Effectiveness of Relay MIMO Transmission by Measured Outdoor Channel State Information

This paper investigates the effectiveness of the multiple input multiple output (MIMO) transmission with the aid of relay nodes by using measured outdoor channel state information (CSI) for the source, relay, and destination which are used in cooperative transmission. Single/multi-user MIMO (SU/MU-MIMO) systems have attracted much attention as the technology enhances the channel capacity with a limited frequency band. In this paper, cooperative transmission using the relay station is applied to SU/MU-MIMO systems: Relay MIMO transmission. Although the performance of relay MIMO transmission is affected by the actual propagation environment, the performance has not yet been investigated using measured propagation channel data in outdoor scenarios. In this paper, we demonstrate that the channel capacity with the relay MIMO transmission can be improved compared to the conventional MIMO transmission without the relay nodes, especially in multi-user scenarios. Moreover, orthogonal polarization is introduced and its effectiveness is shown in further improving the channel capacity of relay MIMO transmission.