Patent ID: 6493409
Filing Date: 2002-12-10
Classification: H04B,H04L,H04N

Abstract:
In an Offset QAM receiver that recovers in-phase signals sampled at in-phase sampling times and quadrature-phase signals sampled at quadrature-phase sampling times, a phase detector comprising:means for separating the in-phase signals into a first data stream at the in-phase sampling times and a second data stream at the quadrature-phase sampling times; means for separating the quadrature-phase signals into a third data stream at the quadrature-phase sampling times and a fourth data stream at the in-phase sampling times; means for generating a fifth data steam representing tentative decisions from the first data stream; means for generating a sixth data steam representing tentative decisions from the third data stream; means for comparing the first and fifth data streams to generate a first error signal; means for comparing the third and sixth data streams to generate a second error signal; means for combining the first error signal and the fourth data stream to form a first phase error signal; and means for combining the second error signal and the second data stream to form a second phase error signal.