The convergence characteristic of the vector approximate message passing soft frequency-domain equalization algorithm is improved by the energy spreading transform at the transmitter. The output of the equalizer can be considered as free of inter-symbol interference. The relation between the output of the equalizer and the transmitted symbols can be modeled by an additive white Gaussian noise channel. Over the bandwidth-constrained additive white Gaussian noise channel, the uniform distribution modulation format has a gap to the Shannon limit. The gap can be closed by probabilistic constellation shaping. The a priori information of unequal probability symbols is used to improve the structure of the equalizer and enhance the performance at the receiver. Theoretical analysis and simulation results show that the proposed algorithm can substantially improve the convergence speed as well as the equalization performance over classical Proakis B and Proakis C multipath channels. There is about 0.5 dB performance gain compared with the uniform distribution signal.
WU Xisheng
,
WU Yanbo
,
ZHU Min
,
LI Dong
,
CHU Runcong
. Vector approximate message passing soft frequency domain equalization for probabilistic constellation shaping[J]. Journal of University of Chinese Academy of Sciences, 2023
, 40(5)
: 694
-700
.
DOI: 10.7523/j.ucas.2022.010
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