Patent ID: 8706133

Claim:
A method of detecting a presence of at least one broadcast signal from an incumbent transmitter, the method comprising: at a non-incumbent transmitter: selecting a first pilot signal candidate within a first RF spectrum; measuring a total power of the first RF spectrum and a power level of the first pilot signal candidate; dynamically determining a difference threshold value, wherein determining the difference threshold value comprises: determining a first ratio between the measured total power of the first RF spectrum and a measured power level of the first pilot signal candidate, measuring a first difference between the first ratio and an expected ratio, and processing at least the first difference to dynamically select the difference threshold value; when an absolute value of the first difference is less than the difference threshold value, registering presence of at least one broadcast signal from the incumbent transmitter and classifying the first RF spectrum as unavailable for communication for the non-incumbent transmitter; and when an absolute value of the first difference is not less than the difference threshold value, registering absence of at least one broadcast signal from the incumbent transmitter and classifying the first RF spectrum as available for communication for the non-incumbent transmitter.