Open-Access Full-Duplex Wireless in the ORBIT and COSMOS Testbeds

Abstract

In order to support experimentation with full-duplex (FD) wireless, we recently integrated two generations of FD radios in the open-Access ORBIT and COSMOS testbeds. First, we integrated a customized 1st generation (Gen-1) narrowband FD radio in the indoor ORBIT testbed. Then, we integrated two 2nd generation (Gen-2) wideband FD radios in the city-scale PAWR COSMOS testbed. 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 40 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 and testbed integration of the two generations of FD radios. 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.