Quaternion based representation of Vector Sensor Receiver

Abstract

The use of vector sensors as receivers for Underwater Acoustic Communications systems is gaining popularity. Traditionally vector sensors have been used for estimating the Direction of Arrival. Of late, vector sensors are finding applications in the area of underwater acoustic communications. The ability of a single vector sensor to provide spatial diversity has resulted in their becoming popular as receivers in underwater acoustic communication systems. An outcome of this trend is that now there is a need to represent the vector sensor signals in a format that is amenable to performing processing and computations. An apt representation for such signals is the quaternion, since we need to represent two complex quantities simultaneously. This representation is motivated from the use of quaternion in vector sensor based RF communications, where diversity is obtained by using different polarization on orthogonal components of the signal. In acoustic communications, diversity is obtained by signal acquisition in orthogonal directions. In this paper we show how to perform manipulations on matrices of quaternions and use those results to obtain a receiver with operations performed entirely in the quaternion domain. This results in a compact representation and saving in computation.