Antonia Papandreou-Suppappola - US grants

EIA-0074663
Papandreou-Suppappola, Antonia
Arizona State University

POWRE: Time-Frequency Analysis of Signals with Non-Linear Structures


This proposal focuses on investigation of the feasibility of obtaining new quadratic time-frequency representations that are matched with non-linear group delay, while exhibiting a maximum concentration and reducing the effect of cross terms. In addition, this work will address a new line of research in analyzing the difficult case of multicomponent signals with different types of linear and/or non-linear structures present simultaneously. The proposed methodology will involve a matching pursuit dictionary with basis functions of different types of group delay.

Engineering - Electrical (55)

Arizona State University is fully developing and evaluating a web-based undergraduate laboratory tool in the areas of undergraduate digital signal processing(DSP), communications, image processing and controls. We have already developed and successfully tested a prototype laboratory tool (J-DSP) for use in the undergraduate DSP class. This web-based prototype supports capabilities for online signal processing simulations and provides laboratory experiences to distance learning and on-campus undergraduate students. The tool is based on a collection of novel Java applets that support a user-friendly object oriented environment. This exemplary Java software supports a simulation environment that enables students to establish and execute experiments from any computer platform that is equipped with a web browser.

This work provides significant extensions of the laboratory prototype to the other areas (communications, image processing and controls), an assessment and dissemination strategy that includes test sites, and a plan to sustain development, dissemination, and evaluation after the CCLI project. The prototype lab and the proposed extensions represent perhaps the first comprehensive effort to provide on-line lab experiences in distance learning environments. We anticipate that this novel concept can be extended to different types of subjects at different levels of education, e.g., on-line experiments at levels and topics ranging from high-school physics to community college science labs and college-level engineering subjects. The prototype J-DSP along with its proposed extensions to "hot" systems topics such as communications, image processing, and advanced controls will enable new web-course developers to seamlessly integrate online experiments to their web-course content.

0134002
Papandreou-Suppappola, Antonia
Arixozona State University

CAREER: Time-Varying Signal Processing For Wideband
Wireless Communications

New and novel signal processing and communication algorithms are required to improve the performance of wireless communications systems, and to meet major challenges that arise from the escalating demand for new higher data rate wireless technologies. These challenges include methodologies to reduce channel impairments, higher data rate and higher bandwidth requirements to provide ubiquitous access, and schemes to improve multiple access transmission. As the nature of the wireless channel is time-varying, these challenges lead to many problems such as multiple access interference and fading due to time and frequency selectivity. Thus, the channel requires two-dimensional time-frequency processing methodologies especially designed to characterize spectral changes with time. Recently, the importance of time-frequency techniques in wireless communications has successfully been demonstrated for interference suppression and channel diversity.

This research involves the development of novel time-frequency methods to address problems that surface due to the time-varying nature of the wireless channel. Specifically, these methodologies develop time-varying modulation schemes for code division and orthogonal frequency division multiple access systems, and investigate the effect of the schemes on fading distortions and multiple access interference. In addition, they design time-frequency transforms to enhance detection performance for multiple access systems and detection techniques for the new modulation schemes. They also utilize time-lag and frequency-lag techniques to jointly estimate multipath and Doppler fading parameters needed to improve detection performance at the receiver. Furthermore, they characterize wideband channels and employ the model to reduce fading and multiple access interference for broadband systems such as underwater or satellite wireless communications and third generation wideband systems. These research contributions impact the role and significance of time-varying signal processing in advancing knowledge to meet the high demands for wireless technological advances.

Signal Processing for Communications (SP-COM) is an area that focuses on re-search associated with the infrastructure, hardware, and algorithms of future generation digital communications systems. The primary objective of the CRCD/EI project is to provide scientific and investigative experiences to under-graduate students by immersing them into state-of-the-art communications and signal processing research. The methods employed to accomplish this ob-jective use curriculum strategies that include: a) immersing research-oriented modules in four existing junior and senior level classes, b) offering a new senior level undergraduate course entitled "Introduction to signal processing and communications research," c) the integration of senior-level capstone projects in the ongoing research activities of the PIs, d) the institution of summer research freshman and sophomore camps along with an outreach program. The project will impact student learning by instilling the process of scientific inquiry through a continuous research exposure in the undergraduate curriculum. Several SP-COM research topics, such as those dealing with channel equaliza-tion, source and channel coding, are immersed in courses within the framework of this CRCD project. CRCD curriculum courses and modules involve at least one self-contained computer laboratory experience. ASU's Java-DSP (J-DSP) web-based simulation environment is used for these laboratories. Students can access J-DSP on the web, perform computer laboratory exercises, and submit electronic lab reports. Significant pedagogical foundations and strategies for the transition of research to the curriculum are formed with the assistance of in-structional specialists. Dissemination and assessment strategies include: an annual CRCD workshop, a CRCD interactive web site, publications in research and education journals, industrial dissemination through industry partners.

