MIMO系统中STTC译码的一种改进型算法

A modified STTC decoding algorithm under the MIMO system

本文对MIMO系统中用于STTC编码器的VA译码算法进行了改进,建立了节点度量的递推方程,并给出了分枝转移的度量方法。改进后的VA算法适用于已经估计出MIMO系统中信道转移阵的条件下。相比于标准的STTC译码算法,改进后的算法可以在一根接收天线上独立进行,并且节点度量可以通过递推方程进行累积。当多根天线独立译码后,可以进一步进行后续比较以再次降低误码率。仿真结果显示:改进VA在比特误码性能上与标准VA算法接近,但是在分段度量计算时收敛速度要远快于标准VA。

This paper modifies the Viterbi algorithm used in STTC encoder under the MIMO system, and gives the recursive metric equation. The modified VA algorithm can be used in the receiver when the MIMO channel information is known a prior. Compared with the standard VA decoding algorithm, the modified VA can be used in the every receiver respectively. When the decoding stage finishes, the further comparison can be used to reduce the error probability among the total receivers. Simulation results show that the modified VA is near to the standard VA algorithm, however, its metric convergence speed is faster than the standard VA algorithm.