1. Computational Models of the Human Auditory System Prof. S. Shamma   Over the last few years, Prof. Shamma's group has conducted summer projects for high school students and has also had several undergraduates from the University participate in a variety of projects dealing with how the auditory system processes sound, from the ear up to the brain. Projects suitable for RITE participants are those involving the use of an extensive library of auditory signal processing algorithms and graphics dedicated to speech and music analysis and editing. Developed in MATLAB at the University, the package includes help and graphics features, as well as sophisticated interfaces and interactive capabilities that make it particularly easy to use by undergraduates. In using this software, students focus initially on the basic description of the processing stages and their underlying concepts, treating the computational elements as black boxes. They learn first how to perform various useful operations on sound signals such as transformations between time and frequency domains, conditioning, morphing sentences into each other, and altering voices. Once they acquire familiarity and facility with the package, they move on to examine the underlying principles behind each command and operation. In the process, students learn how to use MATLAB commands, various linear system concepts and operations, filtering, and some nonlinear transformations. In many cases, particularly interested and bright students may go on to create new algorithms (albeit simple), to modify existing ones, or to invent new applications ranging from recognition of musical instruments to the synthesis of music and speech. The projects described above are fully supported by extensive computational and laboratory facilities at the Neural Systems Laboratory.   Among Prof. Shamma's past undergraduate research interns are M. Ensor (Berkeley, then Lucent Bell Labs), S. Sujon (Exxon Corp), G. Chettiar (IBM), Philip Wiser (Stanford), and Isaac Brownell (Baylor School of Medicine).   Last summer, Professor Shamma supervised Matt Guyton (University of Maryland) with his project "Auditory Measures of Speech Intelligibility." Matt received the most promising award during the RITE Site fair.   2. Fiber Optics Based ATM Network Prof. M. Dagenais   The goal of this project is to design and implement a fiber optics based optical ATM network for transport of voice, video, and data. The research issues include studying different interfacing approaches to the present telephone network. It also includes understanding the best approaches to line aggregation, transport across different types of networks, and ensuring quality of services. The technical issues will involve digitizing the phone signal, doing the segmentation and reassembly of ATM cells using available chips, recovering the signal, including clock and data recovery. Other issues involve the design of optical transmitters and receivers, and the interfacing with the optical network. The underpinning goal of the project is to make it inexpensive so that this technology will one day appear in the residential premisses.   The idea is to offer an inexpensive approach for providing internet access, enhanced phone services, and high quality video using fiber optics technology. The student will become familiar with fiber optics technology, including semiconductor lasers, detectors, optical fibers, connectors, transmitters and receivers, in addition to learning about networks from the physical layer to issues related to network control, protocols, and quality of services. This is a hands-on project, which will lead to building up a real optical network.   Professor Dagenais will direct this project. Professor Dagenais has extensive experience with optical components and fiber optics technology. He directs the Photonic Switching and Integrated Optoelectronics Laboratory. He is also Director of the NSF sponsored Center for Optoelectronic Devices, Interconnects, and Packaging. Last year, Dr. Dagenais directed two students from the Woman in Engineering Program on testing and characterization of optoelectronic components and the study of reliability of semiconductor lasers. One of these two students is now doing her Graduate work at Stanford University, and the other one is now an engineer working for TRW.   During Summer, 1998, Professor Dagenais worked with Susan Tsao and John Kim (University of Maryland) in the RITE Site program. Jitter, which is the variation in packet inter-arrival time, is a crucial quantity affecting the perceived quality of voice. IP Telephony, or voice over IP, is the real-time delivery of voice signals across a computer network using the Internet protocols. An experiment was conducted to study the degradation of narrow-band speech quality in the presence of network congestion with respect to jitter, delay, and packets loss. Our results demonstrated that multiple packet drops due to heavy traffic resulted in degraded voice quality and even missing voice segments.   