Patent ID: 6226333
Filing Date: 2001-05-01
Classification: H04L

Abstract:
QAM de-mapping circuit, comprisinga differential decoder (1) to perfom a differential decoding of 2 Bits of each n Bit symbol received,characterized bya rotator (2) to derotate the other n-2 Bits of each n Bit symbol received into the first quadrant on the basis of the 2 Bits of each n Bit symbol supplied to the differential decoder (1), anda single quadrant demapper (3) to assign data bit values to received signal amplitudes on the basis of the derotated n-2 Bits of each n Bit symbol received,wherein 2 output signals of the QAM de-mapping circuit are derived from the differential decoder (1) and n=2 output signals of the QAM de-mapping circuit are derived from said single quadrant demapper (3).