Low-Cost, High-Speed, Efficient Generation of Commmunication Signals Using Chaotic Devices

There is a need in both commercial and military applications for digital transmission methods that can operate at high data rates (several megabits per second end-user rate) in multi-user environments. Existing communication methods will be severelystressed by the difficulties of such an environment: Propagation anomalies such as multipath fading and various types of interference will require intensive digital processing to mitigate their effects. As data rates and environmental problems increase,the use of digital signal processing and error correction becomes costly and complex. Eventually, it will become impossible to degradation. Furthermore, existing multiple access techniques lack flexibility, and as users are added, the difficultiesincrease. By developing a digital signaling approach based on the control of the natural complexity of the chaotic behavior of rf devices, alternative solutions to these fundamental problems emerge.As a limited Phase II effort appropriate to the available funding level, we will develop a chaotic oscillator prototype that has improved behavior over the Colpitts circuit used in Phase I. The purpose of Phase I was to demonstrate the feasibility of suchchaos-based signal encoding (via control of an analog oscillator), and we demonstrated not only this, but also a new principle for amplifying communication signals with tremendous signal gain. In Phase II we will improve upon the oscillator design used inour Phase I effort. We will address such fundamental issues as signal performance in noise, signal predictability, oscillator efficiency, and spectral characteristics. We will also investigate frequency scaling, and the advantages of this approach overtraditional methods for digital communication.