A Beidou satellite navigation system full-frequency transceiver device and method

Abstract

The invention discloses a full-frequency transceiver of a Beidou satellite navigation system. A radio frequency front end is used for grouping received full-band Beidou satellite signals according to the magnitude of a carrier frequency; a radio frequency processing module is used for performing frequency reduction and analog-to-digital conversion processing on each group of signals output by the radio frequency front end, so as to output a digital intermediate frequency signal of each group of signals; a digital signal preprocessing module is used for performing intermediate frequency stripping, anti-aliasing and downsampling processing on each group of digital intermediate frequency signals output by the radio frequency processing module; a tracking module is used for performing tracking processing on all frequency point signals output by a digital signal processing unit; an RDSS time-scale synchronization module is used for maintaining the RDSS signal transmission time according to the code phase received by the tracking module, so as to serve as the RDSS signal transmission time reference of the transceiver; and an RDSS transmission module is used for transmitting the RDSS signal according to the RDSS signal transmission time reference and a transmission enable control command of the RDSS time-scale synchronization module, so as to realize the functions of short message transmission and two-way ranging.

Description

Technical Field

[0001] The present invention relates to the field of Beidou satellite navigation technology, and in particular to a full-frequency transceiver device and method for a Beidou satellite navigation system. Background Art

[0002] The global satellite navigation system can provide high-precision, all-weather, global positioning, navigation and timing services, and has been applied to all aspects of production and life. With the development of science and technology, China's Beidou Satellite Navigation System (BDS) has gradually become an important part of the global satellite navigation system. BDS can not only provide high-precision positioning services, but also has unique functions such as short message communication and precise single-point positioning.

[0003] BDS satellites transmit 8 civil signals on 6 carriers, including B2a, B2b, B2I, B3I, B1I, B1C, S1, and S2C. Receivers supporting multi-frequency signals can provide high-quality positioning, velocity measurement, and timing services, and can achieve precise single-point positioning, RTK technology, anti-interference, and accurate ionosphere modeling.

[0004] The transceiver architecture of the Beidou satellite navigation system mainly includes the RF front end, tracking loop and acquisition module, RDSS (satellite radio positioning system) transmission module, and PVT module. Although the existing transceiver architecture can meet the needs of the Beidou navigation satellite system to a certain extent, it generally needs to take into account multiple systems and multiple frequencies. Due to limited hardware resources and cost considerations, it either cannot support all frequencies or needs to sacrifice performance, which will affect the accuracy and reliability of navigation in some special environments. Summary of the invention

[0005] Based on the above situation, the main purpose of the present invention is to provide a full-frequency transceiver device and method designed specifically for the signal characteristics of the Beidou satellite navigation system, to achieve full-frequency signal reception and transmission of a single BDS system, to obtain the best reception of the Beidou satellite navigation system signal, and to improve the stability and reliability of the system.

[0006] To achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0007] A Beidou satellite navigation system full-frequency transceiver device includes a radio frequency front end, a radio frequency processing module, a digital signal preprocessing module, a tracking module, an RDSS time scale synchronization module and an RDSS transmitting module.

[0008] The radio frequency front end is used to group the received full-band Beidou satellite signals according to the magnitude of the carrier frequency;

[0009] The RF processing module is used to perform frequency reduction and analog-to-digital conversion processing on each group of signals output by the RF front end, so as to output a digital intermediate frequency signal of each group of signals;

[0010] The digital signal preprocessing module is used to perform intermediate frequency stripping, anti-aliasing and down-sampling processing on each group of digital intermediate frequency signals output by the radio frequency processing module;

[0011] The tracking module is used to track all frequency point signals output by the digital signal preprocessing module;

[0012] The RDSS time-scale synchronization module is used to maintain the RDSS signal transmission time according to the code phase received by the tracking module, so as to serve as the RDSS signal transmission time reference of the transceiver device;

[0013] The RDSS transmission module is used to transmit the RDSS signal according to the RDSS signal transmission time reference and the transmission enable control command of the RDSS time scale synchronization module, so as to realize the short message transmission and two-way ranging functions.

[0014] Preferably, the RF front end includes a first duplexer, a second duplexer and a power divider.

[0015] The first duplexer is used to divide the received full-band Beidou satellite signal into a first frequency band signal and a second frequency band signal according to the carrier frequency from low to high, the first frequency band signal includes a low frequency band signal, and the second frequency band signal includes a high frequency band signal;

[0016] The second duplexer is used to divide the high frequency band signal into two groups according to the carrier frequency;

[0017] The power divider is used to expand the low frequency band signal into two groups.

[0018] Preferably, the low-frequency band signals include B2a, B2b, B2I, and B3I signals, and the high-frequency band signals include B1I, B1C, S1, and S2C signals.

[0019] Preferably, the second duplexer divides the high frequency band signal into B1I, B1C frequency band signals and S1, S2C frequency band signals according to the carrier frequency.

[0020] Preferably, the power divider expands the low-band signal into B2a, B2b, B2I and B3I band signals.

[0021] Preferably, the RF processing module includes multiple RF signal processing channels, each of which is used to process Beidou satellite signals of different frequency bands output by the RF front end after grouping.

[0022] The RF signal processing channels each include a mixer and an analog-to-digital conversion circuit. The analog-to-digital conversion circuit of each RF signal processing channel uses the same sampling clock to perform sampling at the same sampling rate. The frequency of the mixer is the same as that of the sampling clock.

[0023] Preferably, the sampling rate is not lower than the widest frequency band of the multiple groups of Beidou satellite signals output by the RF front end.

[0024] Preferably, the digital signal preprocessing module includes multiple digital signal preprocessing channels, each of which includes an intermediate frequency carrier stripping unit, an anti-aliasing filtering unit and a downsampling unit.

