CN108226968B - Navigation signal rapid capturing method - Google Patents

Navigation signal rapid capturing method Download PDF

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CN108226968B
CN108226968B CN201810005376.XA CN201810005376A CN108226968B CN 108226968 B CN108226968 B CN 108226968B CN 201810005376 A CN201810005376 A CN 201810005376A CN 108226968 B CN108226968 B CN 108226968B
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CN108226968A (en
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林静然
张亚乾
利强
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University of Electronic Science and Technology of China
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
    • G01S19/01—Satellite radio beacon positioning systems transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
    • G01S19/13—Receivers
    • G01S19/24—Acquisition or tracking or demodulation of signals transmitted by the system
    • G01S19/30—Acquisition or tracking or demodulation of signals transmitted by the system code related
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01S—RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
    • G01S19/00—Satellite radio beacon positioning systems; Determining position, velocity or attitude using signals transmitted by such systems
    • G01S19/01—Satellite radio beacon positioning systems transmitting time-stamped messages, e.g. GPS [Global Positioning System], GLONASS [Global Orbiting Navigation Satellite System] or GALILEO
    • G01S19/13—Receivers
    • G01S19/24—Acquisition or tracking or demodulation of signals transmitted by the system
    • G01S19/29—Acquisition or tracking or demodulation of signals transmitted by the system carrier including Doppler, related

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  • Radar, Positioning & Navigation (AREA)
  • Remote Sensing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
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Abstract

The invention discloses a navigation signal rapid capturing method, which is characterized in that the two-dimensional searching times are reduced, firstly, the spread spectrum codes of a plurality of satellites are combined to obtain the approximate code phase and Doppler information of each satellite, and then, the visible satellite number is further determined by utilizing one-dimensional searching. The invention realizes a mixed method for searching a plurality of satellites at one time, simplifies the traditional method for capturing the satellite signals by performing two-dimensional search on the satellite signals one by one, and can further reduce the operation complexity and the capturing time of the satellite capturing method.

Description

Navigation signal rapid capturing method
Technical Field
The invention belongs to the technical field of satellite communication, and particularly relates to a design of a navigation signal rapid acquisition method.
Background
In the satellite navigation signal processing process, before starting signal tracking, a receiver needs to estimate two parameters, namely carrier frequency (or carrier doppler shift) and code phase, of a received signal, and then initialize a tracking loop according to the estimated values of the signal parameters to help a receiving channel to track the signal, and the purpose of signal acquisition is to obtain rough estimated values of the carrier frequency and the code phase of all visible satellite signals.
In order to estimate the two parameter values of the carrier frequency and the code phase of a certain satellite signal, the signal acquisition process of the receiver is generally performed by performing a scanning search on the two dimensions of the carrier frequency and the code phase of the satellite signal. Once the signal is searched and confirmed, the acquisition process for the signal is ended.
Before performing a two-dimensional search for frequency and code phase of a satellite signal, the receiver first determines that the satellite is likely to be visible and is worth searching for its signal. Thus, the acquisition of satellite signals is effectively a three-dimensional search process with respect to pseudo code (satellite number), frequency, and code phase.
The basis of signal acquisition is the correlation of the ranging code, so that for the search, the correlator output will only reach a maximum when the carrier and ranging code signals reproduced internally by the receiver coincide with the received signal. As shown in fig. 1, each frequency band corresponds to a carrier frequency search value, each code phase band corresponds to a code phase search value, and an intersection of each frequency band and one code phase band is referred to as a basic search unit.
The first method is a serial search acquisition method, which is the earliest traditional acquisition method proposed by a satellite navigation system to solve the acquisition problem. The method is to perform serial search for code phase and Doppler shift respectively. Since the step size of the code phase search is typically half a chip and one symbol period is long, the serial search is inefficient. The doppler frequency search step is determined by the coherent integration time, usually the reciprocal of the coherent integration time, and the search range is determined by the dynamic state of the receiver.
