线性检测中的最优空时编码设计与分析

Design and Analysis of Optimal Space Time Code with Linear Detection

针对传统空时编码最大似然译码复杂度高的问题,提出一种基于线性检测算法的最优空时编码方案(LO-STBC).首先将发送符号与服从特定规则的传输符号系数矩阵线性组合构成空时编码矩阵,然后将该空时编码矩阵的各行从多根发射天线上并行传输,最后在接收端使用等效信道线性检测译码.相比于传统编码,LO-STBC编码的误比特率性能最优,与信道编码联合使用时可以获得最大分集增益,并且可有效降低自适应传输应用时的计算复杂度.仿真结果表明,在相同传输速率下,LO-STBC编码的误比特率最接近理论性能曲线,比传统编码低0.5 dB,在带有信道编码的系统中分集增益优势明显.

A kind of full rate space time codes based on linear detection with optimal transmission performance （LO-STBC） is proposed to deal with the high complexity of maximum likelihood detection in traditional space-time coding. The LO-STBC is designed by linear combination of data symbols and the dispersion matrices chosen by given rule; then the symbols in a STBC matrix are simultaneously transmitted by the multiple transmit antennas; and the data are linearly detected at the receivers by using the equivalent channel. Compared with the traditional STBC, LO-STBC has the optimal transmission performance with linear detection, can get the most obvious diversity gain using channel coding, and can greatly reduce the computation complexity during the appli- cation of adaptive transmission. The simulation results and comparisons with the traditional STBC show that without channel coding, the performance of LO-STBC approaches the theoretical performance, and the performance advantage is about 0. 5 dB; and that with channel coding, LO- STBC obtains higher diversity gain.