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channel coding and puncturing

Started by Sharan123 3 weeks ago3 replieslatest reply 3 weeks ago69 views

with respect to puncturing associated with channel coding, I have a question.

So, when a code word is punctured at the transmitted how does the receiver know the size of the code word.

This is an example from Wiki - https://en.wikipedia.org/wiki/Puncturing

The original code word is 110110 with code rate of 1/2

After puncturing, the new code word is - 1010 with code rate of 3.4

Second and fourth bits are removed from code word with 1/2 code rate

So, in the above case, how does the receiver know that the code word boundary is 4 bits after puncturing?

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Reply by kazNovember 23, 2019

That is why any user sets FEC rate at receiver as instructed by transmitter

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Reply by Sharan123November 24, 2019

Ok. So, the receiver needs to be informed about the channel encoding configuration/control?

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Reply by kazNovember 24, 2019

Yes. A communication system does not need to put all the burden on receiver to detect parameters automatically. Constants such as FEC rate, bandwidth of signal, centre frequency etc can be part of tx/rx protocol. If these are not constants then the receiver have to be designed differently.