SOFT TRELLIS DE-SHAPER FOR CONSTELLATION SHAPING

In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a receiver. The receiver receives, from a transmitter, a signal carrying a constellation symbol. The receiver processes the received signal by a soft symbol demapper to generate a first soft output of a first set of bits and a second soft output of a second set of bits. The receiver processes the second soft output by a soft syndrome former to generate a third soft output of a third set of bits. The soft syndrome former corresponds to a shaping code applied at the transmitter. The receiver recovers bits represented by the constellation symbol based on the first soft output and the third soft output.