Patent ID: 6421400
Filing Date: 2002-07-16
Classification: H04L

Abstract:
A digital communications receiver which comprises:a phase-shift key (PSK) demodulator configured to accept a receive signal and configured to responsively produce quantized signal components, wherein the quantized signal components include a quantized in-phase component IQ and a quantized quadrature component QQ; and a soft-decision decoder coupled to the PSK demodulator to receive the quantized signal components and configured to convert the quantized signal components into decoded information bits, wherein the soft-decision decoder includes: a distance metric calculator configured to receive the quantized signal components and responsively determine a distance metric for each PSK signal constellation point, wherein the distance metric Di2 for a PSK signal constellation point (Ri, &thgr;i) is calculated according to the equation: Di2=âˆ’IQ cos(&thgr;i)âˆ’QQ sin(&thgr;i).