Everett, EvanSabharwal, Ashutosh2017-05-222017-05-222016Everett, Evan and Sabharwal, Ashutosh. "Spatial degrees-of-freedom in large-array full-duplex: the impact of backscattering." <i>EURASIP Journal on Wireless Communications and Networking,</i> 2016, no. 286 (2016) Springer: https://doi.org/10.1186/s13638-016-0781-3.https://hdl.handle.net/1911/94316The key challenge for in-band full-duplex wireless communication is managing self-interference. Many designs have employed spatial isolation mechanisms, such as shielding or multi-antenna beamforming, to isolate the self-interference waveform from the receiver. Because such spatial isolation methods confine the transmit and receive signals to a subset of the available space, the full spatial resources of the channel may be under-utilized, expending a cost that may nullify the net benefit of operating in full-duplex mode. In this paper, we leverage an antenna-theory-based channel model to analyze the spatial degrees of freedom available to a full-duplex capable base station. We observe that whether or not spatial isolation out-performs time-division (i.e., half-duplex) depends heavily on the geometric distribution of scatterers. Unless the angular spread of the objects that scatter to the intended users is overlapped by the spread of objects that backscatter to the base station, then spatial isolation outperforms time division, otherwise time division may be optimal.engThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License, which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.Journal articlehttps://doi.org/10.1186/s13638-016-0781-3