| 摘要 |
The method for detecting gaps in the UHF spectrum for analogue television is useful for detecting spaces with absence of broadcasted television signal, which may comply with the structure of an analogue standard. The detection may be performed in noisy environments, in which a signal-noise ratio falls down to -20dB. With the detection of gaps in the UHF spectrum, it is ensured that the transmission of signals by a predetermined frequency is not invading the previous frequency, also optimising the transmission and promoting the efficient reuse of the spectrum in certain frequency bands and geographical zones. In order to take advantage of the properties of the self-correlation functions of the Barker Codes, a method is proposed where, once it is applied, a coupled filter is generated for analysing the output signal and concluding if a valid pattern has been found in case a pick in the amplitude is generated, this being an indicator that an input signal is available for frequency spaces .
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