An Investigation for Imperfect CSI Effects on Half-Duplex/Full-Duplex Relaying Network

This study investigates the detrimental effects of feedback delay and channel estimation error on relay-assisted network. The investigation considers that base-station communicates with the destination via half-duplex/full-duplex uni-directional non-regenerative relay terminal. Two cases are considered for the investigation. The first case assumes that the base-station → relay link is imperfect due to feedback delay and channel estimation error while the relay → destination link is perfectly acquired. In the second case, the base-station → relay link is perfectly acquired while the relay → destination link is imperfect because of the channel estimation error or feedback delay. Analytical, asymptotic, and Monte-Carlo simulations reveal that case I and II achieve the same outage performance. The channel estimation error results in system coding gain losses in low signal-to-noise ratios (SNRs) while the detrimental effects of channel estimation error become negligible in high SNRs for case I and II. In low SNR regimes, feedback delay does not have any detrimental effect on the system outage performance while it leads to system coding gain losses and saturation in high SNRs for case I and II.