A Multipurpose Testbed for Full-Duplex Wireless Communications

Unlike in the traditional half-duplex (HD) mode of transmission over a wireless link, in the full-duplex (FD) mode both terminals receive and transmit on the same frequency band, simultaneously. Hence, FD gives us up to twice the spectral efficiency of HD, has the potential to resolve the hidden terminal problem, and makes relaying much more efficient. As such, FD is one of the most promising new physical layer techniques being developed at the moment. However, a major difficulty in achieving FD operation is that it requires cancelation of self-interference. In this demonstration, we show various methods of operating in FD mode, offering live, interactive, and visual insight into the operation of the link. The parameters shown include the power budget, signal-to-interference-and-noise ratio, frequency spectrum, constellation graphs, and bit error rate. We compare the operation of the same link in HD and FD mode, highlight the effect of each type of cancelation, as well as show what happens when self-interference is not mitigated at all.