Time division satellite navigation signal tracking method and device, storage medium, program product, circuit and used pseudo code generator

Abstract

The invention discloses a time division satellite navigation signal tracking method and device, a storage medium, a program product, a circuit and a used pseudo code generator, relates to the field of satellite navigation, and is used for improving the timeliness of loop state updating and reducing the complexity of a loop system. The method comprises the following steps: carrying out carrier stripping on an intermediate frequency signal of an obtained time division satellite navigation signal by using a local carrier signal; carrying out code stripping by using the local pseudo code signal, grouping pseudo code copies which can be shared in the local pseudo code signal, and carrying out code stripping on the signal after carrier stripping by taking the group as a unit; carrying out integral zero clearing operation on the signal after code stripping to obtain a coherent result; and finally, respectively updating the local carrier signal and the local pseudo code signal based on a coherent result. According to the invention, the time-division satellite navigation signals can be continuously tracked, and the demand quantity of the coherent device is reduced.

Description

Technical Field

[0001] The present invention relates to the field of satellite navigation technology, and in particular to a time-division satellite navigation signal tracking method, device, storage medium, program product, circuit and pseudo code generator used therein. Background Art

[0002] For satellite navigation and positioning systems, the rapid reception of navigation messages is crucial to the performance of terminal positioning and navigation. In order to increase the transmission rate of navigation message information and thus improve the real-time performance of navigation message reception, two methods can usually be adopted: one is to increase the code rate of the local pseudo-code signal, such as the pseudo-random code (PseudoRandom Noise, PRN), but this will lead to an increase in the spectrum width of the satellite navigation signal; the other is to shorten the chip length of the PRN code, but this will reduce the orthogonality of the PRN code and the quality of information transmission.

[0003] In order to better meet the technical requirements of the positioning and navigation system, some researchers have proposed a coding method that uses PRN sequences of equal length to represent different symbols, such as CSK (Code Shift Keying). Each waveform of CSK modulation is obtained from different cyclic phase shifts of a single basic PRN sequence, so that more information can be transmitted in the same code period without increasing the length of the PRN code, and thus has a higher information transmission rate. However, since CSK has multiple cyclic shifts of PRN codes in the same time slot, the corresponding symbols cannot be directly reproduced locally, so it is impossible to modulate the satellite navigation signal alone. When used, it requires the assistance of other signal components, such as BPSK (Binary PhaseShift Keying), etc., to form a time-division BPSK-CSK satellite navigation signal.

[0004] Time-division BPSK-CSK satellite navigation signals refer to the BPSK (direct spread spectrum) signals and CSK signals sent alternately in a time-division manner, and the PRN codes used by the two signals have the same code length and period. However, the known tracking methods for time-division BPSK-CSK satellite navigation signals are as follows: Figure 1 As shown in the figure, it only updates the loop (carrier tracking loop PLL (Phase Locked Loop) and code tracking loop DLL (Delay Locked Loop)) status in the BPSK signal time slot, and maintains the loop status unchanged in the CSK signal time slot, which results in poor timeliness of loop status update and convergence time. In addition, in the code stripping link of the CSK signal time slot, the demand for coherent devices is large, and the loop system complexity is high. Summary of the invention

[0005] The object of the present invention is to provide a time-division satellite navigation signal tracking method, device, storage medium, program product, circuit and pseudo code generator used to improve the timeliness of loop status update and reduce the complexity of the loop system in order to solve all or part of the above-mentioned problems.

[0006] The technical solution adopted by the present invention is as follows: A time-division satellite navigation signal tracking method, comprising: Acquire the intermediate frequency signal of the time-division satellite navigation signal; Using a local carrier signal to perform carrier stripping on the intermediate frequency signal; Using a local pseudo code signal to perform code stripping on the signal after carrier stripping; wherein pseudo code copies that can be shared in the local pseudo code signal are grouped, and code stripping is performed on the signal after carrier stripping in groups; Perform integration and zeroing operation on the signal after code stripping to obtain a coherent result; The local carrier signal and the local pseudo code signal are updated respectively based on the coherence result.

