TC-OFDM positioning navigation chip

Abstract

The invention provides a TC-OFDM positioning and navigation chip, and relates to the field of positioning and navigation. According to the chip, a PMF-FFT capture method is adopted to carry out coarse capture; three capture modes of 1ms, 5ms and incoherent accumulation are provided, and a reference code phase capture mode is supported; a time domain integral frequency sweep method is adopted to carry out fine capture, and 100-path parallel pseudo code phase correlation is supported; the position resolving module stably tracks two or more base station signals, inputs original observed quantity into the embedded CPU, and executes position resolving; the message demodulation module obtains navigation message information by detecting the integral value of the current I branch in the loop locking state; carrying out bit synchronization and frame synchronization processing on the signal to obtain an original code word sequence, and carrying out CRC (Cyclic Redundancy Check); in the positioning working mode, the tracking channel continuously processes the TC-OFDM signal, and outputs real-time positioning and speed measurement precision through signal capturing and tracking; the problems that an existing TC-OFDM positioning system is insufficient in positioning precision, relatively large in size and high in development cost are solved.

Description

Technical Field

[0001] This document relates to the field of positioning and navigation, and specifically to a TC-OFDM positioning and navigation chip. Background Art

[0002] The current software radio TC-OFDM (Time Code-Orthogonal Frequency Division Multiplexing) positioning system all uses the AD931+XC7Z020 solution. This solution mainly involves the interface design between AD9361 and XC7Z020. The data converted by AD9361 must be converted, calculated and output by XC7Z020.

[0003] The main issues are as follows:

[0004] (1) The data collection volume of AD9361 is relatively large, which requires a large amount of system resources of XC7Z020 for calculation. The positioning accuracy in the TC-OFDM positioning system is not enough.

[0005] (2) The XC7Z020 consumes a lot of power, with a basic power consumption of more than 3W. It needs to provide a separate heat sink, which is not suitable for portable devices.

[0006] (3) The peripheral circuit of XC7Z020 is relatively complex, the size of the circuit board is relatively large, and the system volume is relatively large, which is not suitable for portable devices. The basic size is 97mm×61mm. If the outer shell size is included, the minimum size is 100mm×70mm. Figure 1 shown.

[0007] (4) The software development of XC7Z020 requires the development of both PL and PS, which generally requires a logic development engineer and a system development engineer to complete, resulting in relatively high development costs. Figure 2 As shown, the pink part needs to be developed by PS engineers, and the purple and green parts need to be developed by PL engineers.

[0008] (5) The price of XC7Z020 is relatively expensive, resulting in high equipment costs. In addition, the chip is imported and the supply of the chip cannot be guaranteed, which means that the continuity of the product cannot be guaranteed.

[0009] Therefore, there is an urgent need for a TC-OFDM positioning chip to solve the problems of insufficient positioning accuracy, relatively large size and high development cost of the existing TC-OFDM positioning system. Summary of the invention

[0010] This specification provides a TC-OFDM positioning and navigation chip, which is used to solve the problems of insufficient positioning accuracy, relatively large size and high development cost of the existing TC-OFDM positioning system.

[0011] In a first aspect, this specification provides a TC-OFDM positioning and navigation chip, including: a capture module, a position calculation module, a message demodulation module, and a working mode processing and switching module; wherein:

[0012] The capture module includes a coarse capture unit and a fine capture unit, wherein: the coarse capture unit is used to capture by using a PMF-FFT capture method based on partial matched filtering and FFT unit cascade; the coarse capture unit has three capture modes of 1ms, 5ms and incoherent accumulation, supports reference code phase capture mode, and the coarse capture frequency resolution is 156.25Hz; the fine capture unit is used to capture by using a time domain integral sweep method, and the fine capture frequency resolution is typically 10Hz; supports 100-way parallel pseudo code phase correlation, and supports top-level capture strategy customization;

[0013] The position calculation module is used to stably track two or more base station signals, input the chip count and carrier phase original observation into the embedded CPU, and perform position calculation; wherein the position data update rate is 20Hz;

