A Novel Maximum-Likelihood Estimator with Very High Resolution for Multipath Channels and Its Application in Electrooptical Distance Measurement

In order to determine the impulse response of a multipath channel one can probe the channel with an electromagnetic wave modulated by a spread spectrum signal. A novel maximum-likelihood estimator is presented which estimates the channel parameters without any bias. The application of this estimator in an electrooptical distance measurement system built by the author is shown. With this system, measurements of distances up to several hundred meters are possible with an accuracy of a few millimeters.