并行组合扩频QPSK软判决解调方法

QPSK Soft Decision Modulation Method of PCSS System

传统的并行组合扩频(Parallel Combinatory Spread Spectrum,PCSS)通信系统大多采用硬判决的方式进行解调。本文针对并扩系统QPSK调制解调方法,提出了一种全新的QPSK软判决解调模型。对比传统的硬判决解调方式,该模型具有很高的解调准确性。本文从欧氏距离和汉明距离的角度分析了这种高准确性的缘由并由此提出了该解调模式下QPSK解调的最佳星座映射方法。

Most of the traditional parallel combinatory spread spectrum（PCSS）communication system use hard decision to de-modulate signal. This subject gives out a new QPSK soft decision demodulation model based on parallel combinatoryspread spectrum communication system QPSK demodulation method. Compare with traditional hard decision modula-tion method, the new model has a higher accuracy. Then this subject uses Euclid distance and hamming distance toexplain why this high accuracy exists. At the end of this subject, a best-fit mapping QPSK matrix soft decision demodu-lation method is given out.