A composite loop tracking method, system, computer equipment and storage medium for an anti-interference navigation signal receiver

Abstract

The present application discloses a composite loop tracking method for an anti-interference navigation signal receiver, the method comprising: replicating the pseudo code and carrier corresponding to the satellite signal based on the coarse capture signal; performing coherent operation to obtain a coherent integral value; performing FLL frequency discrimination, PLL phase discrimination, and FFT frequency discrimination on the coherent integral value, and performing weighted processing to obtain a frequency error; performing carrier loop filtering on the frequency error to output a carrier loop tracking result; performing incoherent accumulation to obtain an incoherent integral result and performing DLL phase discrimination to obtain an epoch code loop phase difference; performing code loop filtering on the epoch code loop phase difference to output a code loop tracking result; calculating the first frequency control word corresponding to the code loop according to the wave loop tracking result; and controlling the code loop update based on the first frequency control word and the code loop tracking result. The present application realizes stable tracking of navigation signals that can meet different dynamic and interference scenarios.

Description

Technical Field

[0001] The present application belongs to the technical field of satellite navigation signal reception, and in particular relates to a composite loop tracking method and system for an anti-interference navigation signal receiver. Background Art

[0002] The navigation satellite is far away from the ground and the navigation signal transmission power is limited. When the satellite navigation signal reaches the ground receiving antenna, it is already very weak and submerged in the noise. Therefore, it is difficult to complete stable tracking of the navigation signal in a complex environment.

[0003] In the satellite signal tracking stage, the signal channel starts with the rough estimate of the current satellite signal carrier frequency and code phase obtained in the capture stage, and gradually refines the estimation of these two signal parameters through the tracking loop, while outputting various measurement values ​​of the signal and demodulating the navigation message data bits. The signal tracking loop is actually composed of two parts: the carrier tracking loop (referred to as the carrier loop) and the code tracking loop (referred to as the code loop), which are used to track the carrier and pseudo code in the received signal respectively.

[0004] Traditional carrier tracking loops generally use PLL or FLL. When the signal strength weakens under various complex interference conditions, the errors of these loops will increase rapidly or even lose lock, making it difficult to adapt to complex interference environments such as indoors and in cities.

[0005] When in a high dynamic environment, the carrier will produce Doppler frequency offset and its first and second order change rates. The general signal tracking method needs to increase the loop bandwidth to meet the tracking requirements of the loop, but at the same time it will cause the noise entering the loop to increase, resulting in reduced loop tracking accuracy and tracking loss.

[0006] It can be seen that in complex environments such as high dynamics, dynamics will have a certain impact on the code phase, so the traditional tracking loop is difficult to meet the application requirements of anti-interference and high dynamics at the same time. Summary of the invention

[0007] In order to overcome the shortcomings of the prior art, the present application provides a composite loop tracking method, system, computer equipment and storage medium for an interference-resistant navigation signal receiver, so as to solve the problem that the existing single tracking loop cannot simultaneously meet the requirements of interference resistance and high dynamics. By designing an adaptive matching tracking loop model, the characteristics of large dynamic range of the frequency-locked loop, small error of the phase-locked loop and high sensitivity of the FFT are taken into account. At the same time, by real-time control of the code loop update, navigation signal tracking under different dynamics and interference scenarios can be achieved, and it has strong environmental compatibility.

[0008] In order to achieve the above objectives, this application adopts the following technical solutions:

[0009] A composite loop tracking method for an anti-interference navigation signal receiver, comprising:

[0010] Based on the rough code phase and Doppler frequency obtained from the coarse captured signal, the pseudo code and carrier corresponding to the satellite signal are copied;

[0011] The pseudo code and carrier corresponding to the satellite signal are coherently calculated with the pseudo code and carrier pre-stored locally to obtain coherent integration values ​​I(n) and Q(n); wherein n represents the nth moment;

[0012] The coherent integration values ​​I(n) and Q(n) are subjected to FLL frequency discrimination to obtain the first frequency difference between the carrier and the actual carrier of the signal at the nth moment. ;

