Title :
Modulation and demodulation techniques in optical heterodyne PSK transmission systems
Author :
Chikama, Terumi ; Watanabe, Shigeki ; Naito, Takao ; Onaka, Hiroshi ; Kiyonaga, Tetsuya ; Onoda, Yoshihito ; Miyata, Hideyuki ; Suyama, Masuo ; Seino, Minoru ; Kuwahara, Hideo
Author_Institution :
Fujitsu Lab. Ltd., Kawasaki, Japan
fDate :
3/1/1990 12:00:00 AM
Abstract :
Modulation and demodulation techniques are described for an optical PSK heterodyne transmission system operating at 560 Mb/s and 1.2 Gb/s. Performance limitations affecting the receiver sensitivity in a 1.2-Gb/s DPSK system, such as laser phase noise, phase modulation depth, IF center frequency deviation, and local laser power, are studied. High receiver sensitivities for PSK systems were achieved. The applicability of the Mach-Zehnder modulator as a phase modulator for 1.2-Gb/s DPSK is also demonstrated. A 1.2-Gb/s DPSK transmission of over 100 km, using polarization diversity with novel polarization-insensitive automatic frequency control in an attempt to overcome signal fading caused by polarization fluctuation in the transmitting fiber, is also described. A receiver sensitivity of less than -42.8 dBm and varying within 1.4 dB for all states of polarization was achieved. A multichannel high-definition TV (HDTV) transmission experiment using a DPSK polarization-diversity tunable receiver is described
Keywords :
demodulation; high definition television; light polarisation; optical fibres; optical modulation; phase shift keying; receivers; 1.2 Gbit/s; 100 km; 560 Mbit/s; DPSK system; HDTV; IF center frequency deviation; Mach-Zehnder modulator; demodulation techniques; laser phase noise; local laser power; modulation techniques; multichannel high-definition TV; optical heterodyne PSK transmission systems; phase modulation depth; phase modulator; polarization diversity; polarization fluctuation; polarization-insensitive automatic frequency control; receiver sensitivity; signal fading; transmitting fiber; tunable receiver; Demodulation; Differential quadrature phase shift keying; Optical mixing; Optical modulation; Optical noise; Optical receivers; Optical sensors; Optical variables control; Phase shift keying; Polarization;
Journal_Title :
Lightwave Technology, Journal of
