Patent ID: 8428188
Filing Date: 2013-04-23
Classification: H04L,H04N

Abstract:
1. A system embodied in a modem, the system comprising: a phase offset corrector that receives an equalized signal representative of a quadrature amplitude modulated signal and derives a phase-corrected signal from the equalized signal; a two-level slicer that slices the equalized signal to obtain real and imaginary sequences; a frame synchronizer that performs a correlation of the real and imaginary sequences with corresponding parts of a stored frame-sync pseudo-random sequence; and a phase correction signal provided by the frame synchronizer to the phase offset corrector, wherein the phase correction signal is based on the maximum real and imaginary values of the correlation, and wherein the real and imaginary parts of the frame sync symbols of the quadrature amplitude modulated signal have the same sign, and the signs of the maximum real and imaginary values of the correlation are indicative of phase rotation in the equalized signal.