Patent ID: 8433006
Filing Date: 2013-04-30
Classification: H04L

Abstract:
1. A method for use in a wireless endpoint, the method comprising: selecting one of a number of channels; downconverting a received signal on the selected channel for providing received orthogonal frequency division multiplexed (OFDM) symbols, each OFDM symbol comprising N>1 subcarriers at least some of which are pilot subcarriers; correlating the received OFDM symbols for providing at least one correlated value; generating a metric value as a function of the at least one correlated value; and comparing the metric value to a threshold value for detecting if an incumbent signal is present, wherein the metric value is represented by a parameter T, where T is one of: or where: α V is a maximum symbol index difference of the OFDM symbol correlation, β is a fixed integer, r[n] represents samples of the received signal, d=0, 1, 2, . . . , D−1, D=N/L, L is a length of a cyclic prefix of each OFDM symbol, and M=N+L.