一种新的π/4DQPSK解调译码方案  

A New Demodulation and Decoding Scheme for π/4DQPSK

作　　者：郭道省[1] 张邦宁[1] 杨喜根[1] 甘仲民[1] 李平辉[1] 

机构地区：[1]解放军理工大学通信工程学院无线通信系

出　　处：《信号处理》2001年第3期222-226,共5页Journal of Signal Processing

摘　　要：本文提出了一种新的π／４ＤＯＰＳＫ解调译码方案。该方案利用非冗余纠错差分解调的硬判决信息对Ｖｉｔｅｒｂｉ 软判决译码时的量度加权，从而改变了传统的差分解调结合软判决译码的量度值，使差分解调软输出的信噪比得到改善，提高了Ｖｉｔｅｒｂｉ 软判决译码的性能。计算机仿真表明，相对于传统的差分解调结合软判决译码，该算法在误比特率ＢＥＲ为１０－５时在ＡＷＧＮ信道中有１．４ｄＢ的性能改善，在Ｒｉｃｉａｎ 信道中同样有显著的性能改善。这使得在普遍采用差分解调软判决译码的卫星通信系统中系统容量和通信质量都得到显著改善。This paper propose a new demodulation and decoding scheme for π／4DQPSK. The scheme utilizes the hard-decision information of nonredundat error correction as weighting of the Viterbi soft-decision metric. Thus it changes the metric value of traditional differential demodulation with Viterbi soft-decision decoding and improves the signal and noise ratio of soft output of differential demodulation. Therefore the performance of soft-decision decoding is improved. The simulation results show that the performance improvement of proposed algorithm is superior to conventional differential demodulation with soft-decision decoding by 1 .4dB at a BER of 10-5 in AWGN channel. In Rician channel there is die same notable performance improvements. It is worthwhile for the satellite communication system, which applies widely the differential demodulation combined with Viterbi soft-decision decoding. The system capacity and communication quality is notably improved.

关 键 词：卫星移动通信 解调译码 非冗余纠错 差分解调 量度加权 

分 类 号：TN927.2[电子电信—通信与信息系统]