Performance evaluation of MIMO-OFDM/OQAM in time-varying underwater acoustic channels

In this paper we evaluate the bit error rate (BER) performance of coded and un-coded spatially-multiplexed multiple-input multiple-output (MIMO) filter bank multi-carrier (FBMC) and Orthogonal Frequency Division Multiplexing (OFDM) systems for both horizontally and vertically configured time-varying underwater acoustic channels (UACs). OFDM/Offset Quadrature Amplitude Modulation (OFDM/OQAM) is selected as the FBMC system since it achieves maximum bandwidth efficiency. The theoretical achievable bit rates of the MIMO systems are also presented for both channel configurations. Preamble-based channel estimation using the Interference Approximation Method (IAM) is considered. We show that the MIMO-OFDM/OQAM systems achieve a better error performance and also a higher bit rate than the MIMO-OFDM systems in both the horizontal and vertical channels. This makes FBMC very attractive for wirelessly transmitting multimedia data such as real-time video in an UAC where the bandwidth is extremely limited.