The Full-duplex Wireless: From Integrated Circuits to Networks (FlexICoN) project is motivated by the exponential growth of wireless traffic that calls for the design of spectrum-efficient communication schemes.

Existing wireless systems are half-duplex, where the separation of a user’s transmitted and received signal in either frequency or time causes inefficient utilization of the limited spectrum. An emerging and transformative communication technology that can substantially improve spectrum efficiency is Full-Duplex (FD) communication, namely, the simultaneous transmission and reception on the same frequency channel. FD operation, however, requires the cancellation of extremely powerful transmitter self-interference (SI) that can overwhelm the receiver. Despite recent progress in the development of laboratory bench-top FD transceiver implementations, these designs mostly utilize off-the-shelf components and are not suitable for compact Integrated Circuit (IC) implementations necessary for commercial small-form-factor mobile applications. Moreover, fully utilizing the benefits of FD communication calls for a careful joint redesign of the Physical (PHY) and the Medium Access Control (MAC) layers while taking into account the FD IC characteristics.

The FlexICoN interdisciplinary project directly addresses the important cross-layer challenges stemming from the need to design compact FD ICs and jointly design the MAC and PHY layers. In particular, the main components of the project are the development of next-generation FD ICs that meet these challenging requirements and obtaining a fundamental understanding of the impact of small-form-factor FD IC transceiver nodes on algorithm design, MAC layer protocol design, and network capacity.

Hence, the main research activities include:

  1. developing new FD transceiver concepts and ICs that simultaneously achieve both SI cancellation and robustness to the new interference mechanisms that arise from widely-deployed FD operation;
  2. deriving realistic models for recently developed FD canceller ICs and developing adaptive algorithms for PHY layer cancellation;
  3. developing algorithms for power control, channel allocation, and scheduling, and studying the resulting FD capacity gains (under realistic models); and
  4. understanding the design considerations of FD MAC protocols for random access networks (e.g., Wi-Fi) and for small-cell cellular networks.

The developed algorithms will have a strong theoretical foundation and will be evaluated in a unique software-defined FD testbed (integrated into the COSMOS testbed that is being deployed around Columbia University) composed of the custom-designed FD transceivers developed within the project.