MIMO underwater acoustic communications by using a quasi-orthogonal group space-time architecture

Multiple-Input Multiple-Output (MIMO) systems have been widely applied to underwater acoustic (UWA) communications with promising results. However, the tradeoff between diversity and multiplexing gains in MIMO systems over underwater acoustic channel is less discussed. In this paper, a quasi-orthogonal group space-time (QoGST) scheme by combining space-time coding (STC) and layered space-time (LST) architecture is presented for better diversity and multiplexing gains in MIMO underwater acoustic communications. Simulation results show the presented solution has better performance when compared to the Group Layered Space-Time (GLST) scheme.