[0013] The coherent integral values ​​I(n) and Q(n) are subjected to PLL phase discrimination to obtain the phase difference between the carrier and the actual carrier of the signal at the nth moment. ;

[0014] The coherent integration values ​​I(n) and Q(n) are subjected to FFT frequency discrimination to obtain a second frequency difference between the carrier at the nth moment and the actual carrier of the signal. ;

[0015] The first frequency difference , Phase difference and the second frequency difference Perform weighted processing to obtain the frequency error between the carrier and the actual carrier of the signal at the nth moment ;

[0016] The frequency error Carrier loop filtering is performed to output a carrier loop tracking result M1;

[0017] Performing incoherent accumulation on the coherent integration values ​​I(n) and Q(n) to obtain an incoherent integration result P(n) at the nth moment;

[0018] Performing DLL phase detection on the incoherent integration result P(n) to obtain the epoch code loop phase difference at the nth moment;

[0019] Performing code loop filtering on the epoch code loop phase difference to output a code loop tracking result M2;

[0020] The carrier loop tracking result M1 is sent to a feedback controller, and the feedback controller calculates a first frequency control word M3 corresponding to the code loop according to the carrier loop tracking result M1;

[0021] Based on the first frequency control word M3 and the code loop tracking result M2, the code loop is controlled to update.

[0022] Furthermore, the coherent integration values ​​I(n) and Q(n) are subjected to FLL frequency discrimination to obtain a first frequency difference between the carrier at the nth moment and the actual carrier of the signal. ,include:

[0023] Based on the coherent integration values ​​I(n) and Q(n) and the coherent integration values ​​I(n-1) and Q(n-1) at the previous moment, the dot product P is obtained. dot = I(n-1)×I(n)+Q(n-1)×Q(n) and cross product P cross = I(n-1)×Q(n)-Q(n-1)×I(n);

[0024] For the dot product P dot and cross product P cross Perform FLL frequency discrimination to obtain the first frequency difference between the carrier and the actual carrier of the signal at the nth moment .

[0025] Furthermore, the first frequency difference , Phase difference and the second frequency difference Weighted processing is performed, including:

[0026] When the satellite signal power strength is lower than the first threshold but higher than the second threshold, the first frequency difference The weight is greater than the phase difference and the second frequency difference ; The first threshold is higher than the second threshold;

[0027] When the satellite signal power strength is lower than the second threshold, the second frequency difference The weight is greater than the first frequency difference and phase difference ;

[0028] When the satellite speed is greater than the third threshold, the phase difference The weight is greater than the first frequency difference and the second frequency difference .

[0029] Further, the performing DLL phase detection on the incoherent integration result P(n) to obtain the epoch code ring phase difference at the nth moment includes:

[0030] Based on the non-coherent integration result P(n), the leading, immediate and lagging branch results are obtained;

[0031] The DLL phase detection is performed on the results of the leading, immediate and lagging branches to obtain the epoch code loop phase difference at the nth moment.

[0032] Further, controlling the code loop update based on the first frequency control word M3 and the code loop tracking result M2 includes:

[0033] When the code loop tracking result M2 exists, a weighted operation is performed on the first frequency control word M3 and the code loop tracking result M2 to obtain a second frequency control word M4, and the second frequency control word M4 is used to control the code loop update;

[0034] When the code loop tracking result M2 does not exist, the first frequency control word M3 is directly used to control the code loop update.

[0035] Further, the feedback controller calculates a first frequency control word M3 corresponding to the code loop according to the carrier loop tracking result M1, including:

[0036] ;

[0037] in is the ratio of code rate to carrier rate.

[0038] Further, performing a weighted operation on the first frequency control word M3 and the code loop tracking result M2 to obtain the second frequency control word M4 includes:

[0039] ;

[0040] in, is the weighted value; when under high dynamic conditions, The smaller the signal-to-noise ratio is, the The bigger.

