主要研究多输入多输出正交频分复用(MIMO—OFDM)水声通信判决反馈信道估计技术。针对传统判决反馈信道估计算法在非高斯加性噪声环境下跟踪估计缓慢时变水声信道存在误码遗传的缺点,提出了水声通信打孔判决反馈信道估计算法。利用级联码解编码信息评价水声信道频域响应估计值的可靠性,删除偏差明显的频域子信道,结合插值等手段恢复完整的信道频域响应。作为信道反馈信息。仿真和水池实验结果表明,基于打孔技术的判决反馈信道估计算法相较传统算法能够更好地抑制误码遗传,对抗突发噪声,跟踪信道的缓慢时变,提高水声通信质量。
The technique of channel decision feedback estimation of multiple input/multiple output or- thogonal frequency division multiplexing (MIMO-OFDM) underwater acoustic communication system is studied. To overcome the disadvantage of error code propagation of channel decision feedback estimation algorithm, an improved algorithm based on channel punching technique is proposed. The difference be- tween the received raw signal and the re-coded information signal is used to judge the criteria of channel compensation, and those uncertain sub-channels are punched and revalued by interpolation technique. The experimental results obtained with numerical simulation and tank-trial data are provided, demonstra- ting that the proposed algorithm can effectively confine the propagation of error code , abate the burst noise effect, track the variety of channel and significantly increase the quality of the system.