AbstractAn analysis is presented, for the first time, for an optical fibre PPM system employing central decision detection. Firstly, an ideal matched filter in conjunction with a noise‐whitening filter is considered and secondly a raised cosine filter to eliminate intersymbol interference is modelled. It is shown that the latter offers superior performance. The results for a 155.52 Mb/s system predict a sensitivity of −57.6 dBm, an improvement of 6 dB over an equivalent PCM system. © 2006 Wiley Periodicals, Inc. Microwave Opt Technol Lett 48: 791–794, 2006; Pubished online in Wiley InterScience (www.interscience.wiley.com) DOI 10.1002/mop.21477