[0007] To solve the above problem, the present invention also provides a device, including a processor and a storage medium, wherein the storage medium stores computer instructions, and when the processor runs the computer instructions, it executes the above-mentioned time-division satellite navigation signal tracking method.

[0008] In order to solve the above-mentioned problem, the present invention further provides a computer-readable storage medium storing a computer program, and running the computer program can execute the above-mentioned time-division satellite navigation signal tracking method.

[0009] To solve the above problem, the present invention further provides a computer program product, including a computer program. When the computer program is executed by a processor, the above time-division satellite navigation signal tracking method can be executed.

[0010] On the other hand, the present invention also provides a pseudo code generator, which is configured to: generate a local pseudo code signal required for code stripping of the signal after carrier stripping, group the pseudo code copies that can be shared in the local pseudo code signal for use in group units to code strip the signal after carrier stripping; the signal after carrier stripping is obtained by carrier stripping the intermediate frequency signal of the time-division satellite navigation signal using the local carrier signal.

[0011] To solve the above problem, the present invention further provides a time-division satellite navigation signal tracking circuit, comprising a PLL and a DLL, wherein the above pseudo code generator is arranged on the DLL.

[0012] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: For each time slot of the time-division satellite navigation signal, the present application obtains the intermediate frequency signal of the time-division satellite navigation signal, and further performs carrier stripping, code stripping, and integral zeroing to obtain a coherent result, and then updates the loop state based on the coherent result, that is, continuous tracking in each time slot is achieved, and the timeliness of signal tracking is improved, thereby improving the loop convergence speed and tracking performance, and avoiding the phase error and frequency error accumulated due to the failure to update the loop state in a certain time slot. In addition, for the situation where there is a shared local pseudo-code signal, that is, when there is a shared local pseudo-code signal in a certain time slot, the shared pseudo-code copies are grouped, and the code stripping is performed in groups, so that the pseudo-code copies of the same group only need one coherent device, which greatly reduces the complexity of the loop system and improves the reliability of signal tracking compared to the original loop system in which each pseudo-code copy requires a coherent device. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The present invention will now be described by way of example with reference to the accompanying drawings, in which: Figure 1 This is the structure diagram of the existing time-division BPSK-CSK satellite navigation signal.

[0014] Figure 2 It is a flow chart of the time-division satellite navigation signal tracking method provided in an embodiment of the present application.

[0015] Figure 3 It is a structural diagram of the time-division BPSK-CSK satellite navigation signal in an embodiment of the present application.

[0016] Figure 4 This is an example diagram of the CSK code word generation process in an embodiment of the present application.

[0017] Figure 5 It is an equivalent diagram of a CSK signal time slot code generator in one embodiment of the present application.

[0018] Figure 6 It is a structure diagram of a loop system executed by the time-division satellite navigation signal tracking method provided in an embodiment of the present application.

[0019] Figure 7 It is an equivalent diagram of the CSK signal time slot code generator in another embodiment of the present application. DETAILED DESCRIPTION

[0020] All features disclosed in this specification, or steps in all methods or processes disclosed, except mutually exclusive features and / or steps, can be combined in any manner.

[0021] Any feature disclosed in this specification (including any additional claims and abstract), unless otherwise stated, may be replaced by other alternative features that are equivalent or have similar purposes. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0022] In view of the fact that CSK signals cannot be used alone for satellite navigation signal encoding, and the existing time-division BPSK-CSK satellite navigation signal tracking method has the problem of poor timeliness of loop state update and convergence time due to maintaining the loop state unchanged in the CSK signal time slot, and the problem that the existing time-division BPSK-CSK satellite navigation signal tracking method has an excessively large demand for coherent devices in the CSK signal time slot, the embodiments of the present application provide a time-division satellite navigation signal tracking method, device, storage medium, program product, circuit and pseudocode generator used, which are intended to achieve continuous tracking of the time-division BPSK-CSK satellite navigation signal in each time slot and reduce the demand for coherent devices in the loop system.

[0023] In some embodiments, Figure 2 As shown, the time-division satellite navigation signal tracking method provided in the embodiment of the present application includes the following steps: S1. Obtain an intermediate frequency signal of a time-division satellite navigation signal.

