Performance evaluation of optically preamplified dicode pulse position modulation receivers

An analysis for optically preamplified dicode pulse position modulation (DiPPM) receivers is presented for the first time. The performance at two different bit rates (622 Mbit/s and 2.5 Gbit/s) is analysed and compared with equivalent optically preamplified pulse position modulation (PPM) and on-off keyed non-return-to-zero (OOK NRZ) systems. Additionally a new derivation for the average power of the DiPPM pulse stream is provided and the sensitivity performance is compared with that obtainable from a previous formula, with results that are somewhat more conservative. For optically preamplified systems it is shown that PPM significantly outperforms DiPPM and OOK NRZ, when using the DiPPM average power formula derived here, but DiPPM could still show a sensitivity benefit over OOK NRZ of 4.2 dB. Copyright © 2007 John Wiley & Sons, Ltd.