"Non-Uniform APSK Optimization for BICM Systems" by Keqian Yan, Kewu Peng et al.

Article Title

Non-Uniform APSK Optimization for BICM Systems

Authors

Keqian Yan, Tsinghua National Laboratory for Information Science and Technology (TNList), Department of Electronic Engineering, Tsinghua University, Beijing 100084, China.
Kewu Peng, Tsinghua National Laboratory for Information Science and Technology (TNList), Department of Electronic Engineering, Tsinghua University, Beijing 100084, China.
Fang Yang, Tsinghua National Laboratory for Information Science and Technology (TNList), Department of Electronic Engineering, Tsinghua University, Beijing 100084, China.
Jian Song, Tsinghua National Laboratory for Information Science and Technology (TNList), Department of Electronic Engineering, Tsinghua University, Beijing 100084, China.

Keywords

Bit-Interleaved Coded Modulation (BICM), non-uniform Amplitude Phase Shift Keying (APSK), mutual information, geometrical shaping

Abstract

Traditional Amplitude Phase Shift Keying (APSK) consists of rings with points uniformly spaced. By giving up this uniform-spacing feature, we propose an APSK optimization method based on the uniform APSK with Gray labeling (Gray-APSK). The aim of the optimization is to maximize the Generalized Mutual Information (GMI) of Bit-Interleaved Coded Modulation (BICM) for the targeted code rate and channel. We show that our optimized non-uniform APSK could offer further performance gain compared with the conventional uniform Gray-APSK and considerably outperforms the traditional quadrature amplitude modulation at the targeted SNR and channel.