Loop convergence method, computer storage medium, and terminal

Abstract

The application discloses a loop convergence method, a computer storage medium and a terminal, and comprises the following steps: determining a carrier-to-noise ratio of a satellite signal according to a received satellite signal; and performing phase modulation processing of a tracking loop according to the determined carrier-to-noise ratio; wherein the phase modulation processing comprises at least one of the following: phase modulation processing of a carrier loop and phase modulation processing of a code loop. According to the embodiment of the application, the phase modulation processing is performed according to the carrier-to-noise ratio, so that the convergence speed of the tracking loop is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to, but is not limited to, satellite positioning technology, and relates to a loop convergence method, a computer storage medium and a terminal. BACKGROUND

[0002] In order to accurately and continuously obtain the carrier frequency and code phase, it is necessary to track the satellite signal and then demodulate the navigation message; the tracking loop for tracking the satellite signal usually includes a carrier tracking loop (referred to as a carrier loop) and a code tracking loop (referred to as a code loop).

[0003] In the tracking algorithm in the related art, the carrier loop is used to realize synchronization of the local carrier and the carrier of the received signal by adjusting the local carrier frequency; the code loop is used to make the local code phase consistent with the code phase of the received satellite signal as much as possible by continuously adjusting the local code phase, but the essence is also to realize synchronization of the local pseudo code and the pseudo code of the received signal by adjusting the output frequency of the code number controlled oscillator. Through the joint action of the carrier loop and the code loop, the carrier frequency and the code phase of the received satellite signal can be continuously obtained to demodulate the message and position the receiver.

[0004] However, in the above tracking algorithm, synchronization of the local carrier loop and the code loop with the carrier loop and the code loop of the received satellite signal is a slow process, and it is synchronized by adjusting the output frequency of the local carrier number controlled oscillator and the local code number controlled oscillator, which takes a long time to achieve loop convergence, affecting the positioning speed of the receiver. SUMMARY

[0005] The following is a summary of the subject matter of the detailed description of the present application. This summary is not intended to limit the protection scope of the claims.

[0006] The embodiments of the present application provide a loop convergence method, a computer storage medium and a terminal, which can improve the convergence speed of the tracking loop.

[0007] The embodiments of the present application provide a loop convergence method, which comprises:

[0008] determining the carrier-to-noise ratio of the satellite signal according to the received satellite signal;

[0009] performing phase adjustment processing of the tracking loop according to the determined carrier-to-noise ratio;

[0010] The phase adjustment processing includes at least one of the following: phase adjustment processing of the carrier loop, phase adjustment processing of the code loop.

[0011] On the other hand, the embodiments of the present application also provide a computer storage medium, which stores a computer program, and the computer program is executed by a processor to implement the above loop convergence method.

[0012] In still another aspect, the embodiments of the present application further provide a terminal, comprising: a memory and a processor, the memory having a computer program stored therein; wherein

[0013] The processor is configured to execute the computer program in the memory.

[0014] The computer program, when executed by the processor, implements the loop convergence method as described above.

[0015] The present application has the beneficial effect that the embodiments of the present application perform the phase modulation processing according to the carrier-to-noise ratio, thereby improving the convergence speed of the tracking loop.

[0016] Other features and advantages of the present application will be set forth in the following description, and in part will become apparent to those skilled in the art from the description, or can be learned by practice of the present application. The objects and other advantages of the present application will be realized and attained by the structure particularly pointed out in the written description and claims thereof as well as the appended drawings. BRIEF DESCRIPTION OF DRAWINGS

[0017] The accompanying drawings, which are included to provide a further understanding of the technical solutions of the present application and constitute a part of the specification, illustrate the technical solutions of the present application and are used to explain the technical solutions of the present application together with the embodiments of the present application, and do not constitute a limitation to the technical solutions of the present application.

[0018] Figure 1 The flowchart of the loop convergence method of the embodiments of the present application is shown in

[0019] Figure 2 The composition block diagram of the carrier tracking loop of the embodiments of the present application is shown in

[0020] Figure 3 The composition block diagram of the code tracking loop of the embodiments of the present application is shown in DETAILED DESCRIPTION

[0021] In order to make the objects, technical solutions and advantages of the present application clearer, the embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other in any manner without conflict.

[0022] The steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Moreover, although the logical order is shown in the flowchart, in some cases, the steps shown or described herein can be executed in an order different from that shown herein.

[0023] Figure 1 The flowchart of the loop convergence method of the embodiments of the present application is shown in Figure 1 as follows, comprising:

[0024] Step 101, determining the carrier-to-noise ratio of the satellite signal according to the received satellite signal;

[0025] In an exemplary instance, the embodiment of the application can be performed by the receiver to determine the carrier-to-noise ratio of the currently received satellite signal according to the received satellite signal and the carrier-to-noise ratio estimation based on the correlation principle.

