Underwater acoustic (UWA) channel has the characteristics of large multipath delay and fast varying, thus how to accurately estimate the channel is one of the technical challenges. This paper compares several channel estimation algorithms in orthogonal frequency division multiplexing (OFDM) UWA communication system. The least square estimation (LS) and minimum mean square error estimation (MMSE) algorithm are used to estimate the pilot signal and the suitable channel estimation methods are given by the analysis and comparison under different channel conditions. We compare the performance of nonlinear interpolation and time-frequency conversion interpolation method under different UWA channel conditions, and restore the original signal. We find that the performance difference between LS and MMSE is very small in the region of high signal to noise ratio(SNR), but the performance of the two interpolation methods is very different in different environments.
['Fangsheng Zhong', 'Wuyang Zhou']
Evaluation of Channel Estimation Algorithms in OFDM Underwater Acoustic Communications