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Post by Ali Hassan on Jan 26, 2005 6:14:16 GMT -5
I am not understanding the convolutional encoder of Figure 18 of TCM Tutorial. Is it correct or I am not understanding it properly because the Trellis for that is not making sense as per diagram is concerned.
Please help
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Post by charan langton on Jan 26, 2005 19:47:12 GMT -5
Figure 18 has a line missing from the figure going to the plus sign. It did not translate when I made the PDF. Dont know why. I why seen numerous problems like that when making PDFs.
Figure 19 is the trellis of a rate 1/2 code. Three pieces are shown. Each piece covers just the first transition from to to t1. (first transition is enough to describe a trellis because thereafter it repeats.) The first piece shows the input bit and the output bits in parens. The second piece shows the Euclidean distance of the output bits in parens. The third piece shows the three paths that would bring the trellis back to 00. Instead of doing this in three transitions, I have done it in one. It saves space. You will see it done this way in other places as well.
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