Patent ID: 7970361

Claim:
A method in a communication system of recognizing a presence of a transmitter based on signal measurements, comprising: measuring a received energy at a plurality of different frequencies in a frequency band; enhancing the measured received energies such that noise in the measured received energies is reduced; and determining whether the measured received energies include a specific spectral shape, wherein determining comprises comparing at least one measured received energy to at least one other measured received energy, the measured received energies having been measured at different frequencies, thereby recognizing the presence of the transmitter, and if a comparison of an initial pair of measured received energies indicates that the measured received energies are substantially the same, determining further comprises successively comparing pairs of measured received energies at successively closer frequencies, comparing an inclination from an initial measured received energy to a peak received energy to a threshold, and determining that the specific spectral shape is included based on the comparisons.