3. GPS Based Location Determination Prof. P. S. Krishnaprasad   Building on work done under an undergraduate research project on GPS-aided motion control (ENEE 418G) during Spring 1997, and an undergraduate advanced special topics course on Global Positioning System -Theory and Technology (ENEE 469G) during Fall 1997, it is planned to set up during Spring 1998, the nucleus of a laboratory for research in global positioning system (GPS) design, algorithms signal processing techniques and software and allied wireless communication technology (transceiver chip-sets, modems, etc.). Funding for such a GPS-lab has been received, and by June 1998 an operational rover/base-station pair of communicating GPS receivers capable of receiving and (differentially) processing the L1, L2 carriers and C/A and P codes will be in place. The rover receiver will be installed on a mobile robotic platform. It is proposed that under the auspices of RITE site, two (2) undergraduate students be funded to take part in a project on GPS-aided location determination and navigation of the mobile robot. GPS represents a remarkable integration of several major advances in the field of electrical engineering--from satellite communication, coding, estimation of signals in noise, to real-time signal processing via fast, low power circuitry on portable devices--providing us the capability to determine with increasing precision and accuracy, the location and speed of a GPS-equipped platform practically anywhere on earth. Emerging practical applications of this technology range from high accuracy surveying for geographical information systems (GIS), high-precision geodesy for earth science, to accurate navigation and flight control of aircraft, personal and commercial land vehicles, autonomous farm equipment, autonomous mobile robotics, to name a few. Bringing this technology to the attention of undergraduate students would be useful in strengthening the empirical base and technical preparedness of a typical student.   It is expected that initially, work in the proposed project would emphasize a view of the integration of subject matter inherent to GPS, demonstrating how systems concepts, such as filtering algorithms (e.g. Kalman filters and various nonlinear filters), mathematical descriptions of orbital mechanics of satellites, and differential or interferometric techniques, and phase tracking techniques contribute to the advances in precision and accuracy achievable via GPS. Electrophysical aspects with an impact on a variety of noise/error phenomena (ionospheric distortions, foliage-induced loss-of-lock and multipath) have to be dealt with properly in a successful GPS system. The project will also provide opportunities for studying applications of GPS to motion control, and in this context also investigate integration of a variety of other sensor technologies (example inertial and optical/acoustic proximity sensors) with GPS for this purpose.   Students selected under the RITE site program will be able to pursue software development in this arena (with interesting challenges in integer optimization for phase ambiguity resolution, cycle slip detection and mode switching in satellite tracking). A primary goal of the project will be for students to learn the principles and carry out implementations of motion determination algorithms based on filtering and estimation theory and gain a better appreciation of issues in signal processing influenced by noise characteristics associated to the GPS system. The GPS laboratory will also provide opportunities and stimulus to students interested in the development of new RF electronics.   4. Line-of-Sight Optical Communication Links Prof. C. C. Davis   With the crowding of the electromagnetic spectrum with RF and microwave emissions and the need for regulated spectrum allocation, there has been recent renewed interest in laser-based line-of-sight optical links for both military and industrial uses. These links offer high data rates (>1Gb/s) over modest ranges of a few kilometers, as well as intrinsic security. They operate over modest ranges in all but the most severe conditions of atmospheric obscuration. The project goal is to parameterize the performance of such links so that inexpensive, high performance systems can be deployed for industrial and military uses. As an adjunct, a real, multi-kilometer link testbed will be built for long term studies of atmospheric turbulence and its effects on line-of-sight links.   A number of ongoing experiments are ideal for undergraduate participation. The current test setup uses a water-filled, heated tube to mimic the effects of a kilometer-length atmospheric path that can generate turbulence conditions ranging from weak to strong. The type of experience that RITE participants would obtain in the laboratory is best illustrated by the work of Julie Freidlin, an former undergraduate member of the research team. Julie designed the mounts to hold the turbulence tube and supervised their manufacture. She also designed and built a variable gain optical receiver and is currently writing code to collect and analyze data.   