Control method and system of GNSS signal capturing device under weak signal
By performing sampling point format conversion, signal type matching and integral result table sliding compensation in the GNSS signal capture device, the problem of insufficient signal-to-noise ratio under weak signals is solved, and the accuracy and efficiency of signal capture are improved.
Patent Information
- Application Number
- CN202510496742.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-21
- Publication Date
- 2025-07-04
AI Technical Summary
The existing GNSS signal capture engines are difficult to accumulate sufficient energy under weak signals, resulting in insufficient signal-to-noise ratio and affecting the signal capture effect.
Convert the sampling points into the required format inside the GNSS signal capture device, and match the signal type and satellite signal, generate local pseudo codes, perform sliding compensation and peak search of the integral result table, and improve the peak signal-to-noise ratio of the phase-frequency grid.
In a weak signal environment, the capture accuracy and efficiency of GNSS signals are improved, and the refined processing of signals is realized.
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Figure CN120254904A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the technical field of GNSS signal acquisition devices, and in particular, to a control method and system for a GNSS signal acquisition device under weak signals. Background Art
[0002] In recent years, with the development of GNSS, its high-precision and all-weather position services have gained a large user group. And the large user group has promoted the miniaturization and low cost of navigation devices. Thus, position services based on satellite navigation are easily accessible and inexpensive, and will surely be accepted by more users. In the civilian field, GNSS chips have become an indispensable part of automobiles, smart phones, smart watches, etc.; in the industrial field, GNSS chips play an important role in devices such as base stations and surveying instruments; in the military field, GNSS chips have become an important part of aviation, aerospace, and marine navigation devices. In the case where GNSS weak signal usage scenarios are widespread, existing GNSS signal acquisition engines are difficult to accumulate enough energy to provide sufficient signal-to-noise ratio for subsequent decisions, which affects the application scenarios of GNSS signal acquisition engines in weak signals. Summary of the Invention
[0003] The purpose of this application is to overcome the deficiencies of the prior art. This application provides a control method and system for a GNSS signal acquisition device under weak signals. Under weak signals, the sampling points are converted into the format required inside the GNSS signal acquisition device, and the sampling points are written into the first storage space. At this time, the first storage space stores multiple GNSS signals; define the signal types of the configuration signals, and generate the required local pseudo-code according to the signal types and the corresponding satellite numbers; match the GNSS signals of the sampling points with the local pseudo-code, and create an integration result table; before the integration result table, perform sliding compensation on the phase slips caused by code Doppler for each frequency bin; and trigger peak search based on the integration result table, define multiple peaks in the integration result table, and sort according to the multiple peaks to output to the second storage space. At this time, perform sliding compensation on the phase slips caused by code Doppler for each frequency bin, so as to complete the sliding compensation of the phase slips caused by code Doppler, thereby improving the peak signal-to-noise ratio of the phase-frequency bin based on the sliding compensation and coping with the application scenarios of weak signals, so as to achieve the refined processing of GNSS signals.
[0004] To solve the above technical problems, an embodiment of this application provides a control method for a GNSS signal acquisition device under weak signals, including:
[0005] S11: Under weak signals, convert the sampling points into the format required inside the GNSS signal acquisition device, and write the sampling points into the first storage space. At this time, multiple GNSS signals are stored in the first storage space;
[0006] S12: Define the signal type of the configuration signal, and generate the required local pseudo-code according to the signal type and the corresponding satellite number;
[0007] S13: Match the GNSS signal of the sampling point with the local pseudo-code, and create an integration result table; before the integration result table, perform sliding compensation on the phase slip caused by code Doppler for each frequency bin; and
[0008] S14: Trigger peak search based on the integration result table, define multiple peaks in the integration result table, and sort according to the multiple peaks to output to the second storage space;
[0009] Among them, step S13 includes:
[0010] Match the GNSS signal of the sampling point with the local pseudo-code, and output the corresponding matching value;
[0011] Trigger the corresponding coherent accumulation process based on the matching value, and output the coherent integration value;
[0012] Trigger FFT operation based on the coherent integration value, and output the FFT result. At this time, there is a phase-frequency correspondence relationship in the FFT result;
[0013] Trigger non-coherent accumulation according to the FFT result network, and output the non-coherent result; freeze the non-coherent accumulation of the FFT result network; before the non-coherent accumulation of the FFT result network, calculate the code phase slip at each search frequency for the current non-coherent accumulation, and define the phase slip caused by code Doppler for each frequency bin;
[0014] Trigger sliding compensation based on the phase slip caused by the code Doppler for each frequency bin to improve the peak signal-to-noise ratio of the phase-frequency bin; and
[0015] Create an integration result table according to the non-coherent result and the result table. In the integration result table, the horizontal direction of the integration result table represents the code phase, and the vertical direction of the integration result table represents the carrier Doppler;
[0016] The sliding compensation includes:
[0017] When the code phase slide of the current incoherent search frequency grid fre0 is Δ, the integral value of the ρ-th phase needs to be added to the phase value corresponding to fre0 in the incoherent accumulation result network by ρ + Δ to form a new incoherent result, and so on for all elements in the incoherent result network;
[0018] Among them, the calculation formula for the code phase slide amount is as follows:
[0019]
[0020] The variable definitions in the formula are as follows, where round represents rounding down: Δ(k) represents the code phase compensation amount required for the k-th incoherence; f d represents the code carrier Doppler; T coh represents the coherent integration time; f code represents the nominal chip rate; f RF represents the carrier frequency; m represents that one chip contains m sampling points.
