Tutorial 4: Full-Duplex Communications: State-of-the-Art and Applications

  • Monday, 12 June 2017, 9:00-12:30, Room IT106



  • Taneli Riihonen (Aalto University, Finland)
  • Hirley Alves (University of Oulu, Finland)


Motivation and Context

The in-band full-duplex (FD) technology, by which devices transmit and receive simultaneously on the same frequency band, has attracted a lot of research attention lately. Since FD radios can potentially double the spectral efficiency, they are a promising technology for 5G and future wireless networks. However, FD radios suffer from severe self-interference (SI), as well as extra cross-directional coupling between simultaneous uplink and downlink operation, which further degrades the overall network performance.

The topic is especially relevant and interesting for the EuCNC audience because, due to the physical nature of the SI problem, FD communications poses new research challenges and solutions from analog and digital signal processing at the physical layer up to the MAC and network layers. To this end, many research groups around the world have developed new transceiver designs, new analog and digital SI mitigation algorithms, new MAC protocols and have also implemented advanced FD prototypes. Moreover, it has been shown that SI can be mitigated almost down to the noise floor, or even below in some cases. All these accomplishments prove the baseline feasibility of the FD technology and its applicability for future wireless networks but, despite these fundamental results and advances, there are still many challenges and open problems to resolve. In order to achieve the full potential of FD transmission, it is necessary to develop new mechanisms and efficient protocols to cope with the self- and cross-interference caused by FD transmissions.

This tutorial covers all the aspects mentioned above and as such it will be very useful for anybody who is doing research or commercial product development on the topic, or just interested in catching up with it. The research area is still receiving soaring attention and there is lot of room for new developments before the concept is mature enough for full commercial use.



Structure and Content

In particular, we have planned organizing a half-day tutorial (~3h) split into two parts that address the following topics:

  • Self-interference characterization (1:30h – first part)
    • What is SI and how does it manifest itself in modern FD antenna/transceiver designs?
    • How to overcome SI? Introduction to advanced SI mitigation techniques: physical isolation, analog and digital signal processing, spatial-domain suppression with multi-antenna techniques, non-linear cancellation and compensation of transceiver hardware impairments
  • Full-duplex communications: applications and open challenges (1:30h – second part)
    • Characterization of the residual SI from imperfect mitigation: hardware impairments, countermeasures and analytical modelling vs. advanced waveform simulations
    • Point-to-point links, relaying systems
    • Cellular/small-cells, self-backhauling, massive MIMO, mmWave Cognitive radios and physical-layer security