Payam Nayeri, PhD
Assistant Professor, Adaptive Microwave & Antenna Systems Research Group
Electrical Engineering Department, Colorado School of Mines

Abstract

Digital beamforming (DBF) is the platform for smart antenna technology, and with the rapid growth of our wireless infrastructure, DBF is considered a major necessity for 5G and beyond. Adaptive algorithms coupled with these arrays enable automatic rejection of interference and can maximize the communication throughput in any dynamic environment. In general, the challenge is that hardware implementation is very high cost, and as a result very few practical implementations of digital beamformers have been reported. We propose an implementation of DBF arrays using software defined radios (SDRs). The SDR platform is a versatile, low cost solution to DBF and at the same time provides a practical testbed for rapid testing of different beamforming algorithms.

In this seminar, we outline the process of hardware implementation, synchronization, and calibration of our in-house, low-cost, digital beamformer that uses an array of NI USRP SDRs, and then present experimental results for DBF using classic techniques such as LMS, RLS, and SMI. We then extend this discussion to high-interference scenarios and show that classical approaches to DBF often cannot distinguish between the intended signal and interferences, disrupting the intended operation. We then present a novel beamforming methodology based on evolutionary search techniques that is capable of adaptive interference cancellation in high-interference environments. We present experimental results on the performance of our proposed technique using our in-house developed digital beamformer and show that our system is capable of complete interference cancellation in several high interference scenarios.

Bio. 

Dr. Payam Nayeri is an Assistant Professor of Electrical Engineering and the principal investigator of the Adaptive Microwave and Antenna Systems (AMAS) research group at Colorado School of Mines (CSM). His current research is in the areas of multifunctional and adaptive microwave circuits, adaptive beamforming, active and wideband antenna arrays, additively manufactured microwave devices, and wireless energy harvesting. He is a senior member of IEEE, and a member of URSI (Commission B), Sigma Xi, and Phi Kappa Phi, and has co-authored 3 books, and more than 80 journal and conference articles.

Email Address: pnayeri@mines.edu