This chapter builds on the author’s prior work on signal-to-noise ratio (SNR) estimation by proposing a new stochastic maximum-likelihood-based (SML-based) approach for estimating the direction-of-arrival (DOA) of a single narrow-band amplitude-distorted wavefront received by any antenna array. The complex-valued circular AR (1) model with unknown coefficients is supposed to alter the distorted amplitude wavefront. The contribution of this chapter is to create an approximate SML-based technique for estimating the DOA in a high SNR environment. It demonstrates how to remove the noise and AR (1) nuisance (distortion) parameters from the investigated approximate stochastic likelihood function, yielding an SML DOA estimate via a one-dimensional (1-D) search. For several types of time-varying fading amplitudes, compact Cramer-Rao lower bound (CRB) formulas for the DOA parameter alone are constructed. The determination of numerous CRB properties is also made possible by the development of high and low SNR approximation equations for the. Finally, simulation results verify the theoretical study by demonstrating the effectiveness of the proposed approach.
Taif University, Department of Electrical Engineering, Al-Haweiah, 21974, Saudi Arabia.