of local carrier respectively, peel off carrier wave, and obtain to comprise I road in-phase component and the Q road quadrature component of C/A code.
Wherein, the purpose that the in-phase component SIN of digital intermediate frequency signal and local carrier, quadrature component COS multiply each other is to obtain text and C/A code, peels off carrier wave.
Step 104: code NCO produces local C/A code.
Step 105: I road in-phase component and the Q road quadrature component of the C/A code that obtains in the C/A code of this locality and the step 103 are carried out respectively related operation.
Wherein, adopt the method for coherent accumulation to carry out related operation, for example: the coherent accumulation that carries out 20 milliseconds, be divided into 20 sections with 20 milliseconds, every section is 1 millisecond, in every section with the C/A code of this locality respectively with step 103 in the I road in-phase component of the C/A code that obtains and the data of Q road quadrature component corresponding phase carry out addition, namely obtain altogether 20 sections 1 millisecond data.Wherein, the embodiment of the invention describes take 20 milliseconds as example, and during specific implementation, the embodiment of the invention does not limit this.
Step 106: the result to related operation in the step 105 carries out the FFT conversion, transforms from the time domain to frequency domain.
Step 107: to carry out differential coherence cumulative with the n-1 time quadrature component, in-phase component respectively with the n time quadrature component, in-phase component according to the result of FFT conversion.
Wherein, the quadrature component that is about to 20 milliseconds of the M sections of the n time the quadrature component of 20 milliseconds of M sections and the n-1 time is carried out differential coherence and is added up, it is cumulative that 20 milliseconds in-phase component of the in-phase component of 20 milliseconds of the n time M sections and the n-1 time M section is carried out differential coherence, purpose is in order to eliminate noise, strengthen signal, to improve signal to noise ratio (S/N ratio), wherein, n is the number of times of catching.The embodiment of the invention describes with the data instance of 20 milliseconds of M sections, if the M value is 5, the differential coherence of then carrying out 100 milliseconds is cumulative, and during specific implementation, the embodiment of the invention does not limit this.
Step 108: result and predetermined threshold value after differential coherence is cumulative are adjudicated.
Wherein, specifically comprise: in-phase component and quadrature component after cumulative according to differential coherence obtain | I|+|Q| or
Find the some I of amplitude maximum according to result of calculation
1, Q
1With amplitude time large some I
2, Q
2, find rear calculating (I
1|+| Q
1)/(I
2|+| Q
2|) or
Result of calculation and predetermined threshold value are adjudicated, if result of calculation then represents capturing satellite signal success, execution in step 109 greater than predetermined threshold value; Otherwise the lock-on signal failure, execution in step 110.
Wherein, the predetermined threshold value of embodiment of the invention setting is 2.5, and during specific implementation, according to the fixing difference of empirical value or noise size, predetermined threshold value is also different, and the embodiment of the invention does not limit this.
Step 109: with code phase and the carrier frequency output of C/A code.
Step 110: adjust the phase place of local code, re-execute step 103-step 108, until acquisition success.
Wherein, mobile 0.5 code phase re-starts and catches, if also there is not again mobile 0.5 phase place of acquisition success, can mobile 1023/0.5=2046 time, (wherein, 1023 is the code length of C/A code) all do not capture signal after search 2046 times, then, change a carrier frequency and be about to local carrier frequency and move ± 500Hz, can positive and negative plus-minus 10 times, namely can move altogether 21 times, repeat said process, until the signal capture success.If all code phases and carrier frequency be the complete signal that still do not capture of search all, then this cycle lock-on signal failure.
Wherein, the related operation in the step 105 can also be taked other compute mode, referring to Fig. 4 and Fig. 5, sees for details hereinafter and describes:
Step 201: the receive data of 2L millisecond is carried out segmentation take 2 milliseconds as unit, be divided into the L section.
Wherein, take 20 milliseconds receive datas as example, be about to it and be divided into 10 sections.
Step 202: the replica code that obtains the local L millisecond that produces.
Step 203: behind the replica code of each millisecond, add 1 millisecond zero.
Wherein, add 1 millisecond zero by the zero padding device, the replica code of each millisecond by the zero padding of zero padding device after, namely become 2 milliseconds of data, this locality obtains 2 milliseconds of data of L section altogether.
