Multi-Sensor Array Time-Delay Estimation with Small Phase Incoherences

摘要

The maximum likelihood (ML) estimator for time-delay in a multisensor array in the presence of small phase incoherences is derived. The structure obtained is the canonical ML estimator with a correction term to compensate for the phase. The Cramer-Rao matrix bound is developed and used to evaluate the standard deviation of the time-delay estimate (TDE) as a function of system parameters such as number of sensors, phase variance, bandwidth and center frequency of the source. The curves indicate a sensitivity, at low input SNR, of the TDE variance to phase standard deviation and signal center frequency. (Author)