[0025] The intermediate frequency carrier stripping unit is used to strip the carrier of the digital intermediate frequency signal output by the radio frequency processing module;

[0026] The anti-aliasing filter unit is used to filter out the out-of-band noise and interference in the digital intermediate frequency signal after carrier stripping;

[0027] The downsampling unit is used to perform downsampling processing on the signal output by the anti-aliasing filtering unit. The downsampling rate of each digital signal preprocessing channel is the same, and the downsampling rate is greater than the signal bandwidth.

[0028] Preferably, the tracking module comprises a correlator array and a plurality of playback buffers,

[0029] Each digital signal preprocessing channel corresponds to a playback buffer, and each playback buffer includes two memories, a playback buffer ping and a playback buffer pong. When one of the memories has finished storing data, the newly input sampling point data is stored in the other memory.

[0030] After the correlator array detects that the playback buffer is full of data, data playback and coherent integration operations are started, and different signal tracking channels retrieve data from the corresponding playback buffer.

[0031] Preferably, the RDSS time scale synchronization module includes an RDSS time module and a transmission enable control module.

[0032] The RDSS time module is used to maintain the fractional second time and the integer second time according to the Beidou satellite signal transmission time extracted by the tracking module, so as to serve as the reference of the RDSS signal transmission time of the transceiver;

[0033] The transmission enable control module is used to send a transmission enable control command to the RDSS transmission module when the RDSS time is valid.

[0034] Preferably, the RDSS time module includes a fractional second NCO unit and an integer second calculation unit.

[0035] The fractional second NCO unit is used to maintain the fractional second time according to the Beidou satellite signal transmission time extracted by the tracking module;

[0036] The integer second calculation unit is used to maintain the integer second time according to the Beidou satellite signal transmission time extracted by the tracking module.

[0037] Preferably, the RDSS transmitting module includes a spread spectrum modulator, a BPSK modulator, a low-pass filter shaping filter, a CIC interpolation filter, a digital-to-analog conversion circuit, an analog low-pass filter, a mixer and a power amplifier.

[0038] The spread spectrum modulator is used to perform spread spectrum modulation on the message symbol sequence to be sent, and output a spread spectrum modulated message sequence;

[0039] The BPSK modulator is used to perform non-return-to-0 bipolar modulation on the spread spectrum modulated message sequence signal;

[0040] The low-pass filtering shaping filter is used to filter out part of the side lobe signal in the digital signal output by the BPSK modulator;

[0041] The CIC interpolation filter is used to upsample the digital sampling signal output by the low-pass filtering shaping filter and filter out the image signal;

[0042] The digital-to-analog conversion circuit is used to convert the digital signal output by the CIC interpolation filter into an analog signal;

[0043] The analog low-pass filter is used to filter out the out-of-band interference signal in the analog signal output by the digital-to-analog conversion circuit;

[0044] The mixer is used to modulate the output signal of the analog low-pass filter to the radio frequency band;

[0045] The power amplifier is used to amplify the power of the analog signal output by the mixer so that the satellite end can receive the signal.

[0046] Preferably, it also includes a capture module and a PVT module.

[0047] The capture module is used to detect the Beidou satellite navigation signal and transfer it to the tracking module through the search of code phase and carrier Doppler frequency;

[0048] The PVT module is used to estimate the position, speed and time according to the code phase observation, carrier phase observation, Doppler frequency and navigation message reported by the tracking module.

[0049] The present invention also discloses a Beidou satellite navigation signal full-frequency transceiver chip, which includes the Beidou satellite navigation system full-frequency transceiver device described in any one of the present invention to receive and transmit Beidou satellite navigation signal full-frequency band signals.

[0050] The present invention also discloses a Beidou satellite navigation signal full-frequency transceiver, which adopts the Beidou satellite navigation signal full-frequency transceiver chip of the present invention.

[0051] The present invention also discloses a Beidou satellite navigation system full-frequency transceiver method, comprising the steps of:

[0052] S100, grouping the received full-band Beidou satellite signals according to the magnitude of the carrier frequency;

[0053] S200, performing frequency reduction and analog-to-digital conversion processing on each group of signals to output a digital intermediate frequency signal of each group of signals;

[0054] S300, performing intermediate frequency stripping, anti-aliasing and downsampling processing on each group of digital intermediate frequency signals;

[0055] S400, tracking and processing all frequency point signals outputted in step S300;

[0056] S500, maintaining the RDSS signal transmission time according to the code phase received in step S400 to serve as a RDSS signal transmission time reference;

[0057] S600, transmitting the RDSS signal according to the RDSS signal transmission time reference and the transmission enable control command, to realize short message transmission and two-way ranging functions.

[0058] Preferably, the S100 includes the steps of:

[0059] S101, dividing the received full-band Beidou satellite signal into a first frequency band signal and a second frequency band signal according to the carrier frequency from low to high, wherein the first frequency band signal includes a low frequency band signal, and the second frequency band signal includes a high frequency band signal;

[0060] S102, dividing the high frequency band signal into two groups according to the carrier frequency;

[0061] S103: Expand the low-frequency band signal into two groups.

[0062] Preferably, the low-frequency band signals include B2a, B2b, B2I, and B3I signals, and the high-frequency band signals include B1I, B1C, S1, and S2C signals.

[0063] Preferably, the step S102 includes dividing the high frequency band signal into B1I, B1C frequency band signals and S1, S2C frequency band signals according to carrier frequency.

[0064] Preferably, the step S103 includes extending the low frequency band signal into B2a, B2b, B2I frequency band signals and B3I frequency band signals.

[0065] Preferably, the S300 includes the steps of:

[0066] S301, performing carrier stripping on the digital intermediate frequency signal output in step S200;

[0067] S302, filtering out-of-band noise and interference in the digital intermediate frequency signal after carrier stripping;

[0068] S303, downsampling the signal output in step S302, with each signal having the same downsampling rate, which is greater than the signal bandwidth.

