Adaptive Same-Frequency Repeater Study

摘要

This report presents the results of an investigation of real time, nonsampling, Same-Frequency Repeater (SFR) concepts for various types of analog and digital signals using coherent interference cancellation techniques. The analytical results presented here will develop the concept of a pilot-directed multichannel notch filter interference cancellation system (ICS) to provide isolation between the repeater transmitter and its receiver. The isolation capability of the ICS will be analyzed to determine the effects of signal returns from the SFR antenna, from specular reflectors, and from distributed ground clutter. The results will be given as functions of signal bandwidth and carrier frequency as well as other design parameters of the ICS. Also included are: results of a hardware investigation of approaches for obtaining low signal distortion in the ICS complex weights; an SFR breadboard design; and experimental results.