Multicarrier code division multiple access (MC-CDMA) technique for underwater acoustic communication networks using short spreading sequences

Abstract

Code division multiple access (CDMA) techniques have recently been utilised to achieve reliable multiuser communication in asynchronous shallow water acoustic networks. The authors consider this type of communication technique, which has its origins in spread spectrum principles. The performance of multicarrier (MC) CDMA for short length complex spreading sequences, which demonstrate both good cross-correlation and auto-correlation properties, has been evaluated by means of computer simulations. In MC-CDMA, a set of carrier frequencies is employed to achieve frequency diversity. The proposed adaptive receiver architectures integrate the functions of despreading, multi-access and narrowband interference cancellation, equalisation, and phase-carrier tracking. Results show the effectiveness of the system in a rapidly time-varying, frequency-selective channel.