LDPC Encoder Definition (via Parity Check): Difference between revisions

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[[Category:Block Docs]]
[[Category:Block Docs]]
[[Category:Stub Docs]]
This block creates a LDPC Encoder Definition variable.
This is the template for the [[:Category:Block_Docs|"Page-per-block Docs"]].  This first section should describe what the block does and how to use it, using however many paragraphs necessary.  Note that the title of the wiki page should match the block's name in GRC, i.e. the one defined in the block's .grc file.  Look at the [[FFT]] Block for a good example.


As this is a basic template, it's also in the [[:Category:Stub_Docs|"Stub Docs category"]]. Please improve it.
This encoder performs a reduced complexity algorithm described by Richardson and Urbanke in Appendix A of their book: Modern Coding Theory. Compared to the block [[LDPC Encoder Definition (via Generator)]], this encoder requires orders of magnitude fewer operations to create each codeword. This is accomplished by completing a significant amount of the complex matrix manipulation (including inverse, multiplication, and Gaussian elimination operations) during preprocessing. The disadvantage of this encoder is that it requires a specially formatted matrix. However, GNU Radio includes python scripts to format a standard parity check matrix appropriately for this encoder, as well as a small library of encoding-ready matrices for use.


== Parameters ==
== Parameters ==
(''R''): <span class="plainlinks">[https://wiki.gnuradio.org/index.php/GNURadioCompanion#Variable_Controls ''Run-time adjustable'']</span>


; Param 1 (''R'')
; Parallelism
: Description of parameter, provide any tips or recommended values.  Note that the name of the parameter above should match the param's label that shows up in grc (e.g. Sample Rate).
: For parallel execution of multiple instances of the block (more info is needed on this)


; Param 2
; Dimension 1
: blah blah blah
: For parallelism
 
; Dimension 2
: For parallelism
 
; Parity check matrix
: The specific format of this parity check matrix is described by Richardson and Urbanke in Appendix A of their book: Modern Coding Theory (ISBN 978-0-521-85229-6). The matrix can be loaded by creating a [https://wiki.gnuradio.org/index.php/LDPC_Parity_Check_Matrix LDPC Parity Check Matrix] block and using its Id in this field.


== Example Flowgraph ==
== Example Flowgraph ==


Insert description of flowgraph here, then show a screenshot of the flowgraph and the output if there is an interesting GUI. Currently we have no standard method of uploading the actual flowgraph to the wiki or git repo, unfortunately. The plan is to have an example flowgraph showing how the block might be used, for every block, and the flowgraphs will live in the git repo.
This flowgraph can be found at [https://github.com/gnuradio/gnuradio/blob/master/gr-fec/examples/fecapi_ldpc_encoders.grc]
 
[[File:Fecapi_ldpc_encoders_fg.png|800px]]


== Source Files ==
== Source Files ==


; C++ files
; C++ files
: [https://github.com/gnuradio/gnuradio TODO]
: [https://github.com/gnuradio/gnuradio/blob/main/gr-fec/lib/ldpc_par_mtrx_encoder_impl.cc ldpc_par_mtrx_encoder_impl.cc]


; Header files
; Header files
: [https://github.com/gnuradio/gnuradio TODO]
: [https://github.com/gnuradio/gnuradio/blob/main/gr-fec/lib/ldpc_par_mtrx_encoder_impl.h ldpc_par_mtrx_encoder_impl.h]


; Public header files
; Public header files
: [https://github.com/gnuradio/gnuradio TODO]
: [https://github.com/gnuradio/gnuradio/blob/main/gr-fec/include/gnuradio/fec/ldpc_par_mtrx_encoder.h ldpc_par_mtrx_encoder.h]


; Block definition
; Block definition
: [https://github.com/gnuradio/gnuradio TODO]
: [https://github.com/gnuradio/gnuradio/blob/main/gr-fec/grc/variable_ldpc_encoder_H.block.yml variable_ldpc_encoder_H.block.yml]

Latest revision as of 10:53, 7 June 2022

This block creates a LDPC Encoder Definition variable.

This encoder performs a reduced complexity algorithm described by Richardson and Urbanke in Appendix A of their book: Modern Coding Theory. Compared to the block LDPC Encoder Definition (via Generator), this encoder requires orders of magnitude fewer operations to create each codeword. This is accomplished by completing a significant amount of the complex matrix manipulation (including inverse, multiplication, and Gaussian elimination operations) during preprocessing. The disadvantage of this encoder is that it requires a specially formatted matrix. However, GNU Radio includes python scripts to format a standard parity check matrix appropriately for this encoder, as well as a small library of encoding-ready matrices for use.

Parameters

Parallelism
For parallel execution of multiple instances of the block (more info is needed on this)
Dimension 1
For parallelism
Dimension 2
For parallelism
Parity check matrix
The specific format of this parity check matrix is described by Richardson and Urbanke in Appendix A of their book: Modern Coding Theory (ISBN 978-0-521-85229-6). The matrix can be loaded by creating a LDPC Parity Check Matrix block and using its Id in this field.

Example Flowgraph

This flowgraph can be found at [1]

Fecapi ldpc encoders fg.png

Source Files

C++ files
ldpc_par_mtrx_encoder_impl.cc
Header files
ldpc_par_mtrx_encoder_impl.h
Public header files
ldpc_par_mtrx_encoder.h
Block definition
variable_ldpc_encoder_H.block.yml
Retrieved from "https://wiki.gnuradio.org/index.php?title=LDPC_Encoder_Definition_(via_Parity_Check)&oldid=12336"