A high-precision carrier phase generation device and method for a satellite receiver

Abstract

The application discloses a high-precision carrier phase generation device and method of a satellite receiver, and relates to the technical field of signal processing. The device and method generate a carrier phase sampling time based on a temperature-compensated crystal oscillator, use one satellite receiving channel as an original phase generation channel, and use other receiving channels for satellite acquisition and tracking. The original phase generation channel records a carrier phase value at any time, which is equal to a carrier phase value transmitted by a satellite end, and then a carrier phase measurement value is obtained by subtracting the carrier phase value of the original phase generation channel from a phase-locked loop carrier phase value. Meanwhile, through carrier phase compensation, carrier phase counter overflow processing and an output precision guaranteeing processing method, the satellite receiver can normally and accurately output the carrier phase measurement value.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of signal processing, in particular to a high-precision carrier phase generation device and method for a satellite receiver. BACKGROUND

[0002] The carrier phase measurement value is defined as the phase value of the satellite carrier signal at the satellite end ahead of the phase value at the receiver end at the same time. The carrier phase measurement value is an observation quantity that can represent the distance. The carrier phase observation equation of the satellite receiver and the satellite navigation constellation includes the position and time parameters. The absolute and relative position and time can be calculated by solving the single-difference and double-difference carrier phase equations. The commonly used global satellite navigation system GPS L1 satellite navigation signal carrier wavelength is about 0.19 meters, and the Beidou navigation system BDS B3 satellite navigation signal carrier wavelength is about 0.23 meters. The carrier phase measurement value of one-thousandth of a cycle can achieve millimeter-level distance measurement. The high-precision carrier phase measurement value can be used as the original observation quantity to improve the accuracy of the calculated position and time results. Therefore, it can be applied to the field of high-precision positioning and time service.

[0003] The carrier phase measurement value of the prior art satellite receiver is the phase value of the 0 initial phase signal received by the receiver end of the satellite transmitting end. The synchronization error of the receiver end and the transmitting end will affect the carrier phase measurement value. SUMMARY

[0004] The embodiment of the present application provides a high-precision carrier phase generation device and method for a satellite receiver. The carrier phase measurement value of the satellite receiver is obtained by using the phase relationship of multiple carrier signal receiving processes based on the original phase generation channel. The technical problem that each channel needs to be processed for synchronization error in the prior art is solved.

[0005] The embodiment of the present application adopts the following technical scheme:

[0006] A high-precision carrier phase generation method for a satellite receiver, comprising the following steps:

[0007] A satellite receiving channel of the satellite receiver is set as an original phase generation channel;

[0008] The original phase generation channel starts to generate carrier phase information from 0 degree phase. The original phase generation channel is frequency-locked during the working process of the satellite receiver. The remaining satellite receiving channels of the satellite receiver are allocated with satellites, and satellite acquisition and tracking are performed;

[0009] When the phase-locked loop of the satellite receiving channel allocates the satellite is locked to the carrier signal, the carrier phase value generated by the phase-locked loop is determined as the phase value of the carrier signal transmitted by the satellite at the receiving end of the satellite receiver;

[0010] The carrier phase measurement value of the satellite receiver is calculated: carrier phase measurement value of the satellite receiver = phase value at the receiving end of the satellite receiver - carrier phase value recorded by the original phase generation channel.

[0011] The embodiment of the present application also provides a satellite receiver high-precision carrier phase generation device for implementing the method of any one of the embodiments of the present application, comprising a digital processing unit, a programmable logic unit and a temperature-compensated crystal oscillator; wherein the digital processing unit is used for completing channel control of the satellite receiver, carrier phase measurement value reading and positioning calculation; the programmable logic unit is used for implementing channel processing of GPS and Beidou satellite navigation signals and completing signal acquisition and tracking under the control of the digital processing unit; the programmable logic unit simultaneously receives a clock signal of the temperature-compensated crystal oscillator, constitutes a clock generation unit, and generates a clock signal and a carrier phase measurement value sampling signal required by the channel of the GPS and Beidou satellite navigation signals; and the temperature-compensated crystal oscillator is used for providing an external clock required by carrier phase generation of the satellite receiver.