[0021] Further, step S11 includes:
[0022] Under the weak signal, convert the sampling points into the format required inside the GNSS signal acquisition device;
[0023] Based on the sampling points, trigger the adjustment of the sampling point rate and reduce the sampling point rate to multiple times of the pseudo-code rate;
[0024] Collect the GNSS signals based on the sampling point rate and write the sampling points into the first storage space. At this time, the first storage space stores multiple GNSS signals;
[0025] Trigger data processing according to the GNSS signals and perform low-pass filtering on the sampling points to enhance out-of-band suppression and reduce band aliasing after downsampling.
[0026] Further, step S12 includes:
[0027] Collect the configuration signals corresponding to the acquired GNSS signals and define the corresponding signal types according to the configuration signals;
[0028] Associate the signal types with the corresponding satellite numbers; and
[0029] Generate the required local pseudo-code according to the signal types and the corresponding satellite numbers and store the local pseudo-code in the first storage space. The local pseudo-code includes Gold code, weil code, and storage code.
[0030] Further, step S14 includes:
[0031] Trigger peak search based on the integral result table; and
[0032] During peak search in the integral result table, define multiple peaks in the integral result table.
[0033] Further, step S14 further includes:
[0034] Sort according to the multiple peaks for output to the second storage space. At this time, sort the multiple peaks based on the strategy of heap sort, and improve the sorting efficiency of the multiple peaks.
[0035] In addition, the present application also provides a control system for a GNSS signal acquisition device under weak signals, characterized in that the control system for the GNSS signal acquisition device under weak signals adopts the control method for the GNSS signal acquisition device under weak signals as described above. The control system for the GNSS signal acquisition device under weak signals includes:
[0036] A first storage module, configured to convert sampling points into a format required inside the GNSS signal acquisition device under weak signals and write the sampling points into the first storage space. At this time, the first storage space stores multiple GNSS signals;
[0037] A pseudo-code generation module, configured to define the signal type of the configuration signal and generate the required local pseudo-code according to the signal type and the corresponding satellite number;
[0038] An integral result table module, configured to match the GNSS signal of the sampling points with the local pseudo-code and create an integral result table; before the integral result table, perform sliding compensation on the phase slip caused by code Doppler for each frequency bin; and
[0039] A second storage module, configured to trigger peak search based on the integral result table, define multiple peaks in the integral result table, and sort according to the multiple peaks for output to the second storage space.
[0040] In the embodiments of the present application, through the method in the embodiments of the present application, under weak signals, the sampling points are converted into the format required inside the GNSS signal acquisition device, and the sampling points are written into the first storage space. At this time, the first storage space stores multiple GNSS signals; the signal type of the configuration signal is defined, and the required local pseudo-code is generated according to the signal type and the corresponding satellite number; the GNSS signals of the sampling points are matched with the local pseudo-code, and an integration result table is created; before the integration result table, sliding compensation is performed on the phase slip caused by code Doppler based on each frequency bin; and peak search is triggered based on the integration result table, multiple peaks in the integration result table are defined, and the multiple peaks are sorted to be output to the second storage space. At this time, sliding compensation is performed on the phase slip caused by code Doppler based on each frequency bin, so as to complete the sliding compensation of the phase slip caused by code Doppler, thereby improving the peak signal-to-noise ratio of the phase-frequency bin based on the sliding compensation and coping with the application scenario of weak signals, so as to realize the refined processing of GNSS signals. BRIEF DESCRIPTION OF THE DRAWINGS
[0041] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the following-described drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.
