Full duplex MIMO radios

This paper presents the design and implementation of the first in-band full duplex WiFi-PHY based MIMO ra-dios that practically achieve the theoretical doubling of throughput. Our design solves two fundamental chal-lenges associated with MIMO full duplex: complexity and performance. Our design achieves full duplex with a cancellation design whose complexity scales linearly with the number of antennas, this complexity is close to the optimal possible. Further we also design novel digital estimation and cancellation algorithms that eliminate al-most all interference and achieves the same performance as a single antenna full duplex SISO system, which is again the best possible performance. We prototype our design by building our own analog circuit boards and integrating them with a WiFi-PHY compatible standard WARP software radio implementation. We show exper-imentally that our design works robustly in noisy indoor environments, and provides close to the expected theo-retical doubling of throughput in practice.