Field Experimental Results on E-UTRA Downlink Throughput Using Polarization Diversity Antennas

Abstract

This paper investigates the effect of the antenna (polarization diversity (PD) or space diversity (SD)) configuration at evolved Node B and antenna angle of user equipment (UE) on the throughput performance of multiple input multiple output (MIMO) in Evolved UMTS Terrestrial Radio Access (E-UTRA) field experimental system. The results show that the throughput performance as a function of the measured signal-to-interference plus noise power ratio (SINR) per antenna for the PD configuration is degraded by approximately 1 dB and 3-6 dB in a 2times2 MIMO case for non-line of sight (NLOS) and line of sight (LOS) environments, respectively, and 1-2 dB in a 4times4 MIMO case for a NLOS environment, when the angle of the receiver antenna is 0 degrees due to variation in the average received power gap between vertically-polarized and horizontally-polarized waves. On the other hand, when the receiver antenna angles are 45 or 90 degrees, the throughput performance for the PD configuration is almost the same as those for the NLOS environment and is improved compared to those for the LOS environment, respectively, due to a smaller average received power gap and lower fading correlation. It is also shown that the cumulative distribution function (CDF) of the throughput performance when using the PD configuration is nearly identical to those for the 2times2 and 4times4 MIMO cases irrespective of the UE antenna angle for the NLOS environment. The CDF in this case is also better than those for the SD configuration when the UE antenna angle is 90 degrees for the NLOS environment and 45 and 90 degrees for the LOS environment.