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Coding Theory Group

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Welcome to the home page for the Coding Theory Group at the Department of Mathematics of University of Turku. The group is part of the Turku Centre for Computer Science (TUCS).

Assume that information is sent from a source over a noisy channel to a receiver. A fundamental problem of coding theory is to determine what message was sent on the basis of the approximation that was received. The mathematical theory of error-correcting codes dates back to Shannon who in 1948 published a very remarkable paper on the existence of good error-correcting systems. At the same time Hamming constructed perfect single-error-correcting codes.

The research carried out at the department essentially started in 1971 when Tietäväinen solved the so-called perfect code problem. During last decades the theory of error-correcting codes has developed drastically. From the mathematical point of view it is an application of number theory, algebra and combinatorics. We have studied all these areas. The mathematical coding theory is in part pure basic research, but since the applications are never very far away, many aspects have great significance also on the practical level.

Some number theoretic problems that have been investigated or will be attacked have been considered in the chapter "Codes and Number Theory" (by Honkala and Tietäväinen) of Handbook of Coding Theory. The monograph "Covering Codes" (by Cohen, Honkala, Litsyn and Lobstein) discusses how we can apply algebraic and combinatorial methods to covering radius problems.

All in all eleven PhD theses have been written about coding theory at the Department of Mathematics at the University of Turku. The most recent one was written in 2002 by Kalle Ranto.

The main fields of research are

* Covering Codes
* Identifying Codes
* Z4-Codes

At the moment the Coding Theory Group consists of eight researchers. The leader of the group is Iiro Honkala. For the members of the group and their publications, see

* Research Team
* Publications

The research groups of Finnish mathematics were evaluated during the spring 2000.

* The report of evaluation of Coding Theory Group

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