[0069] Preferably, the S500 includes the steps of:

[0070] S501, maintaining the fractional second time and the integer second time according to the Beidou satellite signal transmission time extracted in step S400 as a reference for the RDSS signal transmission time;

[0071] S502, when the RDSS time is valid, a transmission enable control command is issued.

[0072] Preferably, the S600 includes:

[0073] S601, performing spread spectrum modulation on a message symbol sequence to be sent, and outputting a spread spectrum modulated message sequence;

[0074] S602, performing non-return-to-zero bipolar modulation on the spread spectrum modulated message sequence signal;

[0075] S603, filtering out part of the side lobe signal in the digital signal output by the BPSK modulator;

[0076] S604, upsampling the digital sampling signal output in step S603, and filtering out the image signal;

[0077] S605, converting the digital signal output in step S604 into an analog signal;

[0078] S606, filtering out-of-band interference signals in the analog signal outputted in step S605;

[0079] S607, modulating the signal outputted in step S606 to a radio frequency band;

[0080] S608, power amplifying the analog signal outputted in step S607 so that the satellite terminal can receive the signal.

[0081] Preferably, the method further comprises the steps of:

[0082] S700, detecting the Beidou satellite navigation signal and transferring it to the tracking module by searching the code phase and the carrier Doppler frequency;

[0083] S800, estimate the position, speed and time according to the code phase observation, carrier phase observation, Doppler frequency and navigation message reported in step S400.

[0084] The present invention specifically designs a full-frequency transceiver architecture for the signal characteristics of the Beidou satellite navigation system. By optimizing the transceiver architecture, the full-frequency signal transceiver of a single BDS system is realized, which not only reduces the complexity of design and implementation, but also obtains the best reception of Beidou satellite navigation system signals, which not only reduces the consumption of hardware resources, but also improves the stability and reliability of the system. The receiving function of the transceiver is classified by frequency, and different radio frequency channels and digital signal preprocessing channels are used to effectively suppress interference between different frequency points, thereby improving signal reception performance, which has important national defense strategic significance for realizing full-frequency signal transceiver of a single BDS system in a complex electromagnetic environment.

[0085] Other beneficial effects of the present invention will be explained in the specific implementation manner through the introduction of specific technical features and technical solutions. Through the introduction of these technical features and technical solutions, those skilled in the art should be able to understand the beneficial technical effects brought about by the technical features and technical solutions. BRIEF DESCRIPTION OF THE DRAWINGS

[0086] The preferred implementation of the Beidou satellite navigation system full-frequency transceiver according to the present invention will be described below with reference to the accompanying drawings.

[0087] Figure 1 A structural diagram of a Beidou satellite navigation system full-frequency transceiver according to a preferred embodiment of the present invention;

[0088] Figure 2 A structural diagram of a radio frequency front end in a full-frequency transceiver of a Beidou satellite navigation system according to a preferred embodiment of the present invention;

[0089] Figure 3 It is another radio frequency front-end structure diagram in a Beidou satellite navigation system full-frequency transceiver according to a preferred embodiment of the present invention;

[0090] Figure 4 A structural diagram of a digital signal preprocessing module in a Beidou satellite navigation system full-frequency transceiver according to a preferred embodiment of the present invention;

[0091] Figure 5A structural diagram of a tracking module in a Beidou satellite navigation system full-frequency transceiver according to a preferred embodiment of the present invention;

[0092] Figure 6 A structural diagram of an RDSS time-scale synchronization module in a Beidou satellite navigation system full-frequency transceiver according to a preferred embodiment of the present invention;

[0093] Figure 7 A structural diagram of an RDSS transmitting module in a Beidou satellite navigation system full-frequency transceiver according to a preferred embodiment of the present invention;

[0094] Figure 8 A structural diagram of another Beidou satellite navigation system full-frequency transceiver according to a preferred embodiment of the present invention;

[0095] Fig. 9 The architecture diagram of the Beidou satellite navigation system full-frequency transceiver chip designed according to the technical solution of the present invention;

[0096] Fig.10 The present invention is a flowchart of a Beidou satellite navigation system full-frequency receiving and transmitting method according to a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0097] Figure 1 The present invention is a structural diagram of a full-band transceiver of a Beidou satellite navigation system according to a preferred embodiment of the present invention, comprising a radio frequency front end 100, a radio frequency processing module 200, a digital signal preprocessing module 300, a tracking module 400, an RDSS time-scale synchronization module 500 and an RDSS transmitting module 600, wherein the radio frequency front end 100 is used to group the received full-band Beidou satellite signals according to the magnitude of the carrier frequency; the radio frequency processing module 200 is used to perform frequency reduction and analog-to-digital conversion processing on each group of signals output by the radio frequency front end to output a digital intermediate frequency signal of each group of signals; the digital signal preprocessing module 300 is used to perform frequency reduction and analog-to-digital conversion processing on each group of digital intermediate frequency signals output by the radio frequency processing module The signal is subjected to intermediate frequency stripping, anti-aliasing and down-sampling processing; the tracking module 400 is used to track all frequency point signals output by the digital signal preprocessing module 300; the RDSS time-scale synchronization module 500 is used to maintain the RDSS signal transmission time according to the code phase received by the tracking module 400, so as to serve as the RDSS signal transmission time reference of the transceiver; the RDSS transmission module 600 is used to transmit the RDSS signal according to the RDSS signal transmission time reference and the transmission enable control command of the RDSS time-scale synchronization module 500, so as to realize the short message transmission and two-way ranging functions, and the navigation data of the transceiver may include time data for ranging, etc.

[0098] The present invention specifically designs a full-frequency transceiver architecture for the signal characteristics of the Beidou satellite navigation system. By optimizing the transceiver architecture, the full-frequency signal transceiver of a single BDS system is realized, which not only reduces the complexity of design and implementation, but also obtains the best reception of Beidou satellite navigation system signals, which not only reduces the consumption of hardware resources, but also improves the stability and reliability of the system. The receiving function of the transceiver is classified by frequency, and different radio frequency channels and digital signal preprocessing channels are used to effectively suppress interference between different frequency points, thereby improving signal reception performance, which has important national defense strategic significance for realizing full-frequency signal transceiver of a single BDS system in a complex electromagnetic environment.

