宽带MIMO系统低复杂度压扩变换Turbo频域均衡

Low complexity Turbo frequency domain equalization with companding-based transformation for broadband MIMO systems

针对循环前缀(cyclic prefix,CP)编码单载波(single carrier,SC)空间复用多输入多输出(multipleinput multiple-output,MIMO)系统,基于变分推理,本文提出一种新的低复杂度压扩变换Turbo频域均衡(Turbo frequency domain equalization,TFDE)算法。相对于传统的TFDE算法,文中算法有两点明显不同,一是采用解码器压扩后验信息,计算软输入软输出(soft-in soft-out,SISO)频域均衡器(frequency domain equalizer,FDE)的数据先验均值和方差矩阵,二是采用SISO FDE外部数据均值、方差以及解码器压扩外信息,计算解码器先验信息。分析和仿真结果表明,这种新的TFDE算法在误码率(bit error rate,BER)性能、迭代收敛速度和总体计算复杂度方面均优于传统的MIMO TFDE算法。

A new low complexity Turbo frequency equalization （TFDE） scheme with companding-based transformation is proposed for cyclic prefix （CP） single carrier （SC） spatial multiplexing multiple-input multi pie-output （MIMO） systems based on the variational inference method. Compared to the traditional TFDE method for MIMO systems, the proposed scheme has two distinct features. First, the a priori mean and vari anee matrix of the transmitted data symbols are computed with the companding a posteriori information from the decoder within the soft in soft-out （SISO） frequency domain equalizer （FDE）. Second, the a priori information for decoding is calculated by the extrinsic mean and variance of data symbols gleaned from the SIS（） FDE and the companding extrinsic information coming from the decoder. Analysis and simulation results demonstrate that the proposed scheme outperforms the traditional MIMO TFDE algorithm in terms of bit error rate （BER） per formance, convergence speed of iteration and the global computational complexity.