Method, computer storage medium and terminal for implementing satellite signal acquisition

Abstract

The application discloses a method, a computer storage medium and a terminal for realizing satellite signal acquisition, comprising: generating a ladder code; reading acquisition data and the generated ladder code; and performing satellite signal acquisition by using the read acquisition data and the ladder code. In the signal acquisition stage, the disclosed embodiment increases the acquisition coherent integration time by using the generated ladder code, obtains higher integration gain, and improves the signal acquisition sensitivity of the receiver; the ladder code has better inter-pseudo code correlation performance, reduces the false alarm probability of the receiver in weak signal acquisition, and reduces the influence of inter-correlation interference on the receiver.

Description

Technical Field

[0001] This application relates to, but is not limited to, satellite navigation technology, including a method for acquiring satellite signals, a computer storage medium, and a terminal. Background Technology

[0002] With the development of navigation systems, the spread spectrum modulation of satellite navigation signals has begun to employ more complex pseudocodes. For example, in addition to the primary pseudocode, a secondary pseudocode is added, and a longer pseudocode is constructed through certain mechanisms. In related technologies, navigation receiver schemes search for and acquire signals at the primary pseudocode level when acquiring navigation signals. This limits the coherent integration time, affecting the receiver's ability to acquire weak signals and failing to meet the operational requirements of high-sensitivity navigation receivers. Consequently, the performance of traditional navigation receivers is significantly reduced in application scenarios such as under trees, on bridges, and in urban canyons. Simultaneously, cross-correlation interference between primary and secondary pseudocodes can affect the receiver's signal acquisition, leading to a probability of acquiring erroneous cross-correlation signals, thus impacting receiver performance. Furthermore, related technologies require message bit synchronization processing after successful satellite acquisition before subsequent processing such as high-sensitivity tracking and frame synchronization can be performed. However, high-sensitivity bit synchronization algorithms are often complex, time-consuming, have low tolerance for Doppler bias, and exhibit a certain error rate. These factors affect the receiver's positioning time, dynamic performance, and stability. Summary of the Invention

[0003] The following is an overview of the subject matter described in detail in this application. This overview is not intended to limit the scope of the claims.

[0004] This disclosure provides a method for satellite signal acquisition, a computer storage medium, and a terminal, which can improve the overall performance of the receiver.

[0005] This disclosure provides a method for satellite signal acquisition, including:

[0006] Generate ladder code;

[0007] Read the captured data and the generated ladder code;

[0008] Satellite signals are captured by reading the captured data and ladder code.

[0009] On the other hand, this disclosure also provides a computer storage medium storing a computer program that, when executed by a processor, implements the above-described method for acquiring satellite signals.

[0010] Furthermore, embodiments of this disclosure also provide a terminal, including: a memory and a processor, wherein the memory stores a computer program; wherein,

[0011] The processor is configured to execute computer programs in memory;

[0012] When the computer program is executed by the processor, it implements the method for satellite signal acquisition as described above.

[0013] In the signal acquisition stage, this embodiment increases the acquisition coherent integration time by generating a ladder code, thereby obtaining a higher integration gain and improving the signal acquisition sensitivity of the receiver. The ladder code has better pseudo-code cross-correlation performance, which reduces the false alarm probability of the receiver in weak signal acquisition and mitigates the impact of cross-correlation interference on the receiver.

[0014] Other features and advantages of this application will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the application. The objectives and other advantages of this application may be realized and obtained by means of the structures particularly pointed out in the description, claims and drawings. Attached Figure Description

[0015] The accompanying drawings are used to provide a further understanding of the technical solutions of this application and constitute a part of the specification. They are used together with the embodiments of this application to explain the technical solutions of this application and do not constitute a limitation on the technical solutions of this application.

[0016] Figure 1 This is a flowchart illustrating a method for satellite signal acquisition according to a disclosed embodiment;

[0017] Figure 2 This is a schematic diagram of a receiver according to an embodiment of the present disclosure;

[0018] Figure 3 This is a schematic diagram of the combination of ladder codes according to an embodiment of the present disclosure;

[0019] Figure 4 This is a schematic diagram illustrating the reading of captured data according to an embodiment of this disclosure;

[0020] Figure 5 This is a schematic diagram illustrating the reading of the ladder code according to an embodiment of this disclosure;

[0021] Figure 6 This is a schematic diagram of the satellite acquisition and processing flow according to an embodiment of the present disclosure;

[0022] Figure 7 This is a schematic diagram illustrating message bit synchronization in an embodiment of this disclosure. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be arbitrarily combined with each other.