[0041] In addition, the present application also provides a composite loop tracking system for an anti-interference navigation signal receiver, comprising:

[0042] The pre-correlator is used to copy the pseudo code and carrier corresponding to the satellite signal based on the rough code phase and Doppler frequency obtained from the coarse captured signal; the pseudo code and carrier corresponding to the satellite signal are coherently operated with the pseudo code and carrier pre-stored locally to obtain coherent integration values ​​I(n) and Q(n); wherein n represents the nth moment;

[0043] The FLL frequency detector is used to perform FLL frequency detection on the coherent integration values ​​I(n) and Q(n) to obtain a first frequency difference between the carrier and the actual carrier of the signal at the nth moment. ;

[0044] A PLL phase detector is used to perform PLL phase detection on the coherent integration values ​​I(n) and Q(n) to obtain the phase difference between the carrier and the actual carrier of the signal at the nth moment. ;

[0045] The FFT frequency detector is used to perform FFT frequency detection on the coherent integration values ​​I(n) and Q(n) to obtain a second frequency difference between the carrier at the nth moment and the actual carrier of the signal. ;

[0046] An adaptive weighting module is used to adjust the first frequency difference , Phase difference and the second frequency difference Perform weighted processing to obtain the frequency error between the carrier and the actual carrier of the signal at the nth moment ;

[0047] The carrier loop filter is used to Carrier loop filtering is performed to output a carrier loop tracking result M1;

[0048] A non-coherent integrator, used for performing non-coherent accumulation on the coherent integration values ​​I(n) and Q(n) to obtain a non-coherent integration result P(n) at the nth moment;

[0049] A DLL phase detector, used for performing DLL phase detection on the incoherent integration result P(n) to obtain the epoch code loop phase difference at the nth moment;

[0050] A code loop filter, used for performing code loop filtering on the epoch code loop phase difference to output a code loop tracking result M2;

[0051] A feedback controller is used to calculate a first frequency control word M3 corresponding to the code loop according to the carrier loop tracking result M1; and to control the code loop update based on the first frequency control word M3 and the code loop tracking result M2.

[0052] In addition, the present application also provides a computer device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the above-described method when executing the computer program.

[0053] In addition, the present application also provides a computer-readable storage medium, which stores a computer program. When the computer program is executed by a processor, the method described above is implemented.

[0054] Compared with the prior art, this application has the following advantages:

[0055] The present application can solve the problem that a single tracking loop cannot simultaneously meet the requirements of anti-interference (high sensitivity) and high dynamics. By adaptively matching the tracking loop model, the present application can take into account the characteristics of large dynamic range of the frequency-locked loop, small error of the phase-locked loop, and high sensitivity of the FFT. At the same time, the present application can control the weighted processing of the code loop update in real time to achieve stable tracking of navigation signals under different dynamics and interference scenarios, and has strong environmental compatibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0056] The drawings described herein are used to provide a further understanding of the present application and constitute a part of the present application. The illustrative embodiments of the present application and their descriptions are used to explain the present application but do not constitute an improper limitation on the present application. In the drawings:

[0057] Figure 1 A flow chart of the method of this application;

[0058] Figure 2 A schematic diagram of a specific embodiment of the method of the present application;

[0059] Figure 3 This is the system structure diagram of this application;

[0060] Figure 4 A schematic diagram of the structure of the computer device of the present application;

[0061] Figure 5 This is a schematic diagram of the structure of another computer device of the present application. DETAILED DESCRIPTION

[0062] In order to enable those skilled in the art to better understand the solution of the present application, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application.

[0063] In the description of the present application, it should be understood that the orientation or positional relationship indicated by the terms and the like is based on the orientation or positional relationship shown in the accompanying drawings, which is only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device, element, module, system, platform or device referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. The following description of the present application is only understood as a description of individual embodiments of the technical solution of the present application. Other embodiments are not reflected in the following description, but it does not mean that the present application excludes these other embodiments, and the technical solution of the present application is not limited to the specific implementation methods described below, and the protection scope of the present application is not limited to only the specific implementation methods described below. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work should fall within the scope of protection of the present application.

