An inter-carrier interference reduction scheme for OFDM underwater acoustic communications

The inter-carrier interference (ICI) of the orthogonal frequency division multiplexing (OFDM) symbols caused by the transducers dynamic in underwater acoustic (UWA) communications has been presented in this paper. Both the practical experiment and simulation results show that the othorgonality property of OFDM symbols can be affected by the transducers dynamic during the transient period of these devices especially when the OFDM symbol length is comparatively short. A small cyclic prefix (CP) method is proposed to overcome this problem without much loss of the throughput and the bandwidth efficiency. The small CP, with the length just longer than the transient response of the transducer, can eliminate the ICI problem. The theoretical analysis and the simulation results show the efficiency of the method.