Satellite navigation signal tracking method and device, electronic equipment and readable storage medium

Abstract

This application provides a satellite navigation signal tracking method, apparatus, electronic device, and readable storage medium. The method includes: generating a local satellite navigation signal based on a lookup table and current multi-branch local satellite navigation signals; performing calculations on the local satellite navigation signal and a digital intermediate frequency (IF) satellite navigation signal to obtain multiple energy values; accumulating the multiple energy values ​​and inputting the accumulation result into a carrier loop and / or a code loop; and tracking the satellite navigation signal based on the carrier loop and / or the code loop. This application generates a local satellite navigation signal using a lookup table and current multi-branch local satellite navigation signals, and then inputs the signal into a carrier loop and / or a code loop after a series of calculations on the local satellite navigation signal and the IF satellite navigation signal. This allows for tracking of satellite navigation signals with sufficient front-end bandwidth. The entire tracking method has low complexity, simple processing, and is easy to implement.

Description

Technical Field

[0001] This application relates to the field of satellite navigation, and more specifically, to a satellite navigation signal tracking method, apparatus, electronic device, and readable storage medium. Background Technology

[0002] Satellite navigation and positioning technology is being applied in increasingly wider fields. However, in practical applications, satellite signal blockage frequently occurs, causing a sharp drop in the signal CN0 (i.e., carrier-to-noise power spectral density ratio) or even preventing signal reception. Therefore, real-time tracking of satellite navigation signals is necessary to prevent signal loss due to blockage. However, currently, even with sufficient front-end bandwidth, tracking satellite navigation signals is difficult. Summary of the Invention

[0003] In view of this, the purpose of this application is to provide a satellite navigation signal tracking method, apparatus, electronic device and readable storage medium that can stably track satellite navigation signals when the front-end bandwidth is sufficient.

[0004] In a first aspect, embodiments of this application provide a satellite navigation signal tracking method, comprising: generating a local satellite navigation signal based on a lookup table and current multi-branch local satellite navigation signals; performing calculations on the local satellite navigation signal and a digital intermediate frequency satellite navigation signal to obtain multiple energy values; accumulating the multiple energy values ​​and inputting the accumulation calculation result into a carrier loop and / or a code loop; and tracking the satellite navigation signal based on the carrier loop and / or the code loop.

[0005] In the above implementation process, a local satellite navigation signal is generated using a lookup table. This local satellite navigation signal, along with the digital intermediate frequency (IF) satellite navigation signal, is then processed and fed into a carrier loop and / or code loop. Since the local navigation signal is generated using a pre-established lookup table, it is unaffected by other factors. Therefore, tracking of satellite navigation signals with sufficient front-end bandwidth is possible, and the entire tracking method has low complexity, simple processing, and is easy to implement.

[0006] In one embodiment, generating a local satellite navigation signal based on a lookup table and current multi-branch local satellite navigation signals includes: obtaining pseudocode information of multiple branches of the current multi-branch local satellite navigation signal, and message or secondary code information of the multiple branches; searching the lookup table for the pseudocode information and the current signal parameters corresponding to the message or secondary code information; and generating a local satellite navigation signal based on the current signal parameters, the pseudocode information, and the message or secondary code information.

[0007] In the above implementation process, by using the pseudocode information and message or secondary code information of multiple branches of the current multi-branch local satellite navigation signal, the signal parameters at the current moment can be determined in a lookup table to generate satellite navigation information locally. Then, based on the pseudocode information and message or secondary code information, the locally generated satellite navigation information is adjusted to obtain the final local satellite navigation signal. Since local satellite navigation signals can be generated using the above method, various types of digital intermediate frequency satellite navigation signals can be processed using the local satellite navigation information to achieve tracking of multiple types of satellite navigation signals.

[0008] In one embodiment, a portion of the signals in multiple branches are modulated with a message, while the signals in other branches are modulated with a secondary code. The step of searching a lookup table for the pseudo-code information and the current signal parameters corresponding to the message or the secondary code information includes: multiplying or XORing the pseudo-code information of each branch with the message or the secondary code corresponding to that branch based on the modulation information of the current multi-branch local satellite navigation signals; inputting the result of the multiplication or XOR processing into the lookup table; and searching the lookup table for the pseudo-code information and the current signal parameters corresponding to the message or the secondary code information.

[0009] In the above implementation process, by multiplying or XORing the pseudocode information of each branch with the corresponding message or secondary code, the influence of the message or secondary code on the table lookup can be removed, thereby making the information of each branch in the table more accurate and improving the accuracy of the table lookup.

[0010] In one embodiment, before generating a local satellite navigation signal based on the current signal parameters, the pseudocode information, and the message or the secondary code information, the method further includes: obtaining the intercepted code phase in the pseudocode information; inputting the intercepted code phase into the lookup table; and adjusting the pseudocode information and the current signal parameters corresponding to the message or the secondary code information based on the intercepted code phase.

[0011] In the above implementation process, by inputting the intercepted code phase into the lookup table, the current signal parameters matched by the intercepted code phase can be further adjusted so that the generated current signal parameters are more consistent with the actual values ​​of the local satellite navigation signal, thereby improving the accuracy of the local satellite navigation signal.

[0012] In one embodiment, obtaining the pseudocode information of multiple branches of the current multi-branch local satellite navigation signal includes: generating the pseudocode information of multiple branches of the current multi-branch local satellite navigation signal through a multi-bit linear shift register, wherein the multi-bit linear shift register is a multi-bit register unit; or generating the pseudocode information of multiple branches of the current multi-branch local satellite navigation signal through a storage code generation unit, wherein the storage code generation unit is configurable.