[0099] In a preferred embodiment, Figure 2 As shown, the RF front end includes a first duplexer 101, a second duplexer 102 and a power divider 103, wherein the first duplexer 101 is used to divide the received full-band Beidou satellite signal into a first frequency band signal and a second frequency band signal according to the carrier frequency from low to high, wherein the first frequency band signal includes a low frequency band signal, and the second frequency band signal includes a high frequency band signal; the second duplexer 102 is used to divide the high frequency band signal into two groups according to the carrier frequency; and the power divider 103 is used to expand the low frequency band signal into two groups.

[0100] In a preferred embodiment, the low-frequency band signal includes B2a, B2b, B2I, and B3I signals, and the high-frequency band signal includes B1I, B1C, S1, and S2C signals. The present invention adds signal receiving functions such as B2b and S bands, so that the transceiver supports more functions, such as the receiving function of short message communication, precise single point positioning, etc.

[0101] The BDS satellite transmits 8 civil signals on 6 carriers, including B2a, B2b, B2I, B3I, B1I, B1C, S1, and S2C. The first duplexer 101 first divides the frequency band into two frequency bands, one containing the B2a, B2b, B2I, and B3I signals and the other containing the B1I, B1C, S1, and S2C signals. The second duplexer 102 further divides the frequency band containing the B1I, B1C, S1, and S2C signals into two frequency bands, one containing the B1I and B1C signals and the other containing the S1 and S2C signals. The power divider 103 expands the B2a, B2b, B2I, and B3I signals into two output ends, containing the same signal, and the power is generally distributed at a ratio of 1:1. That is to say, the RF front end divides the RF signal into three segments and four output ends according to the frequency band distribution of the eight signals of the BDS system. The four groups of signals correspond to the following from low to high carrier frequencies: (1) the first group of signals are B2a, B2b, and B2I; (2) the second group of signals are B3I; (3) the third group of signals are B1I and B1C; (4) the fourth group of signals are S1 and S2C.

[0102] Among them, signal frequency bands that are far apart can be divided by a duplexer, and the loss of the duplexer within the band is very small. Figure 2 As shown in the second duplexer 102 in FIG. 1 , the input signal includes B1I / B1C and S1 / S2C signal bands, and the power in the B1I / B1C signal band is , the in-band power of S1 / S2C signal is The two output ends of the second duplexer 102 include the B1I / B1C signal and the S1 / S2C signal respectively. The power of the B1I / B1C signal output end within the B1I / B1C signal band is approximately , the power in the S1 / S2C signal band is 0, and the power in the S1 / S2C signal band at the S1 / S2C signal output end is approximately , the power in the B1I / B1C signal band is 0. Signal frequency bands that are close to each other can be divided into power bands by a power divider, which divides the power of the entire frequency band. Figure 2 As shown in the power divider 103 in FIG. 1 , the input signal includes B2a / B2b / B2I and B3I signal bands, and the power in the B2a / B2b / B2I signal band is , the in-band power of the B3I signal is , the two output ends of the power divider contain B2a / B2b / B2I signals and B3I signals. Assuming that the power divider distributes the power 1:1, the power of both output ends is within the B2a / B2b / B2I signal band. , the power in the B3I signal band is .

[0103] Attached Figure 3 An extended classification structure with an equivalent of one input port and four output ports is provided. The first duplexer 101 first divides the frequency band into two frequency bands, which respectively include the frequency bands of B2a, B2b, B2I, B3I, B1I, and B1C signals and the frequency bands of S1 and S2C signals; the second duplexer 102 further divides the frequency bands of B1I and B1C signals into two frequency bands, which respectively include the frequency bands of B2a, B2b, B2I, and B3I signals and the frequency bands of B1I and B1C signals. The power divider 103 expands the signals of B2a, B2b, B2I, and B3I into two output ports.

[0104] In a preferred embodiment, the RF processing module 200 includes multiple RF signal processing channels, each of which is used to process Beidou satellite signals of different frequency bands output after the RF front end is grouped, and each of the RF signal processing channels includes a mixer and an analog-to-digital conversion circuit, and the analog-to-digital conversion circuit of each RF signal processing channel uses the same sampling clock to perform sampling at the same sampling rate, and the frequency of the mixer is homologous to the sampling clock. Only in this way can the carrier-assisted code loop tracking be used in the tracking module to improve the signal tracking performance.

[0105] In a preferred embodiment, the sampling rate is not lower than the widest frequency band of the multiple groups of Beidou satellite signals output by the RF front end 100. For example, the frequency band of the signal grouped by the RF front end, including B2a, B2b, and B2I, is the widest, and if only the main lobe is considered, the bandwidth is 51.15 MHz, then the sampling rate of complex sampling is not lower than this value, and the sampling rate of real sampling is doubled.

[0106] In a preferred embodiment, Figure 4 As shown, the digital signal preprocessing module 300 includes multiple digital signal preprocessing channels, each of which includes an intermediate frequency carrier stripping unit 301, an anti-aliasing filter unit 302 and a downsampling unit 303. Through the preprocessing of the digital signal preprocessing module 300, the storage requirements and data processing volume of subsequent modules can be reduced. Among them, the intermediate frequency carrier stripping unit 301 is used to perform carrier stripping on the digital intermediate frequency signal output by the radio frequency processing module; the anti-aliasing filter unit 302 is used to filter out the out-of-band noise and interference in the digital intermediate frequency signal after carrier stripping, which can prevent the out-of-band signal from aliasing into the band during the downsampling process; the downsampling unit 303 is used to perform downsampling processing on the signal output by the anti-aliasing filter unit 302, and the downsampling rate of each digital signal preprocessing channel is the same, and the downsampling rate is greater than the signal bandwidth. Preferably, considering all Beidou signals, the downsampling rate needs to be greater than 20.46MHz.