The second method is a parallel search capture method, which is proposed to solve the problem of long serial search time. It is common practice to search for code phase in parallel and doppler shift in series. The method utilizes Fast Fourier Transform (FFT) and Inverse Fast Fourier Transform (IFFT) to convert the correlation operation from time domain to frequency domain for carrying out, thereby reducing the time for capturing and laying a foundation for realizing real-time processing. However, the two algorithms still require a large amount of computation in the three-dimensional search process of satellite signals. The key reason is that two-dimensional search is required for capturing each satellite, and how many satellites are required to be subjected to two-dimensional search. The two-dimensional search has large computation amount and high complexity, and brings burden to the capturing process.
Disclosure of Invention
The invention aims to solve the problem that the calculation amount is overlarge due to the fact that the satellite signals need to be searched two-dimensionally one by one in the conventional satellite signal capturing method, and provides a navigation signal rapid capturing method.
The technical scheme of the invention is as follows: a navigation signal fast acquisition method comprises the following steps:
s1, generating the C/A code CA of each satellite in the navigation systemkAnd the C/A code CA is coded by 2 times of code ratekSampling to obtain a sampling C/A code CASamk(ii) a Where K is the number of satellites in the navigation system, K is the {1, 2.
S2, dividing K satellites in the navigation system into J groups, enabling the satellites among the groups not to be repeated, and adding the sampling C/A codes in each group to obtain a sampling C/A code set CASamsetj(ii) a Where J ∈ {1, 2.,. J }.
S3, sampling C/A code set CASamsetjPerforming FFT operation and conjugating the FFT result to obtain a FFT conjugation result
Figure BDA0001538455190000021
And S4, receiving the intermediate frequency sampling signal S.
S5, down-converting the intermediate frequency sampling signal S to obtain a down-converted signal xi(ii) a Where i is a count value and the initial value is 1.
Down converted signal xiThe calculation formula of (2) is as follows:
xi＝s·exp[-j2π(fIF+fD-(i-1)Δf)n/fs] (1)
wherein f isIFFor sampling signals at intermediate frequencies with zero doppler frequency offsetCarrier frequency, fDFor the estimated maximum Doppler shift for the intermediate frequency sampled signal,. DELTA.f for the estimated Doppler shift step for the intermediate frequency sampled signal,. fsIs the sampling rate of the intermediate frequency sampled signal with zero doppler frequency offset.
S6, using 2 times code rate of C/A code to down-converted signal xiPacking, i.e. down-converting the signal xiEach in
Figure BDA0001538455190000022
Accumulating the sampling points into 1 point to obtain a sequence xpackiWherein f isCAIs the code rate of the C/A code.
S7, pairing the sequences xpackiPerforming FFT operation to obtain an FFT sequence XFi。
S8, adding 1 to the count value i.
S9, if I is less than or equal to I, returning to the step S5, otherwise, entering the step S10; wherein I is the number of Doppler frequency offset estimation values of the intermediate frequency sampling signal, and the calculation formula is as follows:
Figure BDA0001538455190000023
s10, setting the count value i to 1 and setting j to 1.
S11, the FFT conjugation result obtained from the step S3
Figure BDA0001538455190000031
And the FFT sequence XF obtained in step S7iCalculating to obtain a correlation operation result corri jThe calculation formula is as follows:
Figure BDA0001538455190000032
where abs [. cndot. ] is the modulo operation and ift (. cndot.) is the inverse fast Fourier transform.
S12, adding 1 to the count value i.
S13, if I is less than or equal to I, returning to the step S11, otherwise, entering the step S14.
S14, setting the counting value i as 1, and adding 1 to j.
S15, if J is less than or equal to J, returning to the step S11, otherwise, entering the step S16.
S16, setting j to 1.
