SOVA 算法的一篇文章

Louise

【文件名】:06613@52RD_ith Soft-Decision Outputs and its Applications.rar
【格　式】:rar
【大　小】:527K
【简　介】:The Viterbi algorithm (VA) is modified to deliver not
only the most likely path sequence in a finite-state
markov chain, but either the a posteriori probability
for each bit or a reliability value. With this reliability
indicator the modified VA produces soft decisions to
be used in decoding of outer codes. The inner Soft-
Output Viterbi Algorithm (SOVA) accepts and deliv-
ers soft sample values and can be regarded as a device
for improving the SNR, similar to an FM demodula-
tor. Several applications are investigated to show the
gain over the conventional hard-deciding VA, includ-
ing concatenated convolutional codes, concatenation
of convolutional and simple block codes, concatena-
tion of Trellis-Coded Modulation with convolutional
FEC codes, and coded Viterbi equalization. For these
applications we found additional gains of 1 - 4 dB as
compared to the classical hard-deciding algorithms.
For comparison, we also investigated the more com-
plex symbol-by-symbol MAP algorithm whose opti-
mal a posteriori probabilities can be tramformed into
soft outputs.
【目　录】:
1 Introduction
2 The Soft-Output Symbol- by-Symbo1 MAP and Viter-bi Algorithm (SOVA)
3 Applications