[0013] In the above implementation process, the current multi-branch local satellite navigation signals are generated through a multi-bit linear shift register or a storage code generation unit. Since the multi-bit linear shift register is a multi-digit register, it can process various satellite navigation signals and generate corresponding pseudo-code information. Because the storage code generation unit is configurable, it can be configured according to different actual situations, thus making it applicable to the generation of pseudo-codes for more satellite navigation signals and increasing the application scenarios of pseudo-code generation.

[0014] In one embodiment, the step of processing the local satellite navigation signal and the digital intermediate frequency satellite navigation signal to obtain multiple energy values ​​includes: performing demodulation or despreading operations on the local satellite navigation signal and the digital intermediate frequency satellite navigation signal to obtain multiple energy values.

[0015] In the above implementation process, by demodulating or despreading the local satellite navigation signal and the intermediate frequency satellite navigation signal, the influence of carrier wave, message or second-level code on the table lookup can be removed, thereby making the information of each branch in the table more accurate and improving the accuracy of the table lookup.

[0016] In one embodiment, the step of accumulating the energy values ​​from multiple sources and inputting the accumulation calculation result into the carrier ring and / or code ring includes: performing coherent accumulation calculation and / or incoherent accumulation calculation on the energy values ​​from multiple sources, and inputting the accumulation calculation result into the carrier ring and / or code ring.

[0017] In the above implementation process, by performing coherent accumulation calculation on multiple energy values, the temporal continuity of the carrier phase can be maintained because this coherent accumulation calculation directly superimposes the amplitudes of the multiple energy values, and the signal-to-noise ratio can be improved through amplitude superposition. Alternatively, by performing incoherent accumulation calculation on multiple energy values, the information of the complex signal is discarded, only the magnitude is retained, and there are no strict phase relationship restrictions, which can expand the application scenarios of this multi-channel energy value calculation.

[0018] In one embodiment, before processing the local satellite navigation signal and the digital intermediate frequency satellite navigation signal to obtain multiple energy values, the method further includes: performing down-conversion processing on the processed satellite navigation signal and the local carrier signal to obtain a digital zero intermediate frequency satellite navigation signal; the processing of the local satellite navigation signal and the digital intermediate frequency satellite navigation signal to obtain multiple energy values ​​includes: processing the local satellite navigation signal and the digital zero intermediate frequency satellite navigation signal to obtain multiple energy values.

[0019] In the above implementation process, by converting the digital intermediate frequency signal into a digital zero intermediate frequency signal, the carrier in the digital intermediate frequency signal can be removed, thereby improving the quality and reliability of the digital intermediate frequency signal.

[0020] Secondly, embodiments of this application also provide a signal tracking device, comprising: a generation module, configured to generate a local satellite navigation signal based on a lookup table and current multi-branch local satellite navigation signals; a processing module, configured to perform calculations on the local satellite navigation signal and a digital intermediate frequency satellite navigation signal to obtain multiple energy values; a calculation module, configured to perform cumulative calculations on the multiple energy values ​​and input the cumulative calculation result into a carrier loop and / or a code loop; and a tracking module, configured to track the satellite navigation signal based on the carrier loop and / or the code loop.

[0021] Thirdly, embodiments of this application also provide an electronic device, including: a processor and a memory, wherein the memory stores machine-readable instructions executable by the processor, and when the electronic device is running, the machine-readable instructions are executed by the processor to perform the steps of the method described in the first aspect above, or any possible implementation of the first aspect.

[0022] Fourthly, embodiments of this application also provide a computer-readable storage medium storing a computer program that, when executed by a processor, performs the steps of the satellite navigation signal tracking method described in the first aspect or any possible implementation of the first aspect.

[0023] To make the above-mentioned objectives, features and advantages of this application more apparent and understandable, specific embodiments are described below in conjunction with the accompanying drawings. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 A flowchart of a satellite navigation signal tracking method provided in an embodiment of this application;

[0026] Figure 2 This is a schematic diagram of local satellite navigation signal generation provided in an embodiment of this application;

[0027] Figure 3 This is a schematic diagram of digital zero intermediate frequency signal generation provided in an embodiment of this application;

[0028] Figure 4 This is a complete feedback diagram of the satellite navigation signal tracking method provided in the embodiments of this application;

[0029] Figure 5 A schematic diagram of the functional modules of the satellite navigation signal tracking device provided in the embodiments of this application;

[0030] Figure 6 This is a block diagram of an electronic device provided in an embodiment of this application. Detailed Implementation

[0031] The technical solutions in the embodiments of this application will now be described with reference to the accompanying drawings.

[0032] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, in the description of this application, terms such as "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0033] The Galileo system is a satellite navigation and positioning system jointly developed by the European Union and the European Space Agency. Currently, the Galileo system mainly operates in three frequency bands: E1, E5, and E6. The E5 band signal uses AltBOC (Alternate Binary Offset Carrier) for transmission, which provides 6dB more energy than receiving and processing only one signal. This stronger signal effectively mitigates signal loss due to signal obstruction. Furthermore, using full-band AltBOC reception significantly improves the pseudocode accuracy of baseband tracking and its multipath resistance compared to BPSK (Binary Phase Shift Keying) signals under similar conditions.

[0034] The inventors of this application have discovered through long-term research that, currently, even with sufficient front-end bandwidth, it is difficult to track satellite navigation signals, such as AltBOC signals and AltBOC-like signals. Currently, there is virtually no direct reception and processing of full-band AltBOC signals and AltBOC-like signals, making it difficult to track them.

[0035] In view of this, the inventors of this application propose a satellite navigation tracking method, which generates a local satellite navigation signal by looking up a table and the current multi-branch local satellite navigation signal, and inputs the local satellite navigation signal and the digital intermediate frequency satellite navigation signal into the carrier loop and / or code loop after performing a series of operations, thereby realizing the tracking of the satellite navigation signal when the front-end bandwidth is sufficient. Moreover, the entire satellite navigation signal tracking method has low implementation complexity, simple processing, and is easy to implement.

