Problem formulation

Abstract

It is well known that stereophonic acoustic echo, due to the coupling between two loudspeakers and two microphones, can be modelled by a two-input/twooutput system with real random variables. In this chapter, we recast this problem as a single-input/single-output system with complex random variables by using the widely linear model. As a consequence, the four real-valued acoustic impulse responses are converted to one complex-valued impulse response. Also, all important conventional measures are reformulated in this new context. The main advantage of this approach is that instead of handling two (real) output signals separately, we only handle one (complex) output signal. This makes it convenient to handle the main three challenges of SAEC, i.e., system identification, double-talk detection, and echo suppression.