[0064] It should be noted that if the terms "first", "second", etc. appear in the specification and claims of the present application and the above-mentioned drawings, the description is only used to distinguish similar objects, and is not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0065] In some embodiments, Figure 1 As shown, a composite loop tracking method for an anti-interference navigation signal receiver includes:

[0066] S1: Based on the rough code phase and Doppler frequency obtained from the coarse captured signal, copy the pseudo code and carrier corresponding to the satellite signal;

[0067] S2: performing coherent operation on the pseudo code and carrier corresponding to the satellite signal and the pseudo code and carrier pre-stored locally to obtain coherent integration values ​​I(n) and Q(n); wherein n represents the nth moment;

[0068] S3: Perform FLL frequency discrimination on the coherent integration values ​​I(n) and Q(n) to obtain the first frequency difference between the carrier at the nth moment and the actual carrier of the signal ;

[0069] S4: Perform PLL phase detection on the coherent integration values ​​I(n) and Q(n) to obtain the phase difference between the carrier and the actual carrier of the signal at the nth moment ;

[0070] S5: Perform FFT frequency discrimination on the coherent integration values ​​I(n) and Q(n) to obtain a second frequency difference between the carrier at the nth moment and the actual carrier of the signal ;

[0071] S6: the first frequency difference , Phase difference and the second frequency difference Perform weighted processing to obtain the frequency error between the carrier and the actual carrier of the signal at the nth moment ;

[0072] S7: For the frequency error Carrier loop filtering is performed to output a carrier loop tracking result M1;

[0073] S8: performing incoherent accumulation on the coherent integration values ​​I(n) and Q(n) to obtain an incoherent integration result P(n) at the nth moment;

[0074] S9: performing DLL phase discrimination on the incoherent integration result P(n) to obtain the epoch code loop phase difference at the nth moment;

[0075] S10: performing code loop filtering on the epoch code loop phase difference to output a code loop tracking result M2;

[0076] S11: sending the carrier loop tracking result M1 to the feedback controller, and the feedback controller calculates the first frequency control word M3 corresponding to the code loop according to the carrier loop tracking result M1;

[0077] S12: Based on the first frequency control word M3 and the code loop tracking result M2, control the code loop to update.

[0078] In some embodiments, the coherent integration values ​​I(n) and Q(n) are subjected to FLL frequency discrimination to obtain a first frequency difference between the carrier at the nth moment and the actual carrier of the signal. ,include:

[0079] Based on the coherent integration values ​​I(n) and Q(n) and the coherent integration values ​​I(n-1) and Q(n-1) at the previous moment, the dot product P is obtained. dot = I(n-1)×I(n)+Q(n-1)×Q(n) and cross product P cross = I(n-1)×Q(n)-Q(n-1)×I(n);

[0080] For the dot product P dot and cross product P cross Perform FLL frequency discrimination to obtain the first frequency difference between the carrier and the actual carrier of the signal at the nth moment .

[0081] In some embodiments, the first frequency difference , Phase difference and the second frequency difference Weighted processing is performed, including:

[0082] When the satellite signal power strength is lower than the first threshold but higher than the second threshold, the first frequency difference The weight is greater than the phase difference and the second frequency difference ; The first threshold is higher than the second threshold;

[0083] When the satellite signal power strength is lower than the second threshold, the second frequency difference The weight is greater than the first frequency difference and phase difference ;

[0084] When the satellite speed is greater than the third threshold, the phase difference The weight is greater than the first frequency difference and the second frequency difference .

[0085] In some embodiments, performing DLL phase discrimination on the incoherent integration result P(n) to obtain the epoch code ring phase difference at the nth moment includes:

[0086] Based on the non-coherent integration result P(n), the leading, immediate and lagging branch results are obtained;

[0087] The DLL phase detection is performed on the results of the leading, immediate and lagging branches to obtain the epoch code loop phase difference at the nth moment.

[0088] In some embodiments, the controlling the code loop update based on the first frequency control word M3 and the code loop tracking result M2 includes:

[0089] When the code loop tracking result M2 exists, a weighted operation is performed on the first frequency control word M3 and the code loop tracking result M2 to obtain a second frequency control word M4, and the second frequency control word M4 is used to control the code loop update;

[0090] When the code loop tracking result M2 does not exist, the first frequency control word M3 is directly used to control the code loop update.