[0042] Figure 1 It is a schematic flowchart of the control method of the GNSS signal acquisition device under weak signals in the embodiments of the present application;
[0043] Figure 2 It is a schematic flowchart of S11 in the control method of the GNSS signal acquisition device under weak signals in the embodiments of the present application;
[0044] Figure 3 It is a schematic flowchart of S12 in the control method of the GNSS signal acquisition device under weak signals in the embodiments of the present application;
[0045] Figure 4 It is a schematic flowchart of S13 in the control method of the GNSS signal acquisition device under weak signals in the embodiments of the present application;
[0046] Figure 5 It is a schematic flowchart of S14 in the control method of the GNSS signal acquisition device under weak signals in the embodiments of the present application;
[0047] Figure 6 It is a schematic diagram of code phase slip search in the control method of the GNSS signal acquisition device under weak signals in the embodiments of the present application;
[0048] Figure 7 It is a schematic structural diagram of the control system of the GNSS signal acquisition device under weak signals in the embodiments of the present application;
[0049] Figure 8 It is a hardware diagram of an electronic device shown according to an exemplary embodiment. Specific embodiments
[0050] Next, the technical solutions in the embodiments of the present application will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present application.
[0051] Method embodiments
[0052] Please refer to Figures 1 to 8 , a control method for a GNSS signal acquisition device under weak signals, which is applied to the control scenario of a GNSS signal acquisition device under weak signals; the control method for a GNSS signal acquisition device under weak signals includes:
[0053] Step S11: Under weak signals, convert the sampling points into the format required inside the GNSS signal acquisition device, and write the sampling points into the first storage space. At this time, the first storage space stores multiple GNSS signals;
[0054] Step S12: Define the signal type of the configuration signal, and generate the required local pseudo-code according to the signal type and the corresponding satellite number;
[0055] Step S13: Match the GNSS signals of the sampling points with the local pseudo-code, and create an integration result table; before the integration result table, perform sliding compensation on the phase slip caused by code Doppler for each frequency bin;
[0056] Step S14: Trigger peak search based on the integration result table, define multiple peaks in the integration result table, and sort according to the multiple peaks to output to the second storage space.
[0057] In an embodiment of the present application, by means of the method in the embodiment of the present application, under weak signals, the sampling points are converted into the format required inside the GNSS signal acquisition device, and the sampling points are written into the first storage space. At this time, multiple GNSS signals are stored in the first storage space; the signal type of the configuration signal is defined, and the required local pseudo-code is generated according to the signal type and the corresponding satellite number; the GNSS signals of the sampling points are matched with the local pseudo-code, and an integration result table is created; before the integration result table, sliding compensation is performed on the phase slip caused by code Doppler for each frequency bin; and peak search is triggered based on the integration result table, multiple peaks in the integration result table are defined, and the multiple peaks are sorted according to the multiple peaks and output to the second storage space. At this time, sliding compensation is performed on the phase slip caused by code Doppler for each frequency bin, so as to complete the sliding compensation of the phase slip caused by code Doppler, thereby improving the peak signal-to-noise ratio of the phase-frequency bin based on the sliding compensation and coping with the application scenario of weak signals, so as to realize the refined processing of GNSS signals.
[0058] In step S11, under weak signals, the sampling points are converted into the format required inside the GNSS signal acquisition device, and the sampling points are written into the first storage space. At this time, multiple GNSS signals are stored in the first storage space;
[0059] In the specific implementation process of the present application, the specific steps may be:
[0060] S111: Under the weak signals, convert the sampling points into the format required inside the GNSS signal acquisition device;
[0061] S112: Trigger the sampling point rate adjustment based on the sampling points, and reduce the sampling point rate to multiple times of the pseudo-code rate;
[0062] S113: Collect the GNSS signals based on the sampling point rate, and write the sampling points into the first storage space. At this time, multiple GNSS signals are stored in the first storage space;
[0063] S114: Trigger data processing according to the GNSS signals, and perform low-pass filtering on the sampling points to enhance out-of-band suppression and reduce band aliasing after downsampling.
