Content deleted Content added
m ISBNs (Build KH) |
|||
Line 67:
*[[John Wozencraft]] and B. Reiffen, ''Sequential decoding'', ISBN 0-262-23006-2
*Rolf Johannsesson and Kamil Sh. Zigangirov, ''Fundamentals of convolutional coding'' (chapter 6), ISBN 0-470-27683-5
1. The Fano algorithm is a sequential decoding algorithm that does
not require a stack .
2. The Fano algorithm can only operate over a code tree because it
cannot examine path merging.
3. At each decoding stage, the Fano algorithm retains the
information regarding three paths: the current path, its
immediate predecessor path, and one of its successor paths.
4. Based on this information, the Fano algorithm can move from
the current path to either its immediate predecessor path or the
selected successor path; hence, no stack is required for queuing
all examined paths.
5. The movement of the Fano algorithm is guided by a dynamic
threshold T that is an integer multiple of a fixed step size ¢.
6. Only the path whose path metric is no less than T can be next
visited. According to the algorithm, the process of codeword
search continues to move forward along a code path, as long as
the Fano metric along the code path remains non-decreasing.
7. Once all the successor path metrics are smaller than T, the
algorithm moves backward to the predecessor path if the
predecessor path metric beats T; thereafter, threshold
examination will be subsequently performed on another successor
path of this revisited predecessor.
8. In case the predecessor path metric is also less than T, the
threshold T is one-step lowered so that the algorithm is not
trapped on the current path.
9. For the Fano algorithm, if a path is revisited, the presently
examined dynamic threshold is always lower than the momentary
dynamic threshold at the previous visit, guaranteeing that
looping in the algorithm does not occur, and that the algorithm
can ultimately reach a terminal node of the code tree, and stop.
<gallery>
File:Example.jpg|Caption1
</gallery>
==External links==
| |||