[0024] The time-division satellite navigation signal contains signals with different coding methods. These signals are sent in sequence and at periodic intervals in a time-division manner. The code length and period of each time slot are the same. Taking the time-division BPSK-CSK satellite navigation signal as an example, its signal structure is as follows: Figure 3 As shown, the entire transmission frame period is seconds, The BPSK signal and the CSK signal are sent alternately in a time-division manner at intervals of seconds. The BPSK signal adopts direct spread spectrum. After the navigation message data and the local pseudo code signal are subjected to modulo-2 operation to obtain the spread spectrum baseband signal, BPSK modulation is performed to obtain the BPSK signal. The CSK signal represents different CSK code words by cyclically shifting the initial local pseudo code signal by different bits to obtain pseudo code copies in different phase states. The code length is The local pseudo code signal is phase states, which can represent at most Different CSK code words. Using PRN code as the local pseudo code signal, The PRN code of binary CSK modulation is first obtained by cyclic shifting through the code delayer Code sequences with different cyclic shift bits To express The code delays between different CSK code words are equal and can be 1 or Chip time Therefore, the number of bits of information that can be transmitted by a CSK codeword is U=log 2 M , then the CSK signal can be expressed as , is the chip length of the cyclic shift interval. Figure 4 Shown Schematic diagram of modulation symbol generation, where the PRN code length is , the cyclic shift interval between different symbols is 1 chip. Two modulation signals are sent within seconds The two signals use different PRN codes, and the code period is seconds, the code length and code rate are the same and , the chip width is , then the code period is , frame period The symbol period of BPSK signal and CSK signal is the code period. An integer multiple of , that is, a symbol contains 1 to code cycle.

[0025] The acquired time-division satellite navigation signal is down-converted to obtain an intermediate frequency signal. In some feasible implementations, the time-division satellite navigation signal is initially filtered, down-converted to obtain an analog intermediate frequency signal, and further analog-to-digital conversion is performed to obtain a digital intermediate frequency signal.

[0026] S2. Use the local carrier signal to perform carrier stripping on the intermediate frequency signal.

[0027] The local carrier signal is usually generated by a carrier numerically controlled oscillator (NCO), and the local carrier signal includes a local sine carrier and a local cosine carrier.

[0028] In some feasible implementations, the (digital) intermediate frequency signal obtained in step S1 is multiplied with the local sine carrier and the local cosine carrier respectively to complete carrier stripping, and an in-phase branch (I branch) signal and a quadrature branch (Q branch) signal are obtained accordingly.

[0029] As an optional implementation, assuming that the time-division satellite navigation signal is Figure 3 The time-division BPSK-CSK satellite navigation signal shown in FIG. 1 includes a BPSK signal and a CSK signal. and They represent the acquired digital intermediate frequency BPSK signal and CSK modulation signal respectively. is the sampling interval, is the sampling point number, then: , , Among them is Signal amplitude; is the angular frequency of the intermediate frequency signal carrier; Indicates the navigation message data carried by the BPSK signal; A PRN code sequence representing a BPSK signal; Indicates the code word corresponding to the CSK signal; Indicates the initial phase of the signal; and All are Gaussian white noise signals; Represents the time slot number, which is an integer and .

[0030] Assuming a local sinusoidal carrier and the local cosine carrier They are: , , in is the angular frequency of the carrier signal generated locally by the receiver (the corresponding frequency is expressed as ); Indicates the initial phase of the locally generated carrier signal.

[0031] Digital IF signal and Respectively with the local sinusoidal signal and the local cosine signal Mixing is performed to obtain the I branch signal and the Q branch signal, which are: , , , , in, and They are and and The multiplication result of and They are and and The multiplication result of , , , , and They are the results of mixing the noise in the BPSK signal and the CSK signal with the local carrier signal.

[0032] The carrier signal can be stripped by the above-mentioned mixing operation, and then the high-frequency components can be filtered out by subsequent integration.

[0033] S3. Use the local pseudo code signal to perform code stripping on the signal after the carrier stripping.

