Large Array Beamforming

In this chapter, we study beamforming with very large arrays, i.e., arrays that contain a very large number of microphones. Conventional beamforming in this context, where a simple complex frequency-dependent weight is applied to each microphone, may not be very practical for obvious reasons such as high complexity, difficulty to accurately estimate statistics of the signals, and dealing with large matrices that can be very ill conditioned. Here, instead, we tackle this problem from a low-rank beamforming perspective, whose flexibility can lead to better performance.