수중음향통신 시스템에서 OFDM방식의 통신성능

Abstract

For Underwater Acoustic (UWA) communication severe multipath propagation and Doppler spread are the major obstacles to realize the high data rate transmission. Recently Orthogonal Frequency Division Multiplexing (OFDM) scheme has been received attract due to its robustness to multipath effects which results in frequency selective fading. OFDM employs a cyclic extension of transmitted OFDM symbols to combat Inter-Symbol Interference (ISI) caused by channel multipath delay spread. It improves the bandwidth efficiency in underwater acoustic channel. In addition, a new Multi-Symbol Encapsulated Orthogonal Frequency Division Multiplexing (MSE-OFDM) system is proposed, in which one cyclic prefix (CP) is used for a frame of multiple OFDM symbol. One cyclic prefix is used for a group of OFDM symbols. In the case for CP-reduced MSE-OFDM, bandwidth efficiency is improved due to a reduced number of CPs inserted between OFDM symbols. In this paper, communication performance of the conventional OFDM and the MSE-OFDM systems is compared in Underwater Acoustic Communication System