QC-LDPC decoding in M-QAM system
Ling Wang · Electronic Design Engineering · 2012
M-QAM modulation/demodulation with the QC-LDPC coding/decoding system is studied.For M-QAM soft demodu-lation,the detailed derivation of posterior probability formula is given.Through derivation,we can get the conclusion that the computational complexity is cut down from O M～(1/2) to OM for square constellation;A simulation experiment is done to estimate performance of different modulation order.The P-TDMP decoding algorithm is adopted as the QC-LDPC decoding scheme,through simulation,a conclusion can be made that P-TDMP decoding has a performance advantage over classic decoding algorithm.