Optical fibre PPM using a PIN-FET receiver and central decision detection

An 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