Introduction to the Special Issue on Array Signal Processing for Angular Models in Massive MIMO Communications

The papers in this special issue focus on array signal processing for angular models in massive MIMO communications. In recent years, there has been tremendous research progress in massive MIMO from communications theory viewpoint. An emerging trend is to explore the angular models of the propagation channels and design the massive system with array signal processing techniques. Particularly, fundamental concepts in array signal processing (e.g., direction of arrival/departure - DOA/DOD), can be conceptualized and exploited.