Patent ID: 6069913
Filing Date: 2000-05-30
Classification: H04L

Abstract:
An apparatus for characterizing an identifying bit sequence contained within a received radio frequency (RF) waveform in terms of a plurality of known bit sequences, the apparatus comprising:a) a scanning receiver for receiving in an RF waveform the identifying bit sequence and for determining samples of the received RF waveform containing the identifying bit sequence;b) a reference waveform generator for generating a plurality of reference sample sets each consisting of samples of a reference waveform characteristic of one of a plurality of known bit sequences;c) a correlator for computing, for each reference sample set in turn, the peak correlation with the received waveform sample set, the correlator determining the peak correlation by comparing each reference sample set to the received waveform sample set for a plurality of positions of the reference sample set relative to the received waveform sample set, so as to provide a comparison that is substantially independent of the phase of the reference sample set relative to the received waveform sample set; andd) a peak correlation comparator for comparing the computed peak correlation values to determine a maximum peak correlation and for providing the maximum peak correlation along with the known bit sequence giving rise to the maximum peak correlation.