Field programmable gate array (FPGA)-based multi-channel real-time global position system (GPS) tracking method and system

Abstract

The invention discloses a field programmable gate array (FPGA)-based multi-channel real-time global position system (GPS) tracking method. The method comprises the following steps of: establishing an FPGA-based coupling circuit of an incoherent delay lock loop and a digital Costas loop to track Doppler drift of a coarse / acquisition (C / A) code phase and carrier frequency, demodulating navigation data during tracking, and adding a lock detector into the digital Costas loop to judge the demodulated result; establishing an FPGA-based single-channel control module and a whole tracking control module, and controlling phase discrimination filtering work in each tracking channel and the whole channel so as to control coordinative operation of the whole multi-channel tracking; and directly copying instantiation on the basis of finishing a single channel, realizing a parallel multi-channel tracking mode, and transmitting the tracked and demodulated multi-path navigation messages to subsequent navigation calculation in a single program initiation (SPI) bus mode.

Description

technical field [0001] The invention relates to a GPS satellite navigation and positioning system, in particular to an FPGA-based multi-channel real-time GPS tracking method and system thereof, belonging to the technical field of satellite navigation and positioning. Background technique [0002] The core technology of GPS terminal equipment is GPS receiver, which is mainly composed of radio frequency front-end data acquisition unit, baseband signal processing unit and navigation calculation unit. One of the core technologies of the GPS receiver is baseband signal processing. The baseband signal processing is divided into two parts: acquisition and tracking. Tracking can only be performed after successful acquisition. Because in order to perform navigation calculations and obtain three-dimensional coordinates, multiple sets of navigation data must be obtained to perform navigation calculations, which requires multiple sets of channels to track, thereby obtaining multiple set...

AI Technical Summary

Problems solved by technology

[0003] ①Because the GPS receiver usually adopts the mode of temporarily storing data and post-processing, after each integration and accumulation, when performing phase detection and filtering, stop reading the collected data, and start the next cycle after the completion of phase detection and filtering When the points are accumulated, continue to read the data, which means that the development of GPS software receivers on PC and DSP platforms will inevitably encounter real-time problems

Because each channel of tracking can only be executed sequentially in sequence, it is also required to adopt the mode of temporarily storing data and post-processing to ensure that each channel repeatedly reads data, and as the number of tracking channels increases, the time to complete tracking will increase. , the efficiency is directly reduced, the real-time problem becomes more serious, the solution is very difficult, the cost is high, and the PC is not convenient to carry

[0004] ②The GPS software receiver developed on the ASIC platform has fast processing speed, but once the chip is finalized, it cannot be changed, so the flexibility is poor, and the cost of performance upgrade is high

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