Open AccessCalculation and error bound of Min‐approximated bitwise log‐likelihood ratios of generalised M ‐ary PAM
Author(s) -
Park SungJoon,
Lee Daniel C.
Publication year - 2020
Publication title -
the journal of engineering
Language(s) - English
Resource type - Journals
ISSN - 2051-3305
DOI - 10.1049/joe.2019.1056
Subject(s) - demodulation , bitwise operation , spectral efficiency , coding gain , algorithm , coding (social sciences) , mathematics , pulse amplitude modulation , computational complexity theory , upper and lower bounds , computer science , channel (broadcasting) , statistics , telecommunications , pulse (music) , decoding methods , programming language , mathematical analysis , detector
In modern digital communication systems, a high‐order modulation and advanced channel coding are often jointly used to increase the spectral efficiency and coding gain. In this work, the authors investigate a computationally efficient method for evaluating the bitwise log‐likelihood ratios of generalised M ‐ary pulse amplitude modulation (PAM) signals with the Min approximation. The proposed scheme is simple and can be applied to demodulate the M ‐ary PAM having an arbitrary symbol spacing and a bit stream mapping. The computational complexity and upper bounds of the approximation error are also provided for a better understanding of the proposed scheme.