Performance predictions for coherent and incoherent processing techniques of time delay estimation

In recent work, a correlator performance estimate (CPE) has been developed which gives a more accurate estimate of performance than the Cramer-Rao lower bound (CRLB) for the cross-correlation technique for time delay estimation (TDE). The impact of this recent work is considered here. In particular, the behavior of the CPE and CRLB is considered as a function of the observation time and the signal-to-noise ratio (SNR). The implications of this behavior are considered as related to coherent and incoherent signal processing methods for TDE. It is shown that, at low SNR, coherent processing yields significant gains in performance over incoherent processing. Simulation results are presented to corroborate these performance predictions.