The Minimum Likelihood--A New Concept for Bit Synchronization

A new bit synchronization concept based on the "minimum likelihood" criterion instead of the conventional "maximum likelihood" concept is developed. The minimum likelihood situation is even easier to reach than the maximum likelihood because the derivative of the log likelihood function becomes identically zero there. Minimum likelihood implies "least likely" for synchronization (the worst case synchronization error) or an "orthogonal" timing condition which simply means that the locally generated clock is synchronized correctly, but with a delay of a half bit period. The structure and performance of the minimum likelihood bit synchronizer are discussed in detail in this paper. The results indicate that the minimum likelihood bit synchronizer has a much simpler structure, but with performance very close to the optimal maximum likelihood synchronizer.