Method and apparatus for soft demapping in rotated quadrature amplitude modulation (QAM) based communication system

摘要

A method and apparatus to perform a soft demapping in a rotated quadrature amplitude modulation (QAM) based communication system is described. The method and the apparatus include pre-processing a symbol based on a priori information and performing a one-dimensional (1D) soft demapping on the pre-processed symbol, continuously.

主权项

1. A method to perform a soft demapping, the method comprising:
pre-processing a symbol, based on a priori information, wherein the preprocessing comprises: pre-processing an I channel symbol of the symbol, based on statistics of a Q channel symbol of a previously estimated symbol, and pre-processing a Q channel symbol of the symbol, based on statistics of an I channel symbol of the previously estimated symbol; wherein the statistics of the Q channel symbol comprise a mean value and a variance value; and wherein the statistics of the I channel symbol comprise a mean value and a variance value; and wherein the a priori information corresponds to one of information about an LLR and information about an extrinsic LLR with respect to the previously estimated symbol; and performing a one-dimensional (1D) soft demapping on the pre-processed symbol.