  In this article, we propose sampled-data design of digital filters that
cancel the continuous-time effect of coupling waves in a single-frequency
full-duplex relay station. In this study, we model a relay station as a
continuoustime system while conventional researches treat it as a discrete-time
system. For a continuous-time model, we propose digital feedback canceler based
on the sampled-data H-infinity control theory to cancel coupling waves taking
intersample behavior into account. We also propose robust control against
unknown multipath interference. Simulation results are shown to illustrate the
effectiveness of the proposed method.
