Patent ID: 6233712
Filing Date: 2001-05-15
Classification: H04L

Abstract:
An apparatus for recovering information bits from in-phase and quadrature components of a stream of quadrature amplitude modulation (QAM) trellis code modulation (TCM) signals, each signal having an in-phase component and a quadrature component, wherein the in-phase component includes a decoded bit and a plurality of uncoded in-phase bits and the quadrature component includes a decoded quadrature bit and a plurality of uncoded quadrature bits, the apparatus comprising:a reencode and puncture circuitry adapted to receive the in-phase and quadrature components of a QAM TCM signal for encoding the decoded in-phase and quadrature bits, wherein the reencode and puncture circuitry punctures the encoded in-phase bit with the uncoded in-phase bits to generate an in-phase component index and wherein the reencode and puncture circuitry punctures the encoded quadrature bit with the remaining quadrature bits to generate a quadrature component index;an inverse mapping circuitry coupled to the reencode and puncture circuitry to receive the in-phase component index and the quadrature component index for recovering a first set of in-phase bits and a second set of quadrature bits; anda recovery circuitry coupled to the inverse mapping circuitry to receive the first set of in-phase bits and the second set of quadrature bits, the recovery circuitry being coupled to receive the decoded in-phase and quadrature bits, wherein the recovery circuitry recovers a set of information bits by assembling the received bits.