CONVERGENCE DYNAMICS OF AN ADAPTIVE TIME-DELAY ESTIMATOR IN MULTIPATHCHANNEL

An adaptive infinite-duration impulse response (IIR) filter for contin uous tracking of multipath delay is analyzed. Although the adaptive al gorithm is originally designed to eliminate a replica whose interpath delay is an integral multiple of the sampling period, it can be modifi ed for estimating any real-valued multipath delay. Using a least mean square (LMS)-style method, the multipath gain and delay estimate are a dapted explicitly and simultaneously, and the updating equations are c omputationally efficient. Convergence dynamics of the system parameter s are given and effects of additive noise are investigated. It is prov ed that this technique can achieve the Cramer-Rao lower bound (CRLB) f or high signal-to-noise ratio (SNR) conditions. The performance of the proposed system is evaluated by computer simulations which show that both static and nonstationary delays can be tracked satisfactorily.