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The research of MIMO-FBMC in underwater acoustic communication

In underwater acoustic channels with long time-delay, Alamouti space-time coded OFDM communication systems show poor performance, which is mainly caused by the unflat topology of the subband of severely frequency-selective channels. To solve this problem, this paper proposes a MIMO-FBMC system based on a subband cutting method. This scheme improves the performance of Alamouti space-time coded OFDM systems in underwater acoustic communication in the following aspects: First, FBMC modulation is introduced to reduce out-of-band leakage through a re-designed window. Besides, FBMC modulation can also increase spectral efficiency because it does not need extra cyclic prefix. Second, the subband cutting method provides more stable bit error performance, benefited from the nonoverlapping feature of channel effect. According to our simulation results for the Alamouti space-time coded OFDM system and subband cutting based MIMO-FBMC system, the latter can achieve better performance, especially in long time-delay underwater acoustic channels.