比特交织编码调制技术分析

Analysis on Bit Interleaved Coded Modulation

为了在不降低频带利用率和功率利用率的情况下以设备的复杂化来换取编码增益,提出了一种将编码和调制方式结合在一起的比特交织编码调制(Bit Interleaved Coded Modulation,BICM)技术。该技术针对网格编码调制(TrellisCoded Modulation,TCM)灵活性差和衰落信道中性能差的缺点,在理想交织时将编码器和调制器分离设计,具有高度的灵活性,并可以得到近似网格编码调制的性能,并且对衰落信道具有很好的鲁棒性。介绍了比特交织编码调制的构成模式、关键技术,包括信道编码、比特交织和调制,给出了BCIM理论分析,并对不同的交织深度、交织方法和高阶调制等进行了性能仿真分析。仿真结果表明比特交织编码调制可以取得良好的误码率性能。

In order to improve the coding gain without reducing spectrum efficiency and power efficiency, Bit Interleaved Coded Modulation （BICM） which combines coding and modulation has been proposed. Considering the low flexibility and bad performance of Trellis Coded Modulation （TCM） in fading channel,coder and modulator are designed separatedly in BICM when bit interleaved is perfect,achieving high flexibility,performance approximate to that of TCM, and robustness in fading channel. The architecture of BICM and the key techniques, including charmel coding, bit interleaving and modulation, have been introduced. Tne theoretical analysis on BICM has been presented. The interleaving depth, interleaving methods and high-order modulation have been simulated. Simulation results show that BICM has good BER performance.