Design of optimal MIMO channel under line-of-sight environment by using directional antennas

Abstract

This paper presents a directional base station antenna for a distributed transmitting antenna arrangement to enhance the channel capacity of multiple-input multiple-output (MIMO) communication system in the line-of-sight (LOS) environment. We verify our simulation results of a ray-tracing technique under indoor environment.

Antenna arrangements realizing a unitary matrix for 4×4 LOS-MIMO system

“…Hori et al proposed the antenna arrangement for 2×2 MIMO system which is effective even in the multipath environment by utilizing a distributed antenna arrangement and directional antennas [6]. Although the unitary condition in this antenna arrangement is not guaranteed due to multipath signals when using omni-directional antennas, the channel matrix is unitary matrix and the high channel capacity is obtained even in multipath environment when the directional antennas are adopted.…”