Wireless data transmission in underwater hydroacoustic environment based on MIMO-OFDM system and application adaptive algorithm at the receiver side

To increase the transmission speed in wireless data transmission systems, it is necessary to change either the bandwidth or the spectral efficiency, or both simultaneously. Systems based on Multi-Input Multi-Output (MIMO) methods can significantly increase spectral efficiency through parallel transmission using several transmitters and receivers. Such systems are particularly attractive for use in underwater acoustic communications systems, which are normally bandwidth-reduced. MIMO system along with OFDM (Orthogonal Frequency-Division Multiplexing) is a popular technology used in wireless networks to provide a high data transfer rate and resistance to multipath and fading of the channel. The implementation of such a system requires being aware of the channel condition at the receiver, and can be provided by means of using channel parameter estimation schemes. The adaptation task on the receiving side, apart from peak of pattern formation in the direction of the signal expected, also includes the interference-source suppression, that is, the issue of implementing spatial filtering of interference from other directions. However, since the signal and noise direction of arrival are unknown, we get a system with adaptive antenna array (AA). In the proposed research, a phase antenna array was used with controlled weighing.