[0107] In a preferred embodiment, Figure 5 As shown, the tracking module 400 includes a correlator array 401 and multiple playback buffers 402, wherein each digital signal preprocessing channel corresponds to a playback buffer, and each playback buffer includes two memories, a playback buffer ping and a playback buffer pong. When one of the memories has stored data, the newly input sampling point data is stored in the other memory; after the correlator array detects that the playback buffer is full of data, it starts data playback and coherent integration operations, and different signal tracking channels take data from the corresponding playback buffer.

[0108] Since the BeiDou satellite navigation system has many satellites and frequencies, in order to reduce hardware resources, a playback tracking strategy is adopted, and the tracking correlator array adopts time division multiplexing. After completing the integration of the specified time, the integration result is used to identify the code phase and carrier phase. Finally, the carrier tracking loop and the code tracking loop use PLL, DLL, etc. to synchronize the local carrier frequency with the carrier frequency of the received signal, and the local spread spectrum code phase with the spread spectrum code phase of the received signal.

[0109] The data sampling rate is about 20.46MHz, the transceiver baseband signal processing module can operate at 200MHz or even higher, the data playback rate is much higher than the data sampling rate, and the coherent integration of up to nearly 10 satellite signals can be achieved through multiple playbacks using a physical tracking correlator array. Therefore, the playback tracking strategy and tracking channel time division multiplexing can effectively reduce hardware resources and costs.

[0110] In a preferred embodiment, Figure 6 As shown, the RDSS time scale synchronization module 500 may include an RDSS time module 501 and a transmission enable control module 502. The RDSS time module 501 is used to maintain the decimal second time and the integer second time according to the Beidou satellite signal transmission time extracted by the tracking module 400, so as to serve as a reference for the RDSS signal transmission time of the transceiver device; the transmission enable control module 502 is used to issue a transmission enable control command to the RDSS transmission module 600 when the RDSS time is valid.

[0111] In a specific implementation, the tracking module 400 extracts the transmission time of the satellite signal based on the code phase and data of the RDSS received signal. The RDSS time module 501 maintains a decimal second time and an integer second time according to the extracted signal transmission time, and uses this as a reference for the RDSS signal transmission time of the transceiver. When the RDSS time is valid, the RDSS signal can be transmitted according to user needs. The RDSS signal needs to be transmitted according to the time rules specified in the protocol. After the user prepares the data, the transmission enable control module sends a pulse signal to the RDSS transmission module to start the transmission at the expected time, thereby realizing the reception and transmission of the RDSS signal, and realizing positioning and short message communication based on the RDSS signal.

[0112] In a preferred embodiment, the RDSS time module 501 may include a fractional second NCO unit and an integer second calculation unit, wherein the fractional second NCO unit is used to maintain the fractional second time according to the Beidou satellite signal transmission time extracted by the tracking module; the integer second calculation unit is used to maintain the integer second time according to the Beidou satellite signal transmission time extracted by the tracking module.

[0113] In a preferred embodiment, Figure 7As shown, the RDSS transmitting module 600 includes a spread spectrum modulator 601, a BPSK modulator 602, a low-pass filter shaping filter 603, a CIC interpolation filter 604, a digital-to-analog conversion circuit 605, an analog low-pass filter 606, a mixer 607 and a power amplifier 608, wherein the spread spectrum modulator 601 is used to perform spread spectrum modulation on the message symbol sequence to be transmitted and output a spread spectrum modulated message sequence; the BPSK modulator 602 is used to perform non-return-to-0 bipolar modulation on the spread spectrum modulated message sequence signal; the low-pass filter shaping filter 603 is used to filter out the digital signal output by the BPSK modulator The CIC interpolation filter 604 is used to upsample the digital sampling signal output by the low-pass filter shaping filter and filter out the image signal; the digital-to-analog conversion circuit 605 is used to convert the digital signal output by the CIC interpolation filter into an analog signal; the analog low-pass filter 606 is used to filter out the out-of-band interference signal in the analog signal output by the digital-to-analog conversion circuit; the mixer 607 is used to modulate the output signal of the analog low-pass filter to the radio frequency band; the power amplifier 608 is used to amplify the power of the analog signal output by the mixer so that the satellite end can receive the signal.

[0114] In a specific implementation, how much side lobe signal is retained by the low-pass filter shaping filter 603 needs to be determined according to industry communication specifications to prevent interference with other communication signals. The passband cutoff frequency of the analog low-pass filter 506 is the cutoff frequency of the useful signal, the stopband cutoff frequency needs to refer to the industry communication specifications, and the transition band is the distance between the passband cutoff frequency and the stopband cutoff frequency.

[0115] In a preferred embodiment, Figure 8 As shown, the Beidou satellite navigation system full-frequency transceiver of the present invention also includes a capture module 700 and a PVT module 800. The capture module 700 is used to detect the Beidou satellite navigation signal and transfer it to the tracking module through the search of code phase and carrier Doppler frequency; the PVT module 800 is used to estimate the position, speed and time according to the code phase observation, carrier phase observation, Doppler frequency and navigation message reported by the tracking module.

[0116] The present invention also discloses a Beidou satellite navigation signal full-frequency transceiver chip, the chip comprises the Beidou satellite navigation system full-frequency transceiver device of the present invention, so as to receive and transmit Beidou satellite navigation signal full-frequency band signals.

[0117] The present invention also discloses a Beidou satellite navigation signal full-frequency transceiver, which adopts the Beidou satellite navigation signal full-frequency transceiver chip of the present invention.

[0118] Fig. 9This is a diagram of the architecture of the Beidou satellite navigation system full-frequency transceiver chip designed according to the technical solution of the present invention.

