The New Jersey Institute of Technology's
Electronic Theses & Dissertations Project

Title:	Performance analysis of the dominant mode rejection beamformer
Author:	Hu, Enlong
View Online:	njit-etd2022-036 (xvi, 110 pages ~ 1.2 MB pdf)
Department:	Department of Electrical and Computer Engineering
Degree:	Doctor of Philosophy
Program:	Electrical Engineering
Document Type:	Dissertation
Advisory Committee:	Ge, Hongya (Committee chair) Haimovich, Alexander (Committee member) Abdi, Ali (Committee member) Shi, Yun Q. (Committee member) Michalopoulou, Eliza Zoi-Heleni (Committee member)
Date:	2022-08
Keywords:	Adaptive beamformer (ABF) Array signal processing Dominant mode rejection (DMR) Eigendecomposition Random matrix theory (RMT) Sample covariance matrix (SCM)
Availability:	Unrestricted
Abstract:	In array signal processing over challenging environments, due to the non-stationarity nature of data, it is difficult to obtain enough number of data snapshots to construct an adaptive beamformer (ABF) for detecting weak signal embedded in strong interferences. One type of adaptive method targeting for such applications is the dominant mode rejection (DMR) method, which uses a reshaped eigen-decomposition of sample covariance matrix (SCM) to define a subspace containing the dominant interferers to be rejected, thereby allowing it to detect weak signal in the presence of strong interferences. The DMR weight vector takes a form similar to the adaptive minimum variance distortion-less response (MVDR), except with the SCM being replaced by the DMR-SCM. This dissertation studies the performance of DMR-ABF by deriving the probability density functions of three important metrics: notch depth (ND), white noise gain (WNG), and signal-to-interference-and-noise ratio (SINR). The analysis contains both single interference case and multiple interference case, using subspace transformation and the random matrix theory (RMT) method for deriving and verifying the analytical results. RMT results are used to approximate the random matrice. Finally, the analytical results are compared with RMT Monte-Carlo based empirical results.