[0064] In an embodiment of the present application, under the weak signals, the sampling points are converted into the format required inside the GNSS signal acquisition device, and the format is controlled, so as to trigger the sampling point rate adjustment based on the sampling points, and reduce the sampling point rate to multiple times of the pseudo-code rate. Optionally, the sampling point rate is reduced to twice the pseudo-code rate, that is, two sampling points per chip.
[0065] At this time, the GNSS signal is collected based on the sampling point rate, and the sampling points are written into the first storage space. At this time, multiple GNSS signals are stored in the first storage space; data processing is triggered according to the GNSS signal, and the sampling points are low-pass filtered to enhance out-of-band suppression and reduce band aliasing after downsampling. Therefore, the sampling points are low-pass filtered to enhance out-of-band suppression and reduce band aliasing after downsampling.
[0066] In step S12, the signal type of the configuration signal is defined, and the required local pseudo-code is generated according to the signal type and the corresponding satellite number;
[0067] In the specific implementation process of this application, the specific steps may be:
[0068] S121: Collect the configuration signal corresponding to the GNSS signal, and define the corresponding signal type according to the configuration signal;
[0069] S122: Associate the signal type and the corresponding satellite number; and
[0070] S123: Generate the required local pseudo-code according to the signal type and the corresponding satellite number, and store the local pseudo-code in the first storage space. The local pseudo-code includes Gold code, Weil code, and storage code.
[0071] In the embodiment of this application, the configuration signal corresponding to the collected GNSS signal is collected, and the corresponding signal type is defined according to the configuration signal, so as to facilitate associating the signal type and the corresponding satellite number, thereby generating the required local pseudo-code according to the signal type and the corresponding satellite number, and storing the local pseudo-code in the first storage space for subsequent related operations. Optionally, the local pseudo-code includes Gold code, Weil code, and storage code.
[0072] In step S13, the GNSS signal of the sampling point is matched with the local pseudo-code, and an integration result table is created; before the integration result table, sliding compensation is performed on the phase slip caused by code Doppler for each frequency bin;
[0073] In the specific implementation process of this application, the specific steps may be:
[0074] S131: Match the GNSS signal of the sampling point with the local pseudo-code, and output the corresponding matching value; trigger the corresponding coherent accumulation process based on the matching value, and output the coherent integration value;
[0075] S132: Trigger FFT operation based on the coherent integration value, and output the FFT result. At this time, there is a phase-frequency correspondence relationship in the FFT result;
[0076] S133: Trigger non-coherent accumulation according to the FFT result network and output the non-coherent result; and
[0077] S134: Create an integral result table according to the non-coherent result and the result table. In the integral result table, the horizontal direction of the integral result table represents the code phase, and the vertical direction of the integral result table represents the carrier Doppler; before the integral result table, freeze the non-coherent accumulation of the FFT result network; before the non-coherent accumulation of the FFT result network, calculate the code phase sliding at each search frequency of the current non-coherent, and define the phase sliding caused by each frequency bin on the code Doppler; trigger sliding compensation based on the phase sliding caused by each frequency bin on the code Doppler to improve the peak signal-to-noise ratio of the phase-frequency bin.
[0078] In an embodiment of the present application, match the GNSS signal of the sampling point with the local pseudo-code and output the corresponding matching value; trigger the corresponding coherent accumulation process based on the matching value and output the coherent integration value, so as to trigger the coherent accumulation process, thereby define the coherent integration value, and then trigger the FFT operation based on the coherent integration value and output the FFT result. At this time, there is a corresponding relationship between the phase and frequency of the FFT result.
[0079] At this time, trigger non-coherent accumulation according to the FFT result network and output the non-coherent result. Create an integral result table according to the non-coherent result and the result table. In the integral result table, the horizontal direction of the integral result table represents the code phase, and the vertical direction of the integral result table represents the carrier Doppler; before the integral result table, freeze the non-coherent accumulation of the FFT result network; before the non-coherent accumulation of the FFT result network, calculate the code phase sliding at each search frequency of the current non-coherent, and define the phase sliding caused by each frequency bin on the code Doppler; trigger sliding compensation based on the phase sliding caused by each frequency bin on the code Doppler to improve the peak signal-to-noise ratio of the phase-frequency bin.
