Title :
Convergence based design of turbo codes
Author :
El Gamal, Hesham ; Hammons, A. Roger, Jr.
Author_Institution :
Dept. of Electr. Eng., Ohio State Univ., Columbus, OH, USA
Abstract :
In earlier work (see IEEE Trans. Inform. Theory, vol.47, no.2, p.671-86, Feb. 2001), we introduced a simple technique for analyzing the iterative decoder that is broadly applicable to different classes of codes defined over graphs in certain fading as well as AWGN channels. This technique is based on the observation that the extrinsic information from constituent MAP decoders is well approximated by Gaussian random variables when the inputs to the decoders are Gaussian. The independent Gaussian model implies the existence of an iterative decoder threshold that statistically characterizes the convergence of the iterative decoder. In this paper, we present an interesting convergence-based construction for asymmetric parallel concatenated convolutional codes
Keywords :
AWGN channels; concatenated codes; convergence of numerical methods; convolutional codes; fading channels; iterative decoding; turbo codes; AWGN channels; Gaussian random variables; asymmetric parallel concatenated convolutional codes; constituent MAP decoders; convergence based design; extrinsic information; fading channels; independent Gaussian model; iterative decoder; turbo codes; AWGN channels; Concatenated codes; Convergence; Convolutional codes; Fading; Floors; Iterative decoding; Random variables; Region 2; Turbo codes;
Conference_Titel :
Information Theory, 2001. Proceedings. 2001 IEEE International Symposium on
Conference_Location :
Washington, DC
Print_ISBN :
0-7803-7123-2
DOI :
10.1109/ISIT.2001.935962