Undergraduate students have consistently contributed to Prof. Davis' research projects. They have built lasers and electronic systems, worked on user-friendly interfaces for experimental control and data collection, and performed data analysis. A few examples follow. Dennis Crain (currently at NASA Goddard Space Flight Center) built a temperature monitoring system using high impedance thermistors and wrote the data acquisition software. His systems are used in collaborative projects with the FDA and the Polytechnic University. Brett Gidge (currently with Wilcoxon Research) worked on LABVIEW interfaces for temperature monitoring. Cyril Spiro (currently in medical school) worked on exposure systems for ELF magnetic field exposure of biological samples and their computer interfaces. George Craig (currently with Arthur Anderson Consulting) was the first undergraduate to work on the line-of-sight link project. He worked on the construction of optical detector systems and wrote computer code for data acquisition and graphic display.   During the first RITE Site program, Summer 1998 Professor Davis worked with two undergraduates (Ronald de Guzman, GWU, and David Wenzel, University of Virginia) on "Characterization of an Optical Communications Channel." David continued his work with Professor Davis during the 1998-99 academic year.   5. Low-Power, High-Speed Electronics Prof. C.-H. Yang   Silicon-based integrated circuits dominate electronics, simply because silicon and the matching insulator, SiO2, are stable. Materials of higher electron mobility are preferable to silicon in low-power, high-speed telecommunications. In the past, the use of these high-mobility materials, e.g., GaAs, has been limited, however, by the lack of a device-quality oxide. We have found a new process of forming device-quality aluminum oxide on top of GaAs with acceptable interface density of states. This proposed research project is to systematically refine the fabrication procedure and to characterize these new low-power, high-speed transistors.   6. Mapping DSP Dataflows into Software Implementations Prof. S. Bhattacharyya   Due to the emergence of highly cost-effective programmable digital signal processor products such as the Motorola 56000 family and the Hitachi SH-DSP, and due to the increasing support for DSP functions in general-purpose microprocessors, the role of software has become very significant in DSP system implementation. A major challenge facing designers of real-time signal processing software is the rapidly increasing complexity of deriving sufficiently predictable and optimized code. In low-cost, consumer-oriented application domains such as wireless communications, extremely competitive time-to-market pressure together with the continually escalating complexity of applications and processor architectures require companies to sustain enormous human resource expenditures for software and firmware development. Similarly, in performance-oriented applications such as PC multimedia technology and radar signal processing, it remains a significant challenge to partition programs and manage interprocessor communication in a manner that efficiently exploits multiprocessor systems. Over the past several years, it has become widely recognized that dataflow is an attractive specification model for DSP system design. This period has witnessed the emergence of several dataflow-based commercial tools for DSP design such as SPW from Cadence and COSSAP from Synopsys, and research-oriented tools that incorporate dataflow such as Ptolemy, Descartes, and GRAPE from universities. Important advantages of dataflow programming models for DSP include support for efficient verification techniques; the ability to expose coarse-grain structure in applications, which can be exploited to synthesize more efficient software or to predict performance more accurately; and intuitive appeal, which stems from the amenability of dataflow to a visual programming style. Despite these advantages, the use of dataflow-based programming environments for DSP is restricted largely to simulation and rapid prototyping, while final implementations are derived by arduous hand-coding and manual optimization in assembly language or C.   This project seeks to thoroughly explore the potential of dataflow-based programming and software synthesis for DSP by investigating effective techniques for mapping dataflow computation models onto uniprocessor and multiprocessor architectures, and implementing prototype programming tools that incorporate dataflow computation models in an intuitive and efficient manner.   The efforts on uniprocessor and multiprocessor software synthesis strategies will involve extensive use of simulators to expose insights into the underlying problems and to validate the results that are developed. In addition to providing valuable intuition about software synthesis trade-offs, the development and use of such simulation tools can be a highly effective means for introducing students to research issues in embedded software implementation. An additional aspect of this project that is suitable for a RITE participant is the development of dataflow models for practical DSP applications, such as filter banks and sound synthesis systems. Such modeling work will give students hands-on experience with leading-edge software design approaches for practical applications, while providing realistic benchmark examples to evaluate the software synthesis strategies developed.   