一种新的基于多级编码的差分空时调制方案

提出一种新的结合多级编码和差分空时调制的联合编码调制方案.该方案通过特定的构造法则,用一个多级低密度校验码取代多级编码中多个分量码,因而具有更低的编译码复杂度.为防止过多错误反馈造成译码失效,提出采用内、外双重迭代方式来提高系统的鲁棒性.同时把LDPC码校验矩阵作为迭代终止判决准则,进一步降低了迭代算法的平均复杂度.在准静态多输入多输出衰落信道下的仿真结果表明,系统性能得到有效提高.

A New Scheme for Differential Space-Time Modulation Using Multilevel Code

To combine multilevel code (MLC) with differential space-time modulation (DSTM), a new scheme based on an multilevel low-density parity-check (LDPC) code with iterative decoding is proposed. This scheme has lower decoding complexity compared to conventional MLC schemes using more than one channel coders. To avoid excessive error feedback that may cause decoding failure, both outer and inner iterations are used. The scheme uses LDPC codes as a criterion to terminate both iterations so as to further reduce the average decoding complexity. Simulation results for a quasi-stationary fading MIMO channel show that the proposed scheme is effective.