Introduction to the Special Issue on Time/Frequency Modulated Array Signal Processing

The papers in this special section focus on time/frequency modulated array signal processing. Phased-array is known for its capability to electronically steer a beam towards a desired direction. However, this beam steering does not account for the target range. There is an increasing need to control the range-dependent transmit energy distribution in applications involving interference suppression, directional communications, and range ambiguity. Towards this end, several advanced array design approaches have been introduced, which include time modulated array (TMA), frequency diverse array (FDA), and frequency diversity or time division based multiple-input multiple-output (MIMO) systems. This special issue (SI) covers a variety of signal processing approaches, all based on time/frequency modulated arrays. It aims to compile relevant research contributions from various disciplines, including statistical signal processing for radar and communications, antenna array design and synthesis, and applied mathematics.