比特交织编码的MultiQAM调制与迭代译码系统

为降低旋转矩阵实现信号空间分集(SSD)的比特交织编码调制(BICM)和迭代译码(ID)系统(BICM-ID-SSD)的解调译码复杂度,将同样能够获得满信号空间分集增益的MultiQAM调制应用于BICM系统,提出BIC-Mul-tiQAM-ID系统结构,并采用最大后验概率解调算法结合软输入软输出译码器进行迭代解调译码。仿真结果表明,经过6次迭代,此系统性能与原有的采用比特交织编码、MultiQAM调制和最大似然解调以及软判决维特比译码(VD)的BIC-MultiQAM-VD系统相比,在调制阶数和分集维数组合分别为(42,)和(2,4)的情况下误比特率性能约改进1.8 dB。

Bit-Interleaved Coded MultiQAM Modulation with Iterative Decoding

To lower the demodulation complexity of traditional bit-interleaved coded modulation (BICM) with iterative decoding (ID) system combined with rotation matrix-based signal space diversity (BICM-ID-SSD), MultiQAM modulation, which can also achieve full SSD diversity, was applied to a BICM-ID system with channel coding and a new architecture called BIC-MultiQAM-ID was proposed. MAP demodulation algorithm, together with a MAP soft-input and soft-output decoder, was used to perform iterative demodulation and decoding of the system. Simulation results showed that better performance was achieved than the original system which used Multi-QAM modulation, ML demodulation and soft-decision Viterbi decoding. When the modulation order and diversity dimension are (4, 2) and (2, 4), the BER performance was improved about 1.8dB.