S17, marking the correlation operation result corr with the same marki jAs a set of correlation results corrjStatistical correlation result set corrjAll peak points r with the middle peak-to-average ratio larger than a predetermined thresholdtAnd recording all peak points rtCorresponding code phase and Doppler frequency offset combinations (p)t,dplt) (ii) a Wherein T ∈ {1, 2.,. Tj}，TjIs the total number of peak points.
S18, if Tj<1, go to step S19, otherwise go to step S21.
S19, adding 1 to j.
S20, if J is less than or equal to J, returning to the step S17, otherwise, ending the capturing phase.
S21, judging sampling C/A code set CASamsetjWhether the signal Doppler frequency offset and the code phase of the corresponding single navigation satellite are acquired is judged, if so, the signal Doppler frequency offset and the code phase of the corresponding single navigation satellite are acquired, the step S19 is returned, and if not, the step S22 is executed.
S22, setting t to 1.
S23, setting L sets of storage space, and collecting the sampling C/A code set into CASamsetjThe C/A codes in the group are added according to the method of step S2, and the added C/A codes are stored in the storage space of the L sets (if the C/A code set is sampled, CASAMET)jResetting the vacated storage space to zero if the number of the satellites in the group is less than L), and obtaining a sampling C/A code group set
Figure BDA0001538455190000033
Where L ∈ {1, 2., L }.
S24, setting l to 1.
S25, press (p)t,dplt) Code phase versus sample C/a code grouping set in
Figure BDA0001538455190000034
Performing cyclic shift to make it and peak point rtCorresponding code phase alignment to obtain C/A code cyclic shift set
Figure BDA0001538455190000035
S26, cyclic shift gathering C/A code
Figure BDA0001538455190000041
And
Figure BDA0001538455190000042
performing correlation operation to obtain a correlation operation result corrval; wherein itIs the peak point rtThe doppler shift of (d) corresponds to the count value.
S27, comparing the relation number corrval with the peak point rtIf | corrval | non-zero<|rtIf not, go to step S28, otherwise go to step S34.
S28, adding 1 to l.
S29, if L is less than or equal to L, returning to the step S25, otherwise, outputting error information, and entering the step S30.
S30, adding 1 to t.
S31, if T is less than or equal to TjThen, the process returns to step S25, otherwise, an error message is output.
S32, adding 1 to j.
S33, if J is less than or equal to J, returning to the step S17, otherwise, ending the capturing phase.
S34 judging C/A code group collection of sampling
Figure BDA0001538455190000043
Whether the signal Doppler frequency offset and the code phase of the corresponding single navigation satellite are acquired is judged, and the step S36 is executed, otherwise, the step S35 is executed.
S35, grouping and collecting the sampled C/A codes
Figure BDA0001538455190000044
The satellites in the set are further divided into L groups and the C/A codes in the groups are processed in stepsThe method of S2 is added and stored into the storage space of L sets (if sampling the C/A code packet set) described in step S23
Figure BDA0001538455190000045
If the number of satellites in the group is less than L, the vacated storage space is reset to zero), and the process returns to step S24.
S36, adding 1 to t.
S37, if T is less than or equal to TjThen, the process returns to step S25, otherwise, the process proceeds to step S38.
S38, adding 1 to j.
S39, if J is less than or equal to J, returning to the step S17, otherwise, ending the capturing phase.
The invention has the beneficial effects that: the core of the invention is to reduce the number of two-dimensional search, firstly, the spread spectrum codes of a plurality of satellites are combined to obtain the approximate code phase and Doppler information of each satellite (at this moment, the code phase and Doppler information do not correspond to the satellite number one by one), and then the visible satellite number is further determined by utilizing one-dimensional search. The invention realizes a mixed method for searching a plurality of satellites at one time, simplifies the traditional method for capturing the satellite signals by performing two-dimensional search on the satellite signals one by one, and can further reduce the operation complexity and the capturing time of the satellite capturing method.
Drawings
Fig. 1 is a schematic diagram of a three-dimensional search for satellite signals.
Fig. 2 is a flowchart of a navigation signal fast acquisition method according to an embodiment of the present invention.
