Exploring data compression for a distributed aerial relay application

Abstract

Beamforming systems typically involve arrays of antenna elements with controllable spacing and little or no motion. However, a distributed beamforming system could leave array geometry and motion largely unconstrained. This work considers an airborne relay communication concept with multiple balloons in which the individual array elements act as relays to a receiver on the ground at a base station. The beamforming operation is performed at the receiver. The link between the relays and receiver suffers from a high bandwidth requirement. This thesis explores ways to reduce this bandwidth requirement by compressing the signals across the relays. A distributed compression algorithm is proposed and applied to both simulated and collected data. We conclude that a compression algorithm across the relays offers a substantial decrease in bit rate requirement, and that a preprocessing step can make the compression performance robust against differential delay and Doppler shifts across the array.