[0034] The local pseudo code signal is usually generated by a code generator. In the embodiment of the present application, the code generator generates a PRN sequence as the local pseudo code signal. Usually, the local pseudo code signal includes an advanced pseudo code copy E, an immediate pseudo code copy P, and a delayed pseudo code copy L. The phase difference between E and P, and between P and L is equal, which is a predetermined chip length, such as 0.5 chip. The signal after carrier stripping will be multiplied by E, P, and L respectively to complete the code stripping.

[0035] For signals with different coding methods, the code stripping methods are different. Assuming that the time-division satellite navigation signal includes a BPSK signal, then in the BPSK signal time slot, step S3 includes: The signal after carrier stripping of the I branch is expressed as , the signal after carrier stripping of the Q branch is expressed as , the signal and The code stripping of the BPSK signal time slot is completed by multiplying them with the pseudo code replicas E, P, and L generated by the code generator respectively.

[0036] Assuming that the time-division satellite navigation signal includes a CSK signal, then in the CSK signal time slot, step S3 includes: The code generator is for M-ary CSK signal Generate M groups of local pseudo code copies locally, each group contains an advance pseudo code copy E, an immediate pseudo code copy P and a delayed pseudo code copy L. , the corresponding pseudo-code copy is expressed as , and ,in, and between, and The phase difference between them is 0.5 chip. , and There are three initial pseudo code copies, and the local pseudo code copies of the remaining groups are obtained by cyclic shifting the initial local pseudo code copies according to a set phase offset (such as 1 code word).

[0037] Since the phase shift between the instantaneous pseudo-code copies of the code words corresponding to adjacent CSK code words is fixed, some local pseudo-code copies between different pseudo-code copy groups are consistent. For example, , the cyclic phase shift between different CSK code words is 1 chip, so the leading pseudo-code copy of the previous symbol and the lagged pseudo-code copy of the next symbol For the same code word, they can be shared, that is In order to reduce the complexity of the loop system and keep the matching degree between the loop state update amount and the signal dynamic change amount as much as possible, the embodiment of the present application groups the pseudo code copies that can be shared in the local pseudo code signal in the CSK signal time slot, and performs code stripping on the signal after carrier stripping in groups. Taking the CSK signal in the above embodiment as an example, , then as an optional implementation, in the CSK signal time slot, the sequence length of the pseudo code replicas generated by the code generator is the same, the advance pseudo code replicas and the lagging pseudo code replicas that can be shared in the local pseudo code signal are grouped, and then the signal after carrier stripping is stripped is stripped in groups, which can reduce the demand for coherent devices. For example, the generated local advance pseudo code replicas with different phase shifts are accumulated according to the phase offset of 4 code chips (adjustable), that is, the advance pseudo code replicas and the lagging pseudo code replicas that can be shared are accumulated according to the predetermined phase offset of 4 code chips to form the sum of 4 groups of advance pseudo code replicas, that is, the pseudo code replica group ,in: , , , .

[0038] In this way, the local pseudo code signal generated by the code generator can be equivalent to Figure 5 The form shown, that is, only contains and The signal after carrier stripping of branch I is expressed as , the signal after carrier stripping of the Q branch is expressed as , the signal and Respectively and Multiplication, that is, multiplying the pseudo code replica group with the carrier stripped signal in groups, completes the code stripping of the carrier stripped signal. In this way, not only can the demand for coherent devices be reduced, but also the coherent calculation speed can be ensured, and the timeliness of signal tracking can be guaranteed.

[0039] S4. Perform an integration and zeroing operation on the signal after code stripping to obtain a coherent result.

[0040] Taking the time-division BPSK-CSK satellite navigation signal as an example, the signals after the BPSK signal time slot is stripped of the code are integrated and cleared to obtain the coherent result. , , , , , ,in By signal It is multiplied by the pseudo-code copy E generated by the code generator and the integral is cleared to zero, and , , , , Similarly, the coherent processing (code stripping and integral zeroing) of the signal after carrier stripping is completed. Similarly, after the signal after code stripping of the CSK signal time slot is integrally cleared, the coherent result is obtained. , , , ,in Depend on and After multiplication, the integral is cleared to zero and we get: , , Similarly. Therefore, the number of coherent devices required is only , and before grouping the pseudo-code copies that can be shared, the number of coherent devices required is , in comparison, the embodiment of the present application reduces The complexity of the loop system is greatly reduced by using a coherent device.