Detailed Description
Exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It is to be understood that the embodiments shown and described in the drawings are merely exemplary and are intended to illustrate the principles and spirit of the invention, not to limit the scope of the invention.
The embodiment of the invention provides a navigation signal rapid capturing method, as shown in fig. 2, comprising the following steps:
s1, generating the C/A code CA of each satellite in the navigation systemkAnd the C/A code CA is coded by 2 times of code ratekSampling to obtain a sampling C/A code CASamk(ii) a Where K is the number of satellites in the navigation system, K is the {1, 2. In the embodiment of the present invention, K is set to 32.
S2, dividing K satellites in the navigation system into J groups, enabling the satellites among the groups not to be repeated, and adding the sampling C/A codes in each group to obtain a sampling C/A code set CASamsetj(ii) a Where J ∈ {1, 2.,. J }. In the embodiment of the present invention, J is set to 8.
S3, sampling C/A code set CASamsetjPerforming FFT operation and conjugating the FFT result to obtain a FFT conjugation result
Figure BDA0001538455190000051
And S4, receiving the intermediate frequency sampling signal S.
S5, down-converting the intermediate frequency sampling signal S to obtain a down-converted signal xi(ii) a Where i is a count value and the initial value is 1.
Down converted signal xiThe calculation formula of (2) is as follows:
xi＝s·exp[-j2π(fIF+fD-(i-1)Δf)n/fs] (1)
wherein f isIFFor the carrier frequency of the intermediate-frequency sampled signal with zero Doppler frequency offset, fDFor the estimated maximum Doppler shift for the intermediate frequency sampled signal,. DELTA.f for the estimated Doppler shift step for the intermediate frequency sampled signal,. fsIs the sampling rate of the intermediate frequency sampled signal with zero doppler frequency offset.
In the embodiment of the invention, f is setD＝±4kHz，Δf＝500Hz。
S6, using 2 times code rate of C/A code to down-converted signal xiPacking, i.e. down-converting the signal xiEach in
Figure BDA0001538455190000052
Accumulating the sampling points into 1 point to obtain a sequence xpackiWherein f isCAIs the code rate of the C/A code.
In the embodiment of the invention, f is setCA＝1.023MHz。
S7, pairing the sequences xpackiPerforming FFT operation to obtain an FFT sequence XFi。
S8, adding 1 to the count value i.
S9, if I is less than or equal to I, returning to the step S5, otherwise, entering the step S10; wherein I is the number of Doppler frequency offset estimation values of the intermediate frequency sampling signal, and the calculation formula is as follows:
Figure BDA0001538455190000061
in the embodiment of the present invention, the first and second substrates,
Figure BDA0001538455190000062
s10, setting the count value i to 1 and setting j to 1.
S11, the FFT conjugation result obtained from the step S3
Figure BDA0001538455190000063
And the FFT sequence XF obtained in step S7iCalculating to obtain a correlation operation result corri jThe calculation formula is as follows:
Figure BDA0001538455190000064
where abs [. cndot. ] is the modulo operation and ift (. cndot.) is the inverse fast Fourier transform.
S12, adding 1 to the count value i.
S13, if I is less than or equal to I, returning to the step S11, otherwise, entering the step S14.
S14, setting the counting value i as 1, and adding 1 to j.
S15, if J is less than or equal to J, returning to the step S11, otherwise, entering the step S16.
S16, setting j to 1.
S17, marking the correlation operation result corr with the same marki jAs a set of correlation results corrjStatistical correlation result set corrjThe mean peak-to-average ratio is greater than a predetermined thresholdAll peak points r of the limittAnd recording all peak points rtCorresponding code phase and Doppler frequency offset combinations (p)t,dplt) (ii) a Wherein T ∈ {1, 2.,. Tj}，TjIs the total number of peak points.
S18, if Tj<1, go to step S19, otherwise go to step S21.
S19, adding 1 to j.