[0091] In some embodiments, the feedback controller calculates the first frequency control word M3 corresponding to the code loop according to the carrier loop tracking result M1, including:

[0092] ;

[0093] in is the ratio of code rate to carrier rate.

[0094] In some embodiments, performing a weighted operation on the first frequency control word M3 and the code loop tracking result M2 to obtain the second frequency control word M4 includes:

[0095] ;

[0096] in, is the weighted value; when under high dynamic conditions, The smaller the signal-to-noise ratio is, the The bigger.

[0097] In some embodiments, the present application provides a specific embodiment to illustrate a specific composite loop tracking method of an anti-interference navigation signal receiver.

[0098] Specifically, Figure 2 The present application provides a composite loop tracking method for an anti-interference navigation signal receiver in a certain type of Beidou receiver. The specific implementation steps are as follows. The following steps are divided into front and back steps for ease of explanation. In the specific implementation, they can be distributed or merged as in this embodiment, and do not affect the overall front and back order.

[0099] S21: The coarse capture signal enters 12 front-stage correlators for 1ms coherent integration, obtains the coherent integration result and performs 20 times of incoherent accumulation to obtain a 20ms incoherent integration result; among them, if the bit synchronization has been completed, 5ms coherent integration can be performed to obtain a 100ms incoherent integration result, thereby improving the signal-to-noise ratio and increasing the tracking sensitivity;

[0100] S22: Perform second-order FLL frequency discrimination processing and third-order PLL phase discrimination processing on the 1ms coherent result, and perform 256-point FFT calculation at the same time, obtain the FLL frequency discrimination, PLL phase discrimination, and FFT frequency discrimination processing results, and obtain the current carrier phase error through adaptive weighting processing, and output the carrier tracking result M1 through carrier loop filtering; wherein, the weight value is measured according to the signal power, speed, acceleration and other limiting conditions of the overall application environment. For example, when the signal power strength is less than -140dBm, the weight of the FLL frequency discrimination processing result is larger, and when the signal power strength is less than -145dBm, the weight of the FFT frequency discrimination processing result is larger; when the speed is greater than 300m / s, the weight of the PLL phase discrimination processing result is larger.

[0101] S23: Perform second-order DLL phase detection using the incoherent lead-minus-lag amplitude method based on the 20ms incoherent accumulated values ​​of the 12 correlators to obtain the code loop phase difference of the current epoch, and output the code loop tracking result M2 through code loop filtering;

[0102] S24: The carrier loop filtering result of each 1ms coherent integration time is sent to the feedback controller in real time. The feedback controller calculates the frequency control word M3 corresponding to the code loop through the carrier loop filtering result, and obtains M4 by combining the carrier-assisted code loop frequency control word M2 obtained by incoherent calculation every 20ms, and coordinately controls the update of the code loop NCO to improve the update rate of the code loop.

[0103] In some embodiments, Figure 3 As shown, the present application also provides a composite loop tracking system 1 for an anti-interference navigation signal receiver, comprising:

[0104] The pre-correlator 11 is used to copy the pseudo code and carrier corresponding to the satellite signal based on the rough code phase and Doppler frequency obtained from the coarse captured signal; perform coherent operation on the pseudo code and carrier corresponding to the satellite signal with the pseudo code and carrier pre-stored locally to obtain coherent integration values ​​I(n) and Q(n); wherein n represents the nth moment;

[0105] The FLL frequency detector 12 is used to perform FLL frequency detection on the coherent integration values ​​I(n) and Q(n) to obtain a first frequency difference between the carrier at the nth moment and the actual carrier of the signal. ;

[0106] The PLL phase detector 13 is used to perform PLL phase detection on the coherent integration values ​​I(n) and Q(n) to obtain the phase difference between the carrier and the actual carrier of the signal at the nth moment. ;

[0107] The FFT frequency detector 14 is used to perform FFT frequency detection on the coherent integration values ​​I(n) and Q(n) to obtain a second frequency difference between the carrier at the nth moment and the actual carrier of the signal. ;

