Performance Analysis of TCM Coded OFDM System in Underwater Acoustic Channel

The main characteristics of underwater acoustic (UWA) channel are Narrow bandwidth, strong interference caused by multi-path and severe noise. At the same time, these disadvantages have been always obstructed the development of high speed and fidelity underwater data transmission. This paper discusses the performance of integration of Trellis-coded modulation (TCM) and OFDM; furthermore, this transmission mode can solve the problems of the bandwidth efficiency and reliability effectively in UWA communication. The theoretical analysis and application of TCM based on OFDM in UWA system are introduced in detail. Simulation results are given in the end. It is proved that this method has a further 3dB coding gain over the non-coded QPSK, so the performance of UWA communication has been improved significantly.