[0024] The steps illustrated in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases the steps shown or described may be performed in a different order than that presented here.

[0025] Figure 1 This is a flowchart illustrating a method for satellite signal acquisition according to an embodiment of the present disclosure, such as... Figure 1 As shown, it includes:

[0026] Step 101: Generate ladder code;

[0027] Step 102: Read the captured data and the generated ladder code;

[0028] Step 103: Capture satellite signals by reading the captured data and ladder code.

[0029] In the signal acquisition stage, the generated ladder code increases the acquisition coherent integration time, resulting in higher integration gain and improved signal acquisition sensitivity of the receiver. The ladder code also has better cross-correlation performance, reducing the false alarm probability of the receiver in weak signal acquisition and mitigating the impact of cross-correlation interference on the receiver.

[0030] In one exemplary instance, satellites of global satellite navigation systems such as BeiDou Navigation Satellite System (BDS), Global Positioning System (GPS), and Galileo in the related technologies all broadcast satellite signals with modulated ladder codes, and embodiments of this disclosure can be applied to these satellite signals.

[0031] In one exemplary embodiment, the method of this disclosure further includes: caching the generated ladder code. In another exemplary embodiment, the above steps can be performed by a receiver as the executing entity, or the above processing can be performed by providing a device with the above functions on the receiver.

[0032] In one exemplary instance, embodiments of this disclosure generate ladder codes, including:

[0033] Generate the primary pseudocode and the secondary pseudocode;

[0034] The generated primary pseudocode and secondary pseudocode are merged to generate an echelon code.

[0035] In one exemplary instance, the ladder code generation process of this disclosure can be implemented with reference to related technologies; the ladder code generation process of this disclosure may include:

[0036] The master pseudocode generator produces a master pseudocode sequence for one cycle, consisting of N chips;

[0037] The secondary pseudocode generator produces a secondary pseudocode sequence for one period, consisting of M chips;

[0038] Each sub-code chip is XORed sequentially with N main pseudo-code chips of one cycle to generate a ladder code of M*N chips. In other words, the ladder code of one cycle is formed by combining the sub-pseudo-code chips of one cycle and the corresponding M main pseudo-code chips.

[0039] In one exemplary instance, before reading the captured data and the generated ladder code, the method of this disclosure embodiment further includes configuring the receiver with the following parameters:

[0040] The total number of sampling points required for capture, the number of parallel branches for phase detection, the number of phase detection rounds, and the length of the phase detection segment;

[0041] The phase detection segment length is equal to the pseudocode period of the ladder code, and the total number of phases searched is equal to the product of the following parameters: the number of parallel branches, the number of phase detection rounds, and the phase detection segment length.

[0042] It should be noted that the embodiments disclosed herein are based on the acquisition of signals using a ladder code, and the receiver operation is configured using the above parameters. For single pseudocodes with only a main pseudocode, the parameters can be configured by referring to relevant technologies.

[0043] In one exemplary instance, this disclosure embodiment reads captured data, including:

[0044] When reading the first round of captured data, starting from the first sample number, the number of samples required for a single phase detection is read sequentially to obtain the captured data of the first round of phase detection;

[0045] Starting from the second round, the initial number of samples for each round of phase detection is determined based on the number of parallel branches of phase detection. Based on the determined initial number of samples, the number of samples required for each single phase detection in each round is read sequentially to obtain the capture data corresponding to each round of phase detection.

[0046] It should be noted that the data acquisition process of this embodiment can be implemented with reference to related technologies. Compared with related technologies, since a ladder code is used for phase detection, the acquired data of each phase detection is different from that of related technologies, depending on the parameter configuration of the receiver. The data can be read according to the configured parameters.

