Blind self-interference cancelation for amplify and forward relaying

Abstract

In this letter we introduce a self-interference (SI) cancelation technique for amplify and forward relays. Relays are used to help forward signals between a transmitter and a receiver. This helps increase the signal coverage and reduce the required transmitted signal power. One issue that faces relays communications is the SI problem where an unwanted leaked signal from the relay's output will contaminate the new signal received from the transmitter at the relay's input. A solution is proposed in this letter to cancel this SI which is based upon using the constant modulus adaptive algorithm. This is performed blindly at the relay without the need of any training, a priori knowledge of the SI channel or any other channel weight estimates nor the need of multiple antennas. Simulation results are provided to verify the performance of the proposed method.