Equalization and Co-Carrier Frequency Offsets Compensations for UWA-OFDM Communication Systems.

The Underwater Acoustic (UWA) wireless communication system is considered one of the most challenging systems for data transmission. The Orthogonal Frequency Division Multiplexing (OFDM) system promises numerous benefits, including high spectrum efficiency and inter-Symbol interference mitigation. But, it is very sensitive to Carrier Frequency Offset (CFO). The implementation of the OFDM necessitates the use of orthogonal transforms such as the Inverse Discrete Fourier Transform (IDFT)/DFT. On the other hand, the Multiple-Input-Multiple Output (MIMO) configuration is affected by co-channel interference. In this paper, we look at another type of co-interference known as the co-CFO. The Linear Zero Forcing (LZF) equalizer suffers from noise enhancement and high computational complexity due to the direct matrix inversion. The Linear Minimum Mean Square Error Equalizer suffers from the noise enhancement problem at high values of the Signal-to-Noise Ratio (SNR), and requires the estimation of the operating SNR to work properly, besides the high computational complexity of the implementation. In this paper, we propose a Joint Low Complexity Regularized LZF equalizer for the UWA-OFDM communication system. The proposed equalizer is driven and takes the effect of the UWA co-channel effect, the noise, and the co-CFO. Simulation results show the important role of the proposed equalizer in configuring the UWA-OFDM communication system. [ABSTRACT FROM AUTHOR]