Wavecom W-BitView V2.5.00 - Manual (Page 44)

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Function Library BitView Manual V2.5.00 WAVECOM W-BV
Standard Depuncturing
In: Punctured bit stream
Out: De-punctured bit stream
Function:
This function adds de-puncturing and probability bits to the input bit stream according to standard
puncture matrices or a user defined matrix. The input stream is converted so that each input bit is
followed by three probability bits within the range “0 … 7”, where “0” indicates an erasure and “7” a
probability of 100%.
Parameter Description
Code rate (Standard
matrices)
Defines code rate for de-puncturing. If the code rate is ½ there is no puncturing. All
other code rates require de-puncturing
Select depuncture
matrix
Selects the type of de-puncture matrix used
User defined matrix Selects the number of de-puncture matrix columns
The standard puncturing matrices for selected code rates:
Code rate Puncturing matrix
1/2 1/1 (no puncturing)
2/3 10/11
3/4 101/110
4/5 1000/1111
5/6 10101/11010
6/7 100101/111010
7/8 1000101/1111010
Decoding the de-punctured bit stream can be done by using the Viterbi decoder configured as listed
below:
Code rate Viterbi decoder settings
Metric No. of decision bits
1/2 Hard decision N.A.
All other rates Soft decision 3
Difference-Decoding
In: Bit stream
Out: Bit stream