Performance Analysis of Opportunistic Transmission in Downlink Cellular DF Relay Network With Channel Estimation Error and RF Impairments

In this correspondence, we analyze the effects of radio frequency impairments and channel estimation error in a cellular decode-and-forward relay network, where multiple antennas are deployed at the base station (BS). Here, a single relay that has the best end-to-end signal-to-noise-plus-distortion-and-error ratio is selected among the available relays, which decode the BS information correctly in each transmission session. Furthermore, we derive an exact closed-form expression for outage probability and expected spectral efficiency in multiuser and multirelay scenario. In addition, simple asymptotic expression at high signal-to-noise ratio (SNR) regime is also obtained, which facilitates the characterization of the achievable diversity order of the practical cellular relay network. To validate the derived analytical expressions, we have presented simulation results, which are sufficiently tight across the entire range of SNRs. Finally, we examine the diversity order for the ideal as well as practical relaying systems.