Spread Spectrum Transceiver System Algorithm And Vlsi Design

The research content of this dissertation is the DS-SS transceiver in software radio. The DS/DMPSK modulation mode has many advantages, such as high spectrum utilization rate, strong anti-jamming ability and good security. DS/DMPSK has been widely used in both military communications and civil communications.A realization scheme for universal digital DS/D-MPSK transceiver is presented, which adopts several advanced technique such as Raised cosine filter, direct digital frequency synthesis, quadrature modulation, digital matched filter and delay difference demodulation. It processes the signal directly on middle frequency, and doesn't need digital down conversion, PN code synchronization and carrier recovery. This scheme has been used in a military Ultra-short wave radio and obtained a good effect.This scheme has been used in the project of "multi-band, multi-mode digital ultrashort wave radio" and "software radio data transmission radio". The project adopts high performance FPGA to form a universal hardware platform. By configuring FPGA dynamically, the radio can realize many kinds of modulation modes (DS/DBPSK, DS/DQPSK, DS/D8PSK etc) in one FPGA. This scheme can also adapt DS/DMPSK modulation and demodulation with different base data rate, different pseudo random codes and different intermediate frequency.The actual test results demonstrate that this scheme is correct and feasible.