[0041] S5. Update the local carrier signal and the local pseudo code signal respectively based on the coherence result.

[0042] In addition to the coherent device, the signal tracking loop system mainly includes PLL and DLL. PLL mainly includes carrier phase detector, carrier loop filter and carrier NCO. DLL mainly includes code NCO, code generator, code loop phase detector and code loop filter. The local carrier signal generated by the carrier NCO includes local sine carrier and local cosine carrier. The intermediate frequency signal is multiplied with the local sine carrier and the local cosine carrier respectively to complete the carrier stripping. Afterwards, the in-phase branch signal and the orthogonal branch signal are multiplied with the local pseudo-code signal (including E, P, L) generated by the code generator (separately or in groups) to complete the code stripping. The branch signals of the code stripping are integrated and cleared to obtain the coherent result. For the BPSK signal time slot, the coherent result is expressed as 、 、 、 、 、 For the CSK signal time slot, multiple sets of coherent results will be obtained, and the symbol corresponding to the maximum coherent result will be used as the received CSK codeword , that is, traverse the coherent results corresponding to the instantaneous pseudo-code copies corresponding to each CSK codeword, and obtain the CSK codeword corresponding to the maximum coherent result. In the case where the local pseudo-code signal is not grouped, its coherent result is expressed as 、 、 、 、 、 , and when the local pseudo code signal is grouped, the coherence result is expressed as 、 、 、 In the BPSK signal time slot, and The phase error between the intermediate frequency signal and the local carrier is obtained by inputting it into the carrier loop phase detector. The local carrier phase error is filtered by the carrier loop filter and then the local carrier signal generated by the carrier NCO is adjusted to keep the local carrier signal and the input intermediate frequency signal carrier at the same frequency and phase. , , and The code phase error of the local pseudo code signal relative to the input intermediate frequency signal is obtained by inputting the code loop phase detector. The code phase error is then filtered by the code loop filter and passed to the code NCO to adjust the time when the code generator generates the local pseudo code signal to keep the local pseudo code signal consistent with the pseudo code phase in the received intermediate frequency signal. When the correlation result of the branch is the largest, the code generator is adjusted to generate the local pseudo code signal in advance; When the code correlation result is the largest, it means that the code tracking loop has correctly tracked the signal; when When the correlation result of the code is the largest, the code generator delay is adjusted to generate the local pseudo code signal; finally, the dynamic adjustment of the entire code tracking loop is completed to achieve the locking of the code tracking loop. The corresponding local pseudo code signal is used to update the local carrier signal and the local pseudo code signal. and Input to the carrier loop phase detector to obtain the local carrier phase error. 、 、 、 or 、 The code phase error of the local pseudo code signal relative to the input intermediate frequency signal is obtained by inputting it into the code loop phase detector, and the rest of the tracking process is the same as the BPSK signal time slot.

[0043] like Figure 6 The basic architecture of the loop system for time-division satellite navigation signal tracking in some optional embodiments of the present application is shown. With reference to the architecture, it can be seen that, as an optional implementation, the present application uses carrier-assisted code loop tracking to perform signal tracking. Specifically, in some feasible implementations, the output result of the carrier loop filter passes through a scaler (generating a scale factor) and is added to the output result of the code loop filter, and the added sum is used to control the output state of the code NCO.

[0044] Then, in the embodiment of the present application, step S5 includes: S51, updating the state of the carrier tracking loop PLL based on the coherent result corresponding to the instant pseudo code replica to update the local carrier signal; S52, updating the state of the code tracking loop DLL based on the coherent results corresponding to the leading pseudo code replica and the lagging pseudo code replica, and weighting the update result of the PLL to the update result of the DLL with a predetermined proportional factor to update the local pseudo code signal.

