Patent ID: 8107443

Claim:
A method of performing cell search in a wireless communications system, the method comprising: receiving a preamble signal; match filtering the preamble signal with a first pseudo noise sequence to form a first filtered preamble signal; match filtering the preamble signal with a second pseudo noise sequence to form a second filtered preamble signal; modifying the second filtered preamble signal to form a modified filtered preamble signal; summing at least the first filtered preamble signal with the modified filtered preamble signal to form one of a plurality of summed preamble signals; choosing a largest summed preamble signal from the plurality of summed preamble signals; determining an estimated pseudo noise sequence index and an estimated integer part frequency offset according to the largest summed preamble signal; match filtering the preamble signal with at least a first pseudo noise sequence and a second pseudo noise sequence corresponding to the estimated pseudo noise sequence index and the estimated integer part frequency offset to form a plurality of filtered preamble signals; and generating an estimated pseudo noise sequence from a largest filtered preamble signal of the plurality of filtered preamble signals.