[0047] In one exemplary instance, this disclosure embodiment reads the generated ladder code, including:

[0048] Based on the length of the phase detection segment, each segment of the ladder code is read separately.

[0049] It should be noted that the method for reading the ladder code in this embodiment can be implemented with reference to related technologies. Compared with related technologies, when using ladder codes for phase detection in this embodiment, the pseudocode of each phase detection read differs from that in related technologies, depending on the parameter configuration of the receiver. It can be read according to the configured parameters.

[0050] In one exemplary instance, this disclosure embodiment performs satellite signal acquisition by reading acquisition data and ladder code, including:

[0051] Determine the sampling time interval of the receiver;

[0052] Based on the sampling rate, main pseudocode rate, and satellite Doppler frequency of the captured data, the pseudocode phase change corresponding to the sampling time interval is calculated. The pseudocode phase change includes the number of pseudocode cycles and the number of pseudocode phases that change.

[0053] For the phase of the ladder code, the pseudo-code phase change corresponding to the compensation conversion time interval is calculated to obtain the satellite pseudo-code phase at the current moment, so as to realize satellite signal acquisition. The satellite pseudo-code phase includes the satellite's message bit position at the current moment and the satellite's main pseudo-code phase.

[0054] In one exemplary instance, after acquiring satellite signals by reading the captured data and ladder code, the method of this disclosure embodiment further includes:

[0055] Satellite signal message bits are synchronized by capturing the phase of the ladder code.

[0056] In one exemplary instance, embodiments of this disclosure perform message bit synchronization of satellite signals using the phase of the captured ladder code, including:

[0057] For the phase of the ladder code, compensate for the change in pseudocode phase corresponding to the sampling time interval to obtain the satellite pseudocode phase at the current moment;

[0058] Based on the obtained satellite pseudocode phase, the message bit edges of the satellite signal are locked to achieve message bit synchronization. This embodiment of the present disclosure, based on the sampling time interval of the intermediate frequency data, the phase of the captured ladder code, and the satellite Doppler frequency, locks the message bit edges and the current main pseudocode phase, thus quickly achieving satellite signal message bit synchronization.

[0059] The embodiments disclosed herein can completely strip away the primary and secondary pseudocodes modulated on the satellite signal during the acquisition phase. During the acquisition-to-tracking phase, the bit positions of the navigation message can be directly locked through phase and time conversion, without having to go through the complex message bit synchronization processing process that the receiver must complete in related technologies. This improves the speed of message bit synchronization, making the bit synchronization sensitivity comparable to the acquisition sensitivity, and improving the efficiency and sensitivity of weak signal message bit synchronization.

[0060] In one exemplary instance, embodiments of this disclosure determine a sampling time interval, including:

[0061] Determine the first sampling time T0 of the receiver intermediate frequency data corresponding to the initial number of samples in the capture data buffer, and the second sampling time T1 of the receiver intermediate frequency data corresponding to the current time of message bit synchronization;

[0062] Subtract the first sampling time T0 from the determined second sampling time T1 to obtain the sampling time interval.

[0063] This disclosure also provides a computer storage medium storing a computer program, which, when executed by a processor, implements the above-described method for acquiring satellite signals.

[0064] This disclosure also provides a terminal, including: a memory and a processor, wherein the memory stores a computer program; wherein,

[0065] The processor is configured to execute computer programs in memory;

[0066] When a computer program is executed by a processor, it implements the method described above for acquiring satellite signals.

[0067] The following application examples briefly illustrate the embodiments of this disclosure. These application examples are only used to illustrate the embodiments of this disclosure and are not intended to limit the scope of protection of this application.

[0068] The method described in this disclosure, based on the ladder code of navigation satellites, achieves high-sensitivity acquisition and fast bit synchronization. Figure 2 This is a schematic diagram of a receiver according to an embodiment of the present disclosure, as shown below. Figure 2 As shown, the receiver in this embodiment includes: a capture data buffer, a pseudo-code generator, a capture pseudo-code buffer, a capture data buffer read control module, a capture pseudo-code buffer read control module, a capture module, a capture-to-tracking message bit synchronization module, and a tracking module; wherein, the pseudo-code generator includes a main pseudo-code generator and a secondary pseudo-code generator;

[0069] The method described in this disclosure includes:

[0070] S1. The intermediate frequency data input to the receiver is preprocessed and stored as acquisition data in the acquisition data buffer for satellite signal acquisition;

[0071] S2. The pseudo-random code generator generates a pseudo-random code for the satellite to be captured and stores it in the capture pseudo-code buffer for satellite signal capture.

