Patent ID: 8949061
Filing Date: 2015-02-03
Classification: H04B,H04N

Abstract:
1. A method of detecting the presence of a digital television (DTV) pilot tone in a high noise environment, comprising: computing a power average of a plurality of Fast Fourier Transform (FFT) output spectra of a digital baseband signal derived from a TV band channel to create a power averaged output spectrum; estimating a power peak in the power averaged output spectrum; computing based upon the estimated power peak, an adjustment parameter to adjust the signal to center the power peak in a Discrete Fourier Transform (DFT) bin of the FFT output spectra; applying the computed parameter to adjust the signal; computing a coherent average of FFT output spectra of the adjusted signal; computing a power spectrum of the coherent averaged output spectrum; testing the power spectrum for the DTV pilot tone by identifying a peak power in the power spectrum of the coherent averaged output spectrum; and determining whether the test exceeds a threshold.