[0108] The adaptive weighting module 15 is used to adjust the first frequency difference , Phase difference and the second frequency difference Perform weighted processing to obtain the frequency error between the carrier and the actual carrier of the signal at the nth moment ;

[0109] The carrier loop filter 16 is used to filter the frequency error Carrier loop filtering is performed to output a carrier loop tracking result M1;

[0110] The incoherent integrator 17 is used to perform incoherent accumulation on the coherent integration values ​​I(n) and Q(n) to obtain the incoherent integration result P(n) at the nth moment;

[0111] A DLL phase detector 18, used for performing DLL phase detection on the incoherent integration result P(n) to obtain the epoch code loop phase difference at the nth moment;

[0112] A code loop filter 19, used for performing code loop filtering on the epoch code loop phase difference to output a code loop tracking result M2;

[0113] The feedback controller 20 is used to calculate a first frequency control word M3 corresponding to the code loop according to the carrier loop tracking result M1; and control the code loop update based on the first frequency control word M3 and the code loop tracking result M2.

[0114] Each module in the composite loop tracking system of the anti-interference navigation signal receiver can be implemented in whole or in part by software, hardware, or a combination thereof. Each module can be embedded in or independent of a processor in a computer device in the form of hardware, or can be stored in a memory in a computer device in the form of software, so that the processor can call and execute operations corresponding to each module.

[0115] In one embodiment, a computer device is provided. The computer device may be a server, and its internal structure diagram may be as follows: Figure 4 As shown. The computer device includes a processor, a memory, an input / output interface (Input / Output, referred to as I / O) and a communication interface. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface is connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system, a computer program and a database. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal through a network connection. When the computer program is executed by the processor, a composite loop tracking method of an anti-interference navigation signal receiver is implemented.

[0116] In one embodiment, a computer device is provided. The computer device may be a terminal, and its internal structure diagram may be as follows: Figure 5As shown. The computer device includes a processor, a memory, an input / output interface, a communication interface, a display unit and an input device. The processor, the memory and the input / output interface are connected through a system bus, and the communication interface, the display unit and the input device are connected to the system bus through the input / output interface. The processor of the computer device is used to provide computing and control capabilities. The memory of the computer device includes a non-volatile storage medium and an internal memory. The non-volatile storage medium stores an operating system and a computer program. The internal memory provides an environment for the operation of the operating system and the computer program in the non-volatile storage medium. The input / output interface of the computer device is used to exchange information between the processor and an external device. The communication interface of the computer device is used to communicate with an external terminal in a wired or wireless manner, and the wireless manner can be implemented through WIFI, a mobile cellular network, NFC (near field communication) or other technologies. When the computer program is executed by the processor, a composite loop tracking method of an anti-interference navigation signal receiver is implemented. The display unit of the computer device is used to form a visually visible image, and can be a display screen, a projection device or a virtual reality imaging device. The display screen can be a liquid crystal display screen or an electronic ink display screen. The input device of the computer device can be a touch layer covered on the display screen, or a button, trackball or touchpad set on the computer device casing, or an external keyboard, touchpad or mouse, etc.

[0117] Those skilled in the art will understand that Figure 4 and Figure 5 The structure shown in the figure is only a block diagram of a part of the structure related to the solution of the present application, and does not constitute a limitation on the computer device to which the solution of the present application is applied. The specific computer device may include more or fewer components than those shown in the figure, or combine certain components, or have a different arrangement of components.

[0118] In one embodiment, a computer device is further provided, including a memory and a processor, wherein a computer program is stored in the memory, and the processor implements the steps in the above method embodiments when executing the computer program.

[0119] In one embodiment, a computer-readable storage medium is provided, storing a computer program, which implements the steps in the above method embodiments when executed by a processor.

[0120] In one embodiment, a computer program product is provided, including a computer program, and when the computer program is executed by a processor, the steps in the above method embodiments are implemented.

