BER Performance Investigation of MIMO Underwater Acoustic Communications

Underwater Acoustic Communications (UWAC) using Multiple Input and Multiple Output (MIMO) system is an emerging technology to enhance the data transmission throughput and allow multiple transmitters to simultaneously communicate in underwater environment. The paper presents the concept and analysis of a 2× 2 MIMO UWAC system, that uses a 4-QAM spatial modulation scheme thus minimizing the decoding complexity and overcoming the Inter Channel Interference (ICI). Bit Error Rate (BER) investigation is carried out over different link distances under acoustic Line of Sight (LOS). The utilization of Zero Forcing (ZF) and Least Mean Square(LMS) equalizers, which estimates the transmitted data proves a success of removing inter symbol interference (ISI).