Equalizers for communications satellites

Abstract

This thesis investigates equalization for advanced protected satellite communications systems in development at MIT Lincoln Laboratory. Equalizers facilitate high data rate communication by correcting dispersion in the transmitter and receiver signal chains. An automated calibration procedure for finding optimal equalizers was developed. Repeated testing addressed questions about noise amplification, filter complexity requirements, and narrow band performance degradation. After examining various architectures, it was determined that the FIR filter was the best equalizer structure given the nature of the channel. The basic calibration procedure was also extended for use at high RF frequencies by using a spectrum analyzer as a tuned receiver.