Interference Avoidance via Adaptive Wavelet Packet Modulation in Wireless Communication Systems

Award Information
Agency: Department of Defense
Branch: Defense Advanced Research Projects Agency
Contract: W31P4Q-05-C-R120
Agency Tracking Number: 04SB3-0047
Amount: $99,000.00
Phase: Phase I
Program: SBIR
Awards Year: 2005
Solicitation Year: 2004
Solicitation Topic Code: SB043-037
Solicitation Number: 2004.3
Small Business Information
868 San Antonio Road, Palo Alto, CA, 94303
DUNS: 829385509
HUBZone Owned: N
Woman Owned: N
Socially and Economically Disadvantaged: Y
Principal Investigator
 Hui-Ling Lu
 Research Scientist
 (650) 213-8585
Business Contact
 P. Menon
Title: President
Phone: (650) 213-8585
Research Institution
The proposal addresses the problem of adaptive modulation/demodulation scheme in the presence of interference for wireless communication systems. The objective is to develop a new class of communication system that is impervious to natural and man-made interferences. Here, motivated by the concept of software-defined radio, we propose an adaptive modulation/demodulation scheme which modifies the user's signature waveforms by maximizing the signal to interference ratio. Changing the transmitting signature waveform is one step beyond the existing adaptive modulation schemes where constellation size, transmission power, symbol time, and coding rate are adapted to the channel fading level. By maximizing the orthogonality between the transmitting signature waveform and the interference, a better and simpler detection can be achieved at the receiver. The idea of maximizing the orthogonality is achieved by representing the signature waveform using the least significant eigenfunction of the interference. There are two essential concepts behind our signature waveform adaptive scheme. Here, we proposed to integrate the basis selection strategy based on Wavelet Packet Analysis with the state-of-art interference avoidance algorithms. In this proposal, we will develop the mathematical foundation for adaptive signature waveform design and deliver the system architecture under the scenario of symbol-synchronous single-cell multi-user system.

* Information listed above is at the time of submission. *

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