Ergodic Rate Analysis on Applying Antenna Selection in D2D Communication Underlaying Cellular Networks

摘要

By reusing the spectrum of a cel-lular network, device-to-device (D2D) com-munications is known to greatly improve the spectral efficiency bypassing the base station (BS) of the cellular network. Antenna selec-tion is the most cost efficient scheme for inter-ference management, which is crucial to D2D systems. This paper investigates the achievable rate performance of the D2D communication underlaying the cellular network where a mul-tiple-antenna base station with antenna selec-tion scheme is deployed. We derive an exact closed-form expression of the ergodic achiev-able rate. Also, using Jensen's inequality, two pairs of upper and lower bounds of the rate are derived and we validate the tightness of the two sets of bounds. Based on the bounds ob-tained, we analyze the ergodic achievable rate in noise-limited scenario, interference-limited high SNR scenario and larger-scale antenna systems. Our analysis shows that the presence of D2D users could be counter-productive if the SNR at cellular UE is high. Further anal-ysis shows that the relationship between the ergodic rate and the number of antennas it positive, but keeps decreasing as the antenna number increasing. These show the inefficien-cy of antenna selection in D2D interference management.