Very Excellent sources of knowledge for students of Digital Communications 

Know of good sites, please post info on bottom of this page!

General topic and forums sites where you can ask questions and get help on topics of digital communications

All about Fourier analysis

Spectral Estimation


DSP – general

Sampling, aliasing and windows


Tools, Software



Phase Lock Loops


Spectrum measurements

Spread Spectrum

Articles on spread spectrum and CDMA

Trellis Coded Modulation


OFDM Tutorials

Spread Spectrum Tutorials

Image Processing

Useful industry sites

13 comments on “Links
  1. Raghav Kapur says:

    Can you please add a link to my website to

    I run a website for the RF & Microwave Industry called everything RF –

    We provide a tool which enables engineers to find products and companies based on their requirement. We also provide a useful White Paper Library.


  2. Derek Kozel says:

    Hello. The link to the discussion on harmonics under the FFT section is dead. Thankfully the wayback machine has a copy including the wav files.

    Your tutorials are excellent, thank you for taking so much time to write them. It’s unfortunately rare to find someone who has a deep understanding of the material, can communicate clearly and efficiently, and covers such a breadth. Thank you.

  3. Madam,

    i am very much impressed with your writing style, and also the content.

    A small request is to verify the URL links given above, as few of them are dead.


  4. George Maher says:

    Dear Ms. Langton,
    Thank you for writing your tutorials. I have taken a lot of advanced EE classes years ago but sometimes had nagging questions about basic things and they were usually covered in a very clear way in your tutorials – which I discovered later. You address complex (obvious pun) concepts in a very approachable way that is similar to how I try to understand new concepts at first. Your tutorials have helped me immensely.


    • Charan L. says:

      Dear George,

      Thank you very much for your nice comments.
      I am so glad you liked the name of the site.
      It is cute.

      I am working on a book right now, which is why I have not posted for a while.

      Thanks again for your comments,

      Charan Langton

  5. David Binner says:

    Hi, Charan.

    Nice website! I came across it when looking for resources relevant to the Discrete Fourier Transform (DFT). I often look around to see what information is available; it helps with my own work. Reading material from a wide range of perspectives usually helps me understand concept better.

    I’d also like to share some of my work that may be relevant to your website: last year (2015), I posted a JavaScript translation of a DFT from the FFTPACK library:

    Discrete Fourier Transform:

    It is simple to use and I hope you find it useful.

  6. Alina says:

    I have this question
    Theoretically, could the bandwith for WCDMA be lower than 3.8Mhz, say 1.9 for instance?
    In Lte the minimum I have seen is 1.4

    Thank you,

    • Charan L. says:

      The bandwidth allocated and bandwidth possible can be two different things. The bandwidth (baseband) required is only a function of the the modulation order and symbol rate.

      One always starts with the data rate required. Lets says that the minimum date rate needed for voice is 9.6 Kbps (for a give BER). Assume modulation is QPSK (as in CDMA), then bandwidth is equal to 2 times the symbol rate. Actually the bit rate for voice cna be as alo as 1.024 Kbs, in which case, the badwidth required would be only two times that.

      Not sure if this was your question. In LTE the channels can provide compressed video as well. So it all depends on the service parameters.


  7. tLin says:

    Hi Charan
    I am looking for a Simulink model for wireless receiver for education purpose. Bumped into this one,, at but it doesn’t work. Do you have one handy?

    Also I think is a good site for ECE research and design. It is new but I like its idea to encourage engineers to share knowledge. I guess you can add it to your list so others can also benefit.


  8. HI, some links don’t work anymore. Actually most of them. Anyway your tutorials are great.

  9. peyman says:

    Excited and respectful and respectful
    I am a graduate student in computer network engineering and study in Iran
    And I’m investigating cryptography and decryption with the convolution of the code
    I need an algorithm to capture and hide the data and submit an image file, and eventually send the data hidden behind the photo to be detected in the receiver.
    please guide me

  10. Marge Espina says:


    I was wondering what your thoughts were on “All About Circuits”, would you consider adding them to the “Links” page? Here is the URL for their website if you would like to have a look:

    I am looking forward to hear from you the soonest.


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