A comparison of coherent digital PPM with PCM

Autor:	Rodney T. Unwin, Alistair J. Massarella, Martin J.N. Sibley, Robert A. Cryan, Ian Garrett
Rok vydání:	1992
Předmět:	Physics Heterodyne Frequency-shift keying business.industry Optical communication computer.file_format Photon counting Optics Modulation Pulse-position modulation Electronic engineering Electrical and Electronic Engineering Pulse-code modulation business computer Phase-shift keying
Zdroj:	European Transactions on Telecommunications. 3:331-340
ISSN:	1541-8251 1124-318X
Popis:	Digital pulse position modulation (PPM) is a preferred modulation format for the ideal photon counting channel and optical intersateilite links. Here we examine its potential for the coherent optical fibre communications channel. We present a thorough performance and optimisation analysis. Comparisons, at a wavelength of 1.5 m, are made with shot-noise limited coherent PCM (homodyne and heterodyne ASK, FSK and PSK) over a range of fibre band-widths and varying PPM word size. We conclude that for moderate to high fibre bandwidths homodyne digital PPM should achieve an improvement in sensitivity of typically 5 dB over homo-dyne PSK PCM
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::e03d52428438b81defd8ac8fe46d99e8 https://doi.org/10.1002/ett.4460030405 Zobrazit plný text záznamu Plný text