August 07, 2017

Wireless MIMO Base Station Near and Far Field Measurement Challenges

  • Moongilan D.

Wireless communication systems use Multiple Input Multiple Output-antenna techniques to increase coverage, data throughput and spectral efficiency. Often beam forming techniques are used to provide additional antenna gain relative to Single Input Single Output systems. Regulatory compliance radiated emissions tests for wireless devices are performed using a single measurement antenna at a specified measurement distance. Radiated measurements above 1 GHz at 3 meters test distance create further complications because long conductors and slots generate near-field radiation conditions beyond 3 meters. This paper examines of near and far-field conditions for MIMO antenna system and suggests how radiated emissions testing could be improved.

View Original Article

Recent Publications

January 01, 2018

Fair Dynamic Spectrum Management for QRD-Based Precoding with User Encoding Ordering in Downstream G.fast Transmission

In next generation DSL networks such as G.fast, employing discrete multi-tone transmission in high frequencies up to 212 MHz, the crosstalk among lines reaches very high levels. To precompensate the crosstalk in downstream transmission, QRD-based precoding has been proposed as a near-optimal dynamic spectrum management (DSM) technique. However, the performance ...

January 01, 2018

Practical Mitigation of Passive Intermodulation in Microstrip Circuits

This paper presents new experimental evidence and a novel practical approach for mitigation of passive intermodulation (PIM) in microstrip circuits fabricated on commercial printed circuit board laminates. The mechanisms of distributed PIM in microstrip circuits are reviewed and a phenomenology of PIM generation due to locally enhanced electromagnetic fields at ...

January 01, 2018

Efficient Cooperative HARQ for Multi-Source Multi-Relay Wireless Networks

In this paper, we compare the performance of three different cooperative Hybrid Automatic Repeat reQuest (HARQ) protocols for slow-fading half-duplex orthogonal multiple access multiple relay channel. Channel State Information (CSI) is available at the receiving side of each link only. Time Division Multiplexing is assumed, where each orthogonal transmission occurs ...