网格编码MQAM直扩多址系统的性能分析

本文将非恒包络高效网格编码调制ＴＣ－ＭＱＡＭ应用于瑞利慢衰落信道下的直接序列扩频多址系统中。针对衰落信道和ＴＣ－ＭＱＡＭ的特点，提出了一种分析ＴＣ－ＭＱＡＭ用于衰落信道下ＤＳ／ＳＳＭＡ系统性能的方法，数值模拟表明在系统用户数、用户信源比特速率以及码相同的条件下，本文所构造的非恒包络１／４ＴＣ－１６ＱＡＭ性能优于同状态数３／４ＴＣ－１６ＱＡＭ和恒包络２／３ＴＣ－８ＰＳＫ。这说明通过增大最小分支数等适

Performance Analysis of Trellis Code MQAM Direct Sequence Spread Spectrum Multiple Access System

In this paper trellis coding with multiple QAM (TC-MQAM)has been applied to direct sequence spread spectrum multiple access system under slow Raayleigh fading environment. We propose a method for analysing the performance of DS/SSMA using TCMQAM in Rayleigh fading channel. Numerical results have proved that the characteristic of 1/4TC-16QAM with 8 states constructed in this paper is better than that of 2/3TC-8PSK and 3/4TC-16QAM under the condition of same number of users, bit rate of information source of users in DS/SSMA System and length of binary psedorandom sequence. This result demonstrates that TC-MQAM can also be used in practical DS/SSMA System by proper encoding.