The Xilinx Puncture block removes a set of user-specified bits from the input words of its data stream.
Based on the Puncture
Code parameter, a binary vector that specifies which bits
to remove, it converts input data of type
(where N is equal to the length of the puncture code) into output data of type
UFixK_0 (where K is equal to the number of ones
in the puncture code). The output rate is identical to the input rate.
This block is commonly used in conjunction with a convolution encoder to implement punctured convolution codes as shown in the figure below.
The system shown implements a rate ½ convolution encoder whose outputs are punctured to produce four output bits for each three input bits. The top puncture block removes the center bit for code 0 ( [1 0 1] ) and bottom puncture block removes the least significant bit for code 1 ( [1 1 0 ] ), producing a 2-bit punctured output. These data streams are serialized into 1-bit in-phase and quadrature data streams for baseband shaping.
The block parameters dialog box can be invoked by double-clicking the icon in your Simulink® model.
Parameters specific to the block are as follows:
- Puncture Code
- The puncture pattern represented as a bit vector, where a zero in position i indicates bit i is to be removed.
Other parameters used by this block are explained in the topic Common Options in Block Parameter Dialog Boxes.