[0080] Specifically, the matching of the GNSS signal of the sampling point with the local pseudo-code and the creation of the integral result table; before the integral result table, perform sliding compensation based on the phase sliding caused by each frequency bin on the code Doppler, and further include:
[0081] If the code phase sliding of the current non-coherent search frequency bin fre0 is the amount Δ, then the integral value of the ρ-th phase needs to be added to the phase value corresponding to fre0 in the non-coherent accumulation result network by ρ + Δ to form a new non-coherent result, and so on for all elements in the non-coherent result network;
[0082] Among them, the calculation formula of the code phase sliding amount is as follows:
[0083]
[0084] In the formula, the variable definitions are as follows, where round represents rounding down: Δ(k) represents the code phase compensation amount required for the k-th non-coherence; f d represents the code carrier Doppler; T coh represents the coherent integration time; f code represents the nominal chip rate; f RF represents the carrier frequency; m represents that one chip contains m sampling points.
[0085] S14: Trigger peak search based on the integral result table, define multiple peaks in the integral result table, and sort according to the multiple peaks to output to the second storage space;
[0086] In the specific implementation process of this application, the specific steps can be:
[0087] S141: Trigger peak search based on the integral result table;
[0088] S142: In the peak search of the integral result table, define multiple peaks in the integral result table; and
[0089] S143: Sort according to the multiple peaks to output to the second storage space. At this time, sort the multiple peaks based on the heap sort strategy, and improve the sorting efficiency of the multiple peaks.
[0090] In the embodiment of this application, trigger peak search based on the integral result table, and define the corresponding peaks in the peak search. At this time, in the peak search of the integral result table, define multiple peaks in the integral result table; sort according to the multiple peaks to output to the second storage space. At this time, sort the multiple peaks based on the heap sort strategy, and improve the sorting efficiency of the multiple peaks.
[0091] In the specific embodiment of this application, the specific implementation process of the GNSS signal acquisition device under weak signals is as follows:
[0092] Step 1: The GNSS signal sampling points enter the data preprocessing module, and the data preprocessing module performs low-pass filtering and downsampling on them to twice the chip rate;
[0093] Step 2: The pseudo-code generation module generates the required pseudo-random code according to the signal type and satellite number;
[0094] Step 3: Divide the search space S1, S2, S3,..., S64 in units of 512 code phases * 64 Doppler frequencies;
[0095] Step 4: The integration operation module performs correlation, coherent accumulation, FFT, code phase sliding compensation, and non-coherent accumulation operations based on the sampling points and the pseudo-code, and outputs the operation results to the result table (physically, it is memory). The horizontal direction of the table represents the code phase, and the vertical direction represents the carrier Doppler;
[0096] Step 5: The peak extraction module compares the data in the integration result table with the 48 peaks stored in itself, and comprehensively selects 48 peaks.
[0097] Step 6: After the search in Step 5 ends, the peak sorting and classification module sorts the 48 peaks obtained in Step 5 from largest to smallest.
[0098] The key technology of the GNSS signal acquisition device proposed in this application under weak signal environment is the code phase sliding compensation strategy. The code phase sliding compensation strategy is as follows:
[0099] Compared with communication signals, the pseudo-code of GNSS signals is longer, and more code phases need to be searched. If all code phases are to be searched at one time, a large amount of correlator resources are required, which is obviously too costly for commercial receivers. Therefore, the signal space to be searched needs to be segmented. The hardware resources of this strategy can search a space of up to 512 phases * 64 frequencies at one time, and this resource will be reused during the signal acquisition process.
[0100] The detailed steps of this strategy are as follows:
[0101] Step 1: Define the process of the acquisition engine processing a search space as a code_round, that is, S1 corresponds to code_round1, S2 corresponds to code_round2, and so on.
[0102] Step 2: A code_round contains 64 frequency bins, fre0, fre1, fre2, …, fre 63 , at the k-th non-coherent time, calculate the phase compensation amounts Δ(k)0, Δ(k)1, Δ(k)2, Δ(k)3, …, Δ(k) 63 .
