A code tracking method and system for joint multi-frequency signals

Abstract

This application belongs to the field of signal processing technology for global satellite navigation systems, and more specifically, relates to a code tracking method and system for joint multi-frequency signals. By performing filtering, amplification, coherent integration, and code discrimination operations on the received signals at multiple frequency points, the digital intermediate frequency (IF) signals corresponding to each received signal and their code delay error estimates can be accurately obtained. By using the variance of the target estimation error values ​​of each obtained IF signal, the target weight of each code delay error estimate is determined. Then, based on each target weight, the code delay error estimates can be weighted and fused to obtain more accurate common-mode code phase output and differential-mode code phase output. This allows for the accurate acquisition of the target code rate correction amount for the inter-frequency deviation corresponding to each received signal, and dynamic correction of each inter-frequency deviation, thereby effectively improving the code tracking accuracy of joint multi-frequency signals.

Description

Technical Field

[0001] This application belongs to the field of signal processing technology for global satellite navigation systems, and more specifically, relates to a code tracking method and system for joint multi-frequency signals. Background Technology

[0002] Code tracking refers to the core technology process by which a receiver, after acquiring a satellite pseudocode signal, uses a closed-loop control mechanism to adjust the phase and rate of its local pseudocode in real time, ensuring precise synchronization with the received satellite pseudocode, thereby continuously and stably extracting pseudocode delay information. To improve the robustness of global navigation satellite systems in complex environments such as signal obstruction, channel fading, and multipath interference, numerous multi-frequency signal joint processing methods have emerged. Compared to traditional single-frequency independent tracking methods, these multi-frequency joint tracking methods can leverage the complementarity of different frequency signals in terms of signal-to-noise ratio, anti-interference capability, and propagation path to achieve performance enhancement.

[0003] While existing code tracking methods using multi-frequency signals can perform collaborative discrimination and filtering on multi-frequency signals to achieve short-time joint tracking between adjacent frequency signals, their inter-frequency deviation compensation relies on pre-measured inter-frequency delay data in open environments. This makes it difficult to dynamically estimate and compensate for inter-frequency deviations, and thus may not meet the code tracking accuracy requirements of multi-frequency signals in complex environments. Summary of the Invention

[0004] In view of the above-mentioned defects in the existing technology, this application provides a code tracking method and system for joint multi-frequency signals, aiming to solve the problem of low code tracking accuracy of existing multi-frequency signal code tracking methods in complex environments.

[0005] In a first aspect, this application provides a code tracking method for joint multi-frequency signals, comprising: S1. Filter and amplify the received signals at multiple different frequency points to obtain the digital intermediate frequency signal corresponding to each received signal; S2. Based on the local pseudocode corresponding to each digital intermediate frequency signal, perform coherent integration processing on the digital intermediate frequency signal to obtain the target integration result corresponding to the digital intermediate frequency signal. S3. Based on the integration results of each target, obtain the code delay error estimate corresponding to the digital intermediate frequency signal; S4. Based on the estimated delay error values ​​of each code, obtain the common-mode code phase output between each digital intermediate frequency signal and the differential-mode code phase output corresponding to each digital intermediate frequency signal; S5. Based on the common-mode code phase output and the differential-mode code phase output, obtain the target code rate correction amount corresponding to each digital intermediate frequency signal, and correct the local pseudo-code corresponding to the digital intermediate frequency signal based on the target code rate correction amount.

[0006] Furthermore, the received signals at multiple different frequencies are filtered and amplified to obtain the digital intermediate frequency (IF) signal corresponding to each received signal, including: The acquired received signal is subjected to bandpass filtering and low-noise amplification to obtain the initial radio frequency signal; Based on the sinusoidal local oscillator signal corresponding to the received signal, the initial radio frequency signal is mixed, down-frequency, filtered, amplified, and converted from analog to digital to obtain the digital intermediate frequency signal.

[0007] Bandpass filtering of the received signal can effectively remove interference noise caused by the environment, while low-noise amplification can improve the signal-to-noise ratio of the received signal with lower noise, so that it can be effectively received by other devices and avoid the received signal being overwhelmed by noise signals in subsequent processing.

