Generalized Mutual Information Analysis for BICM-8QAM with Residual Phase Noise

Qian Wang, Zhi Quan, Suzhi Bi, Changyuan Yu, Pooi Yuen Kam

Research output: Journal article publicationJournal articleAcademic researchpeer-review

Abstract

Generalized mutual information (GMI) has become a key metric for bit-interleaved coded modulation (BICM) system design and performance analysis. As residual phase noise (RPN) normally exists after imperfect phase estimation, the mostly used mismatched Gaussian receiver is suboptimal for GMI analysis in phase noise. This letter thus analyzes the GMI of BICM systems using 8-ary quadrature-amplitude-modulations (QAM) in the presence of both RPN and additive white Gaussian noise (AWGN). We will use the maximum-likelihood receiver derived in our earlier work to calculate the GMI of Star-8QAM, Circular-8QAM, Rect-8QAM and 8PSK. The explicit symbol and bit log-likelihood ratios are specifically expressed in amplitude-phase form with RPN considered. Numerical results are given in details to show the GMI comparison in phase noise and the GMI loss compared to the pure AWGN case. It is shown that Star-8QAM is much more tolerant to large RPN. Moreover, the ratio parameters of Rect-8QAM and Star-8QAM are optimized to maximize the GMI as the RPN variance increases. We also optimize the bit mapping for non-Gray 8QAM.

Original languageEnglish
Pages (from-to)3819-3823
Number of pages5
JournalIEEE Communications Letters
Volume25
Issue number12
DOIs
Publication statusPublished - 1 Dec 2021

Keywords

  • 8PSK
  • bit-interleaved coded modulation (BICM)
  • Circular-8QAM
  • Generalized mutual information (GMI)
  • Rect-8QAM
  • residual phase noise
  • Star-8QAM

ASJC Scopus subject areas

  • Modelling and Simulation
  • Computer Science Applications
  • Electrical and Electronic Engineering

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