[0103] Step 3: Taking k = 2 and Δ(k)0 = 2 as an example, in code_round1, NCS1 represents the first non-coherent accumulation. When NCS2 is executed, since the code phase sliding amount is 2, the integral value of the 0 phase in NCS2 needs to be accumulated with the integral value of the 2 phase in NCS1, and the accumulated result is stored in the cache at the NCS position of 2. The same applies to other phases.
[0104] Step 4: Due to the sliding addition, phases 0 and 1 do not perform the accumulation operation at NCS2, and the number of non-coherent times is one less than that of other phases. When making the signal decision finally, if the signal behavior is in phases 0 to 1, it is very likely to cause missed alarms. To compensate for the above influence, in each NCS process of this strategy, a value α is compensated for the missing phase. Taking NCS2 as an example, this value is the mean value of the integral values of all phases in NCS2.
[0105] Step 5: The first two phases of code_round1 have one less non-coherent accumulation at NCS2 compared to other phases, and the same phenomenon also exists in code_round2. To solve the above problems in code_round2, in this strategy, the code phase search range of code_round1 is 0 to 511, and the search range of code_round2 is 510 to 1021, and there are Δ(k)0 overlapping phases between the two code_rounds. Thus, phases 510 to 511 in code_round2 have one less non-coherent accumulation, but the non-coherent accumulation times of phases 510 to 511 in code_round1 are sufficient. The above strategy solves the problem of insufficient non-coherent times of the first Δ(k)0 phases in each code_round during the code phase sliding compensation process. When dealing with the problems in this step by the existing phase compensation methods, first, the maximum compensation amount a needs to be estimated. Secondly, a storage units are added to both the head and the tail based on the phase storage space of each frequency grid in a code_round, that is, (a + 512 + a) storage units. Since a is fixed, when the compensation amount is greater than a, this method cannot be adjusted and its flexibility is limited.
[0106] Step 6: The subsequent code_round3, code_round4... repeat Step 5.
[0107] Steps 3 - 6 are for the scenario where the phase compensation amount is positive. When the compensation amount is negative, taking k = 2, Δ(k)0 = -2 as an example, the operation process and principle are basically the same,
[0108] The differences are as follows: A. The missing compensation value in Step 4 needs to be accumulated to the last two phases of the last code_round;
[0109] B. The value of phase 2 in NCS2 needs to be accumulated to phase 0 in NCS1, and so on.
[0110] In the embodiments of the present application, through the method in the embodiments of the present application, under weak signals, the sampling points are converted into the format required inside the GNSS signal acquisition device, and the sampling points are written into the first storage space. At this time, multiple GNSS signals are stored in the first storage space; the signal type of the configuration signal is defined, and the required local pseudo-code is generated according to the signal type and the corresponding satellite number; the GNSS signals of the sampling points are matched with the local pseudo-code, and an integration result table is created; before the integration result table, sliding compensation is performed on the phase slips caused by code Doppler based on each frequency bin; and peak search is triggered based on the integration result table, multiple peaks in the integration result table are defined, and the multiple peaks are sorted and output to the second storage space. At this time, sliding compensation is performed on the phase slips caused by code Doppler based on each frequency bin, so as to complete the sliding compensation of the phase slips caused by code Doppler, thereby improving the peak signal-to-noise ratio of the phase-frequency bin based on the sliding compensation, coping with the application scenario of weak signals, and facilitating the refined processing of GNSS signals.
[0111] System embodiment
[0112] Please refer to Figure 7 , Figure 7 which is a schematic structural diagram of the control system of the GNSS signal acquisition device under weak signals in the embodiments of the present application.
[0113] As Figure 7 shown, a control system of a GNSS signal acquisition device under weak signals, the control system of the GNSS signal acquisition device under weak signals includes:
[0114] A first storage module 21, configured to convert sampling points into the format required inside the GNSS signal acquisition device under weak signals, and write the sampling points into the first storage space. At this time, multiple GNSS signals are stored in the first storage space;
[0115] A pseudo-code generation module 22, configured to define the signal type of the configuration signal, and generate the required local pseudo-code according to the signal type and the corresponding satellite number;
[0116] An integration result table module 23, configured to match the GNSS signals of the sampling points with the local pseudo-code, and create an integration result table; before the integration result table, perform sliding compensation on the phase slips caused by code Doppler based on each frequency bin;
[0117] A second storage module 24, configured to trigger peak search based on the integration result table, define multiple peaks in the integration result table, and sort the multiple peaks and output them to the second storage space.
