Title :
On memory redundancy in the BCJR algorithm for nonrecursive shift register processes
Author :
Schmidt, Michael ; Fettweis, Gerhard P.
Author_Institution :
Tech. Univ. Dresden, Germany
fDate :
7/1/2000 12:00:00 AM
Abstract :
For computation of a posteriori probabilities (APPs), the well-known Bahl, Cocke, Jelinek, and Raviv (1974) algorithm is often applied. If the underlying model is a nonrecursive shift register process, it is shown that this algorithm obtains a general memory redundancy if the computation is performed over a commutative semiring with an absorbing zero element. The result is of particular interest for the BCJR algorithm carried out in the max-log domain
Keywords :
binary codes; binary sequences; convolutional codes; decoding; intersymbol interference; probability; shift registers; telecommunication channels; trellis codes; BCJR algorithm; Bahl Cocke Jelinek Raviv algorithm; ISI; a posteriori probabilities; absorbing zero element; binary codes; binary convolutional codes; commutative semiring; discrete-time intersymbol interference channel; max-log domain; memory redundancy; nonrecursive encoders; nonrecursive shift register processes; trellis encoder; Decoding; Equations; Error correction; Interpolation; Notice of Violation; Parallel algorithms; Polynomials; Redundancy; Reed-Solomon codes; Shift registers;
Journal_Title :
Information Theory, IEEE Transactions on
