Data-aided DOA estimation of single source with time-variant Rayleigh amplitudes

This paper focuses on the data-aided (DA) direction of arrival (DOA) estimation of a single narrow-band source in time-varying Rayleigh fading amplitude. The time-variant fading amplitude is modeled by considering the Jakes' and the first order autoregressive (AR1) correlation models. Closed-form expressions of the CRB for DOA alone are derived for fast and slow Rayleigh fading amplitude. As a special case, the CRB under uncorrelated fading Rayleigh channel is derived. A analytical approximate expressions of the CRB are derived for low and high SNR that enable the derivation of a number of properties that describe the bound's dependence on key parameters such as SNR, channel correlation. A high signal-to-noise-ratio maximum likelihood (ML) estimator based on the AR1 correlation model is derived. The main objective is to reduce algorithm complexity to a single-dimensional search on the DOA parameter alone as in the static-channel DOA estimator. Finally, simulation results illustrate the performance of the estimator and confirm the validity of the theoretical analysis.