Patent ID: 7949320
Filing Date: 2011-05-24
Classification: H04B

Abstract:
1. A method for detecting a radio frequency (RF) signal in a receiver, the RF signal having at least one narrowband channel within a wideband spectrum for the RF signal, the method comprising: mixing a local oscillator signal from a local oscillator of the receiver with the RF signal to produce a mixed signal, wherein the local oscillator signal has a frequency at a first channel frequency; converting the mixed signal to a digital mixed signal; in a digital front end, determining an RF channel signal from the digital mixed signal; determining a magnitude of a constant modulus signal for the RF channel signal; determining a magnitude of a noise signal of the RF channel signal; and comparing the magnitude of the constant modulus signal with the magnitude of the noise signal to produce a constant modulus indication value indicating a ratio of the magnitude of the constant modulus signal to the magnitude of the noise signal.