7. Multimedia Encoding for Heterogeneous Networks Prof. N. Farvardin   The increasing demand for multimedia services and the expansion and inter-networking of a variety of transmission links (e.g., twisted-pair copper wire, cable, optical fiber, satellite and cellular systems), place new constraints on the capabilities of signal compression and encoding systems needed for the multimedia communications of the future. In particular, there is great need for signal (voice, image and video) compression and encoding systems that are: scalable -- both in encoding rate and in resolution, {robust} with respect to transmission noise (especially for the wireless part of the network), simple (for transcoding), and implementable in real-time using general purpose processors or digital signal processors. The development and analysis of encoding algorithms which offer some or all of the above-mentioned capabilities is the subject of intensive on-going research in the Department. Many components of this research activity, such as real-time implementation of algorithms on DSP chips and development of fast algorithms, are suitable projects for undergraduate students. In addition, this project nicely lends itself to multimedia applications over the Internet. Typical subprojects include the real-time implementation of video compression on a DSP board, the study of fast vector quantization algorithms for wireless multimedia transmission on portable computers, and the development of Java applets for scalable image browsing over the Internet.   Prof. Farvardin is, and has been, heavily involved with supervising undergraduate research. In the recent past he has supervised three undergraduate students: Jerome Johnson (moving target detection), James Sfekas (low-complexity motion estimation in video coding) and, Stephen Neuendorffer (real-time, software-only video compression using vector quantization). Further, Rajarshi Gupta (currently at UC Berkeley) and Michael Neely (currently at MIT) just completed a project on the DSP implementation of a novel moving target recognition scheme, and Arnold Liu (currently at Stanford) just completed a progressive compression scheme for image browsing over the Internet. Another prominent example of Dr. Farvardin's efforts in undergraduate research is a project on the real-time implementation of a wavelet based video compression algorithm on a Texas Instruments parallel processing development system. This project, which received the American Division Award of the 1995 Texas Instruments DSP Solutions challenge, involved one graduate student and two undergraduates: J. Johnson (EE Honors student) and R. Bhattacharya (EE undergraduate; now pursuing a M.S. degree in the Department).   Last summer, three RITE participants worked on (i) an algorithm for optimal inverse filtering of wavelet coefficients in an image coding system (Jarriel Cook, University of Maryland) , (ii) an algorithm for improved motion estimation in video compression (Teen Sheng, University of Maryland and winner of the 1998 RITE Best Project Award) and (iii) simulation of a wireless network which allows for a tradeoff between the quality of service and network traffic Alan Leung, RPI). Both Teen Sheng and Jarriel Cook continue to work with Prof. Farvardin.   8. Rapid Prototyping of Low-Power/High-Performance VLSI Systems for DSP Applications Prof. K. Nakajima   Low-power and high-performance DSP processors are essential in the development of telecommunications hardware such as Personal Communication System (PCS) devices and Personal Handy System (PHS) devices. This project is motivated by recent advances in DSP design methodology that utilize a multi-rate approach for designing fast DSP chips with low power consumption. The objective of the project is to develop an integrated design automation toolbox for the rapid prototyping of these chips. Subprojects suitable for RITE activities will involve DSP algorithm development (e.g., reformulation of DSP algorithms and their software implementation to incorporate multirate techniques), VLSI design (e.g., full custom design of sample DSP chips including MCM implementation and measurement of area/speed/power consumption) and VLSI CAD software development (e.g., development of a programmable module generator). By participation in this project, undergraduate students will have a rare opportunity to appreciate the importance of a team-based approach to integration of theory, hardware, and software into a real-world application domain.   Professor Nakajima is, and has been, actively involved with supervising undergraduate research and design projects. Currently, he is supervising Daniel Roddy (senior, DSP chip design) and training four other undergraduate students, Harry Stello, Shin Wu, Siming Ye, and James Yeung, in his full custom digital VLSI system design laboratory course, also seven undergraduate students, Michael Doster, David Hawk, Shiloh Heurich, Ken Kissel, Davor Mrkoci, Harry Stello, and Siming Ye, in his HDL-based high-level digital system design laboratory course. Last year, Ilya Khazanov (currently, a M.S. student in the Department) completed a 1.2 micron CPU chip design project with Daniel Roddy (senior), and Jonas Keating (currently at Microsoft) and Pei-Ta Chu (currently at Price Waterhouse) finished another 1.2 micron CPU chip design project.   