DOA Estimation With Non-Uniform Linear Arrays: A Phase-Difference Projection Approach

Phase wrapping is a major problem in direction-of-arrival (DOA) estimation using phase-difference observations. For sensor pair with an inter-sensor spacing greater than half of the wavelength ($\lambda/2$) signal, phase occurs at certain DOA angles leading to ambiguities. Existing unwrapping methods exploit either frequency or spatial diversity. These techniques work by imposing restrictions on utilized frequencies receiver array geometry. In addition sensitivity noise and calibration errors, these may also have high computational complexity. We propose grid-less \emph{phase-difference projection} (PDP) algorithm overcome issues. The concept \emph{wrapped phased-difference pattern} (WPDP) introduced, which allows proposed compute most parameters required for offline manner, hence resulting superior speed realtime. Simulation results demonstrate excellent performance algorithm, both terms accuracy speed.