Performance Analysis of Bidirectional Relay Selection with Imperfect   Channel State Information
  In this paper, we investigate the performance of bidirectional relay selection using amplify-and-forward protocol with imperfect channel state information, i.e., delay effect and channel estimation error. The asymptotic expression of end-to-end SER in high SNR regime is derived in a closed form, which indicates that the delay effect causes the loss of both coding gain and diversity order, while the channel estimation error merely affects the coding gain. Finally, analytical results are verified by Monte-Carlo simulations. 
Hongyu Cui, Rongqing Zhang, Lingyang Song, and Bingli Jiao
cs.NI