[0014] The message demodulation module is used to obtain navigation message information by detecting the integral value of the current I branch in the loop locking state; perform bit synchronization and frame synchronization processing on the signal to obtain the original code word sequence, obtain the original message by decoding, and then perform CRC check;

[0015] The working mode processing and switching module is used to enable the chip to run at full speed in the positioning working mode, and the tracking channel to continuously process the TC-OFDM signal, and output real-time positioning and speed measurement accuracy through signal capture and tracking; when it is turned off, the external device sends a save instruction to the chip through the serial port, and the chip saves the current state and returns a success message, and then the external control chip is powered off; when the chip is powered on again, a load command is sent after the chip is started, and the chip can read the saved state data, quickly capture, and restart to enter the positioning working mode.

[0016] In a second aspect, this specification provides a TC-OFDM positioning and navigation system, including: a radio frequency module, a TC-OFDM positioning and navigation chip, and a solution module, wherein:

[0017] The radio frequency module is used to receive the navigation signal of the TC-OFDM working frequency point, down-convert it to zero intermediate frequency and then send it to the emergency communication baseband chip;

[0018] The TC-OFDM positioning and navigation chip is used to output the code loop count and carrier phase observation to the central processor embedded in the baseband chip after the digitized baseband signal is captured by the pseudo code of the TC signal, the frequency search and the frequency pulling;

[0019] The solution module is used for tracking and positioning solution.

[0020] The beneficial effects of the present invention are as follows:

[0021] This specification provides a TC-OFDM positioning and navigation chip, which adopts the PMF-FFT capture method for coarse capture; it has three capture modes of 1ms, 5ms and incoherent accumulation, and supports reference code phase capture mode; it adopts the time domain integral sweep method for fine capture, and supports 100 parallel pseudo code phase correlation; the position solution module stably tracks two or more base station signals, inputs the original observation quantity into the embedded CPU, and performs position solution; the telegram demodulation module obtains navigation telegram information by detecting the integral value of the current I branch in the loop locking state; the signal is subjected to bit synchronization and frame synchronization processing to obtain the original code word sequence, and CRC check is performed; the working mode processing and switching module, in the positioning working mode, the tracking channel continuously processes the TC-OFDM signal, and outputs real-time positioning and speed measurement accuracy through signal capture and tracking; it solves the problems of insufficient positioning accuracy, relatively large size and high development cost of the existing TC-OFDM positioning system. The chip has a more focused positioning and higher accuracy; it greatly reduces the power consumption of the baseband chip; it is highly integrated and miniaturized, which reduces the terminal's size, making it easier to carry and adaptable to a wider range of scenarios; it also saves development manpower, and the production site is no longer restricted, and it can be produced domestically, reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The drawings described herein are used to provide a further understanding of this specification and constitute a part of this specification. The illustrative embodiments and descriptions of this specification are used to explain this specification and do not constitute an improper limitation on this specification. In the drawings:

[0023] Figure 1 It is a schematic diagram of the structure of a conventional chip XC7Z020 provided in the embodiments of this specification;

[0024] Figure 2 It is a schematic diagram of the architecture of a traditional chip XC7Z020 provided in the embodiments of this specification;

[0025] Figure 3 It is a schematic diagram of a TC-OFDM chip infrastructure provided in an embodiment of this specification;

[0026] Figure 4 It is a schematic diagram of a TC-OFDM positioning and navigation chip architecture design provided in an embodiment of this specification;

[0027] Figure 5It is a schematic diagram of a top view and a bottom view of a chip package provided in an embodiment of this specification;

[0028] Figure 6 is a schematic diagram of a side view of a chip package provided in an embodiment of this specification;

[0029] Figure 7 It is a schematic diagram of a TC-OFDM positioning accuracy test result provided in an embodiment of this specification;

[0030] Figure 8 is a schematic diagram of a power consumption test environment provided in an embodiment of this specification;

[0031] Fig. 9 is a schematic diagram of a chip top provided in an embodiment of this specification;

[0032] Fig.10 It is a schematic diagram of a bottom view of a chip provided in an embodiment of this specification. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of this specification clearer, the technical solutions of this application will be clearly and completely described below in conjunction with the specific embodiments of this application and their corresponding drawings. Obviously, the described embodiments are only part of the embodiments of this specification, not all of them. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this document.

