Teaching Electric Circuit Analysis, Analog and Digital Communications, Senior Project Design, Enhancing Study Skills, Digital Communications (graduate), and Adaptive Filtering and Applications (graduate).

Carrying out research in adaptive filtering, channel estimation, iterative receiver design, multiuser
communication, and seismic signal processing.

Serving on various academic committees.

Characterized scaling laws for the capacity of broadcast multi-user wireless channels that employ multiple antennas with spatial correlation.

Characterized the scaling laws of group broadcast channels in the narrow-band and wideband cases. Scaling was applied to the number of users, antennas, and channels.

Worked with a team of experts on designing, implementing, and testing the physical layer part of the WiMAX Standard IEEE 802.16e for broadband wireless metropolitan access networks. Specifically, worked on designing and evaluating space-time codes, pilot training schemes, and channel estimation algorithms.

Successfully implemented and evaluated various space-time coding schemes using 2,3, and 4 antennas at the base station. The work resulted in 5 proposals to the IEEE 802.16e standard body (2 of which were voted into the standard).

Designed training schemes to improve the operation of the space-time mode of the IEEE 802.16e standard. This resulted in 2 contributions to the IEEE 802.16e standard, one of which was voted in.

Worked with a team of experts to design and implement channel estimation and tracking algorithms for the IEEE 802.16e standard. Came up with a computationally efficient method for channel estimation and tracking in the frequency domain. Work resulted in one patent.

Channel estimation and equalization: Developed adaptive/iterative algorithm for MIMO channel estimation and data detection. Algorithm is able to cope with rapidly time-variant frequency-selective channels by making a collective use of the structure underlying the communication problem. Algorithm minimizes training overhead and is able to perform recovery with no latency, thus minimizing storage requirements and lending itself to real-time applications. Various stages of the algorithm make use of dynamic programming and so can be efficiently implemented using dedicated hardware. The algorithm was applied in the wireless LAN context.

Performance analysis of adaptive algorithms: Performed a unified analysis of a large class of adaptive
algorithms. Analysis unifies and extends earlier analysis approaches; is able to predict stability and learning behavior of many adaptive algorithms very accurately. It allows the user to choose the adaptive algorithm best suited for a given application; applies regardless of type of nonlinearity employed in the algorithm and irrespective of the color or statistics of data driving the adaptive algorithm.

Designed blind/semi-blind iterative algorithms for channel/data recovery for transmission over rapidly time-variant frequency-selective channels. Algorithm used as part of receiver for wireless LAN; algorithm performs channel and data recovery with no latency while minimizing storage overhead. Work resulted in one patent, 2 journal articles, and 6 conference publications.

Designed least-squares algorithm that combines, in an optimal manner, data arising from a finite collection of uncertain models. The algorithm can take into account data uncertainties with different sophistication levels. The algorithm demonstrated improved performance when it was applied to fusion of data arriving from a distributed network of sensors with varying degrees of reliability. The Algorithm was also applied to diversity combining of signals in the presence of microscopic or macroscopic fading.
 

Developed adaptive algorithm with optimum error nonlinearity in the adaptation equation. Nonlinearity is a function of the pdf of the additive noise. Algorithm attains a lower steady-state error compared with adaptive algorithms employing other nonlinearities. Research resulted in 4 conference publications.

Carried out research on critically sampled filter banks. Designed and implemented a wide-band multirate acoustic echo canceller.

Studied and analyzed algorithms for harmonic retrieval in the presence of additive and multiplicative noise. Algorithms use cyclostationary properties to recover harmonic frequencies and amplitudes from output data only, and are robust to the effect of noise regardless of its statistics.

Proposed, analyzed, and tested a set of adaptive algorithms for echo cancellation. Algorithms lend themselves to cancellation of echoes produced by long and sparse channels. Derived adaptive algorithm with optimum nonlinearity in the update equation; proposed algorithm subsumes several existing algorithms as special cases.

Coordinated and instructed the electromagnetics, communications, and telephony labs. Work involved preparing experiments, problem sets, and exams. Guided students, monitored and evaluated their performance. Got consistently excellent evaluations from students.