[0008] Furthermore, based on the local pseudocode corresponding to each digital intermediate frequency (IF) signal, coherent integration processing is performed on the digital IF signals to obtain the target integration result corresponding to the digital IF signals, including: The intermediate frequency carrier and Doppler frequency shift of the digital intermediate frequency signal are stripped to obtain the target baseband signal; The target baseband signal is multiplied by each code delay branch of the local pseudocode corresponding to the digital intermediate frequency signal and coherently integrated to obtain the target integration result, which includes the same-direction components and quadrature components corresponding to the early code delay branch and the late code delay branch.

[0009] Furthermore, based on the integration results of each target, the process of obtaining the code delay error estimate corresponding to the digital intermediate frequency signal is as follows:

[0010] in, Indicates the first i Estimated code delay error of a digital intermediate frequency signal. and They represent the first i The in-direction and quadrature components of the early code delay branch of a digital intermediate frequency signal and They represent the first i The same-direction and quadrature components of the late code delay branch of a digital intermediate frequency signal.

[0011] The early code delay branch slightly precedes the received signal to determine if the local pseudocode is lagging; the late code delay branch slightly lags the received signal to determine if the local pseudocode is ahead. By obtaining the code delay error estimate through the in-direction and quadrature components corresponding to the early and late code delay branches, the real-time performance of the code delay error estimate corresponding to the acquired digital intermediate frequency signal can be effectively improved.

[0012] Furthermore, based on the estimated delay error values ​​of each code, the common-mode code phase output between each digital intermediate frequency signal and the differential-mode code phase output corresponding to each digital intermediate frequency signal are obtained, including: Obtain the variance of the target estimation error value for each code delay error estimate, and obtain the target weight corresponding to each digital intermediate frequency signal based on each variance; Based on the target weights and the corresponding code delay error estimates, the code delay error estimates are weighted and fused.

[0013] Among them, the common-mode code phase is used to characterize the unified code phase change trend of multi-frequency signals, and the differential-mode code phase is used to characterize the inter-frequency code phase deviation of multi-frequency signals. Weighted fusion processing of the estimated code delay errors based on each target weight can effectively increase the proportion of code delay errors corresponding to received signals with high carrier-to-noise ratios in the common-mode code phase construction process, thereby obtaining common-mode code phase outputs and differential-mode code phase outputs that retain more effective information. This improves the accuracy of the target code rate correction for each digital intermediate frequency signal.

[0014] Furthermore, the process of obtaining the variance of the target estimation error value for each code delay error estimate is as follows: ; in, Indicates the first i The standard deviation of the target estimation error value of the received signal and They represent the first i The normalized power spectral density and carrier-to-noise ratio of the received signal. Indicates carrier power. Indicates the power of interference noise. Indicates the coherent integration time. Indicates the first i The frequency of the received signal, Indicates the first i The interval of the code delay branch of the received signal This indicates the filtering bandwidth of the received signal.

[0015] Furthermore, based on the common-mode code phase output and the phase output of each differential-mode code, the target code rate correction amount corresponding to each digital intermediate frequency signal is obtained, including: The common-mode code phase output and the phase output of each differential-mode code are filtered to obtain the common-mode code phase rate correction amount and the differential-mode code phase rate correction amount corresponding to each digital intermediate frequency signal. The phase rate correction of each differential code is summed with the phase rate correction of the common code to obtain the target rate correction for each digital intermediate frequency signal.

[0016] Secondly, this application also provides a code tracking system for joint multi-frequency signals, used to implement any of the methods in the first aspect, including: The radio frequency front-end processing module is used to filter and amplify the received signals at multiple different frequency points to obtain the digital intermediate frequency signal corresponding to each received signal. The coherent integration module is used to perform coherent integration processing on the digital intermediate frequency signals based on the local pseudocode corresponding to each digital intermediate frequency signal, and obtain the target integration result corresponding to the digital intermediate frequency signal. The code phase error identification module is used to obtain the code delay error estimate corresponding to the digital intermediate frequency signal based on the integration results of each target. The weight calculation module is used to obtain the target estimation error value of each code delay error estimate, and to obtain the target weight corresponding to each digital intermediate frequency signal based on each target estimation error value; The code phase output acquisition module is used to perform weighted fusion processing on each code delay error estimate based on each target weight and the code delay error estimate corresponding to each target weight, to obtain the common mode code phase output and each differential mode code phase output. The code rate correction acquisition module is used to acquire the target code rate correction amount corresponding to each digital intermediate frequency signal based on the common mode code phase output and the phase output of each differential mode code. The target pseudocode correction module is used to correct the local pseudocode corresponding to the digital intermediate frequency signal based on the target code rate correction amount.