[0034] The technical solutions provided by the embodiments of this specification are described in detail below in conjunction with the accompanying drawings. Specific embodiment one:

[0036] This embodiment provides a TC-OFDM positioning and navigation chip. Figure 3 , Figure 4 , including: capture module, position solution module, message demodulation module, working mode processing and switching module; among which:

[0037] The capture module includes a coarse capture unit and a fine capture unit, wherein: the coarse capture unit is used to capture by using a PMF-FFT capture method based on partial matched filtering and FFT unit cascade; the coarse capture unit has three capture modes of 1ms, 5ms and incoherent accumulation, supports reference code phase capture mode, and the coarse capture frequency resolution is 156.25Hz; the fine capture unit is used to capture by using a time domain integral sweep method, and the fine capture frequency resolution is typically 10Hz; supports 100-way parallel pseudo code phase correlation, and supports top-level capture strategy customization;

[0038] The position calculation module is used to stably track two or more base station signals, input the chip count and carrier phase original observation into the embedded CPU, and perform position calculation; wherein the position data update rate is 20Hz;

[0039] The message demodulation module is used to obtain navigation message information by detecting the integral value of the current I branch in the loop locking state; perform bit synchronization and frame synchronization processing on the signal to obtain the original code word sequence, obtain the original message by decoding, and then perform CRC check;

[0040] The working mode processing and switching module is used to enable the chip to run at full speed in the positioning working mode, and the tracking channel to continuously process the TC-OFDM signal, and output real-time positioning and speed measurement accuracy through signal capture and tracking; when it is turned off, the external device sends a save instruction to the chip through the serial port, and the chip saves the current state and returns a success message, and then the external control chip is powered off; when the chip is powered on again, a load command is sent after the chip is started, and the chip can read the saved state data, quickly capture, and restart to enter the positioning working mode.

[0041] Furthermore, the code length of the chip is 10230, with a total of 63 groups, a code rate of 10.23Mcps, and a bandwidth of 20MHz.

[0042] Furthermore, the chip also includes: a tracking module, wherein the tracking module supports simultaneous tracking of 16 channels and regularly outputs code chip counts and carrier phase original observation quantities.

[0043] Furthermore, the message encoding method in the message demodulation module is 217 convolutional code and interleaving, and the message rate is 100bps.

[0044] Furthermore, the chip supports two Boot modes: local firmware operation and firmware upgrade operation.

[0045] Furthermore, the chip is provided with a low-speed peripheral interface, wherein the low-speed peripheral interface includes: UARTx4, SPIx4, I2Cx2, GPIOx16.

[0046] Furthermore, the chip also includes: a digital acquisition interface, wherein the digital acquisition interface is adapted to AD9361 single-channel digital input, the signal bandwidth is 20MHz, the sampling rate is 50MSPS, and the sampling bit width is 8bits; supports AD9361 single-ended CMOS1R1T Full Duplex DDR mode zero intermediate frequency digital interface;

[0047] Furthermore, the chip adopts SMIC55NM process, the chip package is BGA, and the chip size is 8mm x 8mm, see Figure 5 , Figure 6 ;

[0048] Furthermore, the chip includes a capture module driver library, a CRU module driver library, a DDC module driver library, a trace module driver library, a Decode module driver library, a DMA module driver library, a frame_sync module driver library, a SPI module driver library, and a TIMER module driver library.

