Full-Duplex Communication

MIDU: Enabling MIMO Full Duplex

Full duplex and MIMO both employ multiple antenna resources and an important question that arises is how to make the choice between MIMO and FD?. Interestingly, we show that optimal performance requires a combination of both to be used. Hence, we present the design and implementation of MIDU, the first MIMO Full-Duplex system for wireless networks. MIDU employs antenna cancellation with symmetric placement of transmit and receive antennas as its primary RF cancellation technique. We show that MIDU’s design provides large amounts of self-interference cancellation with several key advantages: (i) It allows for two stage of additive antenna cancellation in tandem, to yield as high as 45 dB self-interference suppression; (ii) It can potentially eliminate the need for other forms of analog cancellation, thereby avoiding the need for variable attenuator and delays; (iii) It easily scales to MIMO systems, thereby enabling the coexistence of MIMO and Full Duplex.

We have implemented MIDU on the WARP FPGA platform, and evaluated its performance against Half Duplex (HD)-MIMO. Our results reveal that with the same number of RF chains,MIDU can potentially double the throughput achieved by Half Duplex MIMO in a single link; and provide median gains of at least 30% even in single cell scenarios, where Full Duplex encounters inter-client interference. Based on key insights from our results, we also highlight how to efficiently enable scheduling for a MIDU node.

 

Relevant Publications

E. Aryafar (NEC Laboratories America, Inc, Princeton University), M.A. Khojastepour (NEC Laboratories America, Inc), K. Sundaresan (NEC Laboratories America, Inc), S. Rangarajan (NEC Laboratories America, Inc), M. Chiang (Princeton University), "MIDU: Enabling MIMO Full Duplex ", MobiCom 2012, pp. 257-268, 2012

M.A. Khojastepour (NEC Laboratories America, Inc.), K. Sundaresan (NEC Laboratories America, Inc.), S. Rangarajan (NEC Laboratories America, Inc.), X. Zhang (NEC Laboratories America, Inc., University of Michigan), S. Barghi (NEC Laboratories America, Inc., University of California Irvine), "The Case for Antenna Cancellation for Scalable Full-Duplex Communications", HotNets-X

M.A. Khojastepour (NEC Laboratories America, Inc.), S. Rangarajan (NEC Laboratories America, Inc.), "Wideband Digital Cancellation for Full-Duplex Communications", Asilomar 2012

S. Barghi (NEC Laboratories America, University of California, Irvine), M.A. Khojastepour (NEC Laboratories America, Inc), K. Sundaresan (NEC Laboratories America, Inc), S. Rangarajan (NEC Laboratories America, Inc), "Characterizing the Throughput Gain of Single Cell MIMO Wireless Systems with Full Duplex Radios ", WiOpt 2012, pp. 68-74, 2012