[0026] Step 102, performing the phase adjustment processing of the tracking loop according to the determined carrier-to-noise ratio;

[0027] The phase adjustment processing includes one of the phase adjustment processing of the carrier loop and the phase adjustment processing of the code loop.

[0028] The embodiment of the application adds the judgment of adjusting the phase of the code loop and the phase of the carrier loop on the basis of the carrier tracking loop and the code tracking loop of the related art, and improves the convergence speed of the tracking loop by the phase adjustment processing of the local carrier loop and / or the local code loop.

[0029] In an exemplary instance, the embodiment of the application can be performed by the receiver to perform the processing of the loop convergence method.

[0030] In an exemplary instance, when the phase adjustment processing includes the phase adjustment processing of the carrier loop, the embodiment of the application can include at least one of the following according to the determined carrier-to-noise ratio to perform the phase adjustment processing of the tracking loop:

[0031] When the carrier-to-noise ratio (M) is greater than a first carrier-to-noise ratio threshold value (M P ), the carrier loop tracking is performed and the phase adjustment processing is performed on the carrier loop; and when the carrier-to-noise ratio (M) is less than or equal to the first carrier-to-noise ratio threshold value (M P ), the carrier tracking is performed on the signal using the preset carrier loop tracking algorithm.

[0032] In an exemplary instance, the first carrier-to-noise ratio threshold value (M P ) in the embodiment of the application can be set by the person skilled in the art according to the estimation of the convergence time and the accuracy of the phase discrimination result; if the first carrier-to-noise ratio threshold value (M P ) is too large, the phase adjustment processing of the embodiment of the application cannot be triggered when the received satellite signal is weak; and if the first carrier-to-noise ratio threshold value (M P ) is too small, the accuracy of the phase discrimination result of the carrier loop discriminator is affected. In an exemplary instance, the first carrier-to-noise ratio threshold value (M P ) in the embodiment of the application is proportional to the size of the carrier-to-noise ratio value, that is, the larger the carrier-to-noise ratio value is, the larger the corresponding first carrier-to-noise ratio threshold value (M P ) is. In an exemplary instance, the first carrier-to-noise ratio threshold value M P in the embodiment of the application can be 42 decibel-hertz (dB·Hz).

[0033] In an example embodiment, when the carrier-to-noise ratio (M) is greater than a first carrier-to-noise ratio threshold value (M P ), the phase modulation processing of the carrier tracking loop of the example embodiment can include:

[0034] Step 201, down-conversion processing of the satellite signal to obtain a carrier-stripped signal of an in-phase (I) and quadrature (Q) branch;

[0035] Step 202, correlation integration of the obtained carrier-stripped signal of the I and Q branches;

[0036] Step 203, passing the carrier-stripped signal after correlation integration zeroing through a carrier loop phase detector to obtain a first phase detection result (PLLDisc);

[0037] Step 204, determining whether to adjust a local carrier generator at the receiving end according to the first phase detection result based on the number of cycles of the carrier tracking loop.

[0038] In an example embodiment, the determination of whether to adjust the local carrier generator at the receiving end according to the first phase detection result includes:

[0039] When the number of cycles of the carrier tracking loop is less than or equal to a first cycle threshold value (L P ), the local carrier generator is adjusted in phase according to the first phase detection result (PLLDisc) in each cycle of the carrier tracking loop; and when the number of cycles is greater than the first cycle threshold value (L P ), the frequency of the carrier generator is adjusted through a carrier loop filter.

[0040] Figure 2 For a block diagram of the carrier tracking loop of the example embodiment, the processing of steps 201 to 204 of the example embodiment can be implemented by a circuit composed of Figure 2 .

[0041] In an example embodiment, the first cycle threshold value can be determined by a person skilled in the art according to accuracy and convergence speed; a too large first cycle threshold value causes inaccurate phase adjustment; and a too small first cycle threshold value affects the improvement of convergence speed. In an example embodiment, the first cycle threshold value (L P ) can be 4. The processing of adjusting the local carrier generator in phase according to the first phase detection result (PLLDisc) can be implemented according to related technologies, i.e., directly adjusting the phase of the local carrier generator according to the first phase detection result (PLLDisc).

[0042] In an example embodiment, the number of cycles of the carrier tracking loop can be determined according to the related art, and the present application does not limit this.