S20, if J is less than or equal to J, returning to the step S17, otherwise, ending the capturing phase.
S21, judging sampling C/A code set CASamsetjWhether the signal Doppler frequency offset and the code phase of the corresponding single navigation satellite are acquired is judged, if so, the signal Doppler frequency offset and the code phase of the corresponding single navigation satellite are acquired, the step S19 is returned, and if not, the step S22 is executed.
In the embodiment of the invention, a C/A code set is sampled and the CASamset is CASamsetjComposed of the C/a codes of 4 satellites, the process proceeds directly to step S22.
S22, setting t to 1.
S23, setting L sets of storage space, and collecting the sampling C/A code set into CASamsetjThe C/A codes in the group are added according to the method of step S2, and the added C/A codes are stored in the storage space of the L sets (if the C/A code set is sampled, CASAMET)jResetting the vacated storage space to zero if the number of the satellites in the group is less than L), and obtaining a sampling C/A code group set
Figure BDA0001538455190000071
Where L ∈ {1, 2., L }.
In the embodiment of the present invention, L is set to 2.
S24, setting l to 1.
S25, press (p)t,dplt) Code phase versus sample C/a code grouping set in
Figure BDA0001538455190000072
Performing cyclic shift to make it and peak point rtCorresponding code phase alignment to obtain C/A code cyclic shift set
Figure BDA0001538455190000073
S26, cyclic shift gathering C/A code
Figure BDA0001538455190000074
And
Figure BDA0001538455190000075
performing correlation operation to obtain a correlation operation result corrval; wherein itIs the peak point rtThe doppler shift of (d) corresponds to the count value.
S27, comparing the relation number corrval with the peak point rtIf | corrval | non-zero<|rtIf not, go to step S28, otherwise go to step S34.
S28, adding 1 to l.
S29, if L is less than or equal to L, returning to the step S25, otherwise, outputting error information, and entering the step S30.
S30, adding 1 to t.
S31, if T is less than or equal to TjThen, the process returns to step S25, otherwise, an error message is output.
S32, adding 1 to j.
S33, if J is less than or equal to J, returning to the step S17, otherwise, ending the capturing phase.
S34 judging C/A code group collection of sampling
Figure BDA0001538455190000076
Whether the signal Doppler frequency offset and the code phase of the corresponding single navigation satellite are acquired is judged, and the step S36 is executed, otherwise, the step S35 is executed.
S35, grouping and collecting the sampled C/A codes
Figure BDA0001538455190000077
The satellites are further divided into L-2 groups, and the C/a codes in the groups are added according to the method of step S2, and stored in the storage space of L sets (if C/a code group sets are sampled) described in step S23
Figure BDA0001538455190000078
If the number of satellites in the group is less than L, the vacated storage space is reset to zero), and the process returns to step S24.
S36, adding 1 to t.
S37, if T is less than or equal to TjThen, the process returns to step S25, otherwise, the process proceeds to step S38.
S38, adding 1 to j.
S39, if J is less than or equal to J, returning to the step S17, otherwise, ending the capturing phase.
The navigation signal fast acquisition method provided by the embodiment of the invention is compared with the two existing satellite signal acquisition methods in algorithm complexity.
Assuming that a certain satellite navigation system has K satellites in common, I doppler frequency offset estimates and P code phase estimates are provided in the acquisition stage, and the maximum computation required for acquiring one satellite is compared as follows:
the computation load magnitude of the traditional serial code phase searching and capturing method is KIP2。
The computation load magnitude of the traditional parallel code phase search acquisition method is KIPlog2P。
By adopting the navigation signal rapid acquisition method provided by the embodiment of the invention, the navigation signal is divided into J groups during two-dimensional search, and is divided into L groups during satellite PRN confirmation, and the operand magnitude is IJPleg2And P. Due to J<K (e.g., in GPS, K is 32, and J is 4), so the complexity of the algorithm of the present invention is lower than that of the conventional two algorithms.
