Analytical method of parameter determination for OFDM system over measurement-based underwater acoustic channel modeling

Abstract In underwater acoustic (UWA)-OFDM systems, the major problem in implementation of complex equalization algorithms at receiver can be avoided by finding appropriate system parameters. This paper proposes an analytical method for determining the UWA-OFDM system parameters in order to maximize the achievable system capacity and to limit interference power. Unlike most existing research studies that analyzed the system performance without consideration of the inter-carrier interference (ICI), we focus on evaluating the UWA-OFDM system performance under both the ambient noise and ICI effect. The signal-to-interference-plus-noise ratio and the achievable system capacity are formulated by using the simulation UWA channel model, which is derived from the measurement data of the real UWA channel from a very shallow water environment in West Lake, Hanoi, Vietnam. Using the proposed method, the UWA-OFDM system parameters including the symbol duration, the number of subcarriers, the system bandwidth, and the transmit power are determined to achieve the maximal spectral efficiency of 3.2 bits/sec/Hz. The proposed analytical method can be used as a practical guideline to determine appropriate transmission parameters for the design of UWA-OFDM systems.