[0043] In an example embodiment, when the phase modulation processing includes code loop, the phase modulation processing of the code loop is performed according to the determined carrier-to-noise ratio, and can include at least one of the following:

[0044] When the carrier-to-noise ratio (M) is greater than a second preset carrier-to-noise ratio threshold value (M C ), code loop tracking is performed, and the code loop is phase modulated; and when the carrier-to-noise ratio (M) is less than or equal to the second carrier-to-noise ratio threshold value (M C ), the signal is tracked by using a preset code loop tracking algorithm.

[0045] In an example embodiment, when the carrier-to-noise ratio M is greater than the second carrier-to-noise ratio threshold value M C , the phase modulation processing of the code loop can include:

[0046] Step 301: Correlating the processing result of the carrier tracking;

[0047] Step 302: Clearing the correlated processing result of the carrier tracking through a code loop discriminator to obtain a second phase discrimination result (DLLDisc);

[0048] Step 303: Determining whether to adjust the local code loop generator of the receiving end according to the second phase discrimination result according to the number of cycles of the code tracking loop;

[0049] In an example embodiment, the present application determines whether to adjust the local code loop generator of the receiving end according to the second phase discrimination result, which includes:

[0050] When the number of cycles of the code tracking loop is less than or equal to a second cycle threshold value (L C ), the local code loop generator is phase adjusted according to the second phase discrimination result (DLLDisc) in each cycle of the code tracking loop; and when the number of cycles is greater than the second cycle threshold value (L C ), the frequency of the code generator is adjusted through the code loop filter.

[0051] Figure 3 For the block diagram of the code tracking loop of the present application, the processing of steps 301 to 304 of the present application can be realized by the circuit Figure 3 to perform phase modulation processing.

[0052] In an example embodiment, the second carrier-to-noise ratio threshold value (M C) can be set by the person skilled in the art according to the estimation of the convergence time length and the accuracy of the second phase discrimination result; if the second carrier-to-noise ratio threshold value is too large, the satellite signal received will not be able to trigger the phase modulation processing of the embodiment of the application. If the second carrier-to-noise ratio threshold value is too small, the accuracy of the phase discrimination result of the code loop discriminator will be affected. In an exemplary example, the value of the second carrier-to-noise ratio threshold value in the embodiment of the application is directly proportional to the size of the carrier-to-noise ratio value, and the larger the carrier-to-noise ratio value, the larger the corresponding second carrier-to-noise ratio threshold value. In an exemplary example, the embodiment of the application can take the second carrier-to-noise ratio threshold value M C = 42 dB·Hz.

[0053] In an exemplary example, the second cycle number threshold value in the embodiment of the application can be determined by the person skilled in the art according to the accuracy and convergence speed; if the second cycle number threshold value is too large, the phase adjustment will not be accurate; if the second cycle number threshold value is too small, the improvement of the convergence speed will be affected. In an exemplary example, the embodiment of the application can take the second cycle number threshold value (L D The embodiment of the application can refer to the related technology for the processing of the phase adjustment of the local code loop generator according to the second phase discrimination result (DLLDisc), that is, directly adjusting the phase of the local code loop generator according to the second phase discrimination result (DLLDisc).

[0054] In an exemplary example, the cycle number of the code tracking loop in the embodiment of the application can be determined by referring to the related technology, and the embodiment of the application is not limited.

[0055] For the satellite with high carrier-to-noise ratio, the code phase and the carrier phase of the first few points calculated by the code loop discriminator and the carrier loop discriminator are a relatively accurate value, and the fast convergence of the tracking loop is realized by directly adjusting the phase of the local pseudo code and the local carrier.

[0056] After the satellite signal is tracked in the embodiment of the application, the carrier phase and the code phase results output by the carrier loop discriminator and the code loop discriminator are directly used to adjust the phase of the local carrier generator and the pseudo code generator on the basis of the original tracking loop. After the above phase adjustment, the carrier loop filter is used for adjustment, and the tracking convergence speed of the loop is improved.

[0057] The embodiment of the application also provides a computer storage medium, and the computer storage medium stores a computer program. The computer program is executed by a processor to implement the above-mentioned method for realizing loop convergence.

[0058] The embodiment of the application also provides a terminal, which comprises a memory and a processor. The memory stores a computer program. The processor executes the computer program to implement the above-mentioned method for realizing loop convergence.

[0059] The processor is configured to execute a computer program in the memory;

[0060] The computer program, when executed by the processor, implements the method of achieving loop convergence as described above.