Step 204: with the data after 2 milliseconds of zero paddings of the L section that obtains in 2 milliseconds receive data of L section and the step 203 one by one correspondence carry out related operation.
For example: the value of L is 4, and namely the data after 2 milliseconds of zero paddings of 1,2,3,4, the 1 sections 2 milliseconds receive data and the 1st section are carried out related operation; Data after the 2nd section 2 milliseconds receive data and the 2nd section the 2 milliseconds of zero paddings are carried out related operation; Data after the 3rd section 2 milliseconds receive data and the 3rd section the 2 milliseconds of zero paddings are carried out related operation; Data after the 4th section 2 milliseconds receive data and the 4th section the 2 milliseconds of zero paddings are carried out related operation
Step 205: the data of obtaining the 1st millisecond of correspondence of each section behind the related operation.
Namely can obtain the data of first millisecond of correspondence of L section.
Step 206: whether judge the data of absolute value maximum in every segment data less than 0, if less than 0 execution in step 207, carry out the sign inversion correction; Otherwise execution in step 208.
Wherein, if the data of absolute value maximum are for negative in every segment data, represent that then the symbol of this segment data is for negative; If the data of absolute value maximum are for just in every segment data, the symbol that then represents this segment data is for just.For example the data of the 3rd section correspondence are 3 ,-4, and then the data of absolute value maximum are-4, because-4＜0, then execution in step 207.
Step 207: carry out the sign inversion correction, each numerical value in this segment data is taken advantage of-1.
It is to eliminate the symbol saltus step that each numerical value in this segment data is taken advantage of-1 fundamental purpose, for example: have four segment datas, in each section 3 data are arranged, the 1st section is 1,2,3,10 to be symbol for just, the 2nd section is 1 ,-2,3,20 to be symbol for just, and the 3rd section is 4,5,6,15 to be symbol for just, and the 4th section is 4 ,-5 ,-6 ,-25 to be that symbol is negative, namely there is not the symbol saltus step between the 1st segment data, the 2nd segment data and the 3rd segment data, has the symbol saltus step between the 3rd section and the 4th segment data.Namely only need in the 4th segment data each is on duty-1, the symbol of such the 4th segment data is being for just, so eliminated the symbol saltus step between the 3rd section and the 4th segment data.
Step 208: with the corresponding addition of 1 millisecond of data of L section.
Soon the 1st bit data addition in the 1st bit data in the 1st segment data, the 1st bit data in the 2nd segment data, the 1st bit data in the 3rd segment data, the 4th segment data; In like manner with the 2nd bit data in the 1st segment data, the 2nd bit data in the 2nd segment data, the 2nd bit data in the 3rd segment data, the 2nd bit data addition in the 4th segment data, namely increased the signal gain of each.
Step 209: with the 1 millisecond of data output that obtains after the addition.
Above-mentioned steps is equivalent to the correlation integral time lengthening to the L millisecond, and the data corresponding phase that the L millisecond time is long adds up, and has become 1 millisecond data, and the gain that has increased like this signal, the gain of signal are 10lgL.
Wherein, the various losses of receiver are estimated as follows: if the about 2dB of system noise factor, the unjustified about 0.9dB of data boundary, PN code not the about 2.5dB of complete matching, Doppler shift bring decay to the coherent accumulation that 1dB carries out 2 milliseconds, then signal to noise ratio (S/N ratio) becomes 2dB, cut loss, signal to noise ratio (S/N ratio) becomes SNR
L=-4.4dB (that is, 2-2-0.9-2.5-1=-4.4).
Wherein, if the method in the employing step 201-step 209 is carried out first 1 millisecond of coherent accumulation of L section, then signal to noise ratio (S/N ratio) becomes 101gL, cuts the above-mentioned loss 6.4dB that lists, and signal to noise ratio (S/N ratio) at this moment becomes SNR
L=10lgL-6.4dB.
