Design Of Signal Processing Hardware Platform For Tri-satellite Positioning Receiver

Dual-Satellite Positioning System is a regional positioning system, on the basis of which the paper supplies a method to realize passive positioning by existent tri-satellite on the sea. The paper discusses the principle and method about positioning by tri-satellite and designs the digital positioning receiver.First of all, the paper describes the work principle and method of Dual-Satellite Positioning system, creates its mathematical modeLBesides, the paper analyses the format of the broadcasting signal and purposefully discusses the theory of band-pass sample, also makes a research on the producing pseudo-code, measuring the distance, the OQPSK modulation and demodulation, Viterbi decoder, demodulating broadcasting signal and so on.Secondly,the paper makes research on the synchronous problem of the spread spectrum signal, involving the pseudo-code and carrier synchronization. Sliding correlation method and DPLL are separately used to realize the acquisition and track of the pseudo-code. Costas Loop is used to realize tracking carrier. Barker code is used to generate the synchronous signal of frame which is convenient for decoding. According to the form of the signal, the author discusses the synchronous mathematical model and designs the tracking loop.Finally, the author designs the signal processing hardware platform based on DSP and FPGA, involving power supply, emluator interface, memory interface, UART, the interface between FPGA and DSP,single correlator channel and so on,the paper also carries on the simulation of parts of softwares.