Computer Science – Information Theory
Scientific paper
2007-08-21
Computer Science
Information Theory
6 pages
Scientific paper
We consider the `one-shot frame synchronization problem' where a decoder wants to locate a sync pattern at the output of a channel on the basis of sequential observations. We assume that the sync pattern of length N starts being emitted at a random time within some interval of size A, that characterizes the asynchronism level between the transmitter and the receiver. We show that a sequential decoder can optimally locate the sync pattern, i.e., exactly, without delay, and with probability approaching one as N tends to infinity, if and only if the asynchronism level grows as O(exp(N*k)), with k below the `synchronization threshold,' a constant that admits a simple expression depending on the channel. This constant is the same as the one that characterizes the limit for reliable asynchronous communication, as was recently reported by the authors. If k exceeds the synchronization threshold, any decoder, sequential or non-sequential, locates the sync pattern with an error that tends to one as N tends to infinity. Hence, a sequential decoder can locate a sync pattern as well as the (non-sequential) maximum likelihood decoder that operates on the basis of output sequences of maximum length A+N-1, but with much fewer observations.
Chandar Venkat
Tchamkerten Aslan
Wornell Gregory
No associations
LandOfFree
Optimal Sequential Frame Synchronization does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Optimal Sequential Frame Synchronization, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Optimal Sequential Frame Synchronization will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-135312