[0012] The above at least one technical scheme adopted by the embodiment of the present application can achieve the following beneficial effects: a satellite receiver high-precision carrier phase generation device and method, carrier phase sampling time is generated based on a temperature-compensated crystal oscillator, one satellite receiving channel is used as an original phase generation channel, and other receiving channels are used for satellite acquisition and tracking; the carrier phase value recorded by the original phase generation channel at any moment is equal to the carrier phase value transmitted by the satellite end, so that the carrier phase measurement value output by the satellite receiver = the phase value at the receiving end of the satellite receiver - the carrier phase value of the original phase generation channel. In this way, the synchronization error of each receiving channel can be uniformly calculated as the receiver clock error of the original phase generation channel. Meanwhile, the method of the present application proposes a carrier phase compensation method, a carrier phase counter overflow processing method and a processing method for ensuring output precision, and the receiver can accurately output the carrier phase measurement value under three conditions. BRIEF DESCRIPTION OF DRAWINGS

[0013] The accompanying drawings, which are included to provide a further understanding of the present application and are incorporated in and constitute a part of this application, illustrate embodiments of the present application and serve to explain the present application, and do not limit the present application in any manner. In the drawings:

[0014] Figure 1 A structural block diagram of a satellite receiver high-precision carrier phase generation device provided for the embodiment of the present application;

[0015] Figure 2 A flowchart of a satellite receiver high-precision carrier phase generation method provided for the embodiment of the present application;

[0016] Figure 3 A satellite receiver high-precision carrier phase generation method flowchart embodiment for compensating and correcting the phase value at the receiving end of the satellite receiver through a phase-locked loop.

[0017] Figure 4 The application discloses a satellite receiver high-precision carrier phase generation method. DETAILED DESCRIPTION

[0018] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described clearly and completely below in connection with the embodiments of the present application and corresponding drawings. Obviously, the described embodiments are only some of the embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0019] The technical solutions provided by the embodiments of the present application will be described in detail below in connection with the drawings.

[0020] In the embodiment, a satellite receiver high-precision carrier phase generation device is used to realize the application Figures 2-4 The method described in any one of the embodiments, the device as shown in Figure 1 The device comprises a digital processing unit, a programmable logic unit and a temperature-compensated crystal oscillator. The digital processing unit is used to complete channel control of the satellite receiver, reading of carrier phase measurement values and positioning calculation. The programmable logic unit is used to realize channel processing of GPS and Beidou satellite navigation signals and complete signal acquisition and tracking under the control of the digital processing unit. The programmable logic unit simultaneously receives a clock signal of the temperature-compensated crystal oscillator to form a clock generation unit and generate a clock signal required by the channel of the GPS and Beidou satellite navigation signals and a carrier phase measurement value sampling signal. The temperature-compensated crystal oscillator is used to provide an external clock required by the satellite receiver carrier phase generation.

[0021] In the embodiment, the digital processing unit is realized by an ARM or DSP processor. Meanwhile, in order to ensure the carrier phase output precision, the local sampling clock of the satellite receiver is generated by a 62MHz temperature-compensated crystal oscillator.

[0022] In the embodiment, a satellite receiver high-precision carrier phase generation method comprises the following steps: Figure 2

[0023] Step 101: Set one satellite receiving channel of the satellite receiver as an original phase generation channel, start to generate carrier phase information from 0 degree phase, and the original phase generation channel is frequency-locked in the working process of the satellite receiver and does not perform satellite acquisition, tracking or carrier phase adjustment. Since the satellite end transmitted carrier phase value also starts from 0 degree phase, the carrier phase value recorded by the original phase generation channel is used to replace the satellite end transmitted carrier phase value, and it is assumed that the clock difference between the original phase generation channel and the satellite end is 0.​

[0024] Step 102: Assigning satellites to the rest of the satellite receiving channels of the satellite receiver, carrying out satellite acquisition and tracking; after the satellite receiving channels track the satellites, recording the carrier phase value generated by the phase-locked loop;

[0025] Step 103: When the phase-locked loop of the satellite receiving channel assigned with the satellite locks the carrier signal, taking the carrier phase value generated by the phase-locked loop at the signal receiving moment as the phase value of the carrier signal transmitted by the satellite at this moment at the receiving end of the satellite receiver;

[0026] Step 104: Calculating the carrier phase measurement value of the satellite receiver:

[0027] Carrier phase measurement value of the satellite receiver = phase value at the receiving end of the satellite receiver - carrier phase value recorded by the original phase generation channel.

