The overall mission of the Electrical Engineering Research Laboratory (EERL) is to engage in both dedicated and interdisciplinary research studies in areas related to electromagnetic wave engineering. Examples occur in electronics, telecommunications, radar signatures, remote sensing, optical communications, and other high frequency applications. Much of modern communications technology, from signaling between transistors inside a single integrated circuit over distances of only 10-6 m, to that between satellites and the earth over distance greater than 107 m, is based on the understanding of electromagnetic interactions. The fundamental mission of the EERL is to expand our understanding of such interactions, and to seek new applications of the knowledge so generated. These goals are accomplished through the development of fast computational algorithms for the simulation of electromagnetic phenomena, through new performance prediction methodologies, and through the characterization of transmission channels in mobile/personal satellite communication systems.
This Year's Achievements:
Under funding from the Air Force Non-Cooperative Target Identification (NCTI) program and DARPA's Moving and Stationary Target Acquisition and Recognition (MSTAR) program, we continue the development of the high-frequency radar simulation code XPATCH, which has been distributed to over 350 governmental and industrial organizations to date. The common goal of these two projects is to create fast computer simulation of radar signatures of numerous airplanes and ground targets. Characterization of the Earth-satellite radio propagation channel to enable optimal utilization of limited radio spectrum resources is also under intense study. Through photogrammetric techniques, 3D computer models of an urban setting are being constructed from a sequence of video images taken from an automobile. The 3D model is then used to carry out a full-scale electromagnetic simulation to generate the wireless propagation characteristics of urban environments. Information including cell coverage, fade statistics and delay spread are being generated for the city of Austin. For shorter range communication links and wireless LANs, extensive field trials using our 900 MHz smart antenna test-bed have been used to obtain significant results on vector channel propagation characteristics in various typical wireless communications scenarios. Within electronic systems, interconnect-induced cross talk and signal integrity issues are also under study. During the last year new simulation techniques for the efficient calculation of interconnect and lossy transmission line parameters have been developed for use in design of mixed signal integrated circuits and systems.
The telecommunications industry is one of the key growth sectors of the economy. The demand for personal wireless communications for anyone, anywhere, anytime will continue to grow and with it the demand for greater knowledge of the channel and better ways to exploit its characteristics. Satellite services are a major component of the International/National Information Infrastructure. Our propagation studies will continue to play a critical role in expanding the application of wireless telecommunications technology, and we hope to develop our image processing system into a commercial product. In addition, our work on interconnect/IC packaging modeling should also be of interest and use to both local and national semiconductor companies, especially as higher speed/frequency mixed analog/digital IC designs are attempted.
1. R. Bhalla and H. Ling, "Image-domain ray-tube integration formula for the shooting and bouncing ray technique," Radio Science, vol. 30, pp. 1435-1446, September-October 1995.
2. L. C. Trintinalia and H. Ling, "Super-resolved time-frequency parameterization of electromagnetic scattering mechanisms due to structural dispersion," Microwave Optical Tech. Lett., vol. 10, pp. 82-84, October 1995.
3. L. C. Trintinalia and H. Ling, "Interpretation of scattering phenomenology in slotted waveguide structures via time-frequency processing," IEEE Trans. Antennas Propagat., vol. AP-43, pp. 1253-1261, November 1995.
4. H. Kim and H. Ling, "A fast multiresolution moment method algorithm using wavelet concepts," Microwave Optical Tech. Lett., vol. 6, pp. 317-319, December 1995.
5. L. C. Trintinalia and H. Ling, "Extraction of waveguide scattering features using joint time-frequency ISAR," IEEE Microwave and Guided Wave Letters, vol. 6, pp. 10-12, January 1996.
6. R. Bhalla, H. Ling and H. Nussbaum, "Multi-aspect range profile extrapolation for the shooting and bouncing ray technique," J. Electromag. Waves Applications, vol. 10, pp. 249-268, February 1996.
