Continuous Adaptation Enhancement in Linear Regression Algorithm for Clock Recovery in IPTV Environment

Abstract

This paper presents a new technique for Clock Recovery in MPEG-2 Transport Streams in DVB-IPTV environment. The amount of jitter in this environment is very high compared to DVB-S or DVB-T. Use of linear regression algorithm for clock synchronization over packet switched networks is suggested by researchers in the similar field. However, the stability of such a filter in real time set top box application posed a problem. The continuous adaptive feedback loop used with the linear regression algorithm provides accurate clock synchronization even when subjected to jitter of half a second. This robustness is needed for IP environment because of the increasing network traffic. The algorithm was simulated and found to require low computation time, high jitter attenuation and fast response as needed for the IP network. It is auto-adaptive for both low and high jitter environments by analysing the jitter present in the stream. The algorithm was implemented for real time application in IPTV set top box and tested to be stable in the RTOS environment.