THEORETICAL CHARACTERIZATION AND PRACTICAL IMPLEMENTATION OF OPTICAL-FIBER PPM SELF SYNCHRONIZATION SEQUENCES

A novel technique for estimating the optical fibre PPM frame phase and eliminating the pattern dependent jitter is proposed while practical implementations and a mathematical characterisation for the technique are reported. Use is made of naturally occurring sequences thus-avoidi ng the sensitivity and bit rate penalties associated with the previous methods. Tracking additional sequences is demonstrated and shown to b e beneficial resulting in a frame rate discrete component enhancement of 10.8 dB and timing variance reduction from 12 x 10(-3) rad2 to 3.6 x 10(-3) rad2. Utilising the systematic jitter rejection method propos ed resulted in a measured timing variance reduction from 3.6 x 10(-3) rad2 to 4.2 x 10(-5) rad2. The limit is imposed by the PLL performance while good correlation is depicted with the theoretical model.