[0036] Please see Figure 1 This is a flowchart of the satellite navigation signal tracking method provided in the embodiments of this application. The following will describe... Figure 1 The specific process shown will be explained in detail.

[0037] Step 201: Generate a local satellite navigation signal based on the lookup table and the current multi-branch local satellite navigation signals.

[0038] This lookup table is a table showing the relationship between satellite navigation signals and their signal parameters. The lookup table includes each satellite navigation signal and its corresponding signal parameters, such as phase and amplitude. This lookup table can be pre-built. For example, the lookup table for AltBOC or similar signals can be configured during system initialization. When using this lookup table, the pseudocode and secondary code information of the satellite navigation information can be used to find the corresponding signal parameter in the lookup table.

[0039] The aforementioned current multi-branch local satellite navigation signals are satellite navigation signals from multiple branches acquired locally at the current moment.

[0040] In some embodiments, the current multi-branch local satellite navigation signal is the satellite navigation signal adjusted by a carrier loop or code loop at the current moment.

[0041] Understandably, when generating a local satellite navigation signal, one can first look up the corresponding signal parameters in a lookup table based on the pseudocode information and / or message or secondary code information of the current multi-branch local satellite navigation signals, and finally generate the local satellite navigation signal based on the found signal parameters, pseudocode information and / or message or secondary code information.

[0042] Step 202: Perform calculations on the local satellite navigation signal and the digital intermediate frequency satellite navigation signal to obtain multiple energy values.

[0043] Understandably, after satellite navigation signals are received by an antenna, they undergo radio frequency processing and AD sampling to obtain digital intermediate frequency (IF) satellite navigation signals. The IF satellite navigation signals obtained after AD sampling, along with the local satellite navigation signals, are then processed to obtain the I and Q components of the baseband signal.

[0044] The multiplexed energy value here can include the I component and the Q component. The I component and the Q component can form a set of IQ energy values.

[0045] In some embodiments, after determining the digital intermediate frequency (IF) satellite navigation signal, the digital IF satellite navigation signal can be down-converted to obtain a digital zero IF satellite navigation signal.

[0046] Step 203: Accumulate the energy values ​​of the multiple channels and input the accumulated calculation results into the carrier loop and / or code loop.

[0047] The accumulation calculation here is used to demodulate the multiple energy values ​​to recover the modulated signal from the modulated signal. This accumulation calculation can include coherent accumulation calculation and non-coherent accumulation calculation.

[0048] Step 204: Track satellite navigation signals based on carrier loop and / or code loop.

[0049] The carrier loop is used to track the carrier wave in the satellite navigation signal. The code loop is used to track the pseudocode in the satellite navigation signal.

[0050] The carrier loop here is used to ensure that the replicated carrier signal is consistent with the carrier signal in the received satellite navigation signal, thereby completely stripping the carrier from the satellite navigation signal through a mixing mechanism. If the replicated carrier signal is inconsistent with the carrier signal in the received satellite navigation signal, the carrier in the received signal cannot be completely stripped, meaning the received signal cannot be down-converted to the true baseband.

[0051] Typically, to completely remove the carrier from the digital intermediate frequency (IF) signal and downconvert it from IF to baseband, a carrier loop is equipped with a mixer, and the replicated carrier is synchronized with the input carrier. If the carrier loop detects a phase difference between its replicated carrier and the input carrier, it adjusts the phase of the replicated carrier accordingly to ensure phase synchronization. If the carrier loop detects a frequency difference between its replicated carrier and the input carrier, it adjusts the frequency of the replicated carrier accordingly to ensure frequency synchronization.

[0052] After the carrier loop completely removes the carrier from the digital intermediate frequency signal, it can obtain complete and intact navigation message data bits. In order to assemble the navigation message data bits into words, the receiver can also perform bit synchronization and frame synchronization processing after entering the signal tracking stage, so as to correctly divide the navigation message data bits into structurally meaningful words, thereby obtaining the navigation message parameters.

[0053] Similarly, the code ring here is used to ensure that the copied pseudocode is consistent with the pseudocode in the received satellite navigation signal, thereby completely removing the pseudocode from the satellite navigation signal through the mixing mechanism. If the copied pseudocode is inconsistent with the pseudocode in the received satellite navigation signal, it will affect the correlation of the pseudocode, and the signal energy will be significantly weakened.

[0054] To completely remove pseudo-code from the digital intermediate frequency (IF) signal and down-convert it to baseband, a carrier loop typically includes a mixer, and the copied pseudo-code matches the input pseudo-code. If the code loop detects a phase difference between the copied and input pseudo-code, it adjusts the phase of the copied pseudo-code accordingly to ensure they are in the same phase. Similarly, if the code loop detects a frequency difference between the copied and input pseudo-code, it adjusts the frequency of the copied pseudo-code accordingly to ensure they are in the same frequency.

[0055] Optionally, the accumulated calculation result can be simultaneously input into the carrier loop and the code loop to track the satellite navigation signal through both the carrier loop and the code loop. Alternatively, the accumulated calculation result can be input only into the carrier loop or only into the code loop to track the satellite navigation signal through either the carrier loop or the code loop. The carrier loop and code loop used for tracking this satellite navigation information can be adjusted according to actual conditions, and this application does not impose specific limitations.

[0056] In the above implementation process, a local satellite navigation signal is generated using a lookup table. This local satellite navigation signal, along with the digital intermediate frequency (IF) satellite navigation signal, is then processed and fed into a carrier loop and / or code loop. Since the local navigation signal is generated using a pre-established lookup table, it is unaffected by other factors. Therefore, tracking of satellite navigation signals with sufficient front-end bandwidth is possible. Furthermore, the entire satellite navigation signal tracking method has low complexity, a simple processing procedure, and is easy to implement.

