Detection in the presence of additive noise and unknown offset

The error performance of optical storage and Non-Volatile Memory (Flash) is susceptible to unknown offset of the retrieved signal. Balanced codes offer immunity against unknown offset at the cost of a significant code redundancy, while minimum Pearson distance detection offers immunity with low-redundant codes at the price of lessened noise margin. We will present a hybrid detection method, where the distance measure is a weighted sum of the Euclidean and Pearson distance, so that the system designer may trade noise margin versus amount of immunity to unknown offset.