Turbo charged information theory
Monday 29 September 2008
Dr Johann Briffa and Dr Hans Georg Schaathun had two papers on turbo codes in information theory accepted for presentation at IEEE conferences recently: the IEEE International Symposium on Information Theory and its Applications, Auckland, and the International Symposium on Turbo Codes, Lausanne.
Johann A. Briffa, Hans Georg Schaathun, Improvement of the Davey-MacKay Construction, Proceedings of the IEEE International Symposium on Information Theory and its Applications, Auckland, New Zealand, Dec 7-10, 2008.
"The Davey-MacKay construction is a Deletion-Insertion Correcting Code scheme consisting of an inner code that functions as a pilot sequence to which the receiver seeks to synchronize, and an outer code that provides error protection. We analyse the performance of the inner code in isolation, arguing that these codes provide unequal protection, and demonstrate empirically that the error rate is dependent on the data symbol values. We also propose modifications to the code construction that alleviate this asymmetry. Simulation results show that these codes have an improved performance with no penalty."
Johann A. Briffa, Hans Georg Schaathun, Non-binary turbo codes and applications, Proceedings of the IEEE International Symposium on Turbo Codes & related topics, pp. 294-298, Lausanne, Switzerland, Sep 1-5, 2008.
"In this paper we consider the use of q-ary turbo codes on abstract q-ary channels. Simulations show that our 16-ary codes perform well on the q-ary symmetric channel. This validates their suitability as outer codes in non-binary applications. We also compare with the performance of same codes on conventional PSK and QAM modulation, and demonstrate an application of these codes to the insertion/deletion channel."