[0017] Thirdly, this application also provides an electronic device, comprising: at least one memory for storing a program; and at least one processor for executing the program stored in the memory, wherein when the program stored in the memory is executed, the processor is configured to execute the method described in the first aspect or any possible implementation thereof.

[0018] Fourthly, this application also provides a computer-readable storage medium storing a computer program that, when run on a processor, causes the processor to perform the method described in the first aspect or any possible implementation thereof.

[0019] In summary, compared with the prior art, the above-described technical solutions conceived in this invention have the following beneficial effects: The code tracking method and system for joint multi-frequency signals provided in this application can accurately obtain the digital intermediate frequency signal and its code delay error estimate corresponding to each received signal by performing filtering, amplification, coherent integration, and code discrimination operations on the received signals at multiple frequency points; by using the variance of the target estimation error values ​​of each obtained digital intermediate frequency signal, the target weight of each code delay error estimate is determined; and then, based on each target weight, each code delay error estimate can be weighted and fused to obtain a more accurate common-mode code phase output and differential-mode code phase output, thereby accurately obtaining the target code rate correction amount of the inter-frequency deviation corresponding to each received signal and dynamically correcting each inter-frequency deviation to effectively improve the code tracking accuracy of joint multi-frequency signals. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in this application or related technologies, the accompanying drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a flowchart illustrating a code tracking method provided in an embodiment of this application.

[0022] Figure 2 This is another flowchart illustrating the code tracking method provided in this application embodiment.

[0023] Figure 3 This is a schematic diagram of the code tracking system provided in the embodiments of this application.

[0024] Figure 4 This is a schematic diagram of the structure of the electronic device provided in the embodiments of this application. Detailed Implementation

[0025] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0026] In the following description, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The following description provides multiple embodiments of this application, which can be substituted or combined with each other. Therefore, this application can also be considered to include all possible combinations of the same and / or different embodiments described. Thus, if one embodiment includes features A, B, and C, and another embodiment includes features B and D, then this application should also be considered to include embodiments containing one or more other possible combinations of A, B, C, and D, even if such embodiments are not explicitly described in the following text.

[0027] The following description provides examples and does not limit the scope, applicability, or examples set forth in the claims. Changes may be made to the function and arrangement of the described elements without departing from the scope of this application. Various processes or components may be appropriately omitted, substituted, or added to the examples. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Furthermore, features described with respect to some examples may be combined into other examples.

[0028] Figure 1 This is a flowchart illustrating the code tracking method for joint multi-frequency signals provided in an embodiment of this application, as shown below. Figure 1 As shown, the method includes at least the following steps: S1. Filter and amplify the received signals at multiple different frequency points to obtain the digital intermediate frequency signal corresponding to each received signal.

[0029] In this embodiment, the execution entity for the code tracking method for combining multi-frequency signals can be the controller of the receiving device of a satellite navigation system. The received signal is the communication signal at various frequency points received by the receiving device of the satellite navigation system. Filtering can be implemented using a band-pass filter (BPF), and amplification can be implemented using a low-noise amplifier (LNA).

[0030] In one possible implementation, the received signals at multiple different frequency points are filtered and amplified to obtain the digital intermediate frequency signal corresponding to each received signal, including: The acquired received signal is subjected to bandpass filtering and low-noise amplification to obtain the initial radio frequency signal; Based on the sinusoidal local oscillator signal corresponding to the received signal, the initial radio frequency signal is mixed, down-frequency, filtered, amplified, and converted from analog to digital to obtain the digital intermediate frequency signal.

[0031] In the embodiments of this application, signals at different frequencies carry different types of interference components, mainly including low-frequency and high-frequency components. Bandpass filtering of the received signal can effectively remove interference noise caused by the usage environment, but there are still some intermediate frequency interference signals with frequencies close to the intermediate frequency of the received signal containing useful information. Performing low-noise amplification on the bandpass-filtered received signal can improve the signal-to-noise ratio of the received signal while introducing lower noise, preventing the received signal from being overwhelmed by noise signals during subsequent processing.

[0032] The mixing and down-conversion process involves mixing the input received signal with the sinusoidal signal generated by the local oscillator of the filter, converting the carrier frequency of the received signal to a fixed intermediate frequency (IF) signal, while maintaining the modulation type and parameters. Afterward, spurious frequency components generated during mixing are filtered out, retaining the desired IF signal. This IF signal is then amplified to increase its strength for subsequent processing.

