Biography
Prof. Xiaoming Chen
Prof. Xiaoming Chen
Xi’an Jiaotong University, China
Title: Over-the-Air Testing: from 4G Terminals to 5G MmWave Base Stations
Abstract: 
In the fourth generation (4G) communications, over-the-air (OTA) testing is mainly used for performance evaluation of long term evolution (LTE) user equipment (UE), because the characteristics of the internal antennas of the UE are generally unknown or not accessible. The 4G base station (BS), on the other hand, has well defined antenna ports. Hence, the BS antennas are usually measured separately, whereas the BS without antennas is usually evaluated by conductive testing. Popular 4G multiple-input multiple-output (MIMO) OTA testing methods for LTE UEs are multi-probe anechoic chamber (MPAC), radiated two-stage method (RTS), and reverberation chamber (RC). Throughput is chosen as the performance metric for 4G MIMO-OTA testing. However, different MIMO-OTA methods and even different laboratories of the same MIMO-OTA method usually give results with noticeable differences. A generalized MIMO-OTA throughput model can greatly facilitate the MIMO-OTA harmonization work that is ongoing in the 3rd generation partnership project (3GPP) standardization. In this invited talk, we will compare the pros and cons of different MIMO-OTA methods, with a special focus on their adaptability to 5G millimeter-wave (mmWave) OTA testing. A modified version of the MPAC method is presented as a promising solution for OTA testing of 5G mmWave devices with adaptive beamforming. MmWave OTA performances and open problems are discussed in the presnetation.
Biography: 
Xiaoming Chen received the B.Sc. degree in electrical engineering from Northwestern Polytechnical University, Xi’an, China, in 2006, and M.Sc. and PhD degrees in electrical engineering from Chalmers University of Technology, Gothenburg, Sweden, in 2007 and 2012, respectively. From 2013 to 2014, he was a postdoctoral researcher at Chalmers University of Technology. From 2014 to 2017, he was with Qamcom Research & Technology AB, Gothenburg, Sweden. Since 2017, he has been a professor at Xi’an Jiaotong University, Xi’an, China. His research areas include over-the-air (OTA) testing, reverberation chambers, MIMO antennas, hardware impairments and mitigation, etc. Prof. Chen is a recipient of a national talent project in China. He serves as an Associate Editor (AE) for IEEE Antennas and Wireless Propagation Letters and received the outstanding AE award in 2018. He also received URSI (International Union of Radio Science) Young Scientist Awards in 2017 and 2018.