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Matlab Code to Generate LoRa Symbols


In the previous post you read the theory about LoRa Symbol generation.

Buy the Matlab codes here!

Code generates the following plot.



For theory please refer to  LoRa Symbol generation





If you are a research student and want to sell your work on my Blog here, please reach me on sakshama.ghosliya@gmail.com





19 comments:

  1. Unknown28 June 2017 at 14:08

    Dear Sir,
    In your LoRa modulation function code, the frequency varies linearly with time. Shouldn't the phase increase be a quadratic function of time, since the total phase is the integral of frequency? I'm very confused since your expression is not even a function of time. It would help me understand LoRa much better if you could clarify this point, Sir.
    Thank you in advance!

    ReplyDelete
    Replies
    1. Sakshama Ghoslya30 June 2017 at 17:37

      See, I divided the time in small time bins. You know, you can calculate the the symbol time by SF and BW. You can't see the 'time' variable in the code. See, you divided the complete symbol in some number of samples. Number of samples is related to SF and BW, therefore as the sample number increases you move along with both time and frequency axis.

      Delete
  2. NEED27 September 2017 at 13:23

    I have multiple questions on this plot
    1. Why is the plot at 500KHz when you only use BW, SF, Sampling rate in the code
    2. what does frequency offset away from DC means?
    3. How did you derive equation of number of samples from SF, BW, Fs?
    4. Why is Fs = 1MSPS? is it lora standard?

    ReplyDelete
    Replies
    1. rakr6 November 2017 at 21:07

      Why is the plot at 500kHz? I see in the LoRa function: Frequency_Offset = (Fs/2) - (BW/2);

      This calculation gives about 500kHz. But I think it should be the actual carrier frequency like 868MHz?

      Delete
    2. rakr6 November 2017 at 21:07

      Why is the plot at 500kHz? I see in the LoRa function: Frequency_Offset = (Fs/2) - (BW/2);

      This calculation gives about 500kHz. But I think it should be the actual carrier frequency like 868MHz?

      Delete
    3. Sakshama Ghoslya7 November 2017 at 09:45

      If you want the central frequency to be 868MHz then you don't need to choose Frequency_Offset = (Fs/2) - (BW/2); In the above code it is 500KHz so that you can visualise the symbols clearly in the graph.

      Delete
    4. Ramsha3 September 2018 at 12:04

      Can we directly put 868MHz instead of Frequency_Offset = (Fs/2) - (BW/2); in a code?

      Delete
  3. Nikos12 February 2018 at 22:19

    This comment has been removed by the author.

    ReplyDelete
  4. Nikos12 February 2018 at 22:21

    I would like to ask why you set the number of samples like the following num_samples = Fs*(2^SF)/BW? I know that the symbol time is Ts=(2^SF)/BW

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  5. Unknown25 May 2018 at 13:03

    i developed a matlab code to simulate lorawan throughput by using one gateway, any body can help to provide code of more than gateway in one network to make comparison

    ReplyDelete
  6. Unknown17 June 2018 at 21:48

    This comment has been removed by the author.

    ReplyDelete
  7. Unknown18 June 2018 at 17:47

    Dear Sir,
    In your LoRa modulation function code, I think the " phase = phase + 2*pi*f/Fs;" should be changed to "phase = phase + 2*pi*f/Fs+pi*(BW*BW/Fs/Fs/2^SF);".
    Thank you in advance!

    ReplyDelete
  8. blog do jayme17 October 2018 at 22:50

    Hi the variable symbol is any integer number our is it a bit been 1 or 0?

    ReplyDelete
  9. Unknown9 May 2019 at 10:43

    I am working on LoRa -modulation based communication . Kindly send me the matlab codes

    ReplyDelete
  10. Unknown14 May 2020 at 22:13

    What price og this? 10 Dollars or 15 dollars? On page "How to buy LoRa Matlab Codes?" - 15 dollars. On this page 10 dollars.

    ReplyDelete
  11. Unknown19 November 2020 at 19:51

    hi what means by outp((i-1)*num_samples+1 : i*num_samples) = out_preamble;
    outp what is?

    ReplyDelete
    Replies
    1. Sakshama Ghoslya9 December 2020 at 18:14

      outp is just a new variable in the code which concatenate the out_preamble data.

      Delete