Communication Channel Estimation and Waveform Design: Time Delay Estimation on Parallel, Flat Fading Channels

摘要

A review of performance bounds for time-delay estimation (TDE) is presented, including a discussion of current trends. Then the problem of waveform design for TDE using frequency-hopping (FH) waveforms is analyzed to study the effects of fading and diversity on TDE over parallel channels with flat, Rayleigh fading. The authors present the maximum likelihood estimator (MLE), the Cramer-Rao bound (CRB), and the Ziv-Zakai bound (ZZB) on TDE for several different approaches to modeling the fading channels. Computer simulations of the mean-squared error (MSE) of the MLEs indicate that the ZZB provides a significantly tighter bound than the CRB, and the ZZB exhibits a SNR- threshold region that agrees with the MLE performance.