Full-Duplex Wireless Communication Systems

Full-duplex is a shifting paradigm duplexing scheme in the wireless communication networks. The full-duplex scheme enables the communicating wireless nodes to exchange their data bidirectionally over the same frequency band and without any discontinuities in time, see figure 2. Full-duplex scheme unlocks the potential to double the spectral usage efficiency as a complete reuse of the available spectrum is offered within such duplexing scheme.

The main obstacle that must be tackled in order to realize such duplexing scheme is the overwhelming self-interference – due to the reception of own transmission signal. Figure 3 depicts how the self-interference signal obscures the reception of desired signal due to its relatively high magnitude. At the laboratories of Fraunhofer Heinrich Hertz Institute, years of extensive research made us able to come up with a wireless transceiver concept that is capable of purifying the reception signal from the unwanted self-interference one; the architecture of the transceiver is shown in figure 1. The transceiver is equipped with a self-interference cancellation mechanism that is able to treat the vast self-interference and cancels it in successive manner.

The transceiver is not only engineered to bring the life to the full-duplex scheme, however, it is also backward compatible to the currently-deployed wireless duplexing schemes, i.e., the TDD and FDD. Moreover, the transceiver is designed to enhance on those schemes by taken advantage of the self-interference cancellation mechanism.

Related Publications

[1] Ramez Askar, Thomas Kaiser, Benjamin Schubert, Thomas Haustein, and Wilhelm Keusgen, “Active self-interference cancellation mechanism for full-duplex wireless transceivers”, In Cognitive Radio Oriented Wireless Networks and Communications (CROWNCOM), 2014 9th International Conference on, pages 539–544, June 2014.

 

[2] Ramez Askar, Nidal Zarifeh, Benjamin Schubert, Wilhelm Keusgen, and Thomas Kaiser, “I/Q imbalance calibration for higher self-interference cancellation levels in Full-Duplex wireless transceivers”, In 5G for Ubiquitous Connectivity (5GU), 2014 1st International Conference on, pages 92–97, Nov 2014.

 

[3] Ramez Askar, Benjamin Schubert, Wilhelm Keusgen, and Thomas Haustein, “Full-Duplex Wireless Transceiver in Presence of I/Q Mismatches: Experimentation and Estimation Algorithm”, In IEEE GC 2015 Workshop on Emerging Technologies for 5G Wireless Cellular Networks - 4th International (GC’15 - Workshop - ET5G), December 2015.

[4] Ramez Askar, Benjamin Schubert, Wilhelm Keusgen and Thomas Haustein, "Agile Full-Duplex Transceiver: The Concept and Self-Interference Channel Characteristics", European Wireless 2016; 22th European Wireless Conference, Oulu, Finland, pages 1-7, May2016.