Patent ID: 7583758

Claim:
An apparatus, comprising: an auto-correlation detection module that is operable to: calculate a modified correlation function that varies as a function of each sample of a first plurality of samples of a first moving window and each sample of a second plurality of samples of a second moving window of an OFDM (Orthogonal Frequency Division Multiplexing) packet, wherein the modified correlation function is normalized with respect to a first power corresponding to the first moving window and a second power corresponding to the second moving window; compare the modified correlation function to a modified correlation function threshold; compare the first power corresponding to the first moving window to a first power threshold; and compare the second power corresponding to the second moving window to a second power threshold; and a match filter detection module that is operable to: calculate a match filter function that varies as a function of each sample of the first plurality of samples of the first moving window and each sample of the second plurality of samples of the second moving window of the OFDM packet as compared to a predetermined plurality of samples; identify a first peak in the match filter function by comparing the match filter function to a first match filter function threshold; identify a second peak in the match filter function by comparing the match filter function to a second match filter function threshold; identify a difference in magnitude between the first peak and the second peak; identify whether the match filter function falls below a third match filter function threshold between the first peak and the second peak; identify a predetermined number of peaks in the match filter function after the first peak and the second peak; compare the first power corresponding to the first moving window to a third power threshold; and compare the second power corresponding to the second moving window to a fourth power threshold; and a combining module that is operable to: receive a first output signal from the auto-correlation detection module; receive a second output signal from the match filter detection module; and process the first output signal and the second output signal to generate a carrier detect signal.