[0028] Figure 3 The satellite receiver high-precision carrier phase generation method flow embodiment for compensating and correcting the phase value at the receiving end of the satellite receiver through the phase-locked loop.

[0029] Step 201: Setting one satellite receiving channel of the satellite receiver as the original phase generation channel, starting to generate carrier phase information from 0 degree phase, and locking the working frequency (synchronous step 101);

[0030] Step 202: After the satellite receiving channel tracks the satellite, recording the carrier phase value generated by the phase-locked loop (synchronous step 102); Step 203: When the phase-locked loop of the satellite receiving channel assigned with the satellite locks the carrier signal, judging and compensating the carrier phase generated by the phase-locked loop, and correcting the phase value at the receiving end of the satellite receiver;

[0031] Since the phase-locked loop can lock the carrier signal at 0 degree phase and 180 degree phase, carrier phase judgment and compensation are needed; when the phase-locked loop locks the satellite carrier signal, if the satellite text frame header information is consistent with the given value, it is judged that the phase-locked loop is locked at 0 degree phase, and no compensation is needed, and the carrier phase value generated by the phase-locked loop at the signal receiving moment is taken as the phase value of the carrier signal transmitted by the satellite at this moment at the receiving end of the satellite receiver; when the phase-locked loop locks the satellite carrier signal, if the satellite text frame header information is opposite to the given value, it is judged that the phase-locked loop is locked at 180 degree phase, and the carrier phase value generated by the phase-locked loop is added by 0.5 cycles as the phase value at the receiving end of the satellite receiver;

[0032] Step 204: Calculating the carrier phase measurement value of the satellite receiver (synchronous step 104);

[0033] Figure 4 The satellite receiver high-precision carrier phase generation method flow embodiment for the carrier phase counter overflow.

[0034] Step 301: Set one satellite receiving channel of the satellite receiver as the original phase generation channel, generate the carrier phase information from 0 degree phase, and lock the working frequency (synchronization step 101);

[0035] Step 302: After the satellite receiving channel tracks the satellite, record the carrier phase value generated by the phase-locked loop (synchronization step 102);

[0036] Step 303: Handle the carrier phase counter overflow, and correct the phase value at the receiving end of the satellite receiver;

[0037] The carrier phase value of the phase-locked loop is generated by the carrier phase counter, which is a fixed-bit counter that starts from 0 and accumulates to the maximum value when the count is reset to 0. For example, the carrier phase counter has a bit width of 28 bits, and the maximum count is 268435456. When the carrier count exceeds 268435456, the count is reset to 0, and the carrier phase counter overflow needs to be handled, that is, the carrier phase value generated by the phase-locked loop after the carrier phase counter overflow is increased by the maximum count as the phase value at the receiving end of the satellite receiver, and when the overflow occurs multiple times, the maximum count is increased accordingly;

[0038] Step 304: Calculate the carrier phase measurement value of the satellite receiver (synchronization step 104);

[0039] The carrier phase measurement value of the satellite receiver = the phase value at the receiving end of the satellite receiver - the carrier phase value recorded by the original phase generation channel.

[0040] It should be noted that there is an embodiment of steps 203 and 303 combined. After compensating for the carrier phase generated by the phase-locked loop and handling the carrier phase counter overflow, the carrier phase measurement value of the satellite receiver = the phase value at the receiving end of the satellite receiver after compensating for the carrier phase and handling the carrier phase counter overflow - the carrier phase value of the original phase generation channel.

[0041] It should be noted that since the clock difference between the original phase generation channel and the satellite transmitting end is not 0 in practice, the satellite receiver can be synchronized and calibrated uniformly in the original phase generation channel. Therefore, in all embodiments of the present application, further, the satellite receiver is positioned and the local sampling time is adjusted, and the carrier phase measurement value is output;

[0042] For example, the satellite receiver does not output the carrier phase measurement value before positioning; the satellite receiver first adjusts the local sampling time after positioning, and the time accuracy is 1 warm-up crystal clock period after adjustment, and the value is less than 20ns; the satellite receiver outputs the carrier phase measurement value after the time adjustment is stable.