[0033] Furthermore, the digital intermediate frequency signal obtained from the above operations includes Doppler frequency shift. Therefore, its mathematical model can be expressed as:

[0034] in, i The label indicating the received signal. For signal amplitude, This is a local pseudocode sequence. To delay the transmission time, For the initial phase, For channel noise, The initial radio frequency signal is obtained after mixing, down-conversion, filtering, and amplification. It is a digital intermediate frequency signal.

[0035] S2. Based on the local pseudocode corresponding to each digital intermediate frequency signal, perform coherent integration processing on the digital intermediate frequency signal to obtain the target integration result corresponding to the digital intermediate frequency signal.

[0036] In one possible implementation, based on the local pseudocode corresponding to each digital intermediate frequency (IF) signal, coherent integration processing is performed on the digital IF signals to obtain the target integration result corresponding to the digital IF signals, including: The intermediate frequency carrier and Doppler frequency shift of the digital intermediate frequency signal are stripped to obtain the target baseband signal; The target baseband signal is multiplied by each code delay branch of the local pseudocode corresponding to the digital intermediate frequency signal and coherently integrated to obtain the target integration result, which includes the same-direction components and quadrature components corresponding to the early code delay branch and the late code delay branch.

[0037] In the embodiments of this application, such as Figure 2 As shown, the target integration result is obtained through an integrator coherent, which corresponds to the coherent integration operation module in the figure. The local pseudocode corresponding to the digital intermediate frequency signal is usually divided into three code delay branches: the early code (E) is slightly ahead of the received signal and is used to determine whether the local pseudocode is lagging behind; the late code (L) is slightly behind the received signal and is used to determine whether the local pseudocode is leading; the prompt code (P) is theoretically aligned with the received signal and is used to output the final coherent value and perform data demodulation.

[0038] The calculation process for the same-direction and orthogonal components corresponding to the early code delay branch and the late code delay branch is as follows:

[0039] in, and They represent the first i The in-direction and quadrature components of the early code delay branch of a digital intermediate frequency signal and They represent the first i The in-phase and quadrature components of the late code delay branch of a digital intermediate frequency signal and They represent The real and imaginary parts of a complex number. Indicates local pseudocode. Indicates the target baseband signal. The coherent integration time can be preset according to the type of integrator. This represents the result of the objective integral.

[0040] S3. Based on the integration results of each target, obtain the code delay error estimate corresponding to the digital intermediate frequency signal.

[0041] In one possible implementation, the process of obtaining the code delay error estimate corresponding to the digital intermediate frequency signal based on the integration results of each target is as follows:

[0042] in, Indicates the first i Estimated code delay error of a digital intermediate frequency signal. and They represent the first i The in-direction and quadrature components of the early code delay branch of a digital intermediate frequency signal and They represent the first i The same-direction and quadrature components of the late code delay branch of a digital intermediate frequency signal.

[0043] In the embodiments of this application, such as Figure 2 As shown, by comparing the coherent output difference between the early and late codes using a code discriminator, a code delay error estimate can be obtained. This estimate can then generate a code phase error signal, thereby controlling the code NCO to adjust the local pseudo-code. This ensures that the instantaneous code branch is precisely aligned with the received code and the digital intermediate frequency signal, achieving code tracking. The acquisition of the code delay error estimate is part of the code discrimination operation, and the code discriminator corresponds to... Figure 2 The phase error discrimination module can be a normalized uncorrelated early-delay power discriminator.

[0044] S4. Based on the estimated delay error values ​​of each code, obtain the common-mode code phase output between each digital intermediate frequency signal and the differential-mode code phase output corresponding to each digital intermediate frequency signal.

[0045] In one possible implementation, based on the estimated delay error values ​​of each code, the common-mode code phase output between each digital intermediate frequency (IF) signal and the differential-mode code phase output corresponding to each digital IF signal are obtained, including: Obtain the target estimation error value of each code delay error estimate, and obtain the target weight corresponding to each digital intermediate frequency signal based on each target estimation error value; Based on the target weights and the corresponding code delay error estimates, the code delay error estimates are weighted and fused.

[0046] In the embodiments of this application, such as Figure 2 As shown, taking the processing of received signals at frequencies L1 and L2 as examples, the corresponding code delay error estimates are as follows: and .

