Time-domain analysis of cross-correlation for multitarget/multipath time delay estimation

This paper analyzes the effect of source separation on the estimation accuracy of the TDOA of multiple exponentially autocorrelated signals at two sensors in white noise. The analysis is carried out for uncorrelated signals (separate sources) as well as unity correlated signals, as in multipath propagation from a single source. The estimates are obtained from cross-correlations based on moving average samples of the noisy signals from the two sensors. The effect of the source separation on the degradation ratio is evaluated and compared with the optimal processor. The theoretical performance is verified through simulations for different SNRs and time-bandwidth products. Another advantage of the technique is that it avoids ambiguities in the cross-correlation