Antenna configuration comparison in challenging NLOS locations

Abstract

The objective of this paper is to compare uplink (UL) performance with different antenna technologies when receiving Non-Line of Sight (NLOS) signal in field tests. The antenna configurations in use were a passive antenna system and an active antenna system (AAS). The radiation pattern can be controlled horizontally by changing its azimuth angle and vertically by changing the tilt angle of the antenna. AAS includes a flexible configuration that consists of diversity beams and other features for beam controlling. The field trial benefitted 2-way and 4-way receive (RX) diversity in both antenna systems. The field trial environment consists of three macro-cellular Long Term Evolution (LTE) evolved Node B (eNB) operating in 2.1 GHz band. This trial environment has two AAS and one passive system in use for the measurements. The environment can encompass one macro cell and with vertical controlling, it is possible to add an additional beam and with horizontal controlling it is possible to steer the main beam towards the user equipment (UE). Field trial used drive test software to evaluate the test network performance. Mobile network user had UE in drive testing to evaluate cellular network quality from the mobile device's point of view. The field trial results indicate that AAS beam controlling can achieve remarkable capacity gain in uplink direction when UE does not have a line of sight to the eNB.