Patent ID: 7751996
Filing Date: 2010-07-06
Classification: H04B

Abstract:
1. A method of measuring a D/U ratio for desired and undesired signals in a wireless video transmission system at a shared channel frequency based on a received signal at a geographic location within a respective service area for the desired signal, comprising the steps of: locating measurement equipment to receive the received signal in the respective service area; downconverting the received signal to an intermediate frequency signal in the measurement equipment; demodulating the intermediate frequency signal to generate a baseband video signal in the measurement equipment; identifying horizontal sync pulses within the baseband signal; generating a sampled sync signal containing an undesired signal component; determining a Fourier transform having a plurality of bins in response to the sampled sync signal; finding a bin having a spectral peak corresponding to the frequency of the horizontal sync pulses of the desired signal; finding at least one delta frequency such that a pair of bins symmetrically spaced above and below the frequency of the horizontal sync pulses by the delta frequency exhibit spectral peaks, wherein the delta frequency identifies the frequency of the bin having a spectral peak of the undesired signal; calculating the D/U ratio in response to a magnitude of the identified peak of the undesired signal; and displaying the D/U ratio to a technician using the measurement equipment.