System Level Assessment of Vehicular MIMO Antennas in 4G LTE Live Networks

Abstract

In this contribution, we present the results of a measurement campaign targeting at system level evaluation of vehicular multiple-input-multiple-out (MIMO) antennas. Our measurements are performed on a test track served by a Long Term Evolution (LTE) base station operating in the 800 MHz band. We show system level evaluation results obtained by using two reference monopole antennas and two automotive qualified, integrated prototype antenna systems. The presented results are gathered in line-of-sight (LOS) as well as non-LOS conditions. As vehicular antenna systems are limited by the available integration space, we analyze the specific impact of antenna decoupling on system level performance. System level performance metrics include parameters such as ergodic capacity and condition number of the MIMO channel matrix. We achieve antenna decoupling for the reference monopoles by increasing their separation. In case of the integrated antenna system we use a decoupling branch to decrease antenna coupling and correlation at the measurement frequency. We discuss a system level evaluation process for ranking antenna systems based on channel specific parameters. The applicability of the process for MIMO system performance evaluation is shown with a comparison of an integrated antenna system with the described reference antenna system.

A Low-Profile Pattern Reconfigurable Antenna System for Automotive Mimo Applications

“…Furthermore, not only the number of mobile services is growing but also the number of antennas per service. Automotive MIMO systems [1][2][3][4] are proposed to increase the data throughput and to assure continuous reception even if the system is affected by fading. This issue is especially important since mobile communication standards are now being adapted for intelligent transportation systems (ITS) [5,6] in order to increase road safety and enable autonomous driving in the future.…”

“…A very important issue for an automotive antenna is its radiation characteristic. Currently antennas with omnidirectional radiation are used [2]. At first thought it seems to be the right choice, since signals can impinge the car from all angular directions as the car is moving and changing its driving direction.…”