[0057] In one possible implementation, step 201 includes: obtaining pseudocode information and message or secondary code information of multiple branches of the current multi-branch local satellite navigation signal; searching for the pseudocode information and the current signal parameters corresponding to the message or secondary code information in a lookup table; and generating a local satellite navigation signal based on the current signal parameters, pseudocode information, and message or secondary code information.

[0058] In this system, some branches of the multiple branches are modulated with a message, while others are modulated with a second-order code. Alternatively, all branches within the multiple branches can be modulated with a message, or all branches can be modulated with a second-order code. The message or second-order code modulated for each branch can be adjusted according to the specific circumstances.

[0059] The multiple branches of the current multi-branch local satellite navigation signal can be 2 branches, 4 branches, etc. The number of branches can be determined based on actual circumstances, and this application does not impose specific limitations. For example, if the current multi-branch local satellite navigation signal has 4 branches, their pseudocodes are E5aI, E5aQ, E5bI, and E5bQ, respectively. The E5aI and E5bI signals are modulated with a message, while the E5aQ and E5bQ signals are modulated with a secondary code. Understandably, each branch of the current multi-branch local satellite navigation signal has its corresponding pseudocode information and secondary code information. The processed pseudocode information and secondary code information of each branch can be used as input to a lookup table to find the current signal parameters of the local satellite navigation signal.

[0060] In addition, the code phases of the pseudocode and the second-level code can also be used as inputs to the lookup table to adjust the locally generated satellite navigation signal, thereby obtaining the final local satellite navigation signal.

[0061] The aforementioned current signal parameter can be either the phase or the amplitude at the current moment. The specific type of this current signal parameter can be adjusted according to the actual situation, and this application does not impose any specific restrictions.

[0062] In the above implementation process, by using the pseudocode information and message or secondary code information of multiple branches of the current multi-branch local satellite navigation signal, the signal parameters at the current moment can be determined in a lookup table to generate satellite navigation information locally. Then, based on the pseudocode information and message or secondary code information, the locally generated satellite navigation information is adjusted to obtain the final local satellite navigation signal. Since local satellite navigation signals can be generated using the above method, various types of digital intermediate frequency satellite navigation signals can be processed using the local satellite navigation information to achieve tracking of multiple types of satellite navigation signals.

[0063] In one possible implementation, searching a lookup table for the pseudocode information and the corresponding current signal parameters for the message or secondary code information includes: multiplying or XORing the pseudocode information of each branch with the corresponding message or secondary code based on the modulation information of the current multi-branch local satellite navigation signals; inputting the result of the multiplication or XOR processing into the lookup table; and searching the lookup table for the pseudocode information and the corresponding current signal parameters for the message or secondary code information. Understandably, the current multi-branch local satellite navigation signals are all signals modulated according to certain modulation rules. When regenerating the local satellite navigation signal, the corresponding modulation information can be extracted by selecting the secondary code or message to multiply or XOR the corresponding branch codes of the current multi-branch local satellite navigation signals according to their modulation information.

[0064] To further understand step 201 in the embodiments of this application, the following will be combined with... Figure 2 Further explanation of the generation and calculation of pseudocode information and secondary code information for multiple branches:

[0065] like Figure 2 As shown, Figure 2 The diagram shows that the NCO (numerically controlled oscillator) code group includes two sets of codes: NCO1 and NCO2. After acquiring the current multi-branch local satellite navigation signal, the precision of the intercepted code can be configured through a multi-rate variation module. Then, codes NCO1 and NCO2 generate corresponding pseudo-codes through multi-bit linear shift register code production units or storage code production units in the wideband full-state channel and / or wideband pilot channel, respectively.

[0066] The pseudocode generated by the multi-bit linear shift register code production unit or the storage code production unit is multiplied or XORed with the upper sideband I message or second-level code, the upper sideband Q message or second-level code, the lower sideband I message or second-level code, or the lower sideband Q message or second-level code, and the processing result is input into a lookup table to determine the corresponding local code information.

[0067] The aforementioned lookup table is a pre-established table showing the relationship between satellite navigation signals and their parameters. After inputting the result of multiplication or XOR processing into this lookup table, the corresponding current signal parameter can be directly matched from the table. This lookup table can be flexibly configured during initialization according to different systems, thus adapting to different systems and different numbers of inputs.

[0068] For example, if the input is two sets of ALTBOC dual pilot branches and two sets of intercepted code phases, the lookup table can be configured as the lookup table of the corresponding ALTBOC pilots, and the output is the local code of the two sets of broadband pilot branches.

[0069] If the input is a set of four branches of ALTBOC and a set of intercepted code phases, the lookup table can be configured as a lookup table corresponding to the full state of ALTBOC, and the output is a set of local codes for the full-wideband signal.

[0070] If the input consists of two sets of ACE-BOC (Non-Uniform Asymmetric Envelope Binary Off-Set Carrier) pilot branches and two sets of truncation code phases, the lookup table can be configured as a lookup table for the corresponding ACE-BOC pilots and the corresponding branch power ratios, and the output is the local code of the two sets of broadband pilot branches.

[0071] If the input is a set of four branches of ACE-BOC and a set of intercepted code phases, the lookup table can be configured as a lookup table of the corresponding ACE-BOC full state and the corresponding branch power ratio, and the output is a set of local codes of the full-wideband signal.

[0072] If the input consists of two channels of two other signals and two sets of intercepted code phases, the lookup table can be configured as a lookup table for the states of the two branches of the other signals, and the output consists of the local codes of the two broadband pilot branches of the other signals.

[0073] If the input is a set of four other signals and a set of intercepted code phases, the lookup table can be configured as a lookup table for the states of the four branches of the other signals, and the output is a set of local codes for the full-wideband signal.

