This overview provides an interface between lines of thought on radio frequency interference (RFI) mitigation in the fields of radio astronomy and signal processing. The goal is to explore the commonality of different approaches to help researchers in both fields interpret each other's concepts and jargon. The paper elaborates on the astronomers' concept of gain closure relations and how they may be used in a self-calibrating system of RFI cancellation. Further discussion of the eigen-decomposition method in terms of RFI power and antenna gains introduces adaptive nulling and RFI cancellation through matrix partitioning. While multipath scattering appears at first glance to be fatal to methods of RFI cancellation, its effect is easily incorporated in frequency-dependent gain coefficients under many circumstances.