[0119] The receiving antenna module is used to receive the radio frequency signals transmitted by the Beidou satellite navigation system satellites, amplify and filter the signals, and input them into the Beidou satellite navigation system full-frequency transceiver.

[0120] The RF front end is used for preprocessing of RF signals, including duplexer-1, duplexer-2 and power divider. According to the frequency band distribution of the 8 signals, the RF signals are divided into 3 segments and 4 output ends. According to the carrier frequency from low to high, they correspond to 4 groups of signals: (1) The first group of signals is B2a, B2b, and B2I; (2) The second group of signals is B3I; (3) The third group of signals is B1I and B1C; (4) The fourth group of signals is S1 and S2C.

[0121] The RF processing module includes 4 RF signal processing channels, which process the 4 RF signals output by the RF front end and output 4 low intermediate frequency or zero intermediate frequency signals. The ADC modules of the 4 RF signal processing channels need to use the same sampling clock for sampling at the same sampling rate, and the mixing frequency needs to be the same source as the sampling clock, that is, derived from the same reference clock multiplied by the frequency.

[0122] The digital signal preprocessing module is used for preprocessing digital signals. It contains 6 digital signal preprocessing channels, which are used to process B2a, B2b / B2I, B3I, B1C and S1 / S2C signals respectively. indivual The pre-processing channel includes intermediate frequency carrier stripping, anti-aliasing filtering, downsampling, etc., which reduces the storage requirements and data processing volume of subsequent modules.

[0123] The capture module is used to detect Beidou satellite navigation signals. It detects signals and transfers them to the tracking module by searching the code phase and carrier Doppler frequency. The capture module generally includes operations such as coherent integration, FFT, and incoherent integration.

[0124] The tracking module is used for tracking and processing all frequency signals of the Beidou satellite navigation system. Each of the 6 digital signal preprocessing channels corresponds to a playback buffer, that is, it includes 6 playback buffers. Each playback buffer contains two memories, playback buffer ping and playback buffer pong. Ping-pong operation is adopted. When one playback buffer has stored all the data, the newly input sampling points are stored in another memory. After the correlator array in the tracking module detects that the playback buffer is full of data, data playback and coherent integration operations are started. Different signal tracking channels take data from the corresponding buffers, and coherent integration of multiple satellite signals is realized after multiple playbacks.

[0125] The RDSS time-scale synchronization module uses the received RDSS signal code phase to maintain the RDSS signal transmission time, ensure the correct RDSS signal transmission time, realize the reception and transmission of RDSS signals, and realize positioning and short message communication based on RDSS signals.

[0126] The PVT module estimates the position, speed and time based on the code phase observation, carrier phase observation, Doppler frequency, navigation message and other information reported by the tracking module.

[0127] RDSS transmitting module is used to transmit RDSS signals and realize short message transmission and two-way ranging functions.

[0128] The modular design of the Beidou navigation satellite system transceiver proposed in the present invention can be flexibly tailored according to different needs to meet the needs of different customers. Fig. 9 For users who do not need to receive short messages, the S1 / S2C signal receiving and processing flow and the RDSS transmitting module can be cut off. That is, modular design allows the Beidou satellite navigation system transceiver with different functions to be customized according to needs.

[0129] The present invention also discloses a Beidou satellite navigation system full-frequency transceiver method, such as Fig.10 As shown, the method includes the steps of: S100, grouping the received full-band Beidou satellite signals according to the size of the carrier frequency; S200, performing frequency reduction and analog-to-digital conversion processing on each group of signals to output digital intermediate frequency signals of each group of signals; S300, performing intermediate frequency stripping, anti-aliasing and downsampling processing on the digital intermediate frequency signals of each group; S400, tracking and processing all frequency point signals output by the step S300; S500, maintaining the RDSS signal transmission time according to the code phase received in the step S400 as the RDSS signal transmission time reference; S600, transmitting the RDSS signal according to the RDSS signal transmission time reference and the transmission enable control command, so as to realize the short message transmission and two-way ranging functions.

[0130] In a preferred embodiment, the S100 includes the steps of: S101, dividing the received full-band Beidou satellite signal into a first frequency band signal and a second frequency band signal according to the carrier frequency from low to high, wherein the first frequency band signal includes a low frequency band signal and the second frequency band signal includes a high frequency band signal; S102, dividing the high frequency band signal into two groups according to the carrier frequency; S103, expanding the low frequency band signal into two groups.

[0131] In a preferred embodiment, the low-frequency band signals include B2a, B2b, B2I, and B3I signals, and the high-frequency band signals include B1I, B1C, S1, and S2C signals.

[0132] In a preferred embodiment, the step S102 includes dividing the high frequency band signal into B1I and B1C frequency band signals and S1 and S2C frequency band signals according to the carrier frequency.

[0133] In a preferred embodiment, the step S103 includes extending the low frequency band signal into B2a, B2b, B2I frequency band signals and B3I frequency band signals.

[0134] In a preferred embodiment, the S300 includes the steps of: S301, performing carrier stripping on the digital intermediate frequency signal outputted from step S200; S302, filtering out-of-band noise and interference in the digital intermediate frequency signal after carrier stripping; and S303, performing downsampling processing on the signal outputted from step S302, wherein the downsampling rate of each signal is the same, and the downsampling rate is greater than the signal bandwidth.

[0135] In a preferred embodiment, the S500 includes the steps of: S501, maintaining the fractional second time and the integer second time according to the Beidou satellite signal transmission time extracted in the step S400 as a benchmark for the RDSS signal transmission time; S502, issuing a transmission enable control command when the RDSS time is valid.

[0136] In a preferred embodiment, the S600 includes, S601, performing spread spectrum modulation on a message symbol sequence to be sent and outputting a spread spectrum modulated message sequence; S602, performing non-return-to-0 bipolar modulation on the spread spectrum modulated message sequence signal; S603, filtering out part of the sidelobe signal in the digital signal output by the BPSK modulator; S604, upsampling the digital sampling signal output by step S603 and filtering out the mirror signal; S605, converting the digital signal output by step S604 into an analog signal; S606, filtering out the out-of-band interference signal in the analog signal output by step S605; S607, modulating the signal output by step S606 to the radio frequency band; S608, power amplifying the analog signal output by step S607 so that the satellite end can receive the signal.