As a participating faculty in the RITE Site program, Professor Nakajima supervised three undergraduate students (Dan Roddy and Justin Bowlus, University of Maryland, and Mikhail Itskovich, University of Virginia) on the project, "Design of Plastic Cell Architecture."   9. Real-Time Operating Systems for Digital Signal Processors Prof. D. Stewart   The heart of any portable telecommunications device is an embedded processor, which executes the software that implements communication and DSP algorithms. To keep the cost of these devices reasonable, low cost microcontrollers and digital signal processors (DSP) are used, rather than modern state-of-the-art RISC processors. Commercial real-time operating systems (RTOS), however, focus on the more modern processors.   There is a need for similar technology in the low-end embedded microcontroller and DSP markets. In particular, microcontrollers and DSPs do not have good hardware support for preemption, thus preemption is too costly. Furthermore, they have severe memory limitations, and operating system overhead is often viewed as too costly, since even simple operations like a 16-bit addition can take 10 microseconds. This research project in the Software Engineering for Real-Time Systems (SERTS) laboratory focuses on developing RTOS technology, both at the kernel level and at the development tool level, that focuses on embedded processors used in the telecommunications industry. Many components of this project are suitable for RITE activities, including alpha testing and debugging, porting to different processors, and graphical user interface design for the development tools.   Prof. Stewart joined the Department recently and has already established a strong program for undergraduate projects. He leads the Pinball Machine Project, an interdisciplinary advanced team project, which brings together 20 students per semester in electrical, computer, and mechanical engineering, to not only design, but also build a pinball redemption machine. Although this project is offered as a course, many aspects of the project require the same skills and provide the same experience needed for a career in research. For example, one of the sub-projects is to develop a video system based on a Texas Instruments TMS320 processor to track a pinball, and communicate with control software to have the machine play on its own. An automated play system can then be used for stress-testing these electro-mechanical systems. The control software for this machine uses an embedded microcontroller, similar to those found in hand-held telephones, to read switches and sensors, and control lights and solenoids. The prototype machine developed by students is already being used to test some features of the non-preemptable RTOS project described above.   During the summer RITE program, Professor Stewart supervised four RITE Site students on two separate project. Melissa Moy and Tom Carley (University of Maryland) on "Echidna: A Reconfigurable Real-Time Operating System for Digital Signal Processors", for which they won the Best Project Award during the RITE Site fair. Lesley Leposo (Carnegie Mellon) and Zeggai Andemariam (RPI) work on "Object-based design of device drivers for Real-Time Operating Systems: A remote controlled embedded system."   10. Self-Consistent Spectrum Analyzer for Fiber-Telecommunications Prof. C.-H. Yang   Wavelength division multiplexing (WDM) is now widely used in telecommunications for their versatility: multiple-color lights share the same optical fiber without interference, and that effectively increases the bandwidth. The transmission and receiving of the lights are still troubled, however, by the lack of stability. We have developed a miniature spectrum analyzer, only 1" X 1" X 3" in size, that can automatically detect the spectrum and feedback to the laser transmitter and receiver for self-tuning. It also offers low-cost diagnosis of the status of the fiber system. All of the enabling technologies are readily available, including Fourier Transform spectroscopy, broad band infrared detector, tunable infrared laser, and computing. The research requires expertise in using the PC, computer interface, optics, and electronic circuits.   11. Source Separation Using Information Theoretic Methods Prof. P.S. Krishnaprasad   12. Studies of Vacuum Electronic Amplifiers for Chaotic Communications Prof. Tom Antonsen   High power vacuum electronic amplifiers are candidate sources for high frequency digital communication systems. The manner in which these amplifiers are used will be affected by the nonlinear properties of the amplification process. For conventional modulation schemes nonlinearity causes distortion. Alternatively, it has been suggested that modulation of the carrier signal can be achieved by allowing the source to oscillate chaotically but be controlled small perturbations of system parameters. The proposed student research project would entail developing models to characterize the nonlinearity and time domain properties of a high power chaotic traveling wave amplifier.   