[0072] S3. The capture data cache reading control module reads the captured data; in an exemplary instance, this embodiment of the disclosure can read the captured data according to the search method of satellite signal pseudocode phase and Doppler frequency with reference to related technologies;

[0073] S4. The capture pseudocode buffer read control module reads the pseudocode of the captured satellite signal. Here, the pseudocode includes the main pseudocode or the ladder code. In an exemplary instance, this embodiment of the present disclosure can read the pseudocode according to the search method of satellite signal pseudocode phase and Doppler frequency with reference to related technologies.

[0074] S5. The acquired data and pseudocode are sent to the acquisition module for satellite pseudocode phase and Doppler frequency search.

[0075] In this embodiment of the present disclosure, the acquisition parameters can be configured by a preset application to the receiver. The acquisition parameters determine the buffer storage of the acquired data and pseudocode in steps S1 and S2, and determine the buffer reading of the acquired data and pseudocode in steps S3 and S4. The acquisition module outputs the acquisition result and sends it to the acquisition-to-tracking message bit synchronization module.

[0076] S6. After the capture-to-track message bit synchronization module obtains the satellite capture result, it allocates a tracking channel and configures information such as satellite tracking phase and Doppler frequency according to the capture result to guide the satellite signal and achieve precise synchronization of satellite phase and Doppler. The phase of the ladder code output by the capture includes the main pseudocode phase and the secondary pseudocode phase. The current message bit edge can be directly locked through phase and time conversion to achieve synchronization of satellite signal message bits. In an exemplary example, this embodiment of the present disclosure utilizes the relationship between the period of the secondary code (secondary pseudocode) in the ladder code and the message period, as well as the characteristic of their edge synchronization, to lock the current message bit edge.

[0077] S7. The message bit synchronization result is sent to the tracking module. In this embodiment of the present disclosure, the tracking module can adjust the tracking parameter configuration to achieve coherent integration of one message length, which is beneficial to improving the tracking sensitivity of the receiver.

[0078] In one exemplary instance, the preprocessing in step S1 of this embodiment may include: data format conversion, downconversion, downsampling, filtering, weighting, and serial-to-parallel conversion, etc. This embodiment records the first sampling time T0 corresponding to the first sampling point (initial number of samples);

[0079] In one exemplary instance, step S2 of this disclosure embodiment may include:

[0080] A primary pseudocode generator generates a primary pseudocode sequence, and a secondary pseudocode generator generates a secondary pseudocode sequence. The generated primary and secondary pseudocode sequences are merged according to a preset method to form a ladder code. In an exemplary embodiment, the merged ladder code can be converted from serial to parallel and then spliced ​​into a pseudocode block of a specified width, which is stored in a pseudocode buffer. The primary and secondary pseudocode generators in this embodiment can generate a pseudocode sequence at any frequency point of any system satellite. The pseudocode sequence includes GNSS satellite pseudocode types such as gold code, weil code, and memory code.

[0081] In one exemplary instance, the ladder code in this disclosure embodiment can be implemented with reference to related technologies. Figure 3 This is a schematic diagram of the combination of ladder codes according to an embodiment of the present disclosure, such as... Figure 3 As shown, the process of generating ladder codes may include:

[0082] The main pseudocode generator generates a main pseudocode sequence with a period of N, and the main pseudocode chips are numbered 0, 1, 2…N-1, for a total of N chips. The secondary pseudocode generator generates a secondary pseudocode sequence with a period of M, and the secondary pseudocode chips are numbered 0, 1, 2…M-1, for a total of M chips. In this embodiment, each secondary chip is XORed sequentially with the N main pseudocode chips of one period to generate a ladder code of M*N chips, forming a ladder code of one period. In this embodiment, M different initial phase ladder codes are generated according to the different initial chips of the secondary pseudocode sequence, and are sequentially recorded as Segment0…SegmentM-1, which can be referred to as ladder code segment 0, segment 1…M-1, respectively.

