New signal-selective parameter estimation approach to time-delay estimation
Yan Zhang, Shuxun Wang · Proceedings of SPIE, the International Society for Optical Engineering/Proceedings of SPIE · 1998
For the problem of estimating the difference in arrival times of radio waves impinging on two spatially separate antennas for the purpose of passively locating the source of a communications or telemetry signal, a new parameter estimation algorithm that is highly tolerant to interference and noise is proposed. By exploiting the cyclostationarity property of the signal of interest, the new algorithm which models the time delay as a finite impulse response filter removes the effects of additive noise and interfering signals. Then from a set of linear equations involving cyclic (cross) correlation, the time delay can be estimated to be the index of the FIR parameter which has maximum value. The new approach exhibits its signal selectivity regardless of the extent of temporal, spectral, or spatial overlap among received signals, it is only required that the signal of interest has a known (or measurable) analog carrier frequency or digital keying rate that is distinct from those of all interfering signals. Yet the computational complexity of this new approach is comparable to that of conventional methods.