METHOD FOR SEARCHING FOR A USEFUL SIGNAL IN A MULTIPLEXING BAND

摘要

A method of searching for the presence of a useful signal of predefined spectral width ΔB in a multiplexing band having a spectral width greater than ΔB, includes calculating a frequency signal representative of a power spectral density in the multiplexing band, calculating a non-useful signal by filtering the frequency signal by means of a filter capable of suppressing all or part of signals having a spectral width equal to or smaller than ΔB, calculating a power ratio signal representative of the ratio of the frequency signal to the non-useful signal, and comparing the power ratio signal with a predefined threshold value. The method may be employed using a computer program product, a receiver unit, and/or a station of a digital telecommunications system comprising such a receiver unit.

主权项

1. A method of searching for a useful signal in a general signal, said useful signal corresponding to a radioelectric signal having a predefined spectral width ΔB transmitted by a terminal in a multiplexing band having a spectral width greater than ΔB, said general signal corresponding to all the radioelectric signals received in the multiplexing band, the method comprising:
generating a frequency signal representative of a power spectral density of the general signal sampled at elementary frequencies of the multiplexing bank; generating a non-useful signal, the generating the non-useful signal including filtering of the frequency signal using a filter to suppress all or part of signals having a spectral width equal to or smaller than ΔB; generating a power ratio signal, representative of a ratio, at each elementary frequency, of the frequency signal to the non-useful signal; comparing the power ratio signal with a defined threshold value; and identifying an elementary frequency for which said power ratio signal has a local maximum value greater than said threshold value as a central frequency of a useful signal present in the general signal.