[0083] In one exemplary instance, step S3 of this disclosure embodiment may include:

[0084] Before capturing and buffering data, configure the receiver with the following parameters according to relevant technologies: the total number of sampling points required for capture, the number of parallel branches for phase detection, the number of phase detection rounds, the length of the phase detection segment, and the total number of phases to be searched is the number of parallel branches multiplied by the number of phase detection rounds, and then multiplied by the number of phase detection segments.

[0085] In one exemplary instance, for signal acquisition processing based on ladder codes, the acquisition data is read starting from the first sample number and sequentially output to the last sample number required for a single phase detection process, completing the acquisition data reading for the first round of phase detection. For each subsequent acquisition data reading, the initial sample number is determined based on the number of parallel branches in the phase detection, and the data is sequentially output to the last sample number required for each single processing round, periodically cyclically outputting the acquisition data for each round of phase detection. This embodiment of the disclosure completes one phase detection acquisition data reading based on the above processing; the above reading operation is repeated to complete the acquisition data reading for all phase detections. A schematic diagram of the acquisition data reading is shown below. Figure 4 As shown.

[0086] In this embodiment of the present disclosure, step S4 includes: when using ladder code for capture processing, reading each ladder code segment according to the phase detection segment length;

[0087] In this embodiment, the ladder code has M segments, namely Segment0, Segment1…SegmentM-1; the length of the phase detection segment in S3 is M. In S3, each round of phase detection data acquisition reading simultaneously reads a segment of ladder code. The reading of this segment of ladder code in each round of phase detection is a repeated reading starting from phase 0. For the next phase segment, the next segment of ladder code is read. After reading all M segments of ladder code, the reading of the capture pseudocode buffer ends. A schematic diagram of the capture buffer ladder code reading in this embodiment is shown below. Figure 5 As shown.

[0088] In one exemplary instance, the captured data and pseudocode output from the pseudocode buffer of this embodiment are sent to the algorithm module for capture processing; the processing of step S5 of this embodiment is described in detail below. Figure 6 The acquisition module includes: short coherent integration, Fast Fourier Transform (FFT), incoherent accumulation, peak sorting, and decision output. This embodiment implements a partially matched filter, which is an acquisition algorithm combined with Fast Fourier Transform. The short coherent integration, i.e., the partially matched filter, has a pre-configurable length. The total coherent integration time and the short coherent integration length together determine the number of Fast Fourier Transform (FFT) points. After searching all primary pseudocode phases, secondary pseudocode phases, and Doppler frequencies, all accumulated energy values ​​are sorted by size, and the required number of peaks (greater than 1) is output in descending order. Simultaneously, the phase and Doppler frequency of the corresponding ladder code for each peak are output. This information determines whether the satellite signal acquisition was successful. If the satellite signal acquisition was successful, the phase and Doppler frequency of the satellite ladder code are output. The phase of the satellite ladder code includes both the primary pseudocode phase and the secondary pseudocode phase.

[0089] In one exemplary embodiment, this disclosure sends information such as the phase and Doppler frequency of the successfully captured satellite ladder code, and the sampling time T0 corresponding to the first sampling point of the capture buffer data, to the capture-to-track and message bit synchronization module. The processing of step S6 in this disclosure embodiment can be found in [reference needed]. Figure 7 ,include:

[0090] The initial sampling number of the captured data buffer corresponds to the intermediate frequency (IF) data sampling time T0 of the receiver, and the current time corresponds to the IF data sampling time T1 of the receiver; the sampling time interval is determined to be T1-T0; based on the sampling rate, the main pseudo-code rate, and the satellite Doppler frequency, the pseudo-code phase change corresponding to T1-T0 can be calculated, which includes the number of changing pseudo-code cycles and the number of changing pseudo-code phases; the phase of the captured output ladder code is used to compensate for the pseudo-code phase change corresponding to T1-T0, and the satellite pseudo-code phase at the current time can be obtained, which includes the current satellite message bit position and the satellite's main pseudo-code phase, thus achieving synchronization of the satellite signal message bits; the current satellite pseudo-code phase and Doppler frequency are sent to the tracking module to achieve tracking of the navigation satellite signal;

[0091] The embodiments disclosed herein can utilize the sampling time interval to convert it into pseudo-code phase through a fixed relationship; the fixed relationship is the conversion between pseudo-code frequency, time and phase; a single pseudo-code cannot convert the message bit phase, and to achieve message bit synchronization, a separate synchronization algorithm is required, which will incur a large time overhead and there is a synchronization probability.