[0074] The other signals here refer to signals other than ALTBOC, ALTBOC-like signals, and ACE-BOC mentioned above. The pseudocode information mentioned above includes the pseudocode and the truncated code phase.

[0075] In some embodiments, when the pseudocode information of the current multi-branch local satellite navigation signal is first obtained, the pseudocode information of each branch of the current multi-branch local satellite navigation signal at the current time point can be determined by using the pseudocode information obtained from other frequency points, the distance, and the frequency difference between frequency points.

[0076] The other frequencies mentioned above are transmitted by the same satellite as the satellite navigation signal that needs to be tracked. Typically, a single satellite can transmit signals at multiple frequencies. For example, in addition to transmitting the E5 signal, the Galileo satellite can also transmit E1, E6, and other signals. When it is necessary to calculate the pseudo-code phase of the E5 signal, the pseudo-code information of E1 at the current time point can be calculated, and then the pseudo-code information of E5 at the current time point can be deduced based on the differences in distance and frequency between E1 and E5.

[0077] In the above implementation process, by multiplying or XORing the pseudocode information of each branch with the corresponding message or secondary code, the influence of the message or secondary code on the table lookup can be removed, thereby making the information of each branch in the table more accurate and improving the accuracy of the table lookup.

[0078] In one possible implementation, before generating a local satellite navigation signal based on the current signal parameters, pseudocode information, and message or secondary code information, the method further includes: obtaining the truncated code phase from the pseudocode information; inputting the truncated code phase into a lookup table; and adjusting the pseudocode information and the current signal parameters corresponding to the message or secondary code information based on the truncated code phase.

[0079] Understandably, the precision of the truncation code phase can be adjusted according to the actual situation when configuring the lookup table. That is, it can be flexibly configured from 1 times the subcarrier width to 1 / N of the subcarrier width, and the value of N can be flexibly configured according to the corresponding system. For example, the configuration number of the ALTBOC signal in the E5 system can be configured as 1 / 8, 1 / 4, 1 / 2, 1 / 5, 1 / 7, 1 / 3, etc., of the subcarrier chip width. The configuration number of the ACE-BOC signal in the BDB2 system can be configured as 1 / 8, 1 / 4, 1 / 2, 1 / 5, 1 / 7, 1 / 3, 1 / 10, 1 / 12, 1 / 13, etc., of the subcarrier chip width. This precision of the truncation code phase can be adjusted according to the signal type and actual situation.

[0080] In some embodiments, the pseudocode information may correspond to multiple signal parameters. The truncated code phase can be input and used to determine the final current signal parameter from the multiple signal parameters corresponding to the pseudocode information.

[0081] For example, the lookup table includes multiple rows and columns. The pseudocode information can be used to determine the corresponding column, which includes multiple rows, each corresponding to a signal parameter. Then, the row value in that column is determined based on the truncated code phase. The signal parameter in that row corresponding to the row value can then be determined as the current signal parameter. This method of determining the current signal parameter is exemplary, and can be adjusted according to actual circumstances.

[0082] In the above implementation process, by inputting the intercepted code phase into the lookup table, the current signal parameters matched by the intercepted code phase can be further adjusted so that the generated current signal parameters are more consistent with the actual values ​​of the local satellite navigation signal, thereby improving the accuracy of the local satellite navigation signal.

[0083] In one possible implementation, obtaining pseudocode information of multiple branches of the current multi-branch local satellite navigation signal includes: generating pseudocode information of multiple branches of the current multi-branch local satellite navigation signal through a multi-bit linear shift register; or generating pseudocode information of multiple branches of the current multi-branch local satellite navigation signal through a stored code generation unit.

[0084] Understandably, once the current multi-branch local satellite navigation signals are acquired, these signals can be used to generate pseudocode using a multi-bit linear shift register. This multi-bit linear shift register is changed from a typical 14-bit shift register unit to a register unit with more bits, enabling the generation of longer codes, thus meeting the pseudocode generation requirements of various satellite navigation signals such as ALTBOC and ALTBOC-like signals.

[0085] In some embodiments, after acquiring the current multi-branch local satellite navigation signals, these signals can be used to generate nonlinear shift register codes via a storage code generation unit. This storage code generation unit can be flexibly configured during initialization to meet the requirements for generating nonlinear shift register codes.

[0086] In the above implementation process, the current multi-branch local satellite navigation signals are generated through a multi-bit linear shift register or a storage code generation unit. Since the multi-bit linear shift register is a multi-digit register, it can process various satellite navigation signals and generate corresponding pseudo-code information. Because the storage code generation unit is configurable, it can be configured according to different actual situations, thus making it applicable to the generation of pseudo-codes for more satellite navigation signals and increasing the application scenarios of pseudo-code generation.

[0087] In one possible implementation, step 202 includes: performing despreading operation on the local satellite navigation signal and the digital intermediate frequency satellite navigation signal to obtain multiple energy values.

[0088] Understandably, when satellite navigation signals approach the ground, their signal power is lower than their noise power. By demodulating or despreading the intermediate frequency satellite navigation signal, the spreading gain can be obtained to successfully track the satellite navigation signal. The despreading operation here can be a complex number operation.

[0089] Demodulation here involves multiplying the carrier wave of the local satellite navigation signal with the digital intermediate frequency satellite navigation signal, while despreading involves multiplying the local code of the local satellite navigation signal with the digital intermediate frequency satellite navigation signal.

[0090] For example, for the E5 ALTBOC signal, the local satellite navigation signal can be represented by the following formula:

[0091]

[0092] Among them, E5 Altboc The local satellite navigation signal code is k(t), where k(t) is the phase and t is the time.

[0093] For the ACE-BOC signal of BDB2 (Beidou-2, the Beidou-2 satellite navigation system), the local satellite navigation signal can be represented by the following formula:

[0094]

[0095] Among them, E5 ACE-BOC The local satellite navigation signal code is k(t), where k(t) is the phase and t is the time.

