Capacity of Dual Hop Underwater Acoustic Communication Using Vector Sensors

As the demand for data rate and capacity increases, there is growing attention on how to exploit multi-hop communication techniques to mitigate this problem. In underwater acoustic communication (UAC), where the bandwidth is limited by the distance between transmitter and receiver, multi-hop communication comes as an endowment. It has been proved that Vector Sensors (VS) enhance the performance of UAC over a long range by measuring particle motion along with pressure changes associated with a sound wave. In this paper, we present dual hop communication model for UAC where the relay is assumed to be a VS. We model path gain for p-th path as a function of angle of arrival (AoA) and observe that it is log-normal distributed when AoA is Gaussian distributed. Channel capacity is computed for different system geometries for two architectures: only relay as VS and both relay and destination as VS and the performance is compared with that for the case when both the receivers are pressure sensor (PS). We provide a thorough analysis of the gain. Expectedly, the VS based communication systems perform better.