Convolutional code: Difference between revisions

Revision as of 22:54, 22 July 2006

Revision as of 00:52, 9 August 2006

Line 66:

Since a convolutional code doesn't use blocks, processing instead a continuous bitstream, the value of <math>t</math> applies to a quantity of errors located relatively near to each other. That is, multiple groups of <math>t</math> errors can usually be fixed when they are relatively far.

Free distance can be interpreted as a minimal length of aan erroneous "burst" at the output of a convolutional decoder. The fact that errors appears as "bursts" should be accounted for when designing a [[concatenated code]] with an inner convolutional code. The popular solution for this problem is to [[interleaver|interleave]] data before convolutional encoding, so that outer block (usually [[Reed-Solomon]]) code can correct most of the errors.

===Decoding Convolutional Codes===