Trellis codes based on amplitude and position modulation for infrared WLAN's

Abstract

In this communication we consider the use of an hybrid modulation method called amplitude and pulse-position modulation (APPM) in infrared WLAN. In this hybrid method the information is conveyed both in the position and amplitude of a pulse. The bandwidth efficiency and the capacity of this new modulation scheme are derived and compared against pulse-position modulation (PPM), which allows us to conclude that APPM can be used to improve the performance of PPM without bandwidth expansion, using trellis-coded modulation (TCM) codes. We also derive the best trellis codes for some A×2-APPM, and the results show that non-negligible coding gains can be obtained with trellis codes of moderate complexity.