ASK digital demodulation scheme for noise immune infrared data communication

A high performance architecture is proposed for the ASK (Amplitude Shift Keying) digital demodulation, which is dedicated to the noise immune wireless infrared data communication. In this architecture, an infrared subcarrier detected by a photodetector is digitized into TTL interface level pulses, and the digitized subcarrier is demodulated by a 1‐bit digital demodulator. To improve the noise immunity against fluorescent lamps, the optical noises from the lamps are analyzed and the behavior of an ASK infrared communication link is modeled under these noises. On the basis of this model, a digital demodulator is synthesized by means of a high level synthesis tool, aiming at implementing an algorithm of discriminating the subcarrier from optical noises. A part of experimental results shows that the ASK receiver realized with the use of this digital demodulator can achieve an error free infrared link even under the intense noises from fluorescent lamps. This revised version was published online in July 2006 with corrections to the Cover Date.