13. Virtual Indoor Wireless Laboratory Profs. A. Papamarcou and J. Gansman   The Indoor Wireless Project is a recently initiated effort to educate seniors and beginning graduate students in the fundamentals of wireless communication technology. The project, which is supported by the NSF Combined Research-Curriculum Development Program, aims at designing, implementing and testing a local-area wireless network for data transfers, voice communication, and video transmission. The network is developed on programmable DSP platforms, which are flexible enough to allow experimentation with different algorithms and protocols in the baseband frequency range. The project is offered as a 400-level course in the EE curriculum, with expected enrollment of 24 undergraduate and graduate students per semester. NSF funding (with cost sharing by the University) will sustain the project through its three-year development phase, after which it will become an integral part of the EE curriculum. The Indoor Wireless Project will offer RITE participants an exciting opportunity to develop a virtual laboratory mirroring the physical project platform. The finished product will simulate network components (base station, portables, etc.) and their subsystems, and will be accessible to distant users via the World Wide Web. By activating appropriate blocks, users will be able to monitor different signals (waveforms, audio, video) as they are generated, transmitted and received, and to also benchmark the performance of the system. In designing the virtual lab, RITE participants will become familiar with a wealth of system operations such as signal compression/decompression, equalization, baseband multipath mitigation, error control coding/decoding, as well as control/routing signaling (including retransmission control and multiple access). Although some conceptual understanding of these operations will be required at the outset, the analytical complexity of this collaborative task will be rather low, and as such, appropriate to the participants' expertise.   During the Summer of 1998, Professor Papamarcou supervised three University of Maryland students (Meenakshi Narayana, Jeffrey Hazen and Julian Requejo) on their project, "Trade off between speech compression and channel coding for a fixed transmission rate."   14. Advanced Components for Mobile and Optical Communication Systems Profs. K. Zaki and A. Iliadis   In this project Micro-Electro-Mechanical Systems (MEMS) technology is employed to miniaturize antennas for mobile communication platforms. Antennas will be modeled and their design optimized for sizes suitable for monolithic integration with personal communication cards and hand held units. Emphasis is placed on developing new geometries and using novel materials deposited by Pulsed Laser Deposition (PLD) such as oxides and metallic compounds, both for the efficient propagation and containment (shielding, isolation) of the signals. MEMS technology and PLD deposition will be applied for the processing and fabrication of these "chip" form antennas.   Current mobile communication hand held units use an analog front-end receiver/transmitter amplifier design that down-shifts (or up-shifts for emission) to an intermediate frequency compatible to the digital signal processor (DSP) unit that then processes the in-coming (or out-going) signals. In this project we study the conditions under which the DSP can be brought to the front end of the system, the specific requirements of the system in terms of shielding, power, and frequency response.   Students will have the opportunity to learn the intricate details of antenna design, use software to model and simulate wave propagation, develop processing and fabrication skills, and understand the properties of novel materials critical to the development of the next generation of microelectronics systems. Furthermore, students will examine and evaluate different circuit design approaches, introduce novel absorbing and shielding materials, and interact with industry.   14. Ultra-Violet/Blue/Infra-Red On-Chip Light Emitters and Optical Interconnects Prof. A. Iliadis   In this project emphasis is placed in developing light emitting devices from wide band gap materials such as GaN, SiC and ZnO on silicon chips for surface and in-plane emission. Silicon-on-insulator (SOI) will be used to provide optical interconnection for in-plane emission, by optical guiding and switching of the optical signals. The light-emitting devices and on-chip optical guides and switches will be modeled and optimized using design software, critical points of interaction for efficient propagation will be identified, and an optimized design will be proposed.   The light emitters will be deposited by Pulsed-Laser-Deposition (PLD), and the emitters and optical guides will be processed and fabricated using standard hotolithographic techniques and processing. Students will have the opportunity to develop an understanding of light generation and propagation through multilayered structures, the properties of these new and exciting light emitting semiconducting materials, improve their skills in processing and fabrication of relaxed geometry devices, and interaction with industry interested in optical communication and computer systems.