The combination
("concatenation") of Reed-Solomon outer code and convolutional inner code
has long been recognized as an effective combination for satellite and
terrestrial radio applications in the presence of Gaussian noise. When a
convolutional encoder / Viterbi decoder pair fails, it tends to fail in
bursts of errors. This is because the convolutional code is a state machine,
and once the decoder guesses the wrong state, a preponderance of correct
data samples are required to force it back into alignment with the correct
state sequence. The Reed-Solomon outer code is especially good at correcting
error bursts, and thus is very effective in combination with the Viterbi
decoder.
Additionally, the
performance of the concatenated code is enhanced by including a rectangular
byte interleaver between the outer and inner codes.
The table below shows all our
concatenated Reed-Solomon / Viterbi devices currently offered as
standard products for sale. The SALxx400-series is the defacto industry
standard (255, 239) / (7, 1/2) combination concatenated code, with a generic
rectangular interleaver between them. The SAL10400-series product is a
highly configurable concatenated code, for customers requiring a more
flexible solution. Contact us at
sales@salamander-ecc.com for
more information, or to request a custom designed solution.
|
Concatenated RS / Viterbi codes |
|
SALxx400E |
RS encoder / interleaver / convolutional
encoder |
|
SALxx400D |
Viterbi decoder / de-interleaver / RS
decoder |
|
SAL10400E |
Parameterizable RS encoder / interleaver
/ convolutional encoder |
|
SAL10400D |
Parameterizable Viterbi decoder /
de-interleaver / RS decoder |
|
Concatenated RS / Viterbi code Design Service |
|
SALxx400DS |
Concatenated Reed-Solomon / Viterbi codec design service |