It will be appreciated by those of ordinary skill in the art that the embodiments described herein are intended to assist the reader in understanding the principles of the invention and are to be construed as being without limitation to such specifically recited embodiments and examples. Those skilled in the art can make various other specific changes and combinations based on the teachings of the present invention without departing from the spirit of the invention, and these changes and combinations are within the scope of the invention.

Claims (5)

1. A navigation signal fast acquisition method is characterized by comprising the following steps:
s1, generating the C/A code CA of each satellite in the navigation systemkAnd the C/A code CA is coded by 2 times of code ratekSampling to obtain a sampling C/A code CASamk(ii) a Wherein K belongs to {1, 2.,. K }, and K is the number of satellites in the navigation system;
s2, dividing K satellites in the navigation system into J groups, enabling the satellites among the groups not to be repeated, and adding the sampling C/A codes in each group to obtain a sampling C/A code set CASamsetj(ii) a Wherein J ∈ {1, 2.., J };
s3, sampling C/A code set CASamsetjPerforming FFT operation and conjugating the FFT result to obtain a FFT conjugation result
Figure FDA0002971312500000011
S4, receiving an intermediate frequency sampling signal S;
s5, down-converting the intermediate frequency sampling signal S to obtain a down-converted signal xi(ii) a Wherein i is a count value and the initial value is 1;
s6, using 2 times code rate of C/A code to down-converted signal xiPacking to obtain a sequence xpacki；
S7, pairing the sequences xpackiPerforming FFT operation to obtain an FFT sequence XFi；
S8, adding 1 to the count value i;
s9, if I is less than or equal to I, returning to the step S5, otherwise, entering the step S10; wherein I is the number of Doppler frequency offset estimated values of the intermediate frequency sampling signal;
s10, setting a count value i as 1 and setting j as 1;
s11, the FFT conjugation result obtained from the step S3
Figure FDA0002971312500000012
And the FFT sequence XF obtained in step S7iCalculating to obtain the correlation operation result
Figure FDA0002971312500000013
S12, adding 1 to the count value i;
s13, if I is less than or equal to I, returning to the step S11, otherwise, entering the step S14;
s14, setting a count value i as 1, and adding 1 to j;
s15, if J is less than or equal to J, returning to the step S11, otherwise, entering the step S16;
s16, setting j to be 1;
s17, marking the correlation operation result corr with the same marki jAs a set of correlation results corrjStatistical correlation result set corrjAll peak points r with the middle peak-to-average ratio larger than a predetermined thresholdtAnd recording all peak points rtCorresponding code phase and Doppler frequency offset combinations (p)t,dplt) (ii) a Wherein T ∈ {1, 2.,. Tj}，TjThe total number of peak points;
s18, if Tj<1, entering step S19, otherwise entering step S21;
s19, adding 1 to j;
s20, if J is less than or equal to J, returning to the step S17, otherwise, ending the capturing phase;
s21, judging sampling C/A code set CASamsetjWhether the single navigation satellite signal is composed of the C/A code of the single satellite or not is judged, if so, the signal Doppler frequency offset and the code phase of the corresponding single navigation satellite are acquired, the step S19 is returned, otherwise, the step S22 is executed;
s22, setting t to be 1;
s23, setting L sets of storage space, and collecting the sampling C/A code set into CASamsetjThe C/A codes in the group are added according to the method of step S2, and are stored in the storage space of the L sets to obtain the sampling C/A code group set
Figure FDA0002971312500000021
Wherein L ∈ {1, 2.., L }; if sampling C/A code set CASamsetjIf the number of the satellites in the group is less than L, the vacated storage space is reset to zero;