Wherein, add up if carry out N section L millisecond differential coherence on the basis of carrying out 1 millisecond of coherent accumulation of L section, then total signal to noise ratio (S/N ratio) becomes: SNR again
Total=-6.4+10lgL+10lgN+Loss (6.4+101gL), wherein, Loss (6.4+10lgL) is the cumulative loss of differential coherence, the value of N and L rationally is set, for example L is set to 20 milliseconds, N is set to 4 or 5, and signal to noise ratio (S/N ratio) is increased to about 15dB, can successful capturing satellite signal.
In sum, solved the very high navigation signal of symbol hop rate by said method, because be restricted its integral time, can not carry out the cumulative problem of long integration, this scheme has realized that above-mentioned signal is carried out long-time integration to add up, thereby improve the signal to noise ratio (S/N ratio) that receives signal, realized the success of weak signal is caught.
Referring to Fig. 6, the device that the embodiment of the invention provides a kind of satellite navigation signals to catch, this acquisition equipment mainly comprises:
Obtain module 201, be used for obtaining to comprise in-phase component and the quadrature component of C/A code;
Differential coherence accumulator module 204 is used for that the result after 203 conversion of FFT conversion module is carried out differential coherence and adds up; Being used for that specifically the n time quadrature component, in-phase component are carried out differential coherence with the n-1 time quadrature component, in-phase component respectively adds up.
Judging module 205 is used for adjudicating according to the cumulative result of differential coherence, if greater than then capturing satellite signal success of threshold value; Otherwise capturing satellite signal failure.
Wherein, obtaining module 201 specifically comprises:
Obtain unit 201B, be used for in-phase component and quadrature component that in-phase component and quadrature component according to digital intermediate frequency signal, local carrier obtain to comprise the C/A code.
Wherein, computing module 202 specifically comprises:
Segmenting unit 202A is used for the receive data of 2L millisecond is carried out segmentation take 2 milliseconds as unit;
Adding device 202B, for the replica code that obtains the local L millisecond that produces, 1 millisecond of interpolation is zero behind the replica code of each millisecond;
Acquiring unit 202C is used for the data that obtain among the receive data of segmenting unit 202A and the adding device 202B are carried out related operation, obtains the data of the 1st millisecond of correspondence of each section behind the related operation;
Judging unit 202D is used for judging that whether the data of data absolute value maximum of the 1st millisecond of correspondence of each section of acquiring unit 202C acquisition are less than 0, if carry out the sign inversion correction less than 0; Otherwise carry out the first output unit 202E;
The first output unit 202E is used for the corresponding addition of 1 millisecond of data of L section, with the 1 millisecond of data output that obtains after the addition.
Wherein, judging unit 202D also comprises:
Computation subunit is used for each numerical value of this segment data is taken advantage of-1.
Wherein, judging module 205 also comprises:
Judging unit 205A is used for adjudicating according to the cumulative result of differential coherence, if then represent the capturing satellite signal success greater than threshold value; Otherwise expression capturing satellite signal failure;
The second output unit 205B is used for after the capturing satellite signal success code phase and the carrier frequency of C/A code being exported;
Wherein, mobile 0.5 code phase re-starts and catches, if also there is not again mobile 0.5 phase place of acquisition success, can mobile 1023/0.5=2046 time, (wherein, 1023 is the code length of C/A code) all do not capture signal after search 2046 times, then, change a carrier frequency and be about to local carrier frequency and move ± 500Hz, can positive and negative plus-minus 10 times, namely can move altogether 21 times, repeat said process, until the signal capture success.If all code phases and carrier frequency be the complete signal that still do not capture of search all, then this cycle lock-on signal failure.
In sum, solved the very high navigation signal of symbol hop rate by said apparatus, because be restricted its integral time, can not carry out the cumulative problem of long integration, this device has realized that above-mentioned signal is carried out long-time integration to add up, thereby improve the signal to noise ratio (S/N ratio) that receives signal, realized the success of weak signal is caught.
Below only be preferred embodiment of the present invention, in order to limit the present invention, within the spirit and principles in the present invention not all, any modification of doing, be equal to replacement, improvement etc., all should be included within protection scope of the present invention.