[0118] Embodiment
[0119] Please refer to Figure 8 , and the following will describe the electronic device 40 according to this embodiment of the present application with reference to Figure 8 . The electronic device 40 shown is merely an example and should not impose any limitations on the functions and scope of use of the embodiments of the present application. Figure 8 The electronic device 40 shown is merely an example and should not impose any limitations on the functions and scope of use of the embodiments of the present application.
[0120] As Figure 8 shown, the electronic device 40 is presented in the form of a general-purpose computing device. The components of the electronic device 40 may include, but are not limited to: at least one of the above-mentioned processing units 41, at least one of the above-mentioned storage units 42, and a bus 43 connecting different system components (including the storage unit 42 and the processing unit 41).
[0121] Among them, the storage unit stores program code, and the program code can be executed by the processing unit 41, so that the processing unit 41 executes the steps according to various exemplary embodiments of the present application described in the "Embodiment Method" section of the present specification above.
[0122] The storage unit 42 may include a readable medium in the form of a volatile storage unit, such as a random access storage unit (RAM) 421 and / or a cache storage unit 422, and may further include a read-only storage unit (ROM) 423.
[0123] The storage unit 42 may also include a program / utilities 424 having a set (at least one) of program modules 425. Such program modules 425 include, but are not limited to: an operating system, one or more application programs, other program modules, and program data. The implementation of a network environment may be included in each or some combination of these examples.
[0124] The bus 43 may represent one or more of several types of bus structures, including a storage unit bus or a storage unit controller, a peripheral bus, a graphics acceleration port, a processing unit, or a local bus using any of the various bus structures.
[0125] The electronic device 40 may also communicate with one or more external devices (such as a keyboard, a pointing device, a Bluetooth device, etc.), and may also communicate with one or more devices that enable a training person to interact with the electronic device 40, and / or communicate with any device that enables the electronic device 40 to communicate with one or more other computing devices (such as a router, a modem, etc.). Such communication may be performed through an input / output (I / O) interface 44. And, the electronic device 40 may also communicate with one or more networks (such as a local area network (LAN), a wide area network (WAN), and / or a public network, such as the Internet) through a network adapter 45. As Figure 8As shown, network adapter 45 communicates with other modules of electronic device 40 via bus 43. It should be understood that although Figure 8 not shown in Figure 8 , other hardware and / or software modules may be used in conjunction with electronic device 40, including but not limited to: microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, tape drives, and data backup planning systems, etc.
[0126] Through the description of the above embodiments, those skilled in the art can easily understand that the exemplary embodiments described herein can be implemented by software or by a combination of software and necessary hardware. Therefore, the technical solutions according to the embodiments of the present disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (which can be a CD-ROM, USB flash drive, mobile hard disk, etc.) or on a network, including several instructions to enable a computing device (which can be a personal computer, server, terminal device, or network device, etc.) to execute the method according to the embodiments of the present disclosure.
[0127] Those of ordinary skill in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing relevant hardware through a program, and the program can be stored in a computer-readable storage medium. The storage medium may include: read-only memory (ROM, Read Only Memory), random access memory (RAM, RandomAccess Memory), magnetic disk or optical disk, etc. And it stores computer program instructions, and when the computer program instructions are executed by a computer, the computer executes the method according to the above.
[0128] In addition, the control method and system of the GNSS signal acquisition device under weak signals provided by the embodiments of the present application have been introduced in detail above. Specific examples have been used in this article to elaborate on the principle and implementation manner of the present application. The description of the above embodiments is only used to help understand the method and its core idea of the present application; at the same time, for those of ordinary skill in the art, according to the idea of the present application, there will be changes in the specific implementation manner and application scope. In summary, the content of this specification should not be construed as a limitation to the present application.