[0121] It should be noted that the user information (including but not limited to user device information, user personal information, etc.) and data (including but not limited to data used for analysis, stored data, displayed data, etc.) involved in this application are all information and data authorized by the user or fully authorized by all parties, and the collection, use and processing of relevant data must comply with relevant laws, regulations and standards of relevant countries and regions.

[0122] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiments can be implemented by instructing the relevant hardware through a computer program, and the computer program can be stored in any type of volatile or non-volatile storage device, or a combination thereof. Among them, the non-volatile memory can be a read-only memory (ROM), a programmable read-only memory (PROM), an erasable programmable read-only memory (EPROM), an electrically erasable programmable read-only memory (EEPROM), a magnetic random access memory (FRAM), a flash memory, a magnetic surface memory, an optical disc, or a compact disc read-only memory (CD-ROM); the magnetic surface memory can be a disk memory or a tape memory. The volatile memory can be a random access memory (RAM), which is used as an external cache.By way of example but not limitation, many forms of RAM are available, such as static random access memory (SRAM), synchronous static random access memory (SSRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (SDRAM), double data rate synchronous dynamic random access memory (DDR SDR AM), enhanced synchronous dynamic random access memory (ESDRAM Enhanced Synchronous Dynamic Random Access Memory), synchronous link dynamic random access memory (SLDRAM), direct memory bus random access memory (DRRAM). The storage media described in the embodiments of the present invention are intended to include, but are not limited to, these and any other suitable types of memory.

[0123] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0124] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A composite loop tracking method for an anti-interference navigation signal receiver, characterized in that: include: Based on the rough code phase and Doppler frequency obtained from the coarse captured signal, the pseudo code and carrier corresponding to the satellite signal are copied; The pseudo code and carrier corresponding to the satellite signal are coherently calculated with the pseudo code and carrier pre-stored locally to obtain coherent integration values ​​I(n) and Q(n); wherein n represents the nth moment; The coherent integration values ​​I(n) and Q(n) are subjected to FLL frequency discrimination to obtain the first frequency difference between the carrier and the actual carrier of the signal at the nth moment. ; The coherent integral values ​​I(n) and Q(n) are subjected to PLL phase discrimination to obtain the phase difference between the carrier and the actual carrier of the signal at the nth moment. ; The coherent integration values ​​I(n) and Q(n) are subjected to FFT frequency discrimination to obtain a second frequency difference between the carrier at the nth moment and the actual carrier of the signal. ; The first frequency difference , Phase difference and the second frequency difference Perform weighted processing to obtain the frequency error between the carrier and the actual carrier of the signal at the nth moment ; The frequency error Carrier loop filtering is performed to output a carrier loop tracking result M1; Performing incoherent accumulation on the coherent integration values ​​I(n) and Q(n) to obtain an incoherent integration result P(n) at the nth moment; Performing DLL phase detection on the incoherent integration result P(n) to obtain the epoch code loop phase difference at the nth moment; Performing code loop filtering on the epoch code loop phase difference to output a code loop tracking result M2; The carrier loop tracking result M1 is sent to a feedback controller, and the feedback controller calculates a first frequency control word M3 corresponding to the code loop according to the carrier loop tracking result M1; Based on the first frequency control word M3 and the code loop tracking result M2, the code loop is controlled to update.

2. The composite loop tracking method of an anti-interference navigation signal receiver according to claim 1, characterized in that: The coherent integration values ​​I(n) and Q(n) are subjected to FLL frequency discrimination to obtain a first frequency difference between the carrier at the nth moment and the actual carrier of the signal. ,include: Based on the coherent integration values ​​I(n) and Q(n) and the coherent integration values ​​I(n-1) and Q(n-1) at the previous moment, the dot product P is obtained. dot =I(n-1)×I(n)+Q(n-1)×Q(n) and cross product P cross = I(n-1)×Q(n)-Q(n-1)×I(n); For the dot product P dot and cross product P cross Perform FLL frequency discrimination to obtain the first frequency difference between the carrier and the actual carrier of the signal at the nth moment .

