My MATLAB Codes for LDPC



Updated June 22,2007

Finally, I completed all four LDPC MATLAB codes I needed for my thesis. I am studying a class of error correcting codes called low-density parity-check codes or LDPC codes. It’s one of the best codes which was developed lately and continues to attract a lot of researches.

A what???

Error correcting codes are important in communications. Imagine sending a text message to someone like “I LOVE YOU”. Due to noise present, the text message gets corrupted and its possible that the text message becomes a different set of unrecognizable characters. This is where a good error correcting code comes in. Once you receive the message, it tries to detect an error and correct it as the same time. This is a neat solution since it saves you from texting again and again until the correct message is received. Of course, this is just a simple and exaggerated example. But error correcting codes made a lot of things we enjoy today possible. Cellphones, satellites, cable, computers, mp3 players and a lot more.

I’m sharing my codes to those who are also interested in learning about LDPC codes. My thesis is devoted to studying the hard-decision bit flipping algorithms and I will be implementing it into a hardware. There are 4 types of algorithm I’m trying to study. Bit Flipping algorithms are the simplest decoding schemes available for LDPC codes. They provide a good trade-off between complexity and performance. These codes are good for those who what to start learnin about LDPC codes.

Here’s a list of the algorithms:

1. Standard Bit Flipping (BF) Algorithm by R Gallager
2. Weighted Bit Flipping (WBF) Algorithm by Y Kou, S Lin, M Fossorier
3. Modified Weighted Bit Flipping (IWBF) Algorithm by J Zhang, M Fossorier
4. Implementation-efficient Reliability Ratio based Weighted Bit-Flipping (IRRWBF) Algorithm by CH Lee and W Wolf

I placed a short instruction on how to use the code with the zip file as well as a few more links.

If you want to know more about LDPC codes, there are a lot of resources in the web. It took me almost six months to gather them and help me understand what my thesis will all be about. I hope my codes will help others who want to learn about LDPC shorten the learning curve.

Click here to download the zip file.



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20 Responses to “My MATLAB Codes for LDPC”

  1. intsik says:

    Nagdugo ilong kag dalunggan ko sa ginbasa ko but I am understanding it through ur explanation on the early part of it!
    Amazing ka gd ya!
    Sales lang storyahan ta ha! hehehehehehe
    Grabe ka complicated gali sg imo nga thesis!
    Hope it does well on its review.

    Sang una ko man ni guina basa daw pati bahulay ko dugo na ang nagaguwa. Pero sang sige lg liwat liwat basa na intiendihan man gd a.

  2. elizabeth says:

    heheh, way ko may na-intindihan jin, hanggang math kag chem lang ako, :). anyway, good luck gid and best wishes sa defense, wow, you’ve traveled a long way, keep it up.

    Thanks Miss Beth. Tani matapos ko ni by July ang proposal. Not even half way there but moving steadily.

  3. konbaar says:

    thank you for matlab code

    Thanks for dropping by. I am happy to know it will help others in their study.

  4. steven says:

    ur matlab code is very helpful for my study in LDPC,thx a lot for ur work,and hope i can discuss more details with u later after i understand it better.

  5. Mahesh says:

    Great work buddy!!! i dunno how to thank u.. will get back to u after i finish reading.. thanks a lot.. not posting email id cuz of spammers..

  6. asad says:

    hey….nice work on ldpc….i am working on it as well….can i have a copy of your thesis?….

  7. Harry Sandhu says:

    Great code. I am working on LDPC coded MIMO systems using variable rate LDPC codes. I need matlab code for variable rate LDPC encoder. Possible??

  8. deniz says:

    Hi,i wonder the performance of your code. İ mean how long does it take for decoding 1000 codewords for 3 db Eb/No?

  9. senouci mustapha says:

    very good sir

  10. senouci mustapha says:

    great ,
    i’am working on the ldpc coded for multiuser
    i need a matlab code source for this project

  11. senouci mustapha says:

    also , can i have a cpie of your thesis and some doc

  12. Alex says:

    May be something is wrong but I cant download LDPC MatLab zip. Abstract is very attractive, just to solve my problem. Can you help?

  13. sara says:

    can anyone help me.
    i want to use ldpc encoder and decoder in matlab in the simulink of dvb s2 but using k,n less than use in the original simulink of dvb how can i chanae it pleas

  14. Alex says:

    Dear Sara!
    I’m looking for LDPC encoding having check matrix H including US patents. But without result. MatLab codes are closed and not accessible for parametrs changing

  15. Maria Gonçalves says:

    Hi Manokan…
    Can you send me your zip file about LDPC to my e-mail?? I don’t have a account in the rapid share….
    Best regards,

  16. Nazli says:

    Hi everyone.

    I am looking for a MATLAB code which simulates hardware implementation of a LDPC decoder using message passing belief propagation algorithm. I need to observe the effect of quantization on the performance.


  17. Tom Brown says:

    I am needing to do a similar simulation for serial concatenated codes using LDPC as a component code. Did you have luck in finding some open codes for Matlab? The included codes in Matlab cannot be modified.


  18. Nalin Jayakody says:

    Thanks alot dear…a reat work

  19. Nalin Jayakody says:



  20. atash says:

    hello.i want to learn ldpc code .but idont know how?
    i need some refrence for learning.can you tell ?
    (i cant download matlab code)

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