[0137] In a preferred embodiment, the method further includes the steps of: S700, detecting the Beidou satellite navigation signal and transferring it to the tracking module by searching the code phase and carrier Doppler frequency; and S800, estimating the position, speed and time according to the code phase observation, carrier phase observation, Doppler frequency and navigation message reported in step S400.

[0138] It should be noted that the use of step numbers (letters or numbers) to refer to certain specific method steps in the present invention is only for the purpose of convenience and brevity of description, and is by no means intended to limit the order of these method steps. Those skilled in the art will understand that the order of the relevant method steps should be determined by the technology itself and should not be inappropriately limited by the existence of step numbers.

[0139] Those skilled in the art will appreciate that, without conflict, the above-mentioned preferred solutions can be freely combined and superimposed.

[0140] It should be understood that the above-mentioned embodiments are merely illustrative and not restrictive. Without departing from the basic principles of the present invention, various obvious or equivalent modifications or substitutions that can be made by those skilled in the art to the above-mentioned details will be included in the scope of the claims of the present invention.

Claims

1. A Beidou satellite navigation system full-frequency transceiver, characterized in that: It includes RF front end, RF processing module, digital signal preprocessing module, tracking module, RDSS time synchronization module and RDSS transmission module. The radio frequency front end is used to group the received full-band Beidou satellite signals according to the magnitude of the carrier frequency; The RF processing module is used to perform frequency reduction and analog-to-digital conversion processing on each group of signals output by the RF front end, so as to output a digital intermediate frequency signal of each group of signals; The digital signal preprocessing module is used to perform intermediate frequency stripping, anti-aliasing and down-sampling processing on the digital intermediate frequency signals of each group of signals output by the radio frequency processing module; The tracking module is used to track and process all frequency point signals output by the digital signal preprocessing module. The tracking module includes a correlator array and multiple playback buffers, wherein each digital signal preprocessing channel corresponds to a playback buffer, and each playback buffer includes two memories, a playback buffer ping and a playback buffer pong. When one of the memories has stored data, the newly input sampling point data is stored in the other memory; after the correlator array detects that the playback buffer is full of data, it starts data playback and coherent integration operations, and different signal tracking channels take data from the corresponding playback buffer. The correlator array adopts time division multiplexing. After completing the integration of the specified time, the integration result is used to identify the code phase and the carrier phase. The carrier tracking loop and the code tracking loop use PLL or DLL to achieve synchronization of the local carrier frequency with the carrier frequency of the received signal, and synchronization of the local spread spectrum code phase with the spread spectrum code phase of the received signal; The RDSS time-scale synchronization module is used to maintain the RDSS signal transmission time according to the code phase received by the tracking module, so as to serve as the RDSS signal transmission time reference of the transceiver device. The RDSS time-scale synchronization module includes an RDSS time module and a transmission enable control module. The RDSS time module is used to maintain the decimal second time and the integer second time according to the Beidou satellite signal transmission time extracted by the tracking module, so as to serve as the reference of the RDSS signal transmission time of the transceiver device; the transmission enable control module is used to issue a transmission enable control command to the RDSS transmission module when the RDSS time is valid; the RDSS time module includes a decimal second NCO unit and an integer second calculation unit, the decimal second NCO unit is used to maintain the decimal second time according to the Beidou satellite signal transmission time extracted by the tracking module; the integer second calculation unit is used to maintain the integer second time according to the Beidou satellite signal transmission time extracted by the tracking module; The RDSS transmission module is used to transmit the RDSS signal according to the RDSS signal transmission time reference and the transmission enable control command of the RDSS time scale synchronization module, so as to realize the short message transmission and two-way ranging functions.

2. The Beidou satellite navigation system full-frequency transceiver according to claim 1, characterized in that: The radio frequency front end includes a first duplexer, a second duplexer and a power divider, The first duplexer is used to divide the received full-band Beidou satellite signal into a first frequency band signal and a second frequency band signal according to the carrier frequency from low to high, the first frequency band signal includes a low frequency band signal, and the second frequency band signal includes a high frequency band signal; The second duplexer is used to divide the high frequency band signal into two groups according to the carrier frequency; The power divider is used to expand the low frequency band signal into two groups.

3. The Beidou satellite navigation system full-frequency transceiver according to claim 2, characterized in that: The low-frequency band signals include B2a, B2b, B2I, and B3I signals, and the high-frequency band signals include B1I, B1C, S1, and S2C signals.

4. The Beidou satellite navigation system full-frequency transceiver according to claim 3, characterized in that: The second duplexer divides the high frequency band signal into B1I and B1C frequency band signals and S1 and S2C frequency band signals according to the carrier frequency.

5. The Beidou satellite navigation system full-frequency transceiver according to claim 3, characterized in that: The power divider expands the low frequency band signal into B2a, B2b, B2I frequency band signals and B3I frequency band signals.

6. The Beidou satellite navigation system full-frequency transceiver according to claim 1, characterized in that: The radio frequency processing module includes multiple radio frequency signal processing channels, each of which is used to process Beidou satellite signals of different frequency bands output by the radio frequency front end after grouping. The RF signal processing channels each include a mixer and an analog-to-digital conversion circuit. The analog-to-digital conversion circuit of each RF signal processing channel uses the same sampling clock to perform sampling at the same sampling rate. The frequency of the mixer is the same as that of the sampling clock.

7. The Beidou satellite navigation system full-frequency transceiver according to claim 6, characterized in that: The sampling rate is not lower than the widest frequency band of the multiple groups of Beidou satellite signals output by the radio frequency front end.