[0096] Understandably, the above formulas for satellite navigation signals are merely illustrative, and different satellite navigation signals correspond to different formulas; this application does not impose any specific limitations.

[0097] In the above implementation process, by performing despreading operations on the local satellite navigation signal and the intermediate frequency satellite navigation signal, the influence of carrier wave, message or second-level code on table lookup can be removed, thereby making the information of each branch in the table more accurate and improving the accuracy of table lookup.

[0098] In one possible implementation, step 203 includes: performing coherent accumulation calculation and / or non-coherent accumulation calculation on the multiple energy values, and inputting the accumulation calculation result into the carrier ring and / or code ring.

[0099] The coherent accumulation calculation here involves superimposing the amplitudes of multiple energy values, thereby accumulating the power of the noise and improving the signal-to-noise ratio. The incoherent accumulation, on the other hand, is performed after the signal envelope is captured. At this point, the information of the complex signal is discarded, only the magnitude is retained, and there is no strict phase relationship.

[0100] Optionally, the multi-channel energy values ​​can be calculated using both coherent and incoherent accumulation, or only coherent accumulation, or only incoherent accumulation. The specific calculation method for the multi-channel energy values ​​can be adjusted according to the actual situation, and this application does not impose specific restrictions.

[0101] Understandably, the coherent accumulation result described above is used as input to the carrier loop. The incoherent accumulation result is used as input to the code loop.

[0102] The carrier loop here is used to adjust the carrier of the satellite navigation signal, and the code loop is used to adjust the pseudocode of the satellite navigation signal.

[0103] In the above implementation process, by performing coherent accumulation calculation on multiple energy values, the temporal continuity of the carrier phase can be maintained because this coherent accumulation calculation directly superimposes the amplitudes of the multiple energy values, and the signal-to-noise ratio can be improved through amplitude superposition. Alternatively, by performing incoherent accumulation calculation on multiple energy values, the information of the complex signal is discarded, only the magnitude is retained, and there are no strict phase relationship restrictions, which can expand the application scenarios of this multi-channel energy value calculation.

[0104] In one possible implementation, prior to step 202, the method further includes: performing down-conversion processing on the processed satellite navigation signal and the local carrier signal to obtain a digital zero-IF satellite navigation signal. Step 202 includes: performing computational processing on the local satellite navigation signal and the digital zero-IF satellite navigation signal to obtain multiple energy values.

[0105] The processed satellite navigation signal here is the satellite navigation signal after radio frequency processing and AD sampling processing.

[0106] The down-conversion process described above is used to convert a digital intermediate frequency (IF) signal into a digital zero IF signal. For example... Figure 3 As shown, the specific implementation process of this down-conversion process can be as follows:

[0107] like Figure 3 As shown, after performing complex multiplication of the processed satellite navigation signal's I and Q signals with the local carrier signal, it can be transformed into a zero-IF I signal and a zero-IF Q signal.

[0108] The local carrier signal here is generated by the phase of the carrier NCO, and then the phase-amplitude conversion is completed by the Sin / Cos list.

[0109] The following is based on Figure 4 Taking an example, the specific implementation process of the satellite navigation signal tracking method in this application embodiment is further described as follows:

[0110] After acquiring the satellite navigation signal, the antenna performs RF input and AD sampling processing on the signal, and then down-converts it with a local carrier signal group (which includes multiple local carrier signals) to obtain a digital zero-IF signal. Simultaneously, the pseudocodes of the in-phase I signal branch, in-phase Q signal branch, quadrature I signal branch, and quadrature Q signal branch from the acquired current multi-branch local satellite navigation signal are processed and used as input to a lookup table to obtain the local satellite navigation signal. Figure 4The diagram shows that the pseudocode of the in-phase Q signal branch, after being multiplied or XORed with the second-level code or message of the in-phase Q signal branch, is used as the input to the lookup table; the pseudocode of the quadrature Q signal branch, after being multiplied or XORed with the second-level code or message of the quadrature Q signal branch, is used as the input to the lookup table; the pseudocode of the in-phase I signal branch, after being multiplied or XORed with the second-level code or message of the in-phase I signal branch, is used as the input to the lookup table; the pseudocode of the quadrature I signal branch, after being multiplied or XORed with the second-level code or message of the quadrature I signal branch, is used as the input to the lookup table. After despreading the digital zero-IF signal and the local satellite navigation signal, coherent accumulation calculation and / or non-coherent accumulation calculation are performed, and the calculation results are input to the carrier loop and / or code loop. This carrier loop and / or code loop is used to adjust the pseudocode phase and carrier frequency of the current multi-branch local satellite navigation signals, thereby achieving tracking of the satellite navigation signals.

[0111] Understandably, Figure 4 The processing flow shown is a composite channel processing flow. In actual processing, there are multiple... Figure 4 The composite channel shown can be flexibly configured according to actual conditions. For example, it can track two broadband pilot signals in parallel or track only one broadband full-state signal.

[0112] For example, if a Figure 4 This is a processing flow for a processing channel. The carrier NCO group generates one carrier NCO1, which is configured as one wideband full-state channel. The output of the usage code NCO1 in the corresponding NCO group is fed to four code generation modules, generating one truncated code phase. The four tributary codes and the truncated code phase are input to a lookup table, configured to correspond to one ALTBOC full-state lookup table, capable of processing the full-bandwidth signal of one satellite. If there are M composite channels, then the wideband full-state signals of M satellites are processed.

