复杂的水声信道会对正交频分复用子载波产生幅度衰落和相位畸变. 针对信道时变和插值带来的误差对信道估计的影响，提出了一种基于判决的水声信道均衡算法. 该算法采用差错控制编码作为判决方式，将判决后的数据作为导频进行信道均衡，根据信道环境的不同分为判决迭代均衡和判决二次均衡两种方式. 仿真和湖上实验结果表明，该算法在不降低频带利用率的情况下可以有效提高系统性能.
Complication of ocean channels causes sub-carrier amplitude fading and phase distortion in underwater communication. To reduce the effects of channel estimation error due to time variation and interpolation error, a decision-directed channel equalization algorithm for OFDM-based communication is proposed. Error control codes are used for decision making so that the data decisions can be used as pilots, with which channel estimation is performed. Taking into account different environment conditions, equalization is done using a decision-directed scheme with block piloting and a decision twice-equalization scheme with comb piloting. Results of simulation and lake experiments are promising, showing that the proposed scheme can effectively
improve system performance without loss of bandwidth efficiency.
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