Research And Implementation Of Software Radio Taichung Ds / Dmpsk Modem,

The research content of this dissertation is the modulation and demodulation technique of DS/DMPSK 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.This dissertation adopts a universal digital DS/DMPSK modulation and demodulation scheme which is based on FPGA. This scheme adopts quadrature balanceable modulation, intermediate frequency sampling, digital matched filtering, delay differential demodulation techniques and so on. It directly processes the digital signals on intermediate frequency without down-conversion, and doesn't need pseudo random codes synchronization and carrier wave extraction circuits. This scheme is characterized by its simplicity, easy implementation, novel ideas and practical value.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 and DSP 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.