Adaptive transmit beamforming for simultaneous transmit and receive

Abstract

Simultaneous transmit and receive (STAR) is an important problem in the field of communications. Engineers have researched many different models and strategies that attempt to solve this problem. One such strategy is to place a transmit-side null at the receiver in order to decouple a system's transmitter and receiver, thus allowing them to operate simultaneously. This thesis discusses the use of gradient based adaptive algorithms to allow for transmit beamforming. Several such algorithms are devised, simulated, and compared in performance. Of these, the best is chosen to study in further detail. A mathematical analysis is performed on this particular algorithm to determine a linearized state space model, which is then used in a noise analysis. An important benefit of these algorithms is that they do not require computationally intensive matrix operations such as inversion or eigen-decomposition. This thesis ultimately provides, explains, and analyzes a viable method that can form a transmit-side null at the receiver and extract a weak signal of interest from the received signal while simultaneously transmitting another signal at high power.