An Improved Relay Selection Scheme for FD-MIMO based System

This paper proposes an improved relay selection method in full dimension-multiple input multiple output (FD-MIMO) system. The conventional best harmonic mean (BHM) relay selection scheme was studied as an optimal method for relay selection. However, instantaneous power based the BHM method has a degradation of error performance in the channel environment where rank is not obtained. To solve this problem, this paper uses the instantaneous condition number of 3D channel environment which is defined by 3rd generation partnership project (3GPP) and 2-dimension transmit array. The proposed scheme has better error performance than the conventional scheme in a wireless channel environment with poor rank by selecting a relay through the harmonic mean of the instantaneous condition number of the wireless channel. Through the computer simulation, it is shown that the proposed relay selection scheme is efficient for the FD-MIMO system which has poor rank channel environment.