[0045] The scaling factor is needed because the Doppler effect on the carrier signal is inversely proportional to the wavelength of the signal. Therefore, for the same relative speed between the satellite transmitter and the receiver, the Doppler effect on the spread spectrum code chip rate is much smaller than the Doppler effect on the carrier, so a scaling factor is needed to weight the Doppler effect on the carrier signal and then apply it to the code tracking loop. In some possible implementations, the scaling factor that compensates for this frequency difference is given by the following formula: Scaling factor = (spread spectrum chip rate + Doppler effect) / local carrier frequency.

[0046] According to the above embodiment, the demand for coherent devices in CSK signal time slots can be greatly reduced, and the complexity of the loop system can be reduced. In another optional implementation, the embodiment of the present application can further reduce the demand for coherent devices in CSK signal time slots, while keeping the loop as timely updated as possible to adapt to dynamic changes in the signal. In this implementation, for the CSK signal time slot, step S3 also includes: The instantaneous pseudo code copies in the local pseudo code signal are grouped together.

[0047] Taking the CSK signal of M codes as an example, the instantaneous pseudo-code copies of each group in the M groups of local pseudo-code signals generated by the code generator are Assigned to a group, still in group units, the signal after the pseudo code copy group and the carrier are stripped and Multiplying them for code stripping can further reduce the required number of correlators to 2, and the local pseudo code signal generated by the code generator can always have a peak value aligned with the mixing results of the in-phase branch and the orthogonal branch.

[0048] In some possible implementations, instantaneous pseudo-code copies belonging to a group The grouping is completed by accumulation. At this time, the code generator is equivalent to Figure 7 The structure shown. The accumulated pseudo-code copies and are then respectively combined with the signal and After code stripping and integration clearing, the carrier phase error is calculated by the carrier loop identifier to perform the subsequent carrier tracking loop state update process. In this embodiment, the code phase error cannot be calculated in the CSK signal time slot, so the state of the code tracking loop cannot be updated. The signal tracking method is based on The carrier tracking loop status is updated periodically (that is, the local carrier signal is updated). In order to periodically update the code tracking loop status (i.e., the local pseudo-code signal), although the status of the PLL and DLL are not updated in each time slot, continuous tracking of the satellite navigation signal in each time slot is still achieved, which is suitable for signal tracking in a high dynamic environment.

[0049] As mentioned above, for the CSK signal time slot, multiple sets of coherent results will be obtained, and the symbol corresponding to the maximum coherent result needs to be selected as the received CSK codeword. As an optional implementation, the CSK code word is selected The methods include: The coherence results of the instantaneous pseudo-code copies corresponding to each CSK codeword in the in-phase branch and the orthogonal branch are respectively traversed; among them, the coherence result of the in-phase branch is expressed as , the coherence result of the orthogonal branch is expressed as .

[0050] A CSK codeword having the largest envelope of the coherence results in the in-phase branch and the quadrature branch is obtained.

[0051] In some feasible implementations, assuming that the CSK codeword to be searched is The codeword index is represented as , then: , in, Indicates CSK codeword The envelope of the coherence result of the instantaneous pseudo code copy in the in-phase branch and the orthogonal branch.

[0052] For CSK signal time slots, since CSK signals carry data only through cyclic shift of PRN codes, there is no phase flip, so the carrier phase error It can be calculated by the following formula: This calculation method has a larger phase detection range.

[0053] The carrier phase error After passing through the carrier loop filter, it is fed back to the carrier NCO to adjust the local carrier signal phase and frequency to achieve the status update of the carrier tracking loop.

[0054] In some optional implementations, after obtaining the index Afterwards, according to and Get the index value of the adjacent leading and lagging pseudo code copy group and , and use the incoherent early-late envelope discriminator to obtain the code phase error .

[0055] In some feasible implementations, the code loop identifier calculates the code phase error by the following formula: : .

[0056] The code phase error is obtained After being filtered by the DLL loop filter, the phase of the code NCO is adjusted by the joint carrier-assisted Doppler shift to control the phase of the codeword of the local pseudo code signal, thereby realizing the state update of the CSK signal time slot code tracking loop.