3. The composite loop tracking method of the anti-interference navigation signal receiver according to claim 2, characterized in that: The first frequency difference , Phase difference and the second frequency difference Weighted processing is performed, including: When the satellite signal power strength is lower than the first threshold but higher than the second threshold, the first frequency difference The weight is greater than the phase difference and the second frequency difference ; The first threshold is higher than the second threshold; When the satellite signal power strength is lower than the second threshold, the second frequency difference The weight is greater than the first frequency difference and phase difference ; When the satellite speed is greater than the third threshold, the phase difference The weight is greater than the first frequency difference and the second frequency difference .

4. The composite loop tracking method of an anti-interference navigation signal receiver according to claim 3, characterized in that: The performing DLL phase detection on the incoherent integration result P(n) to obtain the epoch code ring phase difference at the nth moment includes: Based on the non-coherent integration result P(n), the leading, immediate and lagging branch results are obtained; The DLL phase detection is performed on the results of the leading, immediate and lagging branches to obtain the epoch code loop phase difference at the nth moment.

5. The composite loop tracking method of an anti-interference navigation signal receiver according to claim 4, characterized in that: The controlling the code loop update based on the first frequency control word M3 and the code loop tracking result M2 includes: When the code loop tracking result M2 exists, a weighted operation is performed on the first frequency control word M3 and the code loop tracking result M2 to obtain a second frequency control word M4, and the second frequency control word M4 is used to control the code loop update; When the code loop tracking result M2 does not exist, the first frequency control word M3 is directly used to control the code loop update.

6. The composite loop tracking method of an anti-interference navigation signal receiver according to claim 5, characterized in that: The feedback controller calculates the first frequency control word M3 corresponding to the code loop according to the carrier loop tracking result M1, include: ； in is the ratio of code rate to carrier rate.

7. The composite loop tracking method of an anti-interference navigation signal receiver according to claim 6, characterized in that: The first frequency control word M3 and the code loop tracking result M2 are weighted to obtain a second frequency control word M4. include: ； in, is the weighted value; when under high dynamic conditions, The smaller the signal-to-noise ratio is, the The bigger.

8. A composite loop tracking system for an anti-interference navigation signal receiver, characterized in that: include: A pre-correlator is used to copy the pseudo code and carrier corresponding to the satellite signal based on the rough code phase and Doppler frequency obtained from the rough captured signal; The pseudo code and carrier corresponding to the satellite signal are coherently calculated with the pseudo code and carrier pre-stored locally to obtain coherent integration values ​​I(n) and Q(n); wherein n represents the nth moment; The FLL frequency detector is used to perform FLL frequency detection on the coherent integration values ​​I(n) and Q(n) to obtain a first frequency difference between the carrier and the actual carrier of the signal at the nth moment. ; A PLL phase detector is used to perform PLL phase detection on the coherent integration values ​​I(n) and Q(n) to obtain the phase difference between the carrier and the actual carrier of the signal at the nth moment. ; The FFT frequency detector is used to perform FFT frequency detection on the coherent integration values ​​I(n) and Q(n) to obtain a second frequency difference between the carrier at the nth moment and the actual carrier of the signal. ; An adaptive weighting module is used to adjust the first frequency difference , Phase difference and the second frequency difference Perform weighted processing to obtain the frequency error between the carrier and the actual carrier of the signal at the nth moment ; The carrier loop filter is used to Carrier loop filtering is performed to output a carrier loop tracking result M1; A non-coherent integrator, used for performing non-coherent accumulation on the coherent integration values ​​I(n) and Q(n) to obtain a non-coherent integration result P(n) at the nth moment; A DLL phase detector, used for performing DLL phase detection on the incoherent integration result P(n) to obtain the epoch code loop phase difference at the nth moment; A code loop filter, used for performing code loop filtering on the epoch code loop phase difference to output a code loop tracking result M2; A feedback controller is used to calculate a first frequency control word M3 corresponding to the code loop according to the carrier loop tracking result M1; and to control the code loop update based on the first frequency control word M3 and the code loop tracking result M2.

9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the method according to any one of claims 1 to 7 is implemented.

10. A computer-readable storage medium, characterized in that: The computer-readable storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

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