Theory for optical heterodyne narrow-deviation FSK receivers with delay demodulation

Author

Garrett, I. ; Jacobsen, G.

Author_Institution

British Telecom Res. Lab., Ipswich, UK

Volume

6

Issue

9

fYear

1988

fDate

9/1/1988 12:00:00 AM

Firstpage

1415

Lastpage

1423

Abstract

A theoretical model is presented that includes the effects of laser phase noise, receiver noise, imperfect modulation, IF bandwidth, and postdetection filtering. Detailed numerical results for 140-Mb/s and 400-Mb/s systems are presented, showing excellent agreement with independent published experimental results and strongly supporting the theoretical analysis. It is found that an IF linewidth of less than 0.25% of bit rate is required to avoid degrading the receiver sensitivity by more than 1 dB in a system with a strong local oscillator and modulation index of 0.7. A larger modulation index allows a larger linewidth to be accommodated. If the demodulation is not optimal, a narrower linewidth is necessary

Keywords

demodulation; filtering and prediction theory; frequency shift keying; noise; optical communication equipment; receivers; 140 Mbit/s; 400 Mbit/s; IF bandwidth; delay demodulation; frequency-shift-keying; laser phase noise; modulation index; narrow-deviation FSK receivers; postdetection filtering; receiver noise; Frequency shift keying; Laser modes; Laser noise; Optical filters; Optical mixing; Optical modulation; Optical noise; Optical receivers; Optical sensors; Phase noise;

fLanguage

English

Journal_Title

Lightwave Technology, Journal of

Publisher

ieee

ISSN

0733-8724

Type

jour

DOI

10.1109/50.7891

Filename

7891