关键词：DS扩频；Matlab仿真；PSP调制解调
Abstract: Direct sequence spread spectrum communication system (DS-CDMA) is widely used in many fields because of its strong anti-jamming, good concealment, easy to implement code division multiple access (CDMA), anti-multipath interference, high DS-CDMA communication rate and many other advantages. Firstly, the basic principles of direct spread spectrum and PSK modulation and demodulation are studied, including sampling theorem, FFT and digital filter. Then, the system is abstracted and modeled, and the function description and algorithm realization of each part are completed. Then the system program is written. The program mainly includes two classes: system design and tool design. It mainly includes random source signal generation, m-sequence generation, direct spread spectrum, PSK modulation, Gaussian white noise channel band-pass filtering, PSK demodulation, low-pass filtering, sampling quantization, despreading, sampling, spectrum and waveform drawing, bit error rate calculation and so on. Finally, the experimental results are analyzed according to the requirement facilities parameters and running procedures.
Keywords: DS spread spectrum; Matlab simulation; PSP modulation and demodulation.