[0049] Furthermore, this embodiment also specifically provides other characteristics of the chip, specifically:

[0050] Processor: ARM Cortex M3 dual-core embedded processor

[0051] Bus: AXI 3.0 200MHz, APB 200MHz

[0052] Storage: 512KB SRAM, 8KB CPU ROM, 1MB SiP SPI Flash, support for off-chip SPI flash;

[0053] Peripheral interfaces: 4 SPI, 4 UART, 2 I2C

[0054] Cold start time: less than 15s

[0055] Recapture time: less than 1.5s

[0056] Package type: BGA

[0057] Timer: 14 high-precision timers

[0058] GPIO: 16 GPIOs available for external interrupts

[0059] Boot mode: support built-in SPI flash (SiP) boot, support external SPI FLASH boot, support flash firmware upgrade function;

[0060] Clock reset: power-on self-reset function, external reset

[0061] Debug interface: JTAG

[0062] Chip size: 8mm×8mm×1.41mm.

[0063] Further, the various pins and their functions are shown in Table 1 below;

[0064] Table 1 Pins and their functions

[0065]

[0066]

[0067]

[0068] Furthermore, this embodiment provides a TC-OFDM positioning and navigation system, including: a radio frequency module, a TC-OFDM positioning and navigation chip, wherein:

[0069] The radio frequency module is used to receive the navigation signal of the TC-OFDM working frequency point, down-convert it to zero intermediate frequency and then send it to the TC-OFDM positioning and navigation chip;

[0070] The TC-OFDM positioning and navigation chip is used to output the code loop count and carrier phase observation to the central processor embedded in the baseband chip for tracking and positioning after the digitized baseband signal is captured, frequency searched and frequency pulled by the TC signal pseudo code.

[0071] Furthermore, this embodiment provides a test experiment to verify the effect of this chip.

[0072] (1) The chip of this embodiment improves the positioning accuracy of TC-OFDM, as shown in Figure 7. The green one is the AD9361+XC7Z020 solution, and the blue one is the AD9361+TC-OFDM positioning and navigation system terminal baseband chip solution.

[0073] Through test comparison, the solution of AD9361+TC-OFDM positioning and navigation system terminal baseband chip is closer to the calibrated test track, with more accurate positioning and relatively higher accuracy. The positioning accuracy is improved by using TC-OFDM positioning and navigation system terminal baseband chip.

[0074] (2) The power consumption of the terminal baseband chip of the TC-OFDM positioning and navigation system is greatly reduced.

[0075] The full-speed operation is 600MW, which is comparable to the static power consumption of the XC7Z020 test chip and the power consumption when running at full speed.

[0076] Static power consumption: Figure 8 As shown, the chip IO power supply, chip core power supply, PLL_AVDD power supply, PLL_AVDD5 power supply, and external input 50M clock signal. Without running the program, record the voltage and current values ​​of the four power supplies.

[0077] Full-speed power consumption: When measuring full-speed power consumption, in addition to the chip IO power supply, chip core power supply, PLL_AVDD power supply, PLL_AVDD5 power supply, and external input 50M clock signal, it is also necessary to use 5V voltage from the USB port (to power AD9361, etc.). After running the program through the dual jtag connector, measure the power supply of the four power supplies when the current chip is running.

[0078] The code logic when running at full speed is: the capture state is currently in progress (coherent integration or incoherent integration), 16-channel signal tracking is performed at the same time, and 4-channel signals are output for positioning solution. The chip IO power supply, chip core power supply, PLL_AVDD power supply, and PLL_AVDD5 power supply are measured, and the capture + 15-channel tracking full-speed power is calculated, and all peripherals are in operation.

[0079] Test results: The voltage and current data of each module were recorded, and the chip power was calculated. The recorded results are shown in Table 2 below. The power consumption of the chip at full speed meets the indicator requirement of less than 600mW.

[0080] Table 2 Chip power test

[0081]

[0082] (3) The positioning board designed with the TC-OFDM positioning and navigation system terminal baseband chip has an overall size of 51mmX30mm, which greatly reduces the terminal's overall size and does not require separate heat dissipation for the TC-OFDM positioning and navigation system terminal baseband chip, thereby reducing the overall weight of the terminal. Fig. 9 , Fig.10 ;

[0083] (4) Using the TC-OFDM positioning and navigation system terminal baseband chip to develop a positioning terminal, only one embedded engineer is needed to complete the development work of two engineers for XC7Z020. Due to the high integration of computing, embedded greatly reduces the workload of embedded engineers. The chip provides capture module driver library, CRU module driver library, DDC module driver library, trace module driver library, Decode module driver library, DMA module driver library, frame_sync module driver library, SPI module driver library, TIMER module driver library and other drivers, which greatly reduces the workload of embedded engineers.