Claims
1. A control method for a GNSS signal acquisition device under weak signals, characterized in that, Including: S11: Under weak signals, convert the sampling points into the format required inside the GNSS signal acquisition device, and write the sampling points into the first storage space. At this time, the first storage space stores multiple GNSS signals; S12: Define the signal type of the configuration signal, and generate the required local pseudo-code according to the signal type and the corresponding satellite number; S13: Match the GNSS signal of the sampling point with the local pseudo-code, and create an integration result table; Before the integration result table, perform sliding compensation on the phase slip caused by code Doppler based on each frequency bin; And S14: Trigger peak search based on the integration result table, define multiple peaks in the integration result table, and sort according to the multiple peaks to output to the second storage space; Among them, step S13 includes: Match the GNSS signal of the sampling point with the local pseudo-code, and output the corresponding matching value; Trigger the corresponding coherent accumulation process based on the matching value, and output the coherent integration value; Trigger FFT operation based on the coherent integration value, and output the FFT result. At this time, there is a corresponding relationship between phase and frequency in the FFT result; Trigger non-coherent accumulation according to the FFT result network, and output the non-coherent result; freeze the non-coherent accumulation of the FFT result network; before the non-coherent accumulation of the FFT result network, calculate the code phase slip at each non-coherent search frequency for the current time, and define the phase slip caused by code Doppler for each frequency bin; Trigger sliding compensation based on the phase slip caused by the code Doppler for each frequency bin to improve the peak signal-to-noise ratio of the phase-frequency bin; and Create an integration result table according to the non-coherent result and the result table. In the integration result table, the horizontal direction of the integration result table represents the code phase, and the vertical direction of the integration result table represents the carrier Doppler; The sliding compensation includes: If the code phase slip of the current non-coherent search frequency bin fre0 is the amount Δ, then the integration value of the ρ-th phase needs to be added to the phase value corresponding to fre0 in the non-coherent accumulation result network by ρ + Δ to form a new non-coherent result, and so on for all elements in the non-coherent result network; Among them, the calculation formula of the code phase slip amount is as follows: The variables in the formula are defined as follows, where round represents rounding down: Δ(k) represents the code phase compensation amount required for the k-th non-coherence; f d represents the code carrier Doppler; T coh represents the coherent integration time; f code represents the nominal chip rate; f RF represents the carrier frequency; m represents that one chip contains m sampling points.
2. The control method of the GNSS signal acquisition device under weak signals according to claim 1, wherein Step S11 includes: Under the weak signal, convert the sampling point into the format required inside the GNSS signal acquisition device; Trigger sampling point rate adjustment based on the sampling point, and reduce the sampling point rate to multiple times of the pseudo-code rate; Collect the GNSS signal based on the sampling point rate, and write the sampling point into the first storage space. At this time, the first storage space stores multiple GNSS signals; Trigger data processing according to the GNSS signal, and perform low-pass filtering on the sampling point to enhance out-of-band suppression and reduce band aliasing after downsampling.
3. The control method of the GNSS signal acquisition device under weak signals according to claim 1, characterized in that Step S12 includes: Collect the configuration signal corresponding to the acquired GNSS signal, and define the corresponding signal type according to the configuration signal; Associate the signal type and the corresponding satellite number; and Generate the required local pseudo-code according to the signal type and the corresponding satellite number, and store the local pseudo-code in the first storage space. The local pseudo-code includes Gold code, Weil code, and storage code.
4. The control method of the GNSS signal acquisition device under weak signals according to claim 1, characterized in that, Step S14 includes: Trigger peak search based on the integral result table; and Define multiple peaks in the integral result table during the peak search of the integral result table.
5. The control method of the GNSS signal acquisition device under weak signals according to claim 4, characterized in that, Step S14 further includes: Sort according to multiple peaks and output to the second storage space. At this time, based on the strategy of heap sort, sort multiple peaks and improve the sorting efficiency of multiple peaks.
6. A control system for a GNSS signal acquisition device under weak signals, characterized in that, The control system of the GNSS signal acquisition device under weak signals adopts the control method of the GNSS signal acquisition device under weak signals as described in any one of claims 1-5. The control system of the GNSS signal acquisition device under weak signals includes: A first storage module, configured to convert sampling points into the format required inside the GNSS signal acquisition device under weak signals and write the sampling points into the first storage space. At this time, the first storage space stores multiple GNSS signals; A pseudo-code generation module, configured to define the signal type of the configuration signal and generate the required local pseudo-code according to the signal type and the corresponding satellite number; An integral result table module, configured to match the GNSS signal of the sampling point with the local pseudo-code and create an integral result table; before the integral result table, perform sliding compensation on the phase slip caused by code Doppler for each frequency bin; and A second storage module, configured to trigger peak search based on the integral result table, define multiple peaks in the integral result table, and sort according to multiple peaks and output to the second storage space.