s24, setting l to be 1;
s25, press (p)t,dplt) Code phase versus sample C/a code grouping set in
Figure FDA0002971312500000022
Performing cyclic shift to make it and peak point rtCorresponding code phase alignment to obtain C/A code cyclic shift set
Figure FDA0002971312500000023
S26, cyclic shift gathering C/A code
Figure FDA0002971312500000024
And
Figure FDA0002971312500000025
performing correlation operation to obtain a correlation operation result corrval; wherein itIs the peak point rtThe doppler shift of (a) corresponds to the count value;
s27, comparing the relation number corrval with the peak point rtIf | corrval | non-zero<|rtIf not, go to step S28, otherwise go to step S34;
s28, adding 1 to l;
s29, if L is less than or equal to L, returning to the step S25, otherwise, outputting error information, and entering the step S30;
s30, adding 1 to t;
s31, if T is less than or equal to TjReturning to step S25, otherwise outputting an error message;
s32, adding 1 to j;
s33, if J is less than or equal to J, returning to the step S17, otherwise, ending the capturing phase;
s34 judging C/A code group collection of sampling
Figure FDA0002971312500000026
Whether the single navigation satellite signal is composed of the C/A code of the single satellite or not is judged, if so, the signal Doppler frequency offset and the code phase of the corresponding single navigation satellite are acquired, and the step S36 is executed, otherwise, the step S35 is executed;
s35, grouping and collecting the sampled C/A codes
Figure FDA0002971312500000031
The satellites are continuously divided into L groups, the C/A codes in the groups are added according to the method of the step S2, the L groups of storage spaces are stored in the step S23, and the step S24 is returned; if sampling C/A code group set
Figure FDA0002971312500000032
If the number of the satellites in the group is less than L, the vacated storage space is reset to zero;
s36, adding 1 to t;
s37, if T is less than or equal to TjReturning to step S25, otherwise, proceeding to step S38;
s38, adding 1 to j;
s39, if J is less than or equal to J, returning to the step S17, otherwise, ending the capturing phase.
2. The method for rapidly acquiring navigation signals according to claim 1, wherein the step S5 is to down-convert the signal xiThe calculation formula of (2) is as follows:
xi＝s·exp[-j2π(fIF+fD-(i-1)Δf)n/fs] (1)
wherein f isIFFor the carrier frequency of the intermediate-frequency sampled signal with zero Doppler frequency offset, fDFor the estimated maximum Doppler shift for the intermediate frequency sampled signal,. DELTA.f for the estimated Doppler shift step for the intermediate frequency sampled signal,. fsIs the sampling rate of the intermediate frequency sampled signal with zero doppler frequency offset.
3. The method for rapidly acquiring navigation signals according to claim 1, wherein the step S6 is performed on the down-converted signal xiThe specific method for packaging comprises the following steps: down-converted signal xiEach in
Figure FDA0002971312500000033
Accumulating the sampling points into 1 point to obtain a sequence xpackiWherein f issIn the case of zero Doppler frequency offsetSampling rate of intermediate frequency sampled signal, fCAIs the code rate of the C/A code.
4. The method for rapidly acquiring navigation signals according to claim 1, wherein the calculation formula of the number I of doppler frequency offset estimation values in the step S9 is as follows:
Figure FDA0002971312500000034
wherein f isDAnd delta f is the estimated Doppler frequency shift stepping of the intermediate frequency sampling signal.
5. The method for rapidly capturing navigation signals according to claim 1, wherein the correlation result corr in the step S11i jThe calculation formula of (2) is as follows:
Figure FDA0002971312500000035
where abs [. cndot. ] is the modulo operation and ift (. cndot.) is the inverse fast Fourier transform.
