Patent ID: 7826541

Claim:
A wireless relay system for relaying a radio signal transmitted from a first wireless station to a second wireless station via a wireless relay apparatus, the wireless relay system comprising: a relay control part for receiving transmission symbols transmitted from the first wireless station and refraining from relaying a portion of the transmission symbols; a pilot signal transmission part for transmitting a pilot signal that is inserted into a section of the portion of the transmission symbols such that the wireless relay system relays signals without interruption; a coupling loop interference wave estimation part for receiving the pilot signal and estimating a coupling loop interference wave based on the pilot signal during a time when the pilot signal is being transmitted; and a coupling loop interference wave cancellation part for subtracting the estimated coupling loop interference wave from a reception signal, wherein the first wireless station is configured to insert the portion of the transmission symbols to be refrained from relay according to a desired accuracy for estimating a coupling loop interference wave, and an accuracy of the coupling loop interference wave estimated by the coupling loop interference wave estimation part increases as the portion of the transmission symbols to be refrained from relay increases.