Algorithms for Q-ary Error-Correcting Codes with Partial Feedback and Limited Magnitude

Berlekamp and Zigangirov completely determined the capacity error function for binary error correcting codes with noiseless feedback. It is still an unsolved problem if the upper bound for the capacity error function in the non-binary case of Ahlswede, Lebedev, and Deppe is sharp. We consider channels with limited magnitude and feedback. For several classes of these channels we completely determine the capacity error function. All our algorithms do not use all the feedback immediately. Furthermore, a special case of the problem is equivalent to Shannons zero-error problem.