What is the purpose of puncturing?

[Antonio_Magma]

I was playing around with the Simulink demo hiperlan2 and the model includes a puncture block.

I checked the help file in Simulink and it explains that puncture removes certain bits and preserve certain bits of an input.

May i know what is the purpose of doing that?

And if the depuncture block doesn't know the bits removed was it a 0 or 1, how does it depuncture?

 

[eda_wiz]

bit puncturing

hi ,
puncturing is done for increasing the bit rate.
convolutional encoder introduces redundancy of 2-3x bits per each bit.. puncturing removes some redundancy to increase the TX bit rate. Depuncuring introduces just dummy bits, 1 or 0 doesnt matter. viterbi decoder shud recover the the data from the depunctured data

 

[b.pricope]

what is punctured

Here is a definition of the MATLAB code puncturer.
**broken link removed**

I hope it helps!

 

[chenhua]

what is data puncturing

Depuncture block alway insert 0 (do not need to know exactly). Viterbi decoding will correct that if it is error.

 

[spweda]

how punturing code edaboard

Puncting coudl be for meeting a special requirement for physical layer. For example, if a frame is fixed at 192 bits, the source rate is 144 bits, a punctured covolutional coder could be used to the requirement.

 

[iTdl]

rate 1/2 puncturing vector

Puncturing increases the code rate. So you can reduce further the redundant information.

Depuncturing block always inserts 0s. Decoder has the ability to decode to decode with those many reduced bits. Refer to Viterbi decoder for more info.

 

[k_srinivas_rao]

puncturing rate

Puncturing uses a puncturing vector which is a sequence of 0's and 1's.
For 0, the corresponding bit shall be taken out and shall not be transmitted;
For 1, the corresponding bit shall be retained in the sub-block and shall be transmitted.

 

[zahedi79]

depuncture

I have read about 2 methods.
can any one have some information about those methods.

1. Register exchange algorithm (REA)

2. Trace Back Algorithm (TBA)

thanks a lot

 

[mahankalisatish]

ctc 3/4 rate puncture

puncturing increases the data rate.

suppose if u take wimax u have puncturing rates of 1/2 ,2/3 ,3/4

where u transmit 2 bits and receive 1 bit,
2/3 means u transmit 3 bits and take 2.

these punctured data can be recovered using Viterbi or CTC decoders .