Title :
Convergence and errors in turbo-decoding
Author :
Reid, Andrew C. ; Gulliver, T. Aaron ; Taylor, Desmond P.
Author_Institution :
Dept. of Electr. & Electron. Eng., Canterbury Univ., Christchurch, New Zealand
fDate :
12/1/2001 12:00:00 AM
Abstract :
Turbo-codes are decoded using iterative decoding algorithms with somewhat elusive convergence properties. In this paper, the modes of convergence observed in an extensive series of turbo-code simulations are categorized by examining the bit convergence behavior for each frame. Based on these results, a new method for decoder termination based on average log-likelihood ratios is presented and compared with other methods. As an application, a selective repeat automatic repeat request (ARQ) system is considered
Keywords :
automatic repeat request; coding errors; convergence of numerical methods; convolutional codes; decoding; interleaved codes; turbo codes; BER; RSC code; S-random interleaver; average log-likelihood ratio; bit convergence behavior; convergence properties; decoder termination; decoding errors; iterative decoding algorithms; random interleaver; recursive systematic convolutional code; selective ARQ system; selective repeat automatic repeat request; terminating interleaver; turbo-code simulations; turbo-decoding; Automatic repeat request; Convergence; Convolution; Convolutional codes; Helium; Iterative algorithms; Iterative decoding; Maximum likelihood decoding; Signal to noise ratio; Turbo codes;
Journal_Title :
Communications, IEEE Transactions on
