基于ZoomFFT的水声OFDM信号解调算法

为解决快速傅里叶变换（FFT）栅栏效应对水声正交频分复用（OFDM）通信系统解调性能的限制问题，提出基于选带傅里叶变换（ZoomFFT）的水声OFDM通信解调算法。将接收信号经过移频、降采样等处理得到其细化谱，提高频谱分辨力，削弱栅栏效应；同时对信道响应进行细化处理，基于最小均方误差（MMSE）原理构造信道均衡算法，消除信道影响。仿真结果表明，基于ZoomFFT的水声OFDM解调算法的性能优于传统FFT方法且算法复杂度低，增大降采样系数可以进一步提高算法性能。满足水声通信系统对低复杂度和高性能的要求。

ZoomFFT-Based Demodulation Algorithm for Underwater Acoustic OFDM Signals

The picket fence effect of fast Fourier transform (FFT) restricts the demodulation performance of the underwater acoustic(UWA) communication systemusing orthogonal frequency division multiplexing (OFDM). To solve this problem, we propose a demodulation algorithm based on ZoomFFT. Specifically, the received signal is processed by frequency shifting and downsampling forarefined spectrum, which improves the spectralresolution and weakens the picketfence effect.Meanwhile, the channel response is refined, and the channel equalization algorithm is constructed on the basis of the minimum mean square error (MMSE) principle to eliminate the channel influence. Simulations show that the performance of underwater acoustic OFDM demodulation algorithm based on ZoomFFT is better than that of traditional FFT, and the algorithm complexity is low. Increasing the downsampling coefficient can further enhance the algorithm performance. The proposed algorithm can meet the requirements of low complexity and high performance of a UWA communication system.