频率选择性衰落下一种基于迭代干扰抵消的空时分组码译码算法

Iterative interference cancellation based on decoding algorithm of space-time block coding in frequency-selective fading

针对频率选择性衰落下空时分组码的正交性由于多径干扰而遭到严重破坏,提出一种基于迭代干扰抵消的最大似然序列估计(MLSE)译码方案;并结合最大比合并方法对所提方案进行改进和提高,以进一步降低计算复杂度。这些方案能很好地弥补通常空时分组码在频率选择性衰落下译码时的不足,它们不仅能抵消正交性没有破坏的在偶次项上的多径干扰,还能抵消正交性受到破坏的在奇次项上的多径干扰;有着非常好的性能。而且与直接对长序列信号进行MLSE译码相比,有着非常低的译码复杂度;从而以低复杂度实现了较好的空时分组码译码性能。

Considering that the orthogonality of STBC in frequency-selective fading will be destroyed by the multiple path interference （MPI）, an iterative interference cancellation based maximum likelihood sequence estimation （MLSE） decoding scheme was proposed for STBC in frequency-selective fading. Meanwhile, the maximum ratio combining （MRC） method was introduced to improve the proposed scheme, and decrease the computational complexity further. These schemes could effectively make up for the decoding deficiency of conventional STBC in frequency-selective fading. They canceled not only the MPI from even terms corresponding to the orthogonality undestroyed by fading, but also the MPI from odd terms corresponding to the orthogonality destroyed by fading; they has superior performance. Moreover, they have lower decoding complexity when compared with direct MLSE decoding of the long sequence signal. Thus they implement good decoding performance with low complexity.