Field Experiment of 117 Gbit/s Wireless Transmission Using OAM Multiplexing at a Distance of 200 m on 40 GHz Band

In this paper, we demonstrate outdoor wireless transmission using orbital angular momentum (OAM) multiplexing on a 40 GHz band. OAM beams are generated by a Butler matrix analog radio-frequency (RF) circuit and radiated from uniform circular arrays (UCAs). We implemented an OAM multiplexing transmitter (Tx) and receiver (Rx) on a 40-GHz band. This Tx and Rx can generate and separate seven OAM modes (−3, −2, −1, 0, 1, 2, 3) and two polarizations (vertical and horizontal), a total of 15 streams, including the center antenna element which can transmit OAM mode 0. Each channel carries a 1.5 Gbaud signal. We previously reported a 119 Gbit/s transmission at a distance of 100 m using this equipment. This time, we used signal processing with transmit precoding based on singular value decomposition (SVD) to achieve a greater transmission distance. Then, we evaluated the transmission capacity at distances of 100 m and 200 m. The results show that a 137 Gbit/s wireless data transmission is successful at a distance of 100 m and a 117 Gbit/s wireless data transmission is successful at a distance of 200 m.