US 12,074,640 B2
Terminal devices, communication methods, and communication systems
Ryota Shiina, Musashino (JP); Tomohiro Taniguchi, Musashino (JP); Kazutaka Hara, Musashino (JP); Shinya Tamaki, Musashino (JP); Tomoki Murakami, Musashino (JP); and Toshiro Nakahira, Musashino (JP)
Assigned to NIPPON TELEGRAPH AND TELEPHONE CORPORATION, Tokyo (JP)
Appl. No. 17/785,370
Filed by NIPPON TELEGRAPH AND TELEPHONE CORPORATION, Tokyo (JP)
PCT Filed Dec. 16, 2019, PCT No. PCT/JP2019/049198
§ 371(c)(1), (2) Date Jun. 14, 2022,
PCT Pub. No. WO2021/124406, PCT Pub. Date Jun. 24, 2021.
Prior Publication US 2023/0025646 A1, Jan. 26, 2023
Int. Cl. H04B 10/114 (2013.01)
CPC H04B 10/114 (2013.01) 14 Claims
OG exemplary drawing
 
1. A terminal device that communicates with a base station by an optical wireless communication and an RF (Radio Frequency) wireless communication, the terminal device comprising:
an optical sensor that receives an optical signal of the optical wireless communication from the base station;
a calculation unit that samples an illuminance of the optical signal to acquire a sampling value, and calculates a threshold value for binarizing the optical signal based on transition of the sampling value;
a sensor that acquires physical information other than the illuminance of the optical signal,
wherein the calculation unit changes a smoothing constant used in the calculation of the threshold value based on the sensor information output from the sensor; and
a determination unit that binarizes the optical signal based on the threshold value.