Patent ID: 8411807

Claim:
A method comprising: receiving energy in a frequency band and producing a receive signal representative thereof: analyzing the receive signal to detect occurrence of a packet associated with a transmission by a communication device at a point in time during a payload portion of the packet, wherein the payload portion of the packet comprises a plurality of segments that occur at regular intervals throughout a duration of the packet and each of the segments comprises a first portion and a second portion that contains and repeats part of the first portion, and wherein analyzing is based on a repetition period of the segments and a duration of the second portion of the segments of the packet and comprises computing a metric representing a doubly differential matched filter autocorrelation of the receive signal and comparing the metric with a threshold, which when exceeded, indicates presence of a packet in the receive signal; and detecting an in-progress packet transmitted by the communication device in a particular frequency channel within the frequency band based on said analyzing.