[0057] In order to further reduce the complexity of the loop system, as an optional implementation, the instantaneous pseudo code replica of the local pseudo code signal of the BPSK signal time slot , multiplex the initial instantaneous pseudo code copy of the local pseudo code signal of the adjacent CSK signal time slot .

[0058] In general, the time-division satellite navigation signal tracking method provided in the embodiment of the present application ensures the continuous tracking of the time-division satellite navigation signal, the loop state update speed is fast, so the loop convergence and locking speed is faster, the cumulative error of each time slot is small, so the loop tracking error is small, and the signal tracking accuracy and navigation positioning accuracy are improved.

[0059] In some embodiments, the device provided by the embodiments of the present application includes a processor and a storage medium, in which computer instructions are stored. When the processor runs the computer instructions, the time-division satellite navigation signal tracking method of the above embodiment can be executed.

[0060] In some embodiments, the computer-readable storage medium provided in the embodiments of the present application stores a computer program, and running the computer program can execute the time-division satellite navigation signal tracking method of the above-mentioned embodiments.

[0061] In some embodiments, the computer program product provided by the embodiments of the present application includes a computer program, which, when executed by a processor, can execute the time-division satellite navigation signal tracking method of the above-mentioned embodiments.

[0062] In the embodiments of the present application, the storage medium mentioned may be any available medium that can be accessed by a computer or a data storage device such as a server or a data center that integrates one or more available media. The so-called available medium may be a magnetic medium, such as a floppy disk, a hard disk, a magnetic tape, etc.; it may also be an optical medium, such as a digital video disc (DVD), etc.; it may also be a semiconductor medium, such as a solid state drive (SSD), etc. The processor mentioned is a facility that has a signal reading function and a certain computing power, including but not limited to a central processing unit (CPU), a graphics processing unit (GPU), various dedicated computing chips or computing units, a digital signal processor (DSP), and any equipment or device integrated with the above facilities.

[0063] According to the concept of the present application, a pseudo code generator (or code generator) is also provided in an embodiment of the present application, which is configured to: generate a local pseudo code signal required for code stripping of the signal after carrier stripping, group the pseudo code copies that can be shared in the local pseudo code signal, so as to perform code stripping on the signal after carrier stripping in groups. The signal after carrier stripping is obtained by carrier stripping the intermediate frequency signal of the time-division satellite navigation signal using the local carrier signal. The pseudo code generator can reduce the number of coherent devices when coherently processing the signal in the code stripping stage, and improve the processing speed.

[0064] In addition, an embodiment of the present application also provides a time-division satellite navigation signal tracking circuit, which constitutes a loop for time-division satellite navigation signal tracking. The time-division satellite navigation signal tracking circuit includes a PLL and a DLL, wherein the pseudo-code generator of the above-mentioned embodiment is arranged on the DLL to generate a local pseudo-code signal required for code stripping of the signal after carrier stripping in the code stripping stage, and group the pseudo-code copies that can be shared in the local pseudo-code signal to reduce the number of coherent devices required for coherent processing in the code stripping stage.

[0065] The present invention is not limited to the above-mentioned specific embodiments, but extends to any new features or any new combination disclosed in this specification, as well as any new method or process steps or any new combination disclosed.

Claims

1. A time-division satellite navigation signal tracking method, characterized in that: include: Acquire the intermediate frequency signal of the time-division satellite navigation signal; Using a local carrier signal to perform carrier stripping on the intermediate frequency signal; Using a local pseudo code signal to perform code stripping on the signal after carrier stripping; wherein pseudo code copies that can be shared in the local pseudo code signal are grouped, and code stripping is performed on the signal after carrier stripping in groups; Perform integration and zeroing operation on the signal after code stripping to obtain a coherent result; The local carrier signal and the local pseudo code signal are updated respectively based on the coherence result.

2. The time-division satellite navigation signal tracking method according to claim 1, characterized in that: Grouping the pseudo code copies that can be shared in the local pseudo code signal, including: The pseudo code replicas that can be shared in the local pseudo code signal are accumulated according to a predetermined phase offset to form a corresponding pseudo code replica group.

