基于低复杂度次优译码算法的准正交空时分组码

摘要

Due to the high complexity of the pairwise decoding algorithm and the poor performance of zero forcing ZF /minimum mean square error MMSE decoding algorithm two low-complexity suboptimal decoding algorithms called pairwise-quasi-ZF and pairwise-quasi-MMSE decoders are proposed.First two transmit signals are detected by the quasi-ZF or the quasi-MMSE algorithm at the receiver.Then the two detected signals as the decoding results are substituted into the two pairwise decoding algorithm expressions to detect the other two transmit signals. The bit error rate BER performance of the proposed algorithms is compared with that of the current known decoding algorithms.Also the number of calculations of ZF MMSE quasi-ZF and quasi-MMSE algorithms is compared with each other.Simulation results show that the BER performance of the proposed algorithms is substantially improved in comparison to the quasi-ZF and quasi-MMSE algorithms. The BER performance of the pairwise-quasi-ZF pairwise-quasi-MMSE decoder is equivalent to the pairwise-ZF pairwise-MMSE decoder while the computational complexity is significantly reduced.%针对成对译码算法复杂度高及迫零／最小均方误差算法性能较差等问题，提出了一种pairwise－quasi－ZF／pairwise－quasi－MMSE的低复杂度次优译码算法。利用quasi－ZF或quasi－MMSE算法计算出部分发射信号的统计判决值，将该判决值作为译码结果代入成对译码算法表达式中，从而计算出剩余部分发射信号的统计判决值并作为译码结果。比较了所提算法与几种传统译码算法的系统误比特率性能，并比较了ZF， MMSE，quasi－ZF和quasi－MMSE四种算法的计算量。仿真结果表明所提算法的BER性能与quasi－ZF算法和quasi－MMSE算法相比有明显改善，与pairwise－ZF和pairwise－MMSE算法相比BER性能相近，计算量却大大降低。