RF front-end implementation challenges of in-band full-duplex relay transceivers

This paper presents a study on practical aspects that need to be considered in the implementation of in-band full-duplex wireless relay systems. Especially, the large power level difference between the self-interference and the signal of interest is a key challenge for full-duplex transceivers. Selfinterference can be reduced by using a combination of passive antenna isolation techniques and active analog RF or DSPbased cancellation techniques. In practice, a combination of these techniques is necessary to reduce the self-interference effects successfully. Various RF impairments play a crucial role in the performance of full-duplex communication and, thus, they need to be carefully addressed in order to guarantee successful system operation. We study the effects of the most important RFimpairments, such as IQ imbalance, phase noise, quantization noise from ADC converters and nonlinear distortion from power amplifiers, on the performance of full-duplex relays.