SYSTÈME ET PROCÉDÉ POUR PROTÉGER LES TRANSMISSIONS DE MICROPHONES SANS FIL FONCTIONNANT DANS UN ESPACE BLANC DE BANDE DE TÉLÉVISION

摘要

A method of determining whether a TV band channel is available for use by a TV band device a corresponding device, the method comprising: tuning to a TV band channel; detecting a pilot tone within the TV band channel to obtain a radio frequency signal, wherein the pilot tone is a single tone modulated by a modulating sequence {b} = {+M, -M, +M, -M, +M, -M, +M ...} with a predetermined signal period assigned such that a bandwidth of the modulated pilot tone is maintained within a narrowband centered on the location of an Advanced Television Systems Committee (ATSC) pilot for a DTV broadcast; down-converting the radio frequency signal received on the TV band channel to yield a down-converted signal; performing a predetermined number of Fast Fourier Transforms (FFTs) on the down-converted signal and accumulating an energy of respective bins associated with the respective FFTs; selecting a predetermined number of FFT bins centered at a mandated location of an Advanced Television Systems Committee (ATSC) pilot in the TV Band channel; and analyzing the selected FFT bins to determine if an energy spike is present in any one of the selected FFT bins.