[0043] It should also be noted that the terms "comprising," "including," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises a... " does not, without more constraints, exclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0044] The above description is merely illustrative of the application, and not restrictive. Various modifications and changes can become apparent to those skilled in the art. Incorporating any modification, equivalent substitution, improvement, etc. within the spirit and principle of the application, shall be included in the scope of the claims of the application.

Claims

1. A method for generating high-precision carrier phase in a satellite receiver, characterized in that, Includes the following steps: Set one of the satellite receiving channels of the satellite receiver as the original phase generation channel; The original phase generation channel generates carrier phase information starting from the 0-degree phase. During the operation of the satellite receiver, the original phase generation channel is frequency locked, and neither satellite acquisition and tracking nor carrier phase adjustment is performed. Assign satellites to the remaining satellite receiving channels of the satellite receiver for satellite acquisition and tracking; Once the phase-locked loop of the satellite's receiving channel locks the carrier signal, the phase value of the carrier generated by the phase-locked loop is determined as the phase value of the carrier signal transmitted by the satellite at the receiving end of the satellite receiver. The satellite receiver performs synchronization calibration on the original phase generation channel, adjusts the local sampling time after positioning, and outputs carrier phase measurement values: The carrier phase measurement value of the satellite receiver = the phase value at the receiving end of the satellite receiver - the carrier phase value recorded by the original phase generation channel; The carrier phase value recorded by the original phase generation channel is used to replace the carrier phase value transmitted by the satellite. The local sampling time adjustment refers to the following: after the satellite receiver is positioned, the local sampling time is adjusted, and the time accuracy after adjustment is one temperature-compensated crystal oscillator clock cycle. After the satellite receiver time adjustment is stable, the carrier phase measurement value is output.

2. The high-precision carrier phase generation method for a satellite receiver according to claim 1, characterized in that: The method also performs judgment and compensation on the carrier phase generated by the phase-locked loop to correct the phase value at the satellite receiver's receiving end. The specific method is as follows: When the phase-locked loop (PLL) locks onto the satellite carrier signal, if the satellite message header information is consistent with the given value, the PLL is determined to be 0 degrees phase locked and no compensation is required. When the PLL locks onto the satellite carrier signal, if the satellite message header information is opposite to the given value, the PLL is determined to be 180 degrees phase locked, and the carrier phase value generated by the PLL plus 0.5 cycles is used as the phase value at the receiving end of the satellite receiver.

3. The high-precision carrier phase generation method for a satellite receiver according to claim 1, characterized in that: The method also addresses carrier phase counter overflow by correcting the phase value at the satellite receiver's receiving end, specifically as follows: The carrier phase value generated by the phase-locked loop after the carrier phase counter overflows is incremented by the maximum count value and used as the phase value at the receiving end of the satellite receiver.

4. The high-precision carrier phase generation method for a satellite receiver according to claim 3, characterized in that: The temperature-compensated crystal oscillator clock period is less than 20ns; and / or The carrier phase counter has a bit width of 28 bits and a maximum count value of 268435456.

5. A high-precision carrier phase generation device for a satellite receiver, used to implement the method described in any one of claims 1 to 4, characterized in that, It includes a digital processing unit, a programmable logic unit (PLU), and a temperature-compensated crystal oscillator (TCQS). The digital processing unit is used to perform channel control, carrier phase measurement reading, and positioning calculation for the satellite receiver. The PLU is used to process GPS and BeiDou satellite navigation signals, and to acquire and track signals under the control of the digital processing unit. The PLU also receives clock signals from the TLU to form a clock generation unit, which generates the clock signals required for the GPS and BeiDou satellite navigation signal channels and the carrier phase measurement sampling signals. The TLU provides the external clock required for the satellite receiver to generate the carrier phase.

6. The high-precision carrier phase generation device for a satellite receiver according to claim 5, characterized in that, The digital processing unit is implemented using an ARM or DSP processor.

7. The high-precision carrier phase generation device for a satellite receiver according to claim 5, characterized in that, The local sampling clock of the satellite receiver is generated by a 62MHz temperature-compensated crystal oscillator.

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