[0113] If one Figure 4 This involves a two-channel processing flow. The carrier NCO group generates two carrier NCOs, which are configured as two wideband pilot channels. The output of the code NCO1 in the corresponding code NCO group is fed to two code generation modules, and the output of the code NCO2 is fed to another two code generation modules. Codes NCO1 and NCO2 each generate one truncated code phase. The combination of the two sets of two branch codes and one truncated code phase is input to a lookup table configured as an ALTBOC wideband pilot lookup table. This allows for parallel processing of pilot signals from two satellites. If there are M composite channels, it can process wideband pilot signals from 2M satellites, thus meeting the requirements of dual-antenna RF input or doubling the number of channels for wideband pilot signals. Under the condition of unchanged resources, this increases the flexibility to adapt to different scenarios.

[0114] In the above implementation process, by converting the digital intermediate frequency signal into a digital zero intermediate frequency signal, the carrier in the digital intermediate frequency signal can be removed, thereby improving the quality and reliability of the digital intermediate frequency signal.

[0115] Based on the same concept, this application also provides a satellite navigation signal tracking device corresponding to the satellite navigation signal tracking method. Since the principle of the device in this application is similar to that of the aforementioned satellite navigation signal tracking method, the implementation of the device in this application can refer to the description in the above-mentioned method embodiments, and the repeated parts will not be described again.

[0116] Please see Figure 5 This is a functional module diagram of the satellite navigation signal tracking device provided in this application embodiment. Each module in the satellite navigation signal tracking device in this embodiment is used to execute the steps in the above method embodiments. The satellite navigation signal tracking device includes a generation module 301, a processing module 302, a calculation module 303, and a tracking module 304; wherein,

[0117] The generation module 301 is used to generate local satellite navigation signals based on the lookup table and the current multi-branch local satellite navigation signals.

[0118] The processing module 302 is used to perform calculations on the local satellite navigation signal and the digital intermediate frequency satellite navigation signal to obtain multiple energy values.

[0119] The calculation module 303 is used to accumulate the energy values ​​of the multiple channels and input the accumulation calculation result into the carrier ring and / or code ring.

[0120] The tracking module 304 is used to track satellite navigation signals according to the carrier loop and / or the code loop.

[0121] In one possible implementation, the generation module 301 is further configured to: acquire pseudocode information of multiple branches of the current multi-branch local satellite navigation signal, and message or secondary code information of multiple branches; search for the pseudocode information and the current signal parameters corresponding to the message or secondary code information in a lookup table; and generate a local satellite navigation signal based on the current signal parameters, the pseudocode information, and the message or secondary code information.

[0122] In one possible implementation, the generation module 301 is specifically configured to: multiply or XOR the pseudocode information of each branch with the message or the secondary code corresponding to the branch according to the modulation information of the current multi-branch local satellite navigation signal; input the result of the multiplication or XOR processing into the lookup table; and search for the current signal parameters corresponding to the pseudocode information and the secondary code information in the lookup table.

[0123] In one possible implementation, the signal tracking device further includes an adjustment module for: acquiring the intercepted code phase in the pseudocode information; inputting the intercepted code phase into the lookup table; and adjusting the pseudocode information and the current signal parameters corresponding to the message or the secondary code information according to the intercepted code phase.

[0124] In one possible implementation, the generation module 301 is specifically used to: generate pseudo-code information of multiple branches of the current multi-branch local satellite navigation signal through a multi-bit linear shift register, wherein the multi-bit linear shift register is a multi-bit register unit; or generate pseudo-code information of multiple branches of the current multi-branch local satellite navigation signal through a storage code generation unit, wherein the storage code generation unit is configurable.

[0125] In one possible implementation, the processing module 302 is further configured to: demodulate or despread the local satellite navigation signal and the digital intermediate frequency satellite navigation signal to obtain multiple energy values.

[0126] In one possible implementation, the calculation module 303 is further configured to: perform coherent accumulation calculation and / or incoherent accumulation calculation on the multiple energy values, and input the accumulation calculation results into the carrier ring and / or code ring.

[0127] In one possible implementation, the signal tracking device further includes a preprocessing module for: performing down-conversion processing on the processed satellite navigation signal and the local carrier signal to obtain a digital zero-IF satellite navigation signal.

[0128] In one possible implementation, the processing module 302 is specifically used to: perform calculations on the local satellite navigation signal and the digital zero-IF satellite navigation signal to obtain multiple energy values.

[0129] To facilitate understanding of this embodiment, the electronic device that performs the satellite navigation signal tracking method disclosed in this application embodiment will be described in detail below.

[0130] like Figure 6 The diagram shown is a block illustration of an electronic device. The electronic device 100 may include a memory 111 and a processor 113. Those skilled in the art will understand that... Figure 6 The structure shown is for illustrative purposes only and does not limit the structure of the electronic device 100. For example, the electronic device 100 may also include components that are more... Figure 6 The more or fewer components shown, or having the same Figure 6 The different configurations shown.

[0131] The aforementioned memory 111 and processor 113 are electrically connected to each other directly or indirectly to enable data transmission or interaction. For example, these components can be electrically connected to each other via one or more communication buses or signal lines. The aforementioned processor 113 is used to execute executable modules stored in the memory.

[0132] The memory 111 can be, but is not limited to, Random Access Memory (RAM), Read Only Memory (ROM), Programmable Read-Only Memory (PROM), Erasable Programmable Read-Only Memory (EPROM), Electrically Erasable Programmable Read-Only Memory (EEPROM), etc. The memory 111 stores programs, and the processor 113 executes these programs upon receiving execution instructions. The methods executed by the electronic device 100 as defined in any embodiment of this application can be applied to or implemented by the processor 113.

[0133] The aforementioned processor 113 may be an integrated circuit chip with signal processing capabilities. The processor 113 may be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; it may also be a digital signal processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor may be a microprocessor or any conventional processor.

[0134] The electronic device 100 in this embodiment can be used to perform the various steps in the various methods provided in the embodiments of this application.

