SoftNull: Many-Antenna Full-Duplex Wireless via Digital Beamforming
Abstract
In this paper, we present and study a digital-controlled method, called SoftNull, to enable full-duplex in many-antenna systems. Unlike most designs that rely on analog cancelers to suppress self-interference, SoftNull relies on digital transmit beamforming to reduce self-interference. SoftNull does not attempt to perfectly null self-interference, but instead seeks to reduce self-interference sufficiently to prevent swamping the receiver's dynamic range. Residual self-interference is then cancelled digitally by the receiver. We evaluate the performance of SoftNull using measurements from a 72-element antenna array in both indoor and outdoor environments. We find that SoftNull can significantly outperform half-duplex for small cells operating in the many-antenna regime, where the number of antennas is many more than the number of users served simultaneously.
Cite
@article{arxiv.1508.03765,
title = {SoftNull: Many-Antenna Full-Duplex Wireless via Digital Beamforming},
author = {Evan Everett and Clayton Shepard and Lin Zhong and Ashutosh Sabharwal},
journal= {arXiv preprint arXiv:1508.03765},
year = {2017}
}