8. The Beidou satellite navigation system full-frequency transceiver according to claim 1, characterized in that: The digital signal preprocessing module includes multiple digital signal preprocessing channels, each of which includes an intermediate frequency carrier stripping unit, an anti-aliasing filtering unit and a downsampling unit. The intermediate frequency carrier stripping unit is used to strip the carrier of the digital intermediate frequency signal output by the radio frequency processing module; The anti-aliasing filter unit is used to filter out the out-of-band noise and interference in the digital intermediate frequency signal after carrier stripping; The downsampling unit is used to perform downsampling processing on the signal output by the anti-aliasing filtering unit. The downsampling rate of each digital signal preprocessing channel is the same, and the downsampling rate is greater than the signal bandwidth.

9. The Beidou satellite navigation system full-frequency transceiver according to claim 1, characterized in that: The RDSS transmitting module includes a spread spectrum modulator, a BPSK modulator, a low-pass filter shaping filter, a CIC interpolation filter, a digital-to-analog conversion circuit, an analog low-pass filter, a mixer and a power amplifier. The spread spectrum modulator is used to perform spread spectrum modulation on the message symbol sequence to be sent, and output a spread spectrum modulated message sequence; The BPSK modulator is used to perform non-return-to-0 bipolar modulation on the spread spectrum modulated message sequence signal; The low-pass filtering shaping filter is used to filter out part of the side lobe signal in the digital signal output by the BPSK modulator; The CIC interpolation filter is used to upsample the digital sampling signal output by the low-pass filtering shaping filter and filter out the image signal; The digital-to-analog conversion circuit is used to convert the digital signal output by the CIC interpolation filter into an analog signal; The analog low-pass filter is used to filter out the out-of-band interference signal in the analog signal output by the digital-to-analog conversion circuit; The mixer is used to modulate the output signal of the analog low-pass filter to a radio frequency band; The power amplifier is used to amplify the power of the analog signal output by the mixer so that the satellite end can receive the signal.

10. The Beidou satellite navigation system full-frequency transceiver according to any one of claims 1 to 9, characterized in that: It also includes capture module and PVT module. The capture module is used to detect the Beidou satellite navigation signal and transfer it to the tracking module through the search of code phase and carrier Doppler frequency; The PVT module is used to estimate the position, speed and time according to the code phase observation, carrier phase observation, Doppler frequency and navigation message reported by the tracking module.

11. A Beidou satellite navigation signal full-frequency transceiver chip, characterized in that: The chip includes the Beidou satellite navigation system full-frequency transceiver as described in any one of claims 1-10, so as to receive and transmit the full-frequency band signals of the Beidou satellite navigation signal.

12. A Beidou satellite navigation signal full-frequency transceiver, characterized in that: The Beidou satellite navigation signal full-frequency transceiver chip as claimed in claim 11 is used.

13. A method for full-frequency transceiver using the Beidou satellite navigation system full-frequency transceiver as claimed in any one of claims 1 to 10, characterized in that: Including steps, S100, grouping the received full-band Beidou satellite signals according to the magnitude of the carrier frequency; S200, performing frequency reduction and analog-to-digital conversion processing on each group of signals to output a digital intermediate frequency signal of each group of signals; S300, performing intermediate frequency stripping, anti-aliasing and downsampling processing on the digital intermediate frequency signals of each group of signals; S400, tracking and processing all frequency point signals outputted in step S300; S500, maintaining the RDSS signal transmission time according to the code phase received in step S400 to serve as a RDSS signal transmission time reference; S600, transmitting the RDSS signal according to the RDSS signal transmission time reference and the transmission enable control command, to realize short message transmission and two-way ranging functions.

14. The method according to claim 13, characterized in that The S100 comprises the steps of: S101, dividing the received full-band Beidou satellite signal into a first frequency band signal and a second frequency band signal according to the carrier frequency from low to high, wherein the first frequency band signal includes a low frequency band signal, and the second frequency band signal includes a high frequency band signal; S102, dividing the high frequency band signal into two groups according to the carrier frequency; S103: Expand the low-frequency band signal into two groups.

15. The method according to claim 14, characterized in that The low-frequency band signals include B2a, B2b, B2I, and B3I signals, and the high-frequency band signals include B1I, B1C, S1, and S2C signals.

16. The method according to claim 15, characterized in that The step S102 includes dividing the high frequency band signal into B1I, B1C frequency band signals and S1, S2C frequency band signals according to the carrier frequency.

17. The method according to claim 15, characterized in that The step S103 includes extending the low frequency band signal into B2a, B2b, B2I frequency band signals and B3I frequency band signals.

18. The method according to claim 13, characterized in that The S300 includes the steps of: S301, performing carrier stripping on the digital intermediate frequency signal output in step S200; S302, filtering out-of-band noise and interference in the digital intermediate frequency signal after carrier stripping; S303, downsampling the signal output in step S302, with each signal having the same downsampling rate, which is greater than the signal bandwidth.

19. The method according to claim 13, characterized in that The S500 comprises the steps of: S501, maintaining the fractional second time and the integer second time according to the Beidou satellite signal transmission time extracted in step S400 as a reference for the RDSS signal transmission time; S502, when the RDSS time is valid, a transmission enable control command is issued.

20. The method according to claim 13, characterized in that The S600 includes, S601, performing spread spectrum modulation on a message symbol sequence to be sent, and outputting a spread spectrum modulated message sequence; S602, performing non-return-to-zero bipolar modulation on the spread spectrum modulated message sequence signal; S603, filtering out part of the side lobe signal in the digital signal output in step S602; S604, upsampling the digital sampling signal output in step S603, and filtering out the image signal; S605, converting the digital signal output in step S604 into an analog signal; S606, filtering out-of-band interference signals in the analog signal outputted in step S605; S607, modulating the signal outputted in step S606 to a radio frequency band; S608, power amplifying the analog signal outputted in step S607 so that the satellite terminal can receive the signal.

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