北京邮电大学学报

  • EI核心期刊

北京邮电大学学报 ›› 2011, Vol. 34 ›› Issue (4): 56-60.doi: 10.13190/jbupt.201104.56.zhangjx

• 论文 • 上一篇    下一篇

提高多址接入性能的功率与LDPC码的优化设计

张京席1,2,别志松1,吴伟陵1   

  1. 1.北京邮电大学 信息与通信工程学院, 北京 100876; 2.华北电力大学 电子系, 河北 保定 071053
  • 收稿日期:2010-10-19 修回日期:2011-03-11 出版日期:2011-08-28 发布日期:2011-07-18
  • 通讯作者: 张京席 E-mail:zhjxbupt@eyou.com
  • 基金资助:

    国家自然科学基金项目(60902048); 国家重点基础研究发展计划项目(2007CB310604); 中央高校基本科研业务费资助项目(BUPT 2011RC0109); 国家科技重大专项项目(2008ZX03003005, 2010ZX0300300301)

Design Optimization for Multiple Access via Power and LDPC Code

  • Received:2010-10-19 Revised:2011-03-11 Online:2011-08-28 Published:2011-07-18
  • Contact: Jing-Xi ZHANG E-mail:zhjxbupt@eyou.com

摘要:

为了逼近多址接入信道的容量限,对功率与低密度校验阵(LDPC)码的度分布进行了优化. 基于互信息最大化准则设计了功率分配算法,并得出分配方案,利用高斯近似来近似取得因子图上消息的概率密度函数,得到功率分配条件下优化的LDPC码的度分布. 采用迭代的检测与译码算法进行多址干扰的消除. 仿真结果表明,经功率和LDPC 码优化后的误码性能在误码率为10-5时比等功率只优化LDPC 码度分布时的性能提升了16dB.

关键词: 多址接入信道, 低密度校验阵码, 高斯近似, 交织多址, 功率分配, 码优化

Abstract:

A study on approach multiple access channel capacity by means of power allocation and low density parity check (LDPC) codes optimization is presented. The power allocation scheme is designed based on the maximization of mutual information and then the power profile is obtained. The probability density function of message on factor graph is obtained by Gaussian approximation. The optimized LDPC code degree profiles are obtained by using the power profile. Iterative detection and decoding algorithm is also applied to combat multiple access interference. Simulation showes that the bit error probability performance can be improved by 16dB at 10-5 with the proposed method compared with that of only optimization of LDPC code.

Key words: multiple access channel, low density parity check codes, Gaussian approximation, interleaver division multiple access, power allocation, code optimization