[0084] (5) Chip production can be completed domestically without the need for overseas tape-out, which greatly reduces costs and is no longer subject to foreign restrictions.

[0085] In summary, this embodiment adopts the PMF-FFT capture method for coarse capture; it has three capture modes of 1ms, 5ms and incoherent accumulation, and supports the reference code phase capture mode; it adopts the time domain integral sweep method for fine capture, and supports 100 parallel pseudo code phase correlation; the position solution module stably tracks two or more base station signals, inputs the original observation amount into the embedded CPU, and performs position solution; the message demodulation module obtains the navigation message information by detecting the integral value of the current I branch in the loop lock state; the signal is processed by bit synchronization and frame synchronization to obtain the original code word sequence, and CRC check is performed; the working mode processing and switching module, in the positioning working mode, the tracking channel continuously processes the TC-OFDM signal, and outputs the real-time positioning and speed measurement accuracy through signal capture and tracking; it solves the problems of insufficient positioning accuracy, relatively large volume and high development cost of the existing TC-OFDM positioning system. The positioning of the chip is more comprehensive and accurate; it is highly integrated and miniaturized, which greatly reduces the size of the terminal, and also saves development manpower. The production place is no longer limited, and it can also be produced domestically, which greatly reduces the cost. Specific embodiment 2:

[0087] This embodiment adopts a TC-OFDM positioning and navigation system terminal baseband chip;

[0088] It should be noted that the TC-OFDM positioning and navigation system is referred to as the TC-OFDM system. It is a high-precision indoor and outdoor seamless positioning and navigation system based on the ground network using the TC-OFDM (Time Code-Orthogonal Frequency Division Multiplexing) communication and guidance fusion signal system. This system consists of base stations and user terminals. This project is aimed at the user terminal system and aims to develop a baseband chip for the emergency communication terminal system. The emergency communication system terminal is mainly composed of radio frequency, baseband and solution parts. The radio frequency is responsible for receiving the navigation signal of the TC-OFDM working frequency point, and down-converting it to zero intermediate frequency and sending it to the emergency communication baseband chip; the baseband chip is responsible for the digitized baseband signal. After the pseudo code capture, frequency search and frequency pulling of the TC signal, the code loop count, carrier phase and other observations are output to the embedded central processor of the baseband chip for tracking and positioning solution. The baseband chip adopts 55nm process, and the final size after packaging is 8mm x 8mm.

[0089] The chip mentioned in this embodiment includes the following contents:

[0090] (1) Code system: code length 10230, a total of 63 groups, code rate 10.23Mcps, bandwidth 20MHz;

[0091] (2) Capture function: Coarse capture uses the PMF-FFT capture method based on partial matched filtering and FFT unit cascade, with three capture modes: 1ms, 5ms, and incoherent accumulation, and supports reference code phase capture mode. The coarse capture frequency resolution is 156.25Hz; fine capture uses the sweep frequency method of time domain correlation integration, and the typical value of fine capture frequency resolution is 10Hz. It supports 100 parallel pseudo code phase correlation and supports customization of top-level capture strategies.

[0092] (3) Tracking function: supports simultaneous tracking of 16 channels and timely output of raw observations such as chip count and carrier phase;

[0093] (4) Position calculation: After the chip stably tracks signals from two or more base stations, it inputs raw observations such as chip count and carrier phase into the embedded CPU to perform position calculation; the position data update rate is 20 Hz;

[0094] (5) Message demodulation function: In the loop locked state, the navigation message information is obtained by detecting the integral value of the current I branch; after the chip performs bit synchronization and frame synchronization on the signal, it obtains the original code word sequence, obtains the original message through decoding (deinterleaving + Viterbi decoding), and then performs CRC check; message encoding method: 217 convolutional code + interleaving; message rate: 100bps.

[0095] (6) Data acquisition interface: Adapt to AD9361 single-channel digital input, signal bandwidth 20MHz, sampling rate 50MSPS, sampling bit width 8bits; support AD9361 single-ended CMOS1R1T Full Duplex DDR mode zero intermediate frequency digital interface. In this design, the sampling bandwidth is 20MHz and the sampling frequency is 50MSPS, which is used for resampling to 20.46MSPS during capture;

[0096] (7) Low-speed peripheral interfaces: UARTx4, SPIx4, I2Cx2, GPIOx16;

[0097] (8) Working mode: supports positioning working mode and shutdown mode. In the positioning working mode, the chip runs at full speed, and the tracking channel continuously processes the TC-OFDM signal. Through signal capture and tracking, it outputs real-time positioning and speed measurement accuracy. When it needs to be shut down, the external device sends a save command to the chip through the serial port. The chip saves the current status (stable working base station number) and returns a success message. After that, the external control chip is powered off; when the chip is powered on again, a load command can be sent after the chip is started. The chip can read the saved status data, quickly capture, and restart to enter the positioning working mode;

[0098] (9) Boot mode: supports two Boot modes: local firmware operation and firmware upgrade operation;

[0099] Specifically, this embodiment also provides the characteristics of the chip, specifically:

[0100] Process: SMIC 55nm;

[0101] Processor: ARM Cortex M3 dual-core embedded processor

[0102] Bus: AXI 3.0 200MHz, APB 200MHz

[0103] Storage: 512KB SRAM, 8KB CPU ROM, 1MB SiP SPI Flash, support for off-chip SPI flash;

[0104] Peripheral interfaces: 4 SPI, 4 UART, 2 I2C

[0105] Cold start time: less than 15s

[0106] Recapture time: less than 1.5s

[0107] Package type: BGA

[0108] DMA: Support SPI, I2C, UART peripherals

[0109] Timer: 14 high-precision timers

[0110] GPIO: 16 GPIOs available for external interrupts

[0111] Boot mode: support built-in SPI flash (SiP) boot, support external SPI FLASH boot, support flash firmware upgrade function;

[0112] Clock reset: power-on self-reset function, external reset

[0113] Debug interface: JTAG

[0114] Chip size: 8mm×8mm×1.41mm.

[0115] See Table 1 for each pin and its function;

[0116] Furthermore, this embodiment also provides a design idea and implementation comparison table of a TC-OFDM positioning and navigation system terminal baseband chip, see Table 3;

[0117] Table 3 Design ideas and implementation comparison of TC-OFDM positioning and navigation system terminal baseband chips

[0118]

[0119]

[0120]

[0121]

[0122] In summary, this embodiment adopts the PMF-FFT capture method for coarse capture; it has three capture modes of 1ms, 5ms and incoherent accumulation, and supports the reference code phase capture mode; it adopts the time domain integral sweep method for fine capture, and supports 100 parallel pseudo code phase correlation; the position solution module stably tracks two or more base station signals, inputs the original observation amount into the embedded CPU, and performs position solution; the message demodulation module obtains the navigation message information by detecting the integral value of the current I branch in the loop lock state; the signal is processed by bit synchronization and frame synchronization to obtain the original code word sequence, and CRC check is performed; the working mode processing and switching module, in the positioning working mode, the tracking channel continuously processes the TC-OFDM signal, and outputs the real-time positioning and speed measurement accuracy through signal capture and tracking; it solves the problems of insufficient positioning accuracy, relatively large volume and high development cost of the existing TC-OFDM positioning system. The positioning of the chip is more comprehensive and accurate; it is highly integrated and miniaturized, which greatly reduces the size of the terminal, and also saves development manpower. The production place is no longer limited, and it can also be produced domestically, which greatly reduces the cost.