[0061] Those of ordinary skill in the art will understand that all or some of the steps in the above-disclosed method, the functions of the modules / units in the system, and the apparatus can be implemented as software, firmware, hardware, or appropriate combinations of them. In a hardware implementation, the division between the functional modules / units referred to in the above description does not necessarily correspond to the division between physical components; for example, one physical component can have multiple functions, or one function or step can be performed by several physical components working together. Some or all of the components can be implemented as software executed by a processor, such as a digital signal processor or a microprocessor, or as hardware, or as an integrated circuit, such as an application-specific integrated circuit. Such software can be distributed on computer readable media, which can include computer storage media (or non-transitory media), and communication media (or transitory media). As is well known to those of ordinary skill in the art, the term computer storage media includes volatile and non-volatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Computer storage media includes, but is not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tapes, magnetic disk storage or other magnetic storage devices, or any other medium which can be used to store the desired information and which can be accessed by a computer. Further, it is common in the art for a person of ordinary skill in the art to understand that communication media typically embodies computer readable instructions, data structures, program modules or other data in a modulated data signal such as a carrier wave or other transport mechanism and can include any information delivery media.

Claims

1. A loop convergence method, comprising: Determine the carrier-to-noise ratio of the satellite signal based on the received satellite signal; Phase modulation processing of the tracking loop is performed based on the determined carrier-to-noise ratio of the satellite signal; The phase modulation processing includes at least one of the following: phase modulation processing of the local carrier loop, and phase modulation processing of the local code loop; when the phase modulation processing includes the phase modulation processing of the carrier loop, the step of performing phase modulation processing of the tracking loop according to the determined carrier-to-noise ratio includes at least one of the following: when the carrier-to-noise ratio is greater than a preset first carrier-to-noise ratio threshold, carrier loop tracking is performed, and phase modulation processing is performed on the carrier loop; when the carrier-to-noise ratio is less than or equal to the first carrier-to-noise ratio threshold, a preset carrier loop tracking algorithm is used to perform carrier tracking on the satellite signal, wherein the first carrier-to-noise ratio threshold is determined based on convergence. The duration is estimated and the accuracy of the phase detection result of the carrier loop discriminator is set. When the phase modulation process includes the phase modulation process of the code loop, the phase modulation process of the tracking loop is performed according to the determined carrier-to-noise ratio, including at least one of the following: when the carrier-to-noise ratio is greater than a preset second carrier-to-noise ratio threshold, code loop tracking is performed and the code loop is phase-modulated; when the carrier-to-noise ratio is less than or equal to the second carrier-to-noise ratio threshold, a preset code loop tracking algorithm is used to perform code loop tracking on the satellite signal, and the second carrier-to-noise ratio threshold is set according to the estimated convergence duration and the accuracy of the phase detection result of the code loop discriminator.

2. The loop convergence method according to claim 1, characterized in that, The phase modulation processing of the carrier loop includes: The satellite signal is down-converted to obtain the carrier stripping signal of the in-phase I quadrature Q branch; The carrier stripping signal of the obtained IQ branch is subjected to correlation integration; After clearing the correlation integral of the carrier stripping signal to zero, the first phase detection result is obtained by passing it through the carrier loop phase detector; Based on the number of cycles in the carrier tracking loop, determine whether to adjust the local carrier generator at the receiver based on the first phase detection result.

3. The loop convergence method according to claim 2, characterized in that, The step of determining whether to adjust the local carrier generator at the receiver based on the first phase detection result includes: When the number of cycles of the carrier tracking loop is less than or equal to a preset first cycle number threshold, the phase of the carrier generator is adjusted according to the first phase detection result in each cycle of the carrier tracking loop. When the number of cycles in the carrier tracking loop exceeds the first cycle count threshold, the frequency of the carrier generator is adjusted by the carrier loop filter.

4. The loop convergence method according to claim 3, characterized in that, The threshold for the first number of cycles is 4.

5. The loop convergence method according to claim 1, characterized in that, The phase modulation process for the code ring includes: Perform relevant integration on the carrier tracking processing results; After clearing the correlation integral of the carrier tracking processing result to zero, the second phase detection result is obtained by passing it through the code ring discriminator; Based on the number of code tracking loop cycles, determine whether to adjust the local code loop generator at the receiver based on the second phase detection result.

6. The loop convergence method according to claim 5, characterized in that, The step of determining whether to adjust the local code ring generator at the receiver based on the second phase detection result includes: When the number of cycles of the code tracking loop is less than or equal to the second cycle number threshold, the phase of the code loop generator is adjusted according to the second phase detection result in each cycle of the code tracking loop. When the number of cycles in the code tracking loop exceeds the second cycle number threshold, the frequency of the code loop generator is adjusted by the code loop filter.

7. The loop convergence method according to claim 6, characterized in that, The second loop count threshold is 3.

8. A computer storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the loop convergence method as described in any one of claims 1 to 7.

9. A terminal, comprising: A memory and a processor, wherein the memory stores a computer program; wherein, The processor is configured to execute computer programs in memory; When the computer program is executed by the processor, it implements the loop convergence method as described in any one of claims 1 to 7.

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