An Optical Heterodyne PSK Receiver using an Improved Decision Directed PLL in Presence of Adjacent Channel Interference

Abstract

An optical phase-shift-keying (PSK) heterodyne receiver using synchronous detection by means of a decision directed phase locked loop (PLL) has been investigated taking the effect of shot noise, phase noise, adjacent channel interference and loop propagation delay. The evaluation of phase-error variance and error probability calculations are performed without affecting the loop stability. The plots of error probability with PNB are presented as a function of normalised optical domain channel spacing for several linewidth-to-bit-rate ratios. A relative improvement in error probability of 4 dB has been obtained with normalised control parameter of 0.4, D = 10R_b & δf = 0.001R_b.

Indexing terms:

• Phase error variance
• Shot noise
• Phase noise
• Adjacent channel interference