Claims (8)
1. the catching method of a satellite navigation signals is characterized in that, described method comprises:
Acquisition comprises in-phase component and the quadrature component of C/A code;
The C/A code in-phase component and the quadrature component that obtain are carried out related operation with local C/A code respectively;
Result to related operation carries out the FFT conversion;
It is cumulative that the result of FFT conversion is carried out differential coherence;
The result cumulative according to differential coherence adjudicates, if greater than then capturing satellite signal success of threshold value; Otherwise capturing satellite signal failure;
Wherein, described C/A code in-phase component and quadrature component with acquisition specifically comprises with the step that local C/A code carries out related operation respectively:
Steps A: the receive data of 2L millisecond is carried out segmentation take 2 milliseconds as unit;
Step B: obtain the replica code of the local L millisecond that produces, behind the replica code of each millisecond, add 1 millisecond zero;
Step C: the data that obtain among the receive data in the steps A and the step B are carried out related operation, obtain the data of the 1st millisecond of correspondence of each section behind the related operation;
Step D: judge that whether the data of absolute value maximum in the data of the 1st millisecond of correspondence of described each section are less than 0, if carry out the sign inversion correction less than 0; Otherwise execution in step E;
Step e: with the corresponding addition of 1 millisecond of data of L section, with the 1 millisecond of data output that obtains after the addition.
2. the method for claim 1, it is characterized in that, whether the data of absolute value maximum are less than 0, if specifically comprise less than 0 step of carrying out the sign inversion correction: each numerical value in this segment data is taken advantage of-1 in the data of described the 1st millisecond of correspondence judging described each section.
3. the method for claim 1 is characterized in that, described result to the FFT conversion carries out the cumulative step of differential coherence and specifically comprises:
The n time quadrature component, in-phase component are carried out differential coherence with the n-1 time quadrature component, in-phase component respectively to add up.
4. the method for claim 1 is characterized in that, the described result who adds up according to differential coherence adjudicates, if greater than then capturing satellite signal success of threshold value; Otherwise also comprise after the step of capturing satellite signal failure:
If greater than threshold value then after the capturing satellite signal success, with code phase and the carrier frequency output of C/A code; Correspondingly,
If then after the lock-on signal failure, adjust phase place, the carrier frequency of local code less than predetermined threshold value, re-start search.
5. the acquisition equipment of a satellite navigation signals is characterized in that, described device comprises:
Obtain module, described acquisition module is used for obtaining to comprise in-phase component and the quadrature component of C/A code;
Computing module, described computing module are used for C/A code in-phase component and quadrature component that described acquisition module obtains are carried out related operation with local C/A code respectively;
FFT conversion module, described FFT conversion module are used for the result of related operation is carried out the FFT conversion;
Differential coherence accumulator module, described differential coherence accumulator module are used for that the result after the conversion of described FFT conversion module is carried out differential coherence and add up;
Judging module, described judging module are used for adjudicating according to the cumulative result of differential coherence, if greater than then capturing satellite signal success of threshold value; Otherwise capturing satellite signal failure;
Wherein, described computing module specifically comprises:
Segmenting unit, described segmenting unit are used for the receive data of 2L millisecond is carried out segmentation take 2 milliseconds as unit;
Adding device, described adding device is used for obtaining the replica code of the local L millisecond that produces, and adds 1 millisecond zero behind the replica code of each millisecond;
Acquiring unit, described acquiring unit are used for the data that obtain in the receive data of described segmenting unit and the described adding device are carried out related operation, obtain the data of the 1st millisecond of correspondence of each section behind the related operation;
Whether the data of the data absolute value maximum of the 1st millisecond of correspondence of each section that judging unit, described judging unit are used for judging that described acquiring unit obtains are less than 0, if carry out the sign inversion correction less than 0; Otherwise carry out the first output unit;
The first output unit, described the first output unit are used for the corresponding addition of 1 millisecond of data of L section, with the 1 millisecond of data output that obtains after the addition.
6. device as claimed in claim 5 is characterized in that, described judging unit also comprises:
Computation subunit, described computation subunit are used for each numerical value of this segment data is taken advantage of-1.
7. device as claimed in claim 5 is characterized in that, described differential coherence accumulator module is used for that specifically the n time quadrature component, in-phase component are carried out differential coherence with the n-1 time quadrature component, in-phase component respectively and adds up.
