A Compact Six-Port Dielectric Resonator Antenna Array: MIMO Channel Measurements and Performance Analysis

MIMO systems ideally achieve linear capacity gain proportional to the number of antennas. However, the compactness of terminal devices limits the number of spatial degrees of freedom (DOFs) in such systems, which motivates efficient antenna design techniques to exploit all available DOFs. In this contribution, we present a compact six-port dielectric resonator antenna (DRA) array which utilizes spatial, polarization and angle diversities. To evaluate the proposed DRA array, a measurement campaign was conducted at 2.65 GHz in indoor office scenarios for four 6 × 6 multiple antenna systems. Compared to the reference system of monopole arrays which only exploit spatial diversity, the use of dual-polarized patch antennas at the transmitter enriches the channel's DOF in the non-line-of-sight scenario. Replacing the monopole array at the receiver with the DRA array that has a 95% smaller ground plane, the 10% outage capacity evaluated at 10 dB reference signal-to-noise ratio becomes equivalent to that of the reference system, due to the DRA's rich diversity characteristics. In the line-of-sight scenario, the DRA array gives a higher DOF than the monopole array as the receive counterpart to the transmit patch array. However, the outage capacity is 1.5 bits/s/Hz lower, due to the DRA array's lower channel gain.