Prototype of Virtual Full Duplex via Rapid On-Off-Division Duplex

We design and implement a software-radio system for rapid on-off-division duplex (RODD), a scheme to achieve virtual full-duplex communication at the level of a transmission frame. RODD is based on the insight that it is not necessary to separate a node's transmission and reception at the timescale of a frame. Instead, RODD allows each node in a network to follow a different random on-off signaling signature to transmit during its own on-slots and listen to its neighbors through its own off-slots. Over one frame interval, each node broadcasts its message to its neighbors while recovering its neighbors' messages from the superposed signals received via its own off-slots. In this paper, we describe an RODD prototype to prove its key concepts, including redesigned synchronization and coding schemes. Simulation results are presented for comparison with the measurements obtained from a software-defined radio implementation of RODD. The effects of on-off signaling on the performance are investigated experimentally. In particular, the bit error rate is measured and compared with the simulation results. Our results indicate that virtual full duplex is feasible on a USRPs/LabVIEW platform via RODD.