3. The time-division satellite navigation signal tracking method according to claim 1, characterized in that: The code stripping of the signal after the carrier stripping in groups includes: The signal after the carrier stripping is multiplied in groups.

4. The time-division satellite navigation signal tracking method according to any one of claims 1 to 3, characterized in that: The local pseudo code signal includes an advanced pseudo code copy, an immediate pseudo code copy and a delayed pseudo code copy; Grouping the pseudo code copies that can be shared in the local pseudo code signal, including: The advanced pseudo code replica and the delayed pseudo code replica that can be shared in the local pseudo code signal are grouped.

5. The time-division satellite navigation signal tracking method according to claim 4, characterized in that: Updating the local carrier signal and the local pseudo code signal respectively based on the coherence result, comprising: Update the state of a carrier tracking loop PLL based on the coherence result corresponding to the instantaneous pseudo code copy to update the local carrier signal; The state of the code tracking loop DLL is updated based on the coherent results corresponding to the leading pseudo code replica and the lagging pseudo code replica, and the update result of the PLL is weighted to the update result of the DLL with a predetermined proportional factor to update the local pseudo code signal.

6. The time-division satellite navigation signal tracking method as claimed in claim 4, characterized in that: The time-division satellite navigation signal comprises a code shift keying CSK signal; In the CSK signal time slot, the local carrier signal and the local pseudo code signal are updated respectively based on the coherence result, including: Traverse the coherent results corresponding to the instantaneous pseudo-code copies corresponding to each CSK codeword, and obtain the CSK codeword corresponding to the maximum coherent result; Based on the obtained coherence result corresponding to the local pseudo code signal corresponding to the CSK code word, the local carrier signal and the local pseudo code signal are updated respectively.

7. The time-division satellite navigation signal tracking method according to claim 6, characterized in that: The traversing the coherent results corresponding to the instantaneous pseudo-code copies corresponding to each CSK codeword to obtain the CSK codeword corresponding to the maximum coherent result includes: The coherent results of the instantaneous pseudo code copies corresponding to each CSK code word in the in-phase branch and the orthogonal branch are respectively traversed; A CSK codeword having the largest envelope of the coherence results in the in-phase branch and the quadrature branch is obtained.

8. The time-division satellite navigation signal tracking method according to claim 4, characterized in that: The time-division satellite navigation signal includes a binary phase shift keying BPSK signal and a CSK signal; an instantaneous pseudo code copy of a local pseudo code signal of a BPSK signal time slot, and an initial instantaneous pseudo code copy of a local pseudo code signal of an adjacent CSK signal time slot is multiplexed.

9. The time-division satellite navigation signal tracking method according to claim 6, characterized in that: In the CSK signal time slot, the code stripping of the signal after carrier stripping by using the local pseudo code signal also includes: The instantaneous pseudo code copies in the local pseudo code signal are grouped into one group.

10. The time-division satellite navigation signal tracking method according to claim 9, characterized in that: The instantaneous pseudo code copies in the local pseudo code signal are divided into a group as follows: Accumulate the instantaneous pseudo code replicas in the local pseudo code signal.

11. A device comprising a processor and a storage medium, wherein the storage medium stores computer instructions, characterized in that: When the processor runs the computer instructions, it executes the time-division satellite navigation signal tracking method as described in any one of claims 1-10.

12. A computer-readable storage medium storing a computer program, characterized in that: Running the computer program can execute the time-division satellite navigation signal tracking method as described in any one of claims 1-10.

13. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the time-division satellite navigation signal tracking method as described in any one of claims 1-10 can be executed.

14. A pseudo code generator, configured to generate a local pseudo code signal required for code stripping of a carrier stripped signal, wherein the carrier stripped signal is obtained by stripping the carrier of an intermediate frequency signal of a time-division satellite navigation signal using a local carrier signal; characterized in that: The pseudo code generator is further configured to group the pseudo code replicas that can be shared in the local pseudo code signal, so as to perform code stripping on the carrier-stripped signal in groups.

15. A time-division satellite navigation signal tracking circuit, comprising a PLL and a DLL, characterized in that: The pseudo code generator as claimed in claim 14 is arranged on the DLL.

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