Journal of Beijing University of Posts and Telecommunications

  • EI核心期刊

JOURNAL OF BEIJING UNIVERSITY OF POSTS AND TELECOM ›› 2010, Vol. 33 ›› Issue (1): 89-92.doi: 10.13190/jbupt.201001.89.xuchx

• Reports • Previous Articles     Next Articles

QAM Scheme Using Degree Distribution of LDPC Codes

XU Cheng-xin;CHANG Yong-yu;YANG Hong-wen;ZHANG Xin   

  1. (School of Information and Communication Engineering, Beijing University of Posts and Telecommunications, Beijing 100876, China)
  • Received:2009-04-20 Revised:2009-10-14 Online:2010-02-28 Published:2010-02-28
  • Contact: XU Cheng-xin

Abstract:

In order to improve communication quality and promote spectral efficiency, a combination of irregular low-density parity-check (LDPC) codes and high order modulation technique is analyzed. A simple and efficient combination scheme is proposed, in which, the effect of degree distribution of irregular LDPC codes and the unequal error protection (UEP) property of high order modulation technique are considered. Different degree variable nodes have different protection levels during modulation mapping. It is proved that the system performance is promoted when using Gaussian approximation (GA) algorithm. Simulation shows that new scheme can reduce the system error rate.

Key words: irregular low-density parity-check codes, high order modulation, degree distribution, unequal error protection, Gaussian approximation

CLC Number: