Engineering Commons^™

Pulse Shape And Timing Dependence On The Spike-Timing Dependent Plasticity Response Of Ion-Conducting Memristors As Synapses, Kris A. Campbell, Kolton T. Drake, Elisa H. Barney Smith

Electrical and Computer Engineering Faculty Publications and Presentations

Ion-conducting memristors comprised of the layered materials Ge₂Se₃/SnSe/Ag are promising candidates for neuromorphic computing applications. Here, the spike-timing dependent plasticity (STDP) application is demonstrated for the first time with a single memristor type operating as a synapse over a timescale of 10 orders of magnitude, from nanoseconds through seconds. This large dynamic range allows the memristors to be useful in applications that require slow biological times, as well as fast times such as needed in neuromorphic computing, thus allowing multiple functions in one design for one memristor type—a “one size fits all” approach. This work also …

Development And Application Of A Standstill Parameter Identification Technique For The Synchronous Generator, Ahmed M.A. Oteafy, John N. Chiasson, Said Ahmed-Zaid

Electrical and Computer Engineering Faculty Publications and Presentations

This work presents the development of an offline standstill estimation technique, where the synchronous machine is locked at an arbitrary (but known) angle and is excited over a short period of time. The proposed time domain method requires few seconds of captured data in contrast to the well-known standard Standstill Frequency Response (SSFR) technique that could take more than 6 hours to conduct. This is based on nonlinear least squares estimation and algebraic elimination theory. The resulting algorithm is non-iterative where the data is used to construct polynomials that are solved for a finite number of roots which determine the …

A Multiband Ofdma Heterogeneous Network For Millimeter Wave 5g Wireless Applications, Solmaz Niknam, Ali Arshad Nasir, Hani Mehrpouyan, Balasubramaniam Natarajan

Electrical and Computer Engineering Faculty Publications and Presentations

Emerging fifth generation (5G) wireless networks require massive bandwidth in higher frequency bands, extreme network densities, and flexibility of supporting multiple wireless technologies in order to provide higher data rates and seamless coverage. It is expected that utilization of the large bandwidth in the millimeter-wave (mmWave) band and deployment of heterogeneous networks (HetNets) will help address the data rate requirements of 5G networks. However, high pathloss and shadowing in the mmWave frequency band, strong interference in the HetNets due to massive network densification, and coordination of various air interfaces are challenges that must be addressed. In this paper, we consider …

Silver Photo-Diffusion And Photo-Induced Macroscopic Surface Deformation Of Ge33s67/Ag/Si Substrate, M. Ailavajhala, M. Mitkova

Electrical and Computer Engineering Faculty Publications and Presentations

Ge-chalcogenide films show various photo-induced changes, and silver photo-diffusion is one of them which attracts lots of interest. In this paper, we report how silver and Ge-chalcogenide layers in Ge₃₃S₆₇/Ag/Si substrate stacks change under light exposure in the depth by measuring time-resolved neutron reflectivity. It was found from the measurement that Ag ions diffuse all over the matrix Ge₃₃S₆₇layer once Ag dissolves into the layer. We also found that the surface was macroscopically deformed by the extended light exposure. Its structural origin was investigated by a scanning electron microscopy.

High-Rate And Low-Complexity Space-Time Block Codes For 2x2 Mimo Systems, Vida Vakilian, Hani Mehrpouyan

Electrical and Computer Engineering Faculty Publications and Presentations

The main design criteria for space-time block codes (STBCs) are the code rate, diversity order, coding gain, and low decoder complexity. In this letter, we propose a full-rate full-diversity STBC for 2 × 2 multiple-input multiple-output (MIMO) systems with a substantially lower maximum likelihood (ML) detection complexity than that of existing schemes. This makes the implementation of high-performance full-rate codes feasible for practical systems. Our numerical evaluation shows that the proposed code achieves significantly lower decoding complexity while maintaining a similar performance compared to that of existing rate-2 STBCs.

A Small Acoustic Goniometer For General Purpose Research, Michael L. Pook, Sin Ming Loo

Electrical and Computer Engineering Faculty Publications and Presentations

Understanding acoustic events and monitoring their occurrence is a useful aspect of many research projects. In particular, acoustic goniometry allows researchers to determine the source of an event based solely on the sound it produces. The vast majority of acoustic goniometry research projects used custom hardware targeted to the specific application under test. Unfortunately, due to the wide range of sensing applications, a flexible general purpose hardware/firmware system does not exist for this purpose. This article focuses on the development of such a system which encourages the continued exploration of general purpose hardware/firmware and lowers barriers to research in projects …

Channel Estimation, Carrier Recovery, And Data Detection In The Presence Of Phase Noise In Ofdm Relay Systems, Rui Wang, Hani Mehrpouyan, Meixia Tao, Yingbo Hua

Electrical and Computer Engineering Faculty Publications and Presentations

Due to its time-varying nature, oscillator phase noise can significantly degrade the performance of channel estimation, carrier recovery, and data detection blocks in high-speed wireless communication systems. In this paper, we analyze joint channel, carrier frequency offset (CFO), and phase noise estimation plus data detection in orthogonal frequency division multiplexing (OFDM) relay systems. To achieve this goal, a detailed transmission framework involving both training and data symbols is presented. In the data transmission phase, a combtype OFDM symbol consisting of both pilots and data symbols is proposed to track phase noise over an OFDM frame. Next, a novel algorithm …

Dynamic Phase-Control Of A Rising Sun Magnetron Using Modulated And Continuous Current, Sulmer Fernandez-Gutierrez, Jim Browning, Ming-Chieh Lin, David N. Smithe, Jack Watrous

