Patent ID: 9112762
Filing Date: 2015-08-18
Classification: H04L

Abstract:
1. A detector for determining presence or absence of a quadrature amplitude modulated (QAM) signal having a known symbol rate egressing from a broadband communication system (BCS), said detector comprising a mixer to mix a signal received from an environment in a vicinity of said broadband communication system with an oscillator output wherein said oscillator is tuned to operate at a carrier frequency of a QAM band, to develop a quadrature baseband signal, a further mixer for mixing a signal corresponding to said quadrature baseband signal with an output of a further oscillator wherein said further oscillator is tuned to operate at a QAM symbol rate of said QAM band, and a processor to analyze a spectrum of an output of said further mixer to determine said presence or absence of a signal at a frequency corresponding to said QAM symbol rate.