7. A. Filindras, U. O. Larsen and H. Ling, "Scattering from the EMCC dielectric slabs: simulation and phenomenology interpretation," J. Electromag. Waves Applications, vol. 10, pp. 515-535, April 1996.
8. Jeng, S. S., G. Xu, H.-P. Lin, and W. J. Vogel, "Experimental Studies of Spatial Signature Variation at 900 MHz for Smart Antenna Systems, " submitted to IEEE Transactions on Antennas and Propagation, May 1996
9. Lin, H.-P., R. Akturan, and W. J. Vogel, "Satellite Channel Simulation in
Mobile User Environments Using Photogrammetry and Markov Chains, " accepted by ACM Wireless Networks, May 1996
10. Akturan, R. and W. J. Vogel, "Path Diversity for LEO Satellite-PCS in the Urban Environment," accepted by IEEE Transactions on Antennas and Propagation, submitted Nov. 1995
11. Goldhirsh, J. and W. J. Vogel, "An Extended Empirical Roadside Shadowing Model for Estimating Fade Distributions from UHF to K-Band for Mobile Satellite Communications," International Journal on Space Communications, Vol. 13, No. 3, pp. 225-237, 1995
12. Salonen, E. T., J. K. Tervonen, and W. J. Vogel, "Scintillation Effects on Total Fade Distributions for Earth-Satellite Links," IEEE Transactions on Antennas and Propagation, Vol. 44, No. 1, pp. 23-27, Jan 1996.
13. H. Liu and G. Xu, Closed-form Blind Symbol Estimation in Digital Communications, IEEE Trans.~on Signal Processing, Vol. 43, No. 11, pp. 2714-2723, Nov. 1995.
14. G. Xu, H. Liu, L. Tong, and T. Kailath, A Least Squares Approach to Blind Channel Identification, IEEE Trans. on Signal Processing, Vol. 43, No. 12, pp. 2982-2993, Dec. 1995.
15. H. Liu and G. Xu, Smart Antennas in Wireless Systems: Uplink Multiuser Blind Channel and Sequence Detection, to appear in IEEE Trans. on Communications.
16. H. Liu, G. Xu, L. Tong, and T. Kailath, Recent Developments in Blind Channel Equalization: From Cyclostationarity to Subspaces, Special Issue of Signal Processing on Subspace Methods. Vol. 50, Nos. 1-2, April 1996.
17. L.K. Hansen and G. Xu, A Fast Sequential Source Separation Algorithm for Digital Co-Channel Signals, to appear in IEEE Signal Processing Letters.
1. H. Ling, "Joint time-frequency analysis of electromagnetic backscattered data," International Symposium on Signals, Systems and Electronics, Special Session on Time-Frequency Application, pp. 243-246, San Francisco, CA, October 1995.
2. L. C. Trintinalia and H. Ling, "A joint time-frequency ISAR algorithm for imaging targets with non-point scattering features," International Symposium on Signals, Systems and Electronics, Special Session on Time-Frequency Application, pp. 247-250, San Francisco, CA, October 1995.
3. L. C. Trintinalia and H. Ling, "Joint time-frequency ISAR using adaptive processing," National Radio Science Meeting, Boulder, CO, January 1996 (1st Place, Student Paper Competition).
4. L. C. Trintinalia and H. Ling, "Feature extraction from electromagnetic backscattered data using joint time-frequency processing," Third International Conference on Ultra-Wideband, Short-Pulse Electromagnetics, p. 209, Albuquerque, NM, May 1996. (Invited Talk)
5. L. C. Trintinalia and H. Ling, "Feature extraction for electrically large ducts using adaptive Gaussian processing," International IEEE AP-S Symposium, pp. 626-629, Baltimore, MD, July 1996.
6. C. Ozdemir and H. Ling, "Interpretation of scattering phenomenology in dielectric-coated wire via time-frequency processing," International IEEE AP-S Symposium, pp. 630-633, Baltimore, MD, July 1996.
7. R. Bhalla, J. Moore and H. Ling, "3D scattering center model of complex targets," URSI Radio Science Meeting, p. 15, Baltimore, MD, July 1996.