Electrical and Computer Engineering Faculty Publications and Presentations

Phase-control of a magnetron is studied via simulation using a combination of a continuous current source and a modulated current source. The addressable, modulated current source is turned ON and OFF at the magnetron operating frequency in order to control the electron injection and the spoke phase. Prior simulation work using a 2D model of a Rising Sun magnetron showed that the use of 100% modulated current controlled the magnetron phase and allowed for dynamic phase control. In this work, the minimum fraction of modulated current source needed to achieve a phase control is studied. The current fractions (modulated versus …

Power Control And Beamforming Design For Swipt In Af Two-Way Relay Networks, Wei Wang, Rui Wang, Hani Mehrpouyan, Guoan Zhang

Electrical and Computer Engineering Faculty Publications and Presentations

In this paper, we study the problem of joint power control and beamforming design for simultaneous wireless information and power transfer (SWIPT) in an amplify-and-forward (AF) based two-way relaying (TWR) network. The considered system model consists of two source nodes and a relay node. Two single-antenna source nodes receive information and energy simultaneously via power splitting (PS) from the signals sent by a multi-antenna relay node. Our objective is to maximize the weighted sum power at the two source nodes subject to quality of service (QoS) constraints and the transmit power constraints. However, the joint optimization of the relay beamforming …

Modeling Of Mzm-Based Photonic Link Power Budget, Kehan Zhu, Cheng Li, Nan Qi, Marco Fiorentino, Raymond Beausoleil, Vishal Saxena

Electrical and Computer Engineering Faculty Publications and Presentations

An accurate methodology for analyzing the Mach-Zehnder modulator (MZM) based optical link power budget is presented. It optimizes the transceiver’s system-level performance to meet the specifications of the optical links with N-level (N=2,4,8) pulse amplitude modulation format for high-speed signaling.

Seeing In The Dark And Through Walls: Using Ir Cameras In Stem Outreach, Thad B. Welch Iii, Andres Valdepena Delgado, Morgan Brimstein, Drew Buckmiller, Ryan Schwartz, Donna R. Welch, Rhett James Edwards

Electrical and Computer Engineering Faculty Publications and Presentations

The recent introduction of affordable infrared (IR) cameras and IR imaging attachments for smartphones has provided a unique opportunity to enhance the education of K-12 students. We have acquired a number of different IR cameras and IR camera attachments and discuss the utilization of these devices in both a college course and in our STEM and STEAM outreach efforts. While our outreach efforts have placed us in a classroom for just an hour or two at a time, thanks to local IEEE Chapter support, we have placed IR cameras in these classrooms for several weeks at a time.

This paper …

Energy Efficient Switched Parasitic Array Antenna For 5g Networks And Iot, Ahmed Kausar, Hani Mehrpouyan, Mathini Sellathurai, Rongrong Qian, Shafaq Kausar

Electrical and Computer Engineering Faculty Publications and Presentations

This paper includes design and implementation result of an adaptive beam forming antenna for upcoming 5G and Internet of Things (IoT). Switched parasitic array antennas are low cost, small sized and compact circular array antennas that steer beam in a desired direction by variation in switching pattern of parasitic elements. The proposed antenna design has an active center element, which is surrounded by several symmetrically placed parasitic elements. The designed antenna has a gain of 8 dB and is capable of 360 degrees beam steering in steps of 60 degrees each. Simulations are validated with results of the fabricated antenna. …

Timing And Carrier Synchronization In Wireless Communication Systems: A Survey And Classification Of Research In The Last 5 Years, Ali A. Nasir, Salman Durrani, Hani Mehrpouyan, Steven D. Blostein, Rodney A. Kennedy

Electrical and Computer Engineering Faculty Publications and Presentations

Timing and carrier synchronization is a fundamental requirement for any wireless communication system to work properly. Timing synchronization is the process by which a receiver node determines the correct instants of time at which to sample the incoming signal. Carrier synchronization is the process by which a receiver adapts the frequency and phase of its local carrier oscillator with those of the received signal. In this paper, we survey the literature over the last 5 years (2010–2014) and present a comprehensive literature review and classification of the recent research progress in achieving timing and carrier synchronization in single-input single-output (SISO), …

A Teacher’S Journey Integrating Engineering In A Middle School Science Classroom And The Effects On Student Attitudes (Rtp), Christie Jilek, Noah Salzman

Electrical and Computer Engineering Faculty Publications and Presentations

As teachers are encouraged to help students become problem solvers, incorporating engineering methods into the classroom has become an important theme of conversation. The purpose of this paper is to explore the change in student attitudes when integrating engineering instruction within a middle school science classroom. This study involves 8th grade students located within a single science teacher’s classroom exploring the integration of engineering activities and content for the first time. We assessed student attitudes using a survey constructed by the Friday Institute¹ aimed measuring perception toward STEM related fields and study. Surveys were administered before and after engineering …

Connecting Hardware And Software In A Middle School Engineering Outreach Effort-Rtp, Noah Salzman, Sin Ming Loo

Electrical and Computer Engineering Faculty Publications and Presentations

Recent years have seen tremendous growth in outreach programs aimed at bringing computer programming to children and young adults via in-class and extracurricular coding activities. Programs such as the Hour of Code and Girls who Code have introduced millions of young people to programming around the world. For this study, we explored how combining programming with interactive electronics hardware can create a more engaging and dynamic learning environment for some students than what programming alone can achieve.

In this paper, we describe an electrical engineering outreach effort in collaboration with the technology and engineering teacher at a local middle school. …