[0092] This embodiment utilizes a ladder code to acquire satellite signals and simultaneously lock the message bits onto the satellite. The specific principle is based on the relationship between the secondary pseudocode period and the message period in the ladder code, as well as the synchronization characteristics of the secondary code with the message edge. Therefore, it is not necessary to implement a complex message bit synchronization algorithm separately. This embodiment can directly achieve fast bit synchronization through step S6, with high synchronization probability and sensitivity.

[0093] The following comparative analysis of the embodiments of this disclosure is provided through experimental tests. Both Test 1 and Test 2 use a satellite navigation signal simulator as the satellite signal source, connected to a satellite navigation OEM board via an active power divider. In Test 1, OEM board 1 is used to implement the satellite signal acquisition method of this disclosure embodiment, while OEM board 2 is used to implement a satellite signal acquisition method in related technologies. In Test 2, OEM board 1 is used to implement the satellite signal acquisition method of this disclosure embodiment, while OEM board 2 is used to implement both the satellite signal acquisition method of this disclosure embodiment and the message bit synchronization method in related technologies. Both maintain consistency in hardware circuits such as radio frequency and analog-to-digital conversion, and in software methods such as signal tracking and positioning calculation, ensuring the rationality of the comparative experimental tests.

[0094] Experimental Test 1: The satellite navigation signal simulator outputs the I-branch signal of the BDS B1 frequency point, which, after passing through a low-noise amplifier and a power divider, is connected to the RF input ports of OEM board 1 and OEM board 2. The test system sends cold start test commands to each OEM board via serial port and collects the positioning results reported by each OEM board. If no positioning result is received from the OEM board within 300 seconds, the test is considered to have no result, and the cold start fails. Twenty cold start tests are performed for each signal power. After completion, the signal output power is adjusted, and the test is repeated to obtain test results under different signal power levels. The test results of this embodiment show that the extreme cold start capture sensitivity of OEM board 1 is -149dBmw, and the extreme cold start capture sensitivity of OEM board 2 is -137dBmw. It is evident that the capture sensitivity of the method in this embodiment is higher.

[0095] Experimental Test 2:

[0096] The satellite navigation signal simulator outputs the I-branch signal at the BDS B1 frequency with a signal power of -146dBmw. After passing through a low-noise amplifier and a power divider, it is connected to the RF input ports of OEM board 1 and OEM board 2. The test system sends cold start test commands to each OEM board via serial port, collects the positioning results reported by each OEM board, and collects the satellite acquisition results reported by each OEM board, including satellite Doppler information. The test is repeated 20 times. The test results show that OEM board 1 reported 20 sets of positioning results with satisfactory positioning accuracy, and the uploaded satellite acquisition results were complete and accurate. OEM board 2 only uploaded 8 sets of positioning results within 300 seconds, but uploaded 20 sets of satellite acquisition results. After confirming that the satellite acquisition results in the 12 tests with no positioning results were normal and the number of captured satellites was sufficient, the message bit synchronization of the satellite signal was not successfully completed, and the satellite tracking was unsuccessful, resulting in positioning failure. As can be seen, the embodiments of this disclosure can achieve message bit synchronization while capturing weak signals, thereby achieving signal tracking. However, the message bit synchronization sensitivity of related technologies is limited and cannot achieve message bit synchronization for weak signals.

