darthvader1
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I thought that I completely understand the idea of convolutional coding and viterbi decoding.However,now,there is one funny question in my mind that I have never thought about.
I am not sure how we compare received data code words with outputs on trellis diagram and find hamming distances,branch metrics and so on.I mean should I imagine like "trellis again drawn in viterbi decoder"? No,I don't think so because,to find hamming distances,we already have encoded data outputs on trellis? So,what? how decoder knows these encoded data outputs if there is a noise? If decoder knows these encoder outputs, i mean code words, to compare received noisy code words,why do we need decoder then? I know I am thinking completely wrong now and I would like to learn if you guys make some comments.
I hope my english was enough to explain what my concerns are.Thank you for your helps.
I am not sure how we compare received data code words with outputs on trellis diagram and find hamming distances,branch metrics and so on.I mean should I imagine like "trellis again drawn in viterbi decoder"? No,I don't think so because,to find hamming distances,we already have encoded data outputs on trellis? So,what? how decoder knows these encoded data outputs if there is a noise? If decoder knows these encoder outputs, i mean code words, to compare received noisy code words,why do we need decoder then? I know I am thinking completely wrong now and I would like to learn if you guys make some comments.
I hope my english was enough to explain what my concerns are.Thank you for your helps.