The Effect of Baseline Wander on the Performance of Digital Pulse Interval Modulation

This paper examines the effect of baseline wander on systems employing digital pulse interval modulation (DPIM). Computer simulation results are presented, and comparisons are made with onoff keying (OOK) and pulse position modulation (PPM). It is shown that, since the power spectral density of DPIM does not go to zero at DC, DPIM is more susceptible to the effects of baseline wander than PPM, but is more robust than OOK. 1. INTRODUCTION Infrared wireless transceivers usually operate in environments containing an intense amount of ambient light, emanating from both natural and artificial sources. Sunlight and incandescent lamps represent essentially unmodulated sources of background radiation. The average power of the background radiation generates a D.C. photocurrent in the photodetector, giving rise to shot noise, which is the dominant noise source in a typical diffuse receiver.