Abstract: Underwater acoustic（UWA） channel has a sparse impulse response.To this end，sparse channel estimation is proposed for UWA Single Carrier Frequency Domain Equalization（SC-FDE） communication.The sparse UWA channel estimate can be obtained by selecting a few vectors in the dictionaries，composed by the column vectors of transmitted signal matrix，as the sparse representation of the received vector.The projection of the residual vector onto the selected vector is maximum.Then，the frequency domain equalization is processed by time-frequency transform of the estimated channel.Simulation results indicate that the proposed method has much better performances than the traditional one in estimation precision and Bit Error Ratio（BER）.

Key words: Single Carrier Frequency Domain Equalization（SC-FDE）, underwater acoustic communication, channel estimation, sparse channel, matching pursuit

摘要： 针对水声信道时域冲激响应的稀疏特性，提出基于稀疏信道估计的单载波频域均衡（SC-FDE）水声通信方法。该方法利用匹配跟踪思想，在发射信号矩阵列向量构成的字典中，选择使残余向量投影值最大的列向量去近似拟合接收信号，从而得到水声信道的时域冲激响应，然后通过时-频变换来进行频域均衡。仿真结果表明：该方法可以准确估计出水声信道，其信道估计精度和误码率性能都优于传统的SC-FDE水声通信方法。

关键词: 单载波频域均衡, 水声通信, 信道估计, 稀疏信道, 匹配跟踪