[0135] Furthermore, embodiments of this application also provide a computer-readable storage medium storing a computer program, which, when executed by a processor, performs the steps of the satellite navigation signal tracking method described in the above method embodiments.

[0136] The computer program product of the satellite navigation signal tracking method provided in this application includes a computer-readable storage medium storing program code. The instructions included in the program code can be used to execute the steps of the satellite navigation signal tracking method described in the above method embodiments. For details, please refer to the above method embodiments, which will not be repeated here.

[0137] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can also be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0138] In addition, the functional modules in the various embodiments of this application can be integrated together to form an independent part, or each module can exist independently, or two or more modules can be integrated to form an independent part.

[0139] If the aforementioned functions are implemented as software functional modules and sold or used as independent products, they 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, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks. It should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0140] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application. It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0141] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. A satellite navigation signal tracking method, characterized in that, include: Generate local satellite navigation signals based on the lookup table and current multi-branch local satellite navigation signals; The local satellite navigation signal and the digital intermediate frequency satellite navigation signal are processed to obtain multiple energy values; The energy values ​​from multiple paths are accumulated and the accumulated calculation result is input into the carrier loop and / or code loop; Satellite navigation signals are tracked according to the carrier loop and / or the code loop; The step of generating local satellite navigation signals based on a lookup table and current multi-branch local satellite navigation signals includes: Obtain the pseudocode information of multiple branches of the current multi-branch local satellite navigation signal, as well as the message or secondary code information of multiple branches; Search the lookup table for the pseudocode information and the current signal parameters corresponding to the message or the second-level code information; A local satellite navigation signal is generated based on the current signal parameters, the pseudocode information, and the message or the secondary code information; In a plurality of branches, a portion of the signals are modulated with a message, while another portion of the signals are modulated with a secondary code. The step of searching a lookup table for the pseudo-code information and the current signal parameters corresponding to the message or the secondary code information includes: Based on the modulation information of the current multi-branch local satellite navigation signals, the pseudo-code information of each branch is multiplied or XORed with the message or the secondary code corresponding to the branch; Input the result of the multiplication or XOR operation into the lookup table; The lookup table is used to find the pseudocode information and the current signal parameters corresponding to the message or the second-level code information.

2. The method according to claim 1, characterized in that, Before generating a local satellite navigation signal based on the current signal parameters, the pseudocode information, and the message or the secondary code information, the method further includes: Obtain the truncation phase from the pseudocode information; Input the intercepted code phase into the lookup table; The pseudocode information and the current signal parameters corresponding to the message or the second-level code information are adjusted according to the intercepted code phase.

3. The method according to claim 1, characterized in that, The step of obtaining the pseudocode information of multiple branches of the current multi-branch local satellite navigation signal includes: The pseudocode information of multiple branches of the current multi-branch local satellite navigation signal is generated by a multi-bit linear shift register, wherein the multi-bit linear shift register is a multi-bit register unit; or The pseudocode information of multiple branches of the current multi-branch local satellite navigation signal is generated by the storage code generation unit, which is configurable.

4. The method according to claim 1, characterized in that, The step of processing the local satellite navigation signal and the digital intermediate frequency satellite navigation signal to obtain multiple energy values ​​includes: The local satellite navigation signal and the digital intermediate frequency satellite navigation signal are demodulated or despread to obtain multiple energy values.

5. The method according to claim 1, characterized in that, The step of accumulating the energy values ​​from multiple sources and inputting the accumulation result into the carrier loop and / or code loop includes: Perform coherent and / or incoherent accumulation calculations on the multiple energy values, and input the accumulation calculation results into the carrier loop and / or code loop.

6. The method according to claim 1, characterized in that, Before performing calculations on the local satellite navigation signal and the digital intermediate frequency satellite navigation signal to obtain multiple energy values, the method further includes: The processed satellite navigation signal and local carrier signal are down-converted to obtain a digital zero-IF satellite navigation signal. The step of processing the local satellite navigation signal and the digital intermediate frequency satellite navigation signal to obtain multiple energy values ​​includes: The local satellite navigation signal and the digital zero-IF satellite navigation signal are processed to obtain multiple energy values.

7. A satellite navigation signal tracking device, characterized in that, include: The generation module is used to generate local satellite navigation signals based on the lookup table and the current multi-branch local satellite navigation signals; The processing module is used to perform calculations on the local satellite navigation signal and the digital intermediate frequency satellite navigation signal to obtain multiple energy values; The calculation module is used to accumulate the energy values ​​from multiple sources and input the accumulated calculation results into the carrier loop and / or code loop; The tracking module is used to track satellite navigation signals based on the carrier loop and / or the code loop; The generation module is also used to obtain the pseudocode information of multiple branches of the current multi-branch local satellite navigation signal, as well as the message or secondary code information of multiple branches. In a plurality of branches, a portion of the signals are modulated with a message, while another portion of the signals are modulated with a second-level code; the pseudo-code information and the current signal parameters corresponding to the message or the second-level code information are searched in a lookup table; a local satellite navigation signal is generated based on the current signal parameters, the pseudo-code information, and the message or the second-level code information. The generation module is specifically used to multiply or XOR the pseudocode information of each branch with the message or the second-level code corresponding to the branch according to the modulation information of the current multi-branch local satellite navigation signal; Input the result of the multiplication or XOR operation into the lookup table; The lookup table is used to find the pseudocode information and the current signal parameters corresponding to the message or the second-level code information.

8. An electronic device, characterized in that, include: The processor and memory, wherein the memory stores machine-readable instructions executable by the processor, wherein when the electronic device is running, the machine-readable instructions are executed by the processor to perform the steps of the method as described in any one of claims 1 to 6.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a computer program that, when executed by a processor, performs the steps of the method as described in any one of claims 1 to 6.

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