J4 ›› 2011, Vol. 38 ›› Issue (2): 1-7.doi: 10.3969/j.issn.1001-2400.2011.02.001

• Original Articles •     Next Articles

Power allocation algorithm based on outage probability for DF cooperative systems

SONG Jing;GE Jianhua;LI Jing   

  1. (State Key Lab. of Integrated Service Networks, Xidian Univ., Xi'an  710071, China)
  • Received:2010-04-09 Online:2011-04-20 Published:2011-05-26
  • Contact: SONG Jing E-mail:xxsj422@163.com

Abstract:

Since the equal power allocation (EPA) between the source node and the relay node in the decode-forward (DF) cooperative communication system results in resource inefficiency, a power allocation algorithm based on outage probability analysis is proposed. This algorithm aims to reduce the average outage probability of the system, in which the upper and lower bound expressions for the system average outage probability of the model are derived according to the average signal to noise ratios of the upper link channels of and the channels between users. The power allocation factor that leads to a lower system average outage probability is obtained by the golden section method. Simulation results show that, all conditions being the same, this power allocation scheme can achieve a better performance than the equal power allocation (EPA) scheme.

Key words: cooperative communications, decode-and-forward (DF) relaying, golden ratio method, outage probability, power allocation