Time-Modulated Ultra-Wideband Interspacecraft Communication

The key innovation of this proposal is the further development and use of Time Modulated Ultra-wideband radio (TM-UWB) RF transmission for inter-satellite communication and a communication link technology to transfer data from an earth observing balloon or airplane. Within the last few years low cost ultra-high precision delay elements have become available, which now make it possible to build UWB communication systems that have no carrier frequency. The only signals transmitted are pulses, and impulses in the time domain have very wide bandwidth in the frequency domain. In the limit, a perfect impulse has its energy spread evenly through all frequencies. Because only pulses are transmitted, and because there is no carrier frequency, there is no up conversion and no down conversion required, and the output stage is a single transistor which creates a binary pulse, all resulting in decreased radio size and complexity. Other advantages are good propagation through many obstacles, no multipath fading, and low power because of the low transmission duty cycle. Under the proposed SBIR project we will evaluate the types of network architecture that could meet NASA's requirements and exploit the benefits of TM-UWB transmission. Prototype hardware will be configured to validate specific technical questions.