Directional antenna-based single channel full duplex

Single-channel full-duplex (SCFD) radio has recently gained significant attention. It can not only double link throughput, but also provide the capability to solve a few challenging problems in half-duplex wireless systems, including hidden terminals, loss of throughput due to congestion, and large end-to-end delays. Recent works on SCFD have achieved full-duplex communication and claimed to have solved the aforementioned problems. However, when applied to a wireless network consisting of more than three nodes, they fail to solve these problems. One can conclude through analysis that, SCFD with omni-directional antenna as both transmit and receive antennas is inherently incapable of solving these problems. In this study, the authors propose a directional antenna-based solution of SCFD architecture, including a new SCFD radio prototype and a new medium access control (MAC) protocol [differential localization MAC (DL-MAC)] for wireless networks. Experiments on real nodes verify the authors' solution and their radio prototype achieves up to 93% link through put gain over half-duplex system. Numerical simulations show that the network capacity of their solution can be increased by nearly 200%, compared to a half-duplex system in a large-scale wire less network.