Effectiveness of asymmetric line-of-sight MIMO transmission using millimeter-wave

Recently, microwave and millimeter-wave bands have been considered for outdoor applications to cope with the emerging increase in communication traffic. However, a higher the frequency causes larger propagation losses. Consequently, a system that uses UAVs as relay stations to communicate in a line-of-sight (LoS) environment has been studied. In such a system, the numbers of transmitting and receiving antenna elements are different. In this study, we evaluate the performance of an asymmetric LoS-MIMO system with different number of antenna elements for transmission and reception. The effectiveness of the asymmetric LoS-MIMO system is demonstrated by comparing the channel capacity pertaining to the distance between the transmitter and receiver based on a conventional symmetric LoS-MIMO system with an equal number of antenna elements.