8. device as claimed in claim 5 is characterized in that, described judging module specifically comprises:
Decision unit, described decision unit are used for adjudicating according to the cumulative result of differential coherence, if then represent the capturing satellite signal success greater than threshold value; Otherwise expression capturing satellite signal failure;
The second output unit, described the second output unit are used for the code phase of C/A code and carrier frequency output;
Adjustment unit, described adjustment unit is used for adjusting phase place, the carrier frequency of local code.
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| CN103123686A (en) * | 2011-11-18 | 2013-05-29 | 上海宇航系统工程研究所 | Spiral search capturing method based on cooperative targets |
| CN103378934B (en) * | 2012-04-27 | 2018-10-23 | 中国传媒大学 | A kind of 1090MHz ES ADS-B frame signal demodulation methods |
| CN102820904B (en) * | 2012-08-08 | 2015-04-22 | 北京邮电大学 | Method and device for reducing cross-correlation interference of radio network locating signals |
| US9291717B2 (en) * | 2013-05-09 | 2016-03-22 | Samsung Electronics Co., Ltd. | Method and apparatus for efficiently combining satellite navigation signals |
| CN105425251A (en) * | 2015-11-09 | 2016-03-23 | 湖南中森通信科技有限公司 | Method for resisting forwarding-type interference signal for navigation receiver |
| CN105467410A (en) * | 2015-12-04 | 2016-04-06 | 航天恒星科技有限公司 | Navigation signal generation method |
| CN106842247A (en) * | 2015-12-04 | 2017-06-13 | 航天恒星科技有限公司 | The L2C signal creating methods and device of a kind of GPS |
| CN106896385A (en) * | 2015-12-18 | 2017-06-27 | 大唐半导体设计有限公司 | A kind of device of frequency search and the method for realizing frequency search |
| CN107346028B (en) * | 2016-05-06 | 2020-05-22 | 大唐半导体设计有限公司 | Method and device for realizing code phase search |
| CN105842714B (en) * | 2016-06-07 | 2018-01-05 | 北京邮电大学 | Satellite signal tracking method and device |
| CN106019223A (en) * | 2016-08-03 | 2016-10-12 | 北京邮电大学 | Signal capturing method and device |
| CN106199656B (en) * | 2016-08-12 | 2018-11-23 | 南京航空航天大学 | A kind of receiver for satellite weak signal is without assist type catching method |
| CN107991695A (en) * | 2017-11-07 | 2018-05-04 | 南京航空航天大学 | Big Dipper weak signal catching method based on zero padding algorithm and differential coherence algorithm |
| CN109085630B (en) * | 2018-08-20 | 2021-04-30 | 北京邮电大学 | Signal capturing method and device |
| CN111665528B (en) * | 2020-06-24 | 2023-12-26 | 湖南国科微电子股份有限公司 | Satellite signal capturing method, device and storage medium |
| CN115079217A (en) * | 2022-07-20 | 2022-09-20 | 中国人民解放军国防科技大学 | Large dynamic high sensitivity short burst signal loop steady tracking method |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101520505A (en) * | 2009-03-27 | 2009-09-02 | 哈尔滨工业大学 | Adaptive coherent accumulation joint acquisition method under GNSS weak signal |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7209076B2 (en) * | 2002-07-10 | 2007-04-24 | Qualcomm Incorporated | Cross-correlation mitigation method and apparatus for use in a global positioning system receiver |
-
2009
- 2009-12-08 CN CN 200910241405 patent/CN102087361B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101520505A (en) * | 2009-03-27 | 2009-09-02 | 哈尔滨工业大学 | Adaptive coherent accumulation joint acquisition method under GNSS weak signal |
Non-Patent Citations (4)
| Title |
|---|
| 华涛等.基于FFT伪码快速捕获方法及其性能分析.《现代电子技术》.2007,(第23期),42-44. |
| 吴高进等.时频二维搜索捕获算法及其FPGA实现.《北京邮电大学学报》.2009,第32卷(第3期), |
| 基于FFT伪码快速捕获方法及其性能分析;华涛等;《现代电子技术》;20071215(第23期);42-44 * |
| 时频二维搜索捕获算法及其FPGA实现;吴高进等;《北京邮电大学学报》;20090630;第32卷(第3期);91-95 * |
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