Research Article
I/Q Imbalance Calibration for Higher Self-Interference Cancellation Levels in Full-Duplex Wireless Transceivers
@INPROCEEDINGS{10.4108/icst.5gu.2014.258148, author={Ramez Askar and Nidal Zarifeh and Benjamin Schubert and Wilhelm Keusgen and Thomas Kaiser}, title={I/Q Imbalance Calibration for Higher Self-Interference Cancellation Levels in Full-Duplex Wireless Transceivers}, proceedings={1st International Conference on 5G for Ubiquitous Connectivity}, publisher={IEEE}, proceedings_a={5GU}, year={2014}, month={12}, keywords={full-duplex pre-equalization self-interference cancellation i/q imbalance}, doi={10.4108/icst.5gu.2014.258148} }- Ramez Askar
Nidal Zarifeh
Benjamin Schubert
Wilhelm Keusgen
Thomas Kaiser
Year: 2014
I/Q Imbalance Calibration for Higher Self-Interference Cancellation Levels in Full-Duplex Wireless Transceivers
5GU
IEEE
DOI: 10.4108/icst.5gu.2014.258148
Abstract
This paper investigates a Full-Duplex transceiver using an active cancellation technique where an additional transmit chain is employed to create the self-interference cancellation signal. Both transmitters and also the receiver are impaired by frequency-dependent I/Q imbalance with different parameters. It is shown how an I/Q parameter deviation in these chains deteriorates the achievable self-interference suppression level. Three different types of pre-equalization units, with variable complexity degree and different implementation approach, are then introduced and investigated. These units correct the I/Q imbalance and retain the self-interference level to its value as in a perfectly I/Q matched full-duplex transceiver. They can even be used to fully calibrate the I/Q imbalance. Simulative results show that self-interference suppression levels of more than 71 dB can be achieved.