中国邮电高校学报(英文) ›› 2011, Vol. 18 ›› Issue (4): 65-69.doi: 10.1016/S1005-8885(10)60085-4

• Wireless • 上一篇    下一篇

Power allocation of cooperative amplify-and-forward communications with multiple relays

武卓,杨洪兵   

  1. 上海大学
  • 收稿日期:2010-12-27 修回日期:2011-04-06 出版日期:2011-08-31 发布日期:2011-08-24
  • 通讯作者: 武卓 E-mail:zwu@shu.edu.cn
  • 基金资助:

    This work was supported by the National Natural Science Foundation of China (60972055), the Shanghai Educational Development Foundation (09CG40), the Science and Technology Commission of Shanghai Municipality (10220710300).

Power allocation of cooperative amplify-and-forward communications with multiple relays

Hong-Bing Yang2   

  • Received:2010-12-27 Revised:2011-04-06 Online:2011-08-31 Published:2011-08-24
  • Supported by:

    This work was supported by the National Natural Science Foundation of China (60972055), the Shanghai Educational Development Foundation (09CG40), the Science and Technology Commission of Shanghai Municipality (10220710300).

摘要:

Cooperative diversity is one of the most effective ways to mitigate the fading effect of wireless channels and obtain the spatial gain in wireless networks. In this paper, an optimal power allocation (OPA) scheme for a cooperative communication system using the amplify-and-forward (AF) transmit strategy with multiple relay users is proposed by minimizing the bit-error-rate (BER) at the destination under the constraint of the total transmit power of both the source user and the relay users. Simulation results indicate that the proposed power allocation method can achieve significant BER performance improvement than using the equal power allocation (EPA) scheme,while still attains low complexity. The system performance is improved significantly with the increasing of the number of relay users at high signal-noise ratio (SNR). However, at low SNR, the system performance decreases when the relay number increases. Thus, an adaptive relay selection scheme may be used to choose the appropriate relay numbers in different transmission scenarios to provide system performance improvement and keep the power allocation scheme with low complexity.

关键词:

cooperative communication, AF, EPA, PA, multiple relays, BER

Abstract:

Cooperative diversity is one of the most effective ways to mitigate the fading effect of wireless channels and obtain the spatial gain in wireless networks. In this paper, an optimal power allocation (OPA) scheme for a cooperative communication system using the amplify-and-forward (AF) transmit strategy with multiple relay users is proposed by minimizing the bit-error-rate (BER) at the destination under the constraint of the total transmit power of both the source user and the relay users. Simulation results indicate that the proposed power allocation method can achieve significant BER performance improvement than using the equal power allocation (EPA) scheme,while still attains low complexity. The system performance is improved significantly with the increasing of the number of relay users at high signal-noise ratio (SNR). However, at low SNR, the system performance decreases when the relay number increases. Thus, an adaptive relay selection scheme may be used to choose the appropriate relay numbers in different transmission scenarios to provide system performance improvement and keep the power allocation scheme with low complexity.

Key words:

cooperative communication, AF, EPA, PA, multiple relays, BER

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