Provided systems engineering, simulation and modeling, technical expertise and leadership for several commercial and government companies/programs, including:• Led Low-Density Parity-Check (LDPC) code validation service development which provides high-throughput, flexible, and cost-effective service that takes advantage of a massively parallel GPU architecture.• Non-geostationary Constellations ITU Filling Studies: Determined compliance to ITU regulations for multiple non-geostationary Ka/Ku bands satellite constellations system for filing• Mixed Platform Connectivity Study: Evaluated multiple system architectures to provide access to select nations worldwide. System consists of satellite component (Ka/Ku band; LEO/MEO/GEO); unmanned aerial vehicle; and terrestrial segments. • Boeing Training System Development: Developed a java-based custom data editor with a graphical-interface used in creating instructional scenarios involving the operation of sensors and communications systems.• Led group to develop wireless transport network simulation and modeling platform. The model was used to characterize, analyze and compare performance under a wide range conditions, including: various operating scenarios; application traffic characteristics; physical environments; and radio waveform configurations.• Iridium Next Generation global satellite communication system: Developed an OPNET model and analyzed the performance of mixed data traffic on the satellite uplink and downlink in order to maximize capacity• Advanced Navigation and Positioning Corporation (ANPC): Developed flexible multipath model for configurable flight path ILS for airports where rough terrain constraints make traditional ILS infeasible• FAA Global Communications, Navigation and Surveillance System: Modeled and analyzed various competing technologies including Inmarsat MPDS service for satellite-based communications, navigation and surveillance system for Air Traffic Management.

Designed and developed the 802.11a and 802.11g WLAN baseband processor in fixed-point arithmetic (in Matlab/Simulink). Modem includes signal detection, frame synchronization, frequency estimation, IFFT/FFT, timing estimation, channel estimation, amplitude/phase imbalance estimation, frequency and timing tracking, QAM modulation/demodulation, code puncturing, and Viterbi encoding/decoding.Led ASIC engineers to convert baseband processor design to Verilog code for FGPA and ASIC implementation.

Team leader responsible for software tool to predict Teledesic global satellite broadband network system capacity and performance. Software inputs: marketing and business development assumptions, satellite design (payload, user equipment, data link, network traffic, resource management), and regulatory constraints. Output: capacity model used to determine validity of corporate business model. Tool enabled increased the system capacity by 50% --crucial to close the business case (C/C++, SourceSafe, Microsoft Visual C++ on PC).Led six engineers to demonstrate application of Turbo codes (serially concatenated convolutional to broadband links. Includes tradeoffs: code rate, number of states, puncturing pattern, and interleaver design. Directed implementation from floating point, to fixed point, FPGA. (C on Unix)Designed and simulated iterations of Teledesic communication links. Developed software to model the coder (block, convolutional, Turbo), modulator (GMSK, CPM), self-interference interference (ACI, CCI, XPI), and multiple access (Matlab, SPW on Unix)Evaluated technical design proposals for satellite communication payload design from Motorola, Hughes, Boeing, and TRW.

Characterized signal acquisition and tracking for carrier, sub-carrier, symbol tracking loops and signal detection for NASA’s next generation all-digital coherent deep space receiver (SPW).Implemented software systems capable of arraying signals form multiple antennas for NASA’s Deep Space Network. Proposed and conducted analysis and simulations for Full-Spectrum, Complex Symbol, and Symbol Stream Combining multiple antennas combining techniques (SPW)Conducted antenna measurements using the R&D Advanced Receiver in the laboratory and at the DSN Complex, Goldstone, California.Designed multiple access schemes (CDMA, TDMA, FDMA) for the Venus Multi-probe Mission and the Single Aperture Multiple Link Study for Mars. Implemented a Kalman smoother algorithm to improve tracking performance by 3 dB loop SNRs performance for weak Galileo signal from Jupiter.Designed a new class of bandwidth efficient (PCM/PM) modulation schemes suitable for high data rate transmission - the new schemes have less demodulator loss, higher bandwidth efficiency. Conducted measurements to validate the model; new schemes were selected for future space missions.