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Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101464508A (en) * 2008-12-19 2009-06-24 苏州莱迪斯特电子有限公司 Method for capturing C/A code signal of GPS
CN101515820A (en) * 2008-02-22 2009-08-26 上海思谋微电子技术有限公司 Single-channel multi-satellite parallel search method of positioning receiver
CN101819278A (en) * 2010-03-25 2010-09-01 北京航空航天大学 Signal acquisition method of GPS receiver
JP2012256991A (en) * 2011-06-08 2012-12-27 Nec Aerospace Syst Ltd Symbol synchronization acquisition system and method therefor
CN103078660A (en) * 2013-01-06 2013-05-01 中国电子科技集团公司第十研究所 Method for reducing capturing time of spreading code in large dynamic range
CN103197328A (en) * 2013-03-14 2013-07-10 中国人民解放军国防科学技术大学 High dynamic satellite receiver fast capture method based on 2 ms data storage
JP5483750B2 (en) * 2009-11-30 2014-05-07 古野電気株式会社 Unnecessary signal discrimination device, unnecessary signal discrimination method, unnecessary signal discrimination program, GNSS receiver and mobile terminal
CN104101883A (en) * 2013-04-11 2014-10-15 中国科学院微电子研究所 Rapid acquisition method and device for global satellite navigation signals
CN105717522A (en) * 2016-02-23 2016-06-29 电子科技大学 Second-generation BeiDou B1 frequency band weak signal capturing method
CN106814375A (en) * 2017-01-24 2017-06-09 中国电子科技集团公司第五十四研究所 A kind of catching method and receiver of the deception of anti-rotation hairdo
CN107153206A (en) * 2016-10-13 2017-09-12 南京航空航天大学 A kind of Big Dipper satellite signal quick capturing method based on FFT

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN101515820A (en) * 2008-02-22 2009-08-26 上海思谋微电子技术有限公司 Single-channel multi-satellite parallel search method of positioning receiver
CN101464508A (en) * 2008-12-19 2009-06-24 苏州莱迪斯特电子有限公司 Method for capturing C/A code signal of GPS
JP5483750B2 (en) * 2009-11-30 2014-05-07 古野電気株式会社 Unnecessary signal discrimination device, unnecessary signal discrimination method, unnecessary signal discrimination program, GNSS receiver and mobile terminal
CN101819278A (en) * 2010-03-25 2010-09-01 北京航空航天大学 Signal acquisition method of GPS receiver
JP2012256991A (en) * 2011-06-08 2012-12-27 Nec Aerospace Syst Ltd Symbol synchronization acquisition system and method therefor
CN103078660A (en) * 2013-01-06 2013-05-01 中国电子科技集团公司第十研究所 Method for reducing capturing time of spreading code in large dynamic range
CN103197328A (en) * 2013-03-14 2013-07-10 中国人民解放军国防科学技术大学 High dynamic satellite receiver fast capture method based on 2 ms data storage
CN104101883A (en) * 2013-04-11 2014-10-15 中国科学院微电子研究所 Rapid acquisition method and device for global satellite navigation signals
CN105717522A (en) * 2016-02-23 2016-06-29 电子科技大学 Second-generation BeiDou B1 frequency band weak signal capturing method
CN107153206A (en) * 2016-10-13 2017-09-12 南京航空航天大学 A kind of Big Dipper satellite signal quick capturing method based on FFT
CN106814375A (en) * 2017-01-24 2017-06-09 中国电子科技集团公司第五十四研究所 A kind of catching method and receiver of the deception of anti-rotation hairdo

Non-Patent Citations (5)

* Cited by examiner, † Cited by third party
Title
A fast algorithm for long code direct acquisition;Haoxiang Liang等;《 2013 International Workshop on Microwave and Millimeter Wave Circuits and System Technology》;20140515;全文 *
A Fast Time Acquisition Method for PSK-2DSS Systems;LIN Jing-ran等;《2011 International Conference on Computational Problem-Solving (ICCP) 》;20111201;全文 *
GPS信号C/A码快速精密捕获技术研究;李新山等;《计算机应用研究》;20140430;第31卷(第4期);全文 *
Two dimension direct GPS signal acquisition based on unsymmetrical FFT;Hu Lu;《 2009 4th IEEE Conference on Industrial Electronics and Applications》;20090630;全文 *
一种基于FFT的高动态GPS信号快速捕获方法;刘晓莉等;《系统仿真学报》;20070531;第19卷(第10期);全文 *

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