[0123] The above description is only a preferred embodiment of this specification and is not intended to limit this specification. For those skilled in the art, this specification may have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this specification shall be included in the protection scope of this specification.

Claims

1. A TC-OFDM positioning and navigation chip, characterized in that: include: Capture module, position calculation module, message demodulation module, working mode processing and switching module; among which: The capture module includes a coarse capture unit and a fine capture unit, wherein: the coarse capture unit is used to capture by using a PMF-FFT capture method based on partial matched filtering and FFT unit cascade; the coarse capture unit has three capture modes of 1ms, 5ms and incoherent accumulation, supports reference code phase capture mode, and the coarse capture frequency resolution is 156.25Hz; the fine capture unit is used to capture by using a time domain integral sweep method, and the fine capture frequency resolution is typically 10Hz; supports 100-way parallel pseudo code phase correlation, and supports top-level capture strategy customization; The position calculation module is used to stably track two or more base station signals, input the chip count and carrier phase original observation into the embedded CPU, and perform position calculation; wherein the position data update rate is 20Hz; The message demodulation module is used to obtain navigation message information by detecting the integral value of the current I branch in the loop locking state; perform bit synchronization and frame synchronization processing on the signal to obtain the original code word sequence, obtain the original message by decoding, and then perform CRC check; The working mode processing and switching module is used to enable the chip to run at full speed in the positioning working mode, and the tracking channel to continuously process the TC-OFDM signal, and output real-time positioning and speed measurement accuracy through signal capture and tracking; when it is turned off, the external device sends a save instruction to the chip through the serial port, and the chip saves the current state and returns a success message, and then the external control chip is powered off; when the chip is powered on again, a load command is sent after the chip is started, and the chip can read the saved state data, quickly capture, and restart to enter the positioning working mode.

2. The chip according to claim 1, characterized in that: The code length of the chip is 10230, with a total of 63 groups, a code rate of 10.23Mcps, and a bandwidth of 20MHz.

3. The chip according to claim 2, characterized in that: The chip further comprises: a tracking module, wherein the tracking module supports simultaneous tracking of 16 channels and outputs chip counts and original carrier phase observations at regular intervals.

4. The chip according to claim 3, characterized in that: The message encoding method in the message demodulation module is 217 convolutional code and interleaving, and the message rate is 100bps.

5. The chip according to claim 4, characterized in that: The chip supports two Boot modes: local firmware operation and firmware upgrade operation.

6. The chip according to claim 5, characterized in that: The chip is provided with a low-speed peripheral interface, and the low-speed peripheral interface includes: UARTx4, SPIx4, I2Cx2, and GPIOx16.

7. The chip according to claim 5, characterized in that: The chip also includes: a digital acquisition interface, wherein the digital acquisition interface is adapted to AD9361 single-channel digital input, the signal bandwidth is 20MHz, the sampling rate is 50MSPS, and the sampling bit width is 8bits; and supports AD9361 single-ended CMOS1R1T FullDuplex DDR mode zero intermediate frequency digital interface.

8. The chip according to claim 7, characterized in that: The chip adopts SMIC55NM process, the chip package is BGA, and the chip size is 8mm x 8mm.

9. The chip according to claim 8, characterized in that: The chip includes a capture module driver library, a CRU module driver library, a DDC module driver library, a trace module driver library, a Decode module driver library, a DMA module driver library, a frame_sync module driver library, a SPI module driver library, and a TIMER module driver library.

10. A TC-OFDM positioning and navigation system, applied to the chip according to any one of claims 1 to 9, characterized in that: include: RF module, TC-OFDM positioning and navigation chip, including: The radio frequency module is used to receive the navigation signal of the TC-OFDM working frequency point, down-convert it to zero intermediate frequency and then send it to the TC-OFDM positioning and navigation chip; The TC-OFDM positioning and navigation chip is used to output the code loop count and carrier phase observation to the central processor embedded in the baseband chip for tracking and positioning after the digitized baseband signal is captured, frequency searched and frequency pulled on the TC signal.

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