Title :
A batteryless optical-wireless system with white-LED illumination
Author :
Douseki, Takakuni
Author_Institution :
NTT Microsystem Integration Laboratories, NTT Corp., Kanagawa, Japan
Abstract :
A self-powered optical-wireless data-transmission system that uses solar cells and works under white-LED illumination is described. Solar cells have both power-generation and photodetection functions. Digital light modulation based on Manchester-NRZ pulses transmits data without flickering of the illumination. An instantaneous-activation 0.5-V CPU scheme with multi-threshold (MT) CMOS/SOI technology accelerates the clock frequency and shortens the active time, making ultralow-power operation possible. An electrical double-layer capacitor, which is a sub power source for the CPU in the active mode, also contributes to achieving self-powered operation. To verify the effectiveness of the optical-wireless system, we fabricated a wireless message board. The board shows that the system transmits data of up to 100 Kbps without a battery.
Keywords :
CMOS integrated circuits; data communication; large scale integration; light emitting diodes; optical communication; optical modulation; solar cells; 0.5 V; 100 Kbit/s; CMOS technology; digital light modulation; electrical double-layer capacitor; optical-wireless data-transmission system; self-powered operation; solar cells; white-LED illumination; Acceleration; CMOS technology; Clocks; Digital modulation; Frequency; Lighting; Optical modulation; Optical pulses; Photovoltaic cells; Pulse modulation;
Conference_Titel :
Personal, Indoor and Mobile Radio Communications, 2004. PIMRC 2004. 15th IEEE International Symposium on
Print_ISBN :
0-7803-8523-3
DOI :
10.1109/PIMRC.2004.1368776
