Patent ID: 6459743
Filing Date: 2002-10-01
Classification: H03D,H03M,H04L

Abstract:
A receiver, comprising:means for receiving a radio frequency signal; a sigma-delta analog-to-digital converter that samples the radio frequency signal at a sampling rate and generates therefrom 1-bit digital samples representing a digital intermediate frequency signal, wherein the intermediate frequency is one fourth of the sampling rate; and a demodulator for generating in-phase and quadrature samples from the digital intermediate frequency signal, wherein the demodulator comprises: a first mixer that generates a first mixed signal by combining the 1-bit digital samples representing the digital intermediate frequency signal with a first sequence representing a cosine mixing signal, wherein the first mixer is a first exclusive-OR logic gate having a first input coupled to receive the 1-bit digital samples representing the digital intermediate frequency signal, and a second input coupled to receive the first sequence representing the cosine mixing signal; a second mixer that generates a second mixed signal by combining the 1-bit digital samples representing the digital intermediate frequency signal with a second sequence representing a sine mixing signal, wherein the second mixer is a second exclusive-OR logic gate having a first input coupled to receive the 1-bit digital samples representing the digital intermediate frequency signal, and a second input coupled to receive the second sequence representing the sine mixing signal; and means for decimating the first and second mixed signals to generate the in-phase and quadrature samples.