Performance of digital matched filters in a direct sequence spread spectrum receiver

Abstract

Preamble processing combined with an adaptive sampling window technique and selection of the largest value of a certain number of matched-filter output samples is proposed as a data decision strategy for direct-sequence spread-spectrum receivers using digital correlators for baseband matched filtering. The preamble sequence provides exact knowledge of the occurrence of the correlation maximum. System performance is analyzed on the basis of a combinatorial model for the deviation of the signal statistics at the matched filter outputs and a Markov model for the dynamic behavior of the sampling window during reception of a burst. Theoretical system analysis is compared with measurements of the bit-error probability as a function of the receiver input signal/noise ratio.<>