8. B.-T. Lee, E. Tuncer, and D. P. Neikirk, "Efficient 3-D Series Impedance Extraction using Effective Internal Impedance," IEEE 4th Topical Meeting on Electrical Performance of Electronic Packaging, Portland, OR, October 1-4, 1995, pp. 220-222.
9. V. Gupta and D. P. Neikirk, "Design of an Eddy-Current Proximity Sensor using a Two-Coil Planar Transformer," in Micromachined Devices and Components, Ray Roop, Kevin Chau, Editors, Proc. SPIE 2642, pp. 173-182, Austin, Texas, USA, 23-24 October, 1995.
10. S. Kim and D. P. Neikirk, "Compact Equivalent Circuit Model for the Skin Effect," 1996 IEEE-MTT-S International Microwave Symposium, San Francisco, California, June 17-21, 1996, pp. 1815-1818.
11. Vogel, 1996 North American Radio Science Meeting, Boulder CO, Jan. 96.
12. Vogel, 46th IEEE Vehicular Technology Conference, Atlanta, GA April 28 - May 1, 1996.
13. Vogel, 20th NASA Propagation Experimenters Meeting and ACTS Propagation Studies Workshop, Fairbanks, AK, June 4-6, 1996
14. Vogel, 1996 Progress in Electromagnetic Research Symposium (PIERS), Innsbruck, Austria, July 8-12, 1996
15. S.S. Jeng, H.P. Lin, G. Xu and W.J. Vogel, Measurements of Spatial Signatures of an Antenna Array, Proc. of the 6th IEEE International Symposium on Personal, Indoor, and Mobile Radio Communications, Toronto, Canada, September 1995.
16. I.P. Parra and G. Xu, A Least Squares Projective Constant Modulus Approach, Proc. of the 6th IEEE International Symposium on Personal, Indoor, and Mobile Radio Communications, Toronto, Canada, September 1995.
17. H. Liu and G. Xu, A Subspace Method for Signature Waveform Estimation in Synchronous CDMA Systems, Proc. of the 6th IEEE Symposium on Personal, Indoor, and Mobile Radio Communications, pp. 669-672, Toronto, Canada, Sept. 1995.
18. M. Torlak and G. Xu, Performance of CDMA Smart Antenna Systems, Proc. 29th Asilomar Conf. on Signals, Systems, and Computers, pp. 383-387, Pacific Grove, CA, Nov. 1995.
19. M. Torlak, H. Liu, and G. Xu, An Improved Signature Waveform Approach Exploiting Pulse Shaping Information in Synchronous CDMA Systems, Proc. VTC'96, Atlanta, GA, April 1996.
20. G. Okamoto and G. Xu, Throughput Multiplication of Wireless LANs: Spread Spectrum with SDMA, Proc. VTC'96, Atlanta, GA, April 1996.
21. G. Xu, M. Torlak, and H. Liu, Self-recovery in Anti-Jamming Communications, Proc. ICASSP'96, Atlanta, GA, May 1996.
22. A Self-Recovery Scheme in Anti-Jamming Communications, Proc. ICASSP'96, pp. 2567-2570, Atlanta, GA, May 1996.
23. L.K. Hansen and G. Xu, Geometric Properties of the Blind Digital Co-Channel Communications Problem, Proc. ICASSP'96, pp. 1085-1088, Atlanta, GA, May 1996.
24. H. Liu and G. Xu, Blind Equalization for CDMA Systems with Aperiodic Spreading Sequences, Proc. ICASSP'96, Atlanta, GA, May 1996.
25. M. Torlak, H. Liu, and G. Xu, An Improved Signature Waveform Approach Exploiting Pulse Shaping Information in Synchronous CDMA Systems, Proc. ICC'96, Dallas, TX, June 1996.
1. L. C. Trintinalia and H. Ling, "Joint time-frequency representation for synthetic aperture radar imaging," Chapter 10 in Introduction to Joint Time-Frequency Representations, Prentice Hall, Editors S. Qian and D. Chen, 1996.