Multiuser communications for underwater acoustic networks using MIMO-OFDM-IDMA

In this paper, we present MIMO-OFDM-IDMA, a novel multiple-access communications scheme that provides robust performance in the presence of large time-delay spread and the other channel impairments commonly encountered in shallow water acoustic networks. MIMO-OFDM-IDMA is a multiple-input multiple-output system that employs orthogonal frequency division multiplexing scheme with an IDMA overlay, where IDMA is a variant of code-division multiple access (CDMA). Simulation results show that the MIMO-OFDM-IDMA scheme outperforms other common multiple-access schemes in the shallow water acoustic network environment.