Abstract: An efficient method of accurately estimating delay spread in multi-path transmission applications is based on quantifying the effect of the actual delay spread on the shape of the correlation energy profile between the received signal and the synchronization pattern of the receiver. Depending on the degree of the estimated delay spread, an appropriate demodulation technique is selected for optimizing the receiver performance over a range of channel multi-path conditions. The invention is applicable to digital wireless mobile communication systems, as well as to any device that performs characterization or testing of a transmission system.

Abstract: A method for adaptively equalizing an output of a digital communication channel, including steps of: generating an initial channel estimation; determining an initial set of metric states of a trellis, based on known symbols of a received input signal comprising a sequence of symbols; updating the set of metric states according to the initial channel estimation and the received signal; updating a set of paths for the metric states using a delayed tentative decision of a symbol of the received signal, to determine a set of survivor paths; and updating the channel estimation, based on the updated metrics, delayed tentative decision, and the received signal.