[0097] It will be understood by those skilled in the art that all or some of the steps, systems, or apparatuses disclosed above, and their functional modules / units, can be implemented as software, firmware, hardware, or suitable combinations thereof. In hardware implementations, the division between functional modules / units mentioned above does not necessarily correspond to the division of physical components; for example, a physical component may have multiple functions, or a function or step may be performed collaboratively by several physical components. Some or all components may be implemented as software executed by a processor, such as a digital signal processor or microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit (ASIC). Such software may be distributed on a computer-readable medium, which may include computer storage media (or non-transitory media) and communication media (or transient media). As is known to those skilled in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storing information (such as computer-readable instructions, data structures, program modules, or other data). Computer storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technologies, CD-ROM, digital versatile disc (DVD) or other optical disc storage, magnetic cartridges, magnetic tape, disk storage or other magnetic storage devices, or any other medium that can be used to store desired information and can be accessed by a computer. Furthermore, it is well known to those skilled in the art that communication media typically contain computer-readable instructions, data structures, program modules, or other data in modulated data signals such as carrier waves or other transmission mechanisms, and may include any information delivery medium.

Claims

1. A method for acquiring satellite signals, comprising: Generate ladder code; Read the captured data and the generated ladder code; Satellite signals are captured by reading the captured data and ladder code; The satellite signal acquisition via the acquired data and ladder code includes: determining the sampling time interval of the receiver; calculating the pseudo-code phase change corresponding to the sampling time interval based on the sampling rate, main pseudo-code rate, and satellite Doppler frequency of the acquired data, wherein the pseudo-code phase change includes the number of changing pseudo-code cycles and the number of changing pseudo-code phases; compensating for the phase of the ladder code by calculating the pseudo-code phase change corresponding to the sampling time interval to obtain the satellite pseudo-code phase at the current moment, thereby achieving satellite signal acquisition, wherein the satellite pseudo-code phase includes the satellite's message bit position and the satellite's main pseudo-code phase at the current moment.

2. The method according to claim 1, characterized in that, The generation of the ladder code includes: Generate the primary pseudocode and the secondary pseudocode; The generated primary pseudocode and secondary pseudocode are merged to generate the ladder code.

3. The method according to claim 1, characterized in that, Before reading the captured data and the generated ladder code, the method further includes configuring the receiver with the following parameters: The total number of sampling points required for capture, the number of parallel branches for phase detection, the number of phase detection rounds, and the length of the phase detection segment; The length of the phase detection segment is equal to the period of the secondary pseudocode of the ladder code.

4. The method according to claim 1, characterized in that, The reading of captured data includes: When reading the captured data in the first round, starting from the first sample number, the number of samples required for a single phase detection is read sequentially to obtain the captured data of the first round of phase detection; For each round of data capture starting from the second round, the initial number of samples is determined based on the number of parallel branches of the phase detection. Based on the determined initial number of samples, the number of samples required for each single phase detection in each round is read sequentially to obtain the capture data corresponding to each round of phase detection.

5. The method according to claim 3, characterized in that, Read the generated ladder code, including: Each segment of the generated ladder code is read according to the length of the phase detection segment.

6. The method according to any one of claims 1 to 5, characterized in that, Determine the sampling time interval, including: Determine the first sampling time of the receiver intermediate frequency data corresponding to the initial sampling number of the captured data buffer, and the second sampling time of the receiver intermediate frequency data corresponding to the current time of satellite signal message bit synchronization; The sampling time interval is obtained by subtracting the first sampling time from the determined second sampling time.

7. The method according to any one of claims 1 to 5, characterized in that, After acquiring satellite signals by reading the captured data and ladder code, the method further includes: The satellite signal message bits are synchronized by capturing the phase of the ladder code.

8. The method according to claim 7, characterized in that, The step of synchronizing the satellite signal's message bits using the phase of the captured ladder code includes: For the phase of the ladder code, the pseudo-code phase change corresponding to the sampling time interval is compensated and calculated to obtain the satellite pseudo-code phase at the current moment; Based on the obtained satellite pseudocode phase, the message bit edges of the satellite signal are locked to achieve message bit synchronization.

9. A computer storage medium storing a computer program that, when executed by a processor, implements the method for acquiring satellite signals as described in any one of claims 1 to 8.

10. A terminal, comprising: A memory and a processor, wherein the memory stores a computer program; wherein, The processor is configured to execute computer programs in memory; When the computer program is executed by the processor, it implements the method for satellite signal acquisition as described in any one of claims 1 to 8.

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