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VITERBI DECODING

Started by fsm12 December 31, 2009
HI,

   I want to know about error correcting capability of a convolution code
i.e. how many errors can be corrected in a continuous input  data pattern
(e.g.  a 1/2 rate code with constraint length of 7 has free distance of 10
and is said to correct 4 errors, whether these errors cab be burst type
also and what will be the relation of this error correction to input
data)?

 Thanks


On Thu, 31 Dec 2009 08:58:07 -0600, fsm12 wrote:

> HI, > > I want to know about error correcting capability of a convolution > code > i.e. how many errors can be corrected in a continuous input data > pattern (e.g. a 1/2 rate code with constraint length of 7 has free > distance of 10 and is said to correct 4 errors, whether these errors cab > be burst type also and what will be the relation of this error > correction to input data)? > > Thanks
Your question isn't clear. Viterbi decoders (or any other decoders, for convolutional or block codes) have a maximum-length burst that they can correct for (I think that's your "4 errors"), and in general an error rate that they can correct for. Given a long enough burst, any decoder will fall down on the job. Most practical channels tend to suffer from burst errors, so most practical FEC schemes -- convolutional or block -- reorder the encoded data. Then when the data is put back into the correct order at the receiver a burst error is turned into a bunch of individual bit errors which are easier for the decoder to deal with. -- www.wescottdesign.com

fsm12 wrote:

> HI, > > I want to know about error correcting capability of a convolution code > i.e. how many errors can be corrected in a continuous input data pattern > (e.g. a 1/2 rate code with constraint length of 7 has free distance of 10 > and is said to correct 4 errors, whether these errors cab be burst type > also and what will be the relation of this error correction to input > data)?
D = 2t + 1 VLV