Performance Analysis of Multiuser Relay Networks with Feedback Delay

Jie YANG  Xiaofei ZHANG  Kai YANG  

IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences   Vol.E97-A   No.8   pp.1770-1779
Publication Date: 2014/08/01
Online ISSN: 1745-1337
DOI: 10.1587/transfun.E97.A.1770
Type of Manuscript: PAPER
Category: Communication Theory and Signals
AF relay network,  opportunistic scheduling,  beamforming,  Rayleigh fading,  feedback delay,  

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In this paper, we analyze the performance of a dual-hop multiuser amplify-and-forward (AF) relay network with the effect of the feedback delay, where the source and each of the K destinations are equipped with Nt and Nr antennas respectively, and the relay is equipped with a single antenna. In the relay network, multi-antenna and multiuser diversities are guaranteed via beamforming and opportunistic scheduling, respectively. To examine the impact of delayed feedback, the new exact analytical expressions for the outage probability (OP) and symbol error rate (SER) are derived in closed-form over Rayleigh fading channel, which are useful for a large number of modulation schemes. In addition, we present the asymptotic expressions for OP and SER in the high signal-to-noise ratio (SNR) regime, from which we gain an insight into the system performance with deriving the diversity order and array gain. Moreover, based on the asymptotic expressions, we determine power allocation among the network nodes such that the OP is minimized. The analytical expressions are validated by Monte-Carlo simulations.