DCT插值算法在OFDM水声信道估计中的应用

Application of DCT interpolation algorithm in underwater acoustic channel estimation

海洋声信道是一种复杂的时-空-频变参信道,信道估计的准确程度直接影响着整个系统的性能。本文首先分析了水下声信道估计的基本方法,介绍了基于DFT的信道估计算法,并重点介绍了离散余弦变换(DCT)的插值算法,最后在仿真得到的水声信道模型下对两种算法性能进行了仿真。基于DCT的信道估计算法在水声信道时延为非整数倍采样间隔时可有效抑制信号的频谱泄露问题,从而改善系统的性能,更加适合于时变的水声信道。仿真结果表明该算法在改善系统性能方面优于基于DFT的信道估计算法。

Ocean acoustic channel is a complicated channel with variational time-space-frequency parameter.The accuracy of channel estimation directly influence the performance of the whole system.The basic method of underwater acoustic channel estimation is analysed,and the algorithm of channel estimation based on DFT,the interpolation algorithm of DCT are introduced.In the end,the performance of the two channel estimation methods through the simulated channel model is simulated.The channel estimation algorithm based on DCT can effectively restrain the problem of signal spectral leakage,thereby improve the system＇s performance when the time delay of underwater acoustic channel is not the integer multiples of channel sampling interval,so the algorithm fits the time-varying channel better.The simulation results demonstrate that the algorithm is superior to the channel estimation algorithm based on DFT on the part of improving the system performance.