消除冗余循环前缀的水声信道OFDM频域均衡算法

摘要

The traditional OFDM frequency-domain equalization algorithm depends on the long circular prefix which decreases the utilization rate of the underwater acoustic channel. Based on the theory of modulation and demodula-tion of OFDM, a mathematical model based on the influences of multipath effects in the underwater acoustic chan-nel was established. On the basis of this, a multi-level buffering mechanism and decision feedback mechanism were introduced and a new OFDM frequency-domain equalization algorithm was proposed. The computing volume of the new algorithm was simplified and an equalizer order self-adaptive selection scheme was given. The results of the simulations and pool experiment prove that the new algorithm may effectively achieve the compensation for multipath effects in the case of a complete lack of the participation of a redundant circular prefix, which ensures reliable com-munication with high speed and low bit error rates under the condition of a limited bandwidth underwater acoustic channel.%针对OFDM传统频域均衡算法依赖较长冗余循环前缀，造成水声信道利用率下降的问题，依据OFDM的调制解调原理，在对水声信道多径效应造成影响进行数学建模的基础上，引入多级缓冲机制和判决反馈机制，提出了新型的判决反馈OFDM频域均衡算法。对算法计算量进行了简化，并给出均衡器阶数自适应选择方案。通过仿真和水池实验，证明新算法可以在完全没有循环前缀参与情况下，实现对多径效应的有效补偿，保证了有限水声信道带宽条件下的高速、低误码率的可靠通信。