Coding techniques for wireless infrared communications

Abstract

In this communication we consider the use of coding techniques to improve the performance of infrared wireless communication systems. We perform a review of the most common modulation methods used in such systems, and present the expressions for the probability of symbol error and channel capacity. We review the most common coding techniques and address the use of trellis code modulation, to improve the performance of uncoded PPM. To augment the alphabet size of PPM, we propose an hybrid modulation scheme called APPM, and derive the best codes for 2 X 2-APPM. The results show that non-negligible gains can be obtained with convolutional codes of moderate complexity.