A modified ZF algorithm for signal detection in an underwater MIMO STBC-OFDM acoustic communication system

In this paper, we propose a novel signal detection algorithm to improve the performance of the multiple input multiple output (MIMO) space-time block code-orthogonal frequency-division multiplexing (STBC-OFDM) system in the underwater acoustic channel. Our special case for the underwater channel is the 114th station in the Caspian Sea. A model for an underwater MIMO-OFDM system is proposed first. Second, a signal coding method based on space-time block coding is employed. Finally, M-ZF, a modified signal detection algorithm, is then proposed for this system. Moreover, we compare M-ZF to ML, ZF, and MMSE. Another significant aspect of this paper is modeling an underwater acoustic channel using data from the Caspian Sea. In the modeling of the underwater channel, all actual conditions are considered. Ultimately, we evaluate the proposed algorithm in the underwater channel of the Caspian Sea. Simulation results demonstrate that the proposed algorithm has a lower time cost and superior bit error rate (BER) performance than others.