Speaker
Mr
KAGISO J LEBURU
(NELSON MANDELA METROPOLITAN UNIVERSITY)
Description
Telescope networks rely on high frequency clock tones to be distributed to each antenna for driving the digitizers, time stamping the data and for monitoring and control functions. Stringent timing signals also find use in organisations like Square Kilometre Array, National Metrology Institute of South Africa, Coordinated Universal Time and Global Positioning System; as well as in areas of financial systems, telecommunications, transport and the military. However, clocks suffer from time deviation from the true periodicity, known as jitter. Jitter is contributed by noise, thermal effects, and aging of clocks. It can be either random or deterministic. In this study we analyse the jitter contributed by transmission of pulse-per-second (PPS) timing signals over typical optical fibre networks. The PPS timing signals were transmitted in G.652 optical fibre of length 3.21 km. A 1310 nm Vertical Cavity Surface Emitting Laser, biased at 4.79 mA, was modulated using PPS signals. The overall jitter contribution from the optical fibre transmission was found to be 202 picoseconds. This means that the PPS signals’ periodicity deviates by this value, and may cause signal delays in communication and timing systems. This value agrees with the typical acceptable jitter ranges of pico- to femtoseconds. For stringent timing applications, jitter correction mechanisms may be required to effectively compensate for the jittery in such systems.
Keywords: Timing signals, PPS, Jitter, Optical fibre networks
Level for award<br> (Hons, MSc, <br> PhD, N/A)?
MSc
Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?
No
Apply to be<br> considered for a student <br> award (Yes / No)?
Yes
Main supervisor (name and email)<br>and his / her institution
T.B. Gibbon
Tim.Gibbon@nmmu.ac.za
Centre for Broadband Communication, Physics Department, Nelson Mandela Metropolitan University, P. O. Box 77000, South Campus, Summerstrand, Port Elizabeth, 6031, South Africa
Primary author
Mr
KAGISO J LEBURU
(NELSON MANDELA METROPOLITAN UNIVERSITY)
Co-authors
Prof.
Andrew Leitch
(NMMU)
Dr
Duncan Boiyo
(Centre for Broadband Communication, Nelson Mandela Metropolitan University)
Dr
Romeo Reginald Gunther Gamatham
(NRF, Square Kilometre Array South Africa)
Dr
Timothy Gibbon
(NMMU Physics Department)
