Field experiment of 8×8 line-of-sight MIMO channel improved by using reflectarray approach

This paper presents a field experiment using an 11 GHz band 8×8 line-of-sight (LOS) channel for multiple-input multiple-output (MIMO) transmission (LOS-MIMO) to verify the actual improvement in the LOS-MIMO channel when using a previously proposed reflectarray approach. For resolving the issue of the MIMO transmission in the LOS channel, we proposed a reflectarray approach and showed the effectiveness in improving the 4×4 LOS-MIMO channel based on the computer simulation in the previous studies. In this paper, after briefly describing the reflectarray effect in a LOS channel, we introduce details regarding the field experiment with a metal reflector, and a simulation that models the experiment in advance. We present analysis results of the measured data, and compared to the case without the reflector, the channel capacity of the LOS channel is improved by approximately 4.6 bit/s/Hz at 70% of the cumulative distribution function over the entire measurement course when using a reflector. These results clarify the effectiveness of the reflector in a practical environment. In addition, some differences between the simulation and experiment results are studied in this paper.