This full-scale EMD collaborative effort involves five universities, namely, Arizona State University (ASU), the University of Washington Bothell (UWB), the University of Texas at Dallas (UTD), the University of Rhode Island (URI), and the University of Central Florida (UCF). The project involves significant educational technology innovations and software extensions that enable the ASU online prototype software Java-DSP (J-DSP; http://jdsp.asu.edu) to be used in undergraduate courses across the five participating universities. Problems that are being addressed include the delivery of technology-enhanced laboratory experiences to undergraduate students using novel Java tools, and the broad assessment of these practices across the participating universities. The project tasks and objectives include: a) software development towards producing a new delivery technology, b) considerable mathematical functionality extensions of J-DSP, c) development of laboratory exercises by all the Co-PIs at the different universities, d) a geographically-diverse assessment that involves the faculty specialists at all five universities, e) a comprehensive pilot test of a new revolutionary multi-site laboratory concept that allows students in the five universities to concurrently run real-time integrated online simulations using the planned connectivity upgrades on J-DSP, and f) dissemination and publication of all results. The educational innovation is enabling distance learners to conduct laboratories over the Internet. The concepts developed in this project are serving as a model for developing and conducting online labs in other science disciplines.

Title: Biomedical Innovations Using Implementation-Aware
Agile Sensing and Signal Processing
Abstract:
Medical condition diagnosis is heavily based on sensor measurements
and their processing. These measurements correspond to waveforms
that propagate over the complex body environment and are transformed
linearly or nonlinearly according to the characteristic environment properties.
However, the medical community does not fully exploit the potentials of
advanced processing matched to nonlinear structures or modern sensor
technologies such as waveform agility that leads to significant estimation
performance improvements. This research exploits advanced
implementation-aware sensing and processing techniques to improve
medical diagnosis by: (a) efficient processing using compressed sensing
and nonlinear time-varying spectral methods; (b) estimation of environment
descriptors and disease state parameters combined with waveform-agile
sensing; and (c) mapping estimation and waveform-agile sensing algorithms
onto field-programmable gate arrays. This framework brings revolutionary
advances in diagnosing, treating, and tracking disease states that are
otherwise difficult to obtain as advanced processing techniques are either
not available or too costly. The investigators also design on-line software
toolboxes with sensing experiments for use in outreach programs to recruit
and retain freshmen and underrepresented student populations.

The research integrates advanced signal processing, stochastic Bayesian
estimation, and waveform-agile sensing with implementation-aware
algorithms to improve estimation of disease states. The investigators study
time-frequency techniques matched to nonlinear structures to process biomedical
data. Compressive sensing methodologies are developed that reduce the
number of required measurements and allow for alternative computational
algorithms. Mathematical descriptors are designed to model disease states using
time-varying transfer functions. Sequential Bayesian techniques and waveform
adaptation are used to estimate information. Algorithm reconstruction procedures
are developed that trade high performance for reduced implementation cost.
Finally, the investigators design algorithms cognizant of complexity and memory requirements.

Engineering - Other (59)

The project, a collaboration involving Arizona State University (ASU) as the lead institution, Johns Hopkins University (JHU), University of Washington-Bothell (UWB), Prairie View A&M University (PVAMU), and Rose-Hulman Institute of Technology (RHIT), is expanding the use of an award winning software package (J-DSP) and instructional approach into a broad set of new areas including digital signal processing, earth systems and geology, renewable energy systems, arts and media, ion-channel systems, and genomics. Online modules are being designed, deployed, and assessed by a geographically-diverse multidisciplinary team. This educational technology provides free and universally accessible web-based Java software with an intuitive interface that enables instructors to create web-based lectures with synchronized online simulations and animations and to monitor student progress and preferences. It allows students, including distance learners, to conduct online laboratories and collaborate across disciplines, to perform simulations anytime anywhere, and to collaborate online with their colleagues at other universities. The evaluation effort is using self, peer, and instructor assessments to measure the quality of student learning by adapting a set of on-line assessment instruments developed on a previous grant dealing with a set of signal processing courses. The project team is working to disseminate the instructional materials by postings on the project's website and on a discipline-based site (CNX.ORG), by links with the NSDL, by faculty workshops, by conference presentation and journal publications, and by high school and industrial outreach. Broader impacts include an involvement of two MSIs, an outreach effort focused on minorities, multifaceted dissemination involving faculty workshops and web posting on several sites.

The objective of this research is to develop a novel integrative framework for advancing state-of-the-art in biomimetic signal design, underwater acoustic communications, and underwater channel modeling and processing. The challenges brought upon by the highly-distortive nature of underwater sound propagation, such as extended multipath spread, frequency-dependent path loss, and Doppler scale and nonlinear phase changes, are addressed non-invasively by utilizing marine mammal sounds that match the propagation environment. The proposed approach is to develop signal models with time-varying signatures to represent characteristic mammal sounds, design a digital communications system with channel-matched biomimetic transmission signals, characterize the underwater channel and estimate nonlinearly-changing dynamic parameters, and perform information theoretic analysis and optimal channel code design.

Transformative research emerging from integrating the use of biomimetic signals with underwater environment matched processing techniques is expected to set up set the groundwork for revolutionary advances in underwater acoustic communications. These advances will directly impact development of new communications products with applications in scientific research, ocean geology, ecology, diving safety, and maritime archeology. The technology will also impact covert underwater acoustic communications for defense, environmental monitoring or oil exploration applications.

This research will have broader impacts on scientific underwater research as it can affect future scientific discoveries and their consequential benefits to society. Furthermore, through the integration of research and education, curriculum innovations will be advanced, including an educational toolbox with web-based exercises and demonstrations offering research opportunities for undergraduate students through senior design and honors projects and providing an avenue for minority and outreach activities.