The severe multipath delay of the underwater acoustic channel, the Doppler shift, the severe time-varying characteristics, and sparsity make it difficult to obtain the channel state information in the channel estimation of the virtual time-reverse mirror OFDM, which makes the virtual time mirror subcarrier orthogonality easy to suffer damage; the focusing effect is not obvious. Therefore, this paper proposes a virtual time-inverse OFDM underwater acoustic channel estimation algorithm based on compressed sensing. The algorithm extracts the detection signal, constructs a sparse signal model of the delay-Doppler shift, and then performs preestimation of the underwater acoustic channel based on the compressed sensing theory. Then, by predicting the timing of the underwater acoustic channel and convolving with the received signal, the algorithm improves the focusing effect better. Experimental simulations show that compared with LS and OMP algorithms, the algorithm can accurately recover channel information from a small number of observations, reduce the bit error rate by 10%, and improve the accuracy of channel estimation and the time-inverse OFDM performance of virtual time.

中文翻译：

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基于压缩感知的虚拟时间逆OFDM水下声信道估计算法

水下声信道的严重多径延迟，多普勒频移，严重的时变特性和稀疏性使得在虚拟时间倒向镜OFDM的信道估计中难以获得信道状态信息，从而使虚拟时间镜副载波的正交性容易遭受破坏；聚焦效果不明显。因此，本文提出了一种基于压缩感知的虚拟时间逆OFDM水下声信道估计算法。该算法提取检测信号，构造一个延迟多普勒频移的稀疏信号模型，然后基于压缩感知理论对水下声通道进行预估计。然后，通过预测水下声学通道的时间并与接收信号进行卷积，该算法可以更好地提高聚焦效果。实验仿真表明，与LS和OMP算法相比，该算法可从少量观测值中准确地恢复信道信息，将误码率降低10％，并提高了信道估计的准确性和虚拟信道的OFDM时间逆性能。时间。