Pulse-Position Modulation for Transmission Over Optical Fibers with Direct or Heterodyne Detection. - Ian Garrett (IEEE Trans. Commun., 1983)

A comparison of coherent digital PPM with PCM. - Robert A. Cryan; Rodney T. Unwin; Alistair J. Massarella; Martin J. N. Sibley; Ian Garrett (Eur. Trans. Telecommun., 1992)