J4 ›› 2011, Vol. 38 ›› Issue (4): 160-166.doi: 10.3969/j.issn.1001-2400.2011.04.029

• 研究论文 • 上一篇    下一篇

双瑞利衰落信道下双天线接收系统分集特性分析

李兆训;胡捍英   

  1. (解放军信息工程大学 信息工程学院,河南 郑州  450002)
  • 收稿日期:2010-05-24 出版日期:2011-08-20 发布日期:2011-09-28
  • 通讯作者: 李兆训
  • 作者简介:李兆训(1968-),男,副教授,解放军信息工程大学博士研究生,E-mail: lizxun@126.com.
  • 基金资助:

    国家科技重大专项资助项目(2009ZX03003-008-02, 2009ZX03003-005)

Diversity analysis of the double-antenna receiving system over double-Rayleigh fading channels

LI Zhaoxun;HU Hanying   

  1. (College of Info. Eng., PLA Info. Eng. Univ., Zhengzhou  450002, China)
  • Received:2010-05-24 Online:2011-08-20 Published:2011-09-28
  • Contact: LI Zhaoxun

摘要:

基于双瑞利衰落模型,对采用最大比合并(MRC)和选择式合并(SC)的双天线接收系统的分集特性和平均误符号率性能展开研究.分析了不同合并方式的接收信噪比的统计特性,采用基于矩生成函数的方法,导出了平均误符号率通用表达式.数值计算结果表明: 采用双天线接收技术可以对抗双瑞利衰落的影响,减小接收系统的平均误符号率;双瑞利衰落时分集接收系统难以获得满分集增益,可获得的有效分集增益de随信噪比的提高而缓慢上升,且随调制阶数的增大而变小; 在信噪比为80dB时,BPSK调制对应的de近似为2.5dB(MRC)和2.41dB(SC), 而64QAM调制时的de减至1.25dB(MRC)和1.13dB(SC).

关键词: 双瑞利衰落, 双天线接收, 最大比合并, 选择式合并, 平均误符号率, 分集增益

Abstract:

On the basis of the double-Rayleigh fading model, the paper investigates the diversity performance and average symbol error rate (ASER) for the double-antenna receiving system assuming maximal ratio combining (MRC) and selection combining (SC) strategies. The statistical properties of the receiving signal-to-noise ratio (SNR) are analyzed and a generalized expression on ASER is derived through MGF (moment generating function) based approach for MRC and SC schemes. Numerical calculations show that the fading effects are mitigated and that the ASER of the system is decreased by double-antenna receiving methods. They also manifest that the effective diversity gain achievable, de, cannot reach the full diversity order and go up slowly with the increase in SNR in double-Rayleigh fading. It also decreases with the increase in modulating orders, e. g., while the SNR is 80dB, de is about 2.5dB for MRC or 2.41dB for SC under BPSK modulation and it drops to 1.25dB for MRC or 1.13dB for SC under 64QAM modulation.

Key words: double-Rayleigh fading, double antennas receiving, maximal ratio combining, selection combining, average symbol error rate, diversity gain

中图分类号: 

  • TN850.9