[0047]

[0048] in, Indicates common-mode code phase output. This indicates the differential code phase output corresponding to the first digital intermediate frequency signal. This indicates the differential code phase output corresponding to the second digital intermediate frequency signal. Indicates the first i The target weights of each digital intermediate frequency (IF) signal. The common-mode code phase output and differential-mode code phase output can effectively reflect the code delay consistency and inter-frequency differences among the digital IF signals.

[0049] When the number of digital intermediate frequency (IF) signals at different frequencies is greater than two, the calculation methods for the common-mode code phase output and the differential-mode code phase output are similar. For example, when there are three sets of digital IF signals, the calculation formula is as follows:

[0050] In one possible implementation, the process of obtaining the variance of the target estimation error value for each code delay error estimate is as follows:

[0051] in, Indicates the first i The standard deviation of the target estimation error value of the received signal and They represent the first i The normalized power spectral density and carrier-to-noise ratio of the received signal. Indicates carrier power. Indicates the power of interference noise. Indicates the coherent integration time. Indicates the first i The frequency of the received signal, Indicates the first i The interval of the code delay branch of the received signal This indicates the filtering bandwidth of the received signal.

[0052] The target estimation error is the interference introduced during the code delay error estimation process by the code discriminator itself. Therefore, the variance of the target estimation error is closely related to the carrier-to-noise ratio (CNR) of the corresponding received signal. The CNR effectively reflects the proportion of useful information in the received signal. Therefore, ensuring a higher CNR in the received signal accounts for a larger proportion of the target code rate correction effectively improves the accuracy of the common-mode code phase output. Simultaneously, preserving the relative deviation information of the received signal at each frequency point can be retained as much as possible in the differential-mode code phase output.

[0053] Target weight satisfy The calculation formula is as follows:

[0054] in, Indicates the first i The variance of the target estimation error value of the received signal Indicates the first i The target weight of the received signal.

[0055] S5. Based on the common-mode code phase output and the differential-mode code phase output, obtain the target code rate correction amount corresponding to each digital intermediate frequency signal, and correct the local pseudo-code corresponding to the digital intermediate frequency signal based on the target code rate correction amount.

[0056] In one possible implementation, the target code rate correction amount corresponding to each digital intermediate frequency signal is obtained based on the common-mode code phase output and the phase output of each differential-mode code, including: The common-mode code phase output and the phase output of each differential-mode code are filtered to obtain the common-mode code phase rate correction amount and the differential-mode code phase rate correction amount corresponding to each digital intermediate frequency signal. The phase rate correction of each differential code is summed with the phase rate correction of the common code to obtain the target rate correction for each digital intermediate frequency signal.

[0057] In this embodiment, the filtering process for the common-mode code phase output and the differential-mode code phase output can be accomplished using a second- or third-order loop filter. This suppresses high-frequency noise and achieves a smooth adjustment effect on code phase changes, resulting in the common-mode code phase rate correction. PAND / Difference mode code phase rate correction Target code rate correction amount corresponding to each digital intermediate frequency signal equal and The superposition, that is Then, the target code rate correction amount is used as the input of the pseudo-code numerically controlled oscillator (NCO) to generate the corresponding control code to adjust the local pseudo-code, so that the instantaneous code branches of the global navigation satellite system's received code and the local pseudo-code are aligned, thereby enhancing the signal dynamic tracking capability.

[0058] Figure 3 This is a schematic diagram of the structure of a code tracking system for joint multi-frequency signals provided in an embodiment of this application, as shown below. Figure 3 As shown, the system includes at least: The radio frequency front-end processing module is used to filter and amplify the received signals at multiple different frequency points to obtain the digital intermediate frequency signal corresponding to each received signal. The coherent integration module is used to perform coherent integration calculation on the digital intermediate frequency signals based on the local pseudocode corresponding to each digital intermediate frequency signal, and obtain the target integration result corresponding to the digital intermediate frequency signal. The code phase error identification module is used to obtain the code delay error estimate corresponding to the digital intermediate frequency signal based on the integration results of each target. The weight calculation module is used to obtain the target estimation error value of each code delay error estimate, and to obtain the target weight corresponding to each digital intermediate frequency signal based on each target estimation error value; The code phase output acquisition module is used to perform weighted fusion processing on each code delay error estimate based on each target weight and the code delay error estimate corresponding to each target weight, to obtain the common mode code phase output and each differential mode code phase output. The code rate correction acquisition module is used to acquire the target code rate correction amount corresponding to each digital intermediate frequency signal based on the common mode code phase output and the phase output of each differential mode code. The target pseudocode correction module is used to correct the local pseudocode corresponding to the digital intermediate frequency signal based on the target code rate correction amount.

[0059] like Figure 4 As shown, Figure 4 This is a schematic diagram of the structure of an electronic device provided in an embodiment of this application. The electronic device may include: a processor 401, a communications interface 402, a memory 403, and a communication bus 404. The processor 401, communications interface 402, and memory 403 communicate with each other via the communication bus 404. The processor 401 can call software instructions in the memory 403 to execute the methods described in the above embodiments.

[0060] Furthermore, the logical instructions in the aforementioned memory 403 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, in essence, or the part that contributes to the prior art, or a part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods of the various embodiments of this application.

[0061] Based on the methods in the above embodiments, this application provides a computer-readable storage medium storing a computer program that, when run on a processor, causes the processor to execute the methods in the above embodiments.

[0062] Based on the methods in the above embodiments, this application provides a computer program product that, when run on a processor, causes the processor to execute the methods in the above embodiments.

[0063] It is understood that the processor in the embodiments of this application can be a CPU (Central Processing Unit), or other general-purpose processors, DSPs (Digital Signal Processors), ASICs (Application Specific Integrated Circuits), FPGAs (Field Programmable Gate Arrays), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. A general-purpose processor can be a microprocessor or any conventional processor.

[0064] The method steps in this application embodiment can be implemented in hardware or by a processor executing software instructions. The software instructions can consist of corresponding software modules, which can be stored in random access memory (RAM), flash memory, ROM (Read-only Memory), PROM (Programmable ROM), EPROM (Erasable PROM), EEPROM (Electrically Erasable EPROM), registers, hard disks, portable hard disks, CD-ROMs, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor, enabling the processor to read information from and write information to the storage medium. Of course, the storage medium can also be a component of the processor. The processor and the storage medium can reside in an ASIC.

[0065] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented in software, it can be implemented, in whole or in part, as a computer program product. A computer program product includes one or more computer instructions. When the computer program instructions are loaded and executed on a computer, all or part of the flow or function according to the embodiments of this application is generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer instructions can be stored in or transmitted through a computer-readable storage medium. The computer instructions can be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wired (e.g., coaxial cable, fiber optic, digital subscriber line DSL) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that a computer can access or a data storage device such as a server or data center that integrates one or more available media. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., SSD (Solid State Disk)).

[0066] It is understood that the various numerical designations used in the embodiments of this application are merely for the convenience of description and are not intended to limit the scope of the embodiments of this application.

[0067] Those skilled in the art will readily understand that the above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A code tracking method for joint multi-frequency signals, characterized in that, include: S1. Filter and amplify the received signals at multiple different frequency points to obtain the digital intermediate frequency signal corresponding to each received signal; S2. Based on the local pseudocode corresponding to each of the digital intermediate frequency signals, perform coherent integration processing on the digital intermediate frequency signals to obtain the target integration result corresponding to the digital intermediate frequency signals. S3. Based on the integration results of each target, obtain the code delay error estimate corresponding to the digital intermediate frequency signal; S4. Based on the estimated code delay error values, obtain the common-mode code phase output between the digital intermediate frequency signals and the differential-mode code phase output corresponding to each digital intermediate frequency signal; S5. Based on the common-mode code phase output and each of the differential-mode code phase outputs, obtain the target code rate correction amount corresponding to each of the digital intermediate frequency signals, and correct the local pseudo-code corresponding to the digital intermediate frequency signal based on the target code rate correction amount.

2. The code tracking method for joint multi-frequency signals according to claim 1, characterized in that, The step of filtering and amplifying the received signals at multiple different frequency points to obtain the digital intermediate frequency signal corresponding to each received signal includes: The acquired received signal is subjected to bandpass filtering and low-noise amplification to obtain the initial radio frequency signal; Based on the sinusoidal local oscillator signal corresponding to the received signal, the initial radio frequency signal is subjected to mixing, down-conversion, filtering, amplification, and analog-to-digital conversion to obtain a digital intermediate frequency signal.

