Open-access full-duplex wireless in the ORBIT and COSMOS testbeds

Abstract In order to support experimentation with full-duplex (FD) wireless, we integrated two generations of FD radios in the open-access ORBIT and COSMOS testbeds. In the indoors ORBIT testbed, we integrated a customized 1st generation (Gen-1) narrowband FD radio. In the city-scale PAWR COSMOS testbed, we integrated four 2nd generation (Gen-2) wideband FD radios, alongside static and mobile Gen-1 FD radios. Each integrated FD radio consists of an antenna, a customized RF self-interference (SI) canceller box, a USRP software-defined radio (SDR), and a remotely accessible compute node. The Gen-1/Gen-2 RF SI canceller box includes an RF canceller printed circuit board (PCB) which emulates a customized integrated circuit (IC) RF canceller implementation. The amplitude- and phase-based Gen-1 narrowband RF canceller achieves  45 dB RF SIC across  5 MHz . The Gen-2 wideband canceller is based on the technique of frequency-domain equalization (FDE) and achieves  50 dB RF SI cancellation (SIC) across  20 MHz . In this paper, we present the design of the two generations of FD radios, and their integration in various forms in the ORBIT and COSMOS testbeds. We then present example experiments that can be remotely run and modified by experimenters. Finally, we discuss future improvements and potential FD wireless experiments that can be supported by these open-access FD radios integrated in the COSMOS testbed. 1