A wireless infrared system using a dual-band receiver and a pulse width on–off keying modulation scheme

In this paper, we propose a dual-band infrared receiver and a pulse width on–off keying (PWOOK) modulation scheme for wireless systems. The dual-band receiver recovers the signal from two different subcarrier waves: 37.9 kHz for the conventional remote control systems and 113.7 kHz for the human interface device (HID) applications which require relatively fast data-transfer-rate and high infrared noise immunity under various optical environments. The PWOOK modulation scheme is a combined form of the pulse width modulation (PWM) and the on–off keying (OOK) using the subcarrier intensity-modulated (SIM) infrared signal. This paper also describes a wireless infrared system that is designed with the proposed dual-band infrared receiver and the PWOOK modulation scheme to demonstrate practical use of them. The dual-band infrared receiver is fabricated in a 0.5 μm CMOS process and the PWOOK modulation scheme transfers data at average bit-transfer-rate of 2.75 kbit/s through the wireless infrared link.