3. The code tracking method for joint multi-frequency signals according to claim 2, characterized in that, The step of performing coherent integration processing on the digital intermediate frequency signals based on the local pseudocode corresponding to each of the digital intermediate frequency signals to obtain the target integration result corresponding to the digital intermediate frequency signals includes: The intermediate frequency carrier and Doppler frequency shift of the digital intermediate frequency signal are stripped to obtain the target baseband signal; The target baseband signal is multiplied and coherently integrated with each code delay branch of the local pseudocode corresponding to the digital intermediate frequency signal to obtain the target integration result. The target integration result includes the same-direction components and quadrature components corresponding to the early code delay branch and the late code delay branch.

4. The code tracking method for joint multi-frequency signals according to claim 3, characterized in that, pass Obtain the code delay error estimate corresponding to the digital intermediate frequency signal; in, Indicates the first i Estimated code delay error of a digital intermediate frequency signal. and They represent the first i The in-direction and quadrature components of the early code delay branch of a digital intermediate frequency signal and They represent the first i The same-direction and quadrature components of the late code delay branch of a digital intermediate frequency signal.

5. The code tracking method for joint multi-frequency signals according to claim 4, characterized in that, The step of obtaining the common-mode code phase output between each of the digital intermediate frequency signals and the differential-mode code phase output corresponding to each of the digital intermediate frequency signals based on the estimated code delay error values ​​includes: Obtain the variance of the target estimation error value for each of the code delay error estimates, and obtain the target weight corresponding to each of the digital intermediate frequency signals based on the variances. Based on each of the target weights and the code delay error estimates corresponding to each of the target weights, the code delay error estimates are weighted and fused.

6. The code tracking method for joint multi-frequency signals according to claim 5, characterized in that, pass Obtain the variance of the target estimation error value for each code delay error estimate; in, Indicates the first i The standard deviation of the target estimation error value of the received signal and They represent the first i The normalized power spectral density and carrier-to-noise ratio of the received signal. Indicates carrier power. Indicates the power of interference noise. Indicates the coherent integration time. Indicates the first i The frequency of the received signal, Indicates the first i The interval of the code delay branch of the received signal. This indicates the filtering bandwidth of the received signal.

7. The code tracking method for joint multi-frequency signals according to claim 5, characterized in that, The step of obtaining the target code rate correction amount corresponding to each of the digital intermediate frequency signals based on the common mode code phase output and each of the differential mode code phase outputs includes: The common-mode code phase output and each of the differential-mode code phase outputs are filtered to obtain the common-mode code phase rate correction amount and the differential-mode code phase rate correction amount corresponding to each of the digital intermediate frequency signals. The differential code phase rate correction amount is summed with the common code phase rate correction amount to obtain the target rate correction amount corresponding to each digital intermediate frequency signal.

8. A code tracking system for combining multi-frequency signals, for implementing the method as described in any one of claims 1-7, characterized in that, include: The radio frequency front-end processing module is used to filter and amplify the received signals at multiple different frequency points to obtain the digital intermediate frequency signal corresponding to each received signal. The coherent integration module is used to perform coherent integration processing on the digital intermediate frequency signals based on the local pseudocode corresponding to each of the digital intermediate frequency signals, and obtain the target integration result corresponding to the digital intermediate frequency signals. The code phase error identification module is used to obtain the code delay error estimate corresponding to the digital intermediate frequency signal based on the integration results of each target. The weight calculation module is used to obtain the target estimation error value of each code delay error estimate, and to obtain the target weight corresponding to each digital intermediate frequency signal based on each target estimation error value; The code phase output acquisition module is used to perform weighted fusion processing on each code delay error estimate based on each target weight and the code delay error estimate corresponding to each target weight, to obtain the common mode code phase output and each differential mode code phase output; The code rate correction acquisition module is used to acquire the target code rate correction amount corresponding to each of the digital intermediate frequency signals based on the common mode code phase output and the differential mode code phase output. The target pseudocode correction module is used to correct the local pseudocode corresponding to the digital intermediate frequency signal based on the target code rate correction amount.

9. An electronic device, characterized in that, include: At least one memory for storing computer programs; At least one processor is configured to execute a program stored in the memory, wherein when the program stored in the memory is executed, the processor is configured to perform the method as described in any one of claims 1-7.

10. A computer-readable storage medium having a computer program stored thereon, the computer-readable storage medium storing instructions that, when executed on a computer or processor, cause the computer or processor to perform the steps of the method as claimed in any one of claims 1-7.

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