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ADALM PLUTO SDR

Category: Software
Product Number: ADALM PUTO

Hi everyone, 

I am a beginner, I have a question: we are using the  Adalm Pluto and Matlab to transmit and receive wireless signals. After configuration for sdrtx and sdrrx using Matlab, I can transmit and receive the signal.

However, sometimes, I cannot receive the transmitted signal, when I plot the received signal, it is only noise. Therefore, I think the signal is not transmitted by the Adalm Pluto successfully. I am using
transmitRepeat function to transmit signal by Matlab. How can verify that the Adalm Pluto is transmitted successfully? 

Thank you so much

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  • Hi, 

    I am using Adalm Pluto to transmit PSK ( narrow band signal) by using transmitRepeat function. At the receiver, I configured a rxPluto to receive the wireless signal. 

    the configuration for TxPluto and rxPluto are given as follows: 
    rxPluto = sdrrx('Pluto','BasebandSampleRate', 7.5e6, 'CenterFrequency',2402225000, 'RadioID','usb:1'); %2402225000, 2411600000, 2411756000
    rxPluto.ShowAdvancedProperties = true;
    rxPluto.SamplesPerFrame = 24700;
    rxPluto.GainSource = 'AGC Fast Attack';
    rxPluto.Gain = 70;
    rxPluto.EnableQuadratureCorrection = true;
    rxPluto.FrequencyCorrection = 0;
    txPluto = sdrtx('Pluto','BasebandSampleRate', 7.5e6, 'CenterFrequency',2402225000,'RadioID','usb:1'); % 241256250
    txPluto.ShowAdvancedProperties = true;
    txPluto.FrequencyCorrection = 0;
    % txPluto.BISTLoopbackMode = true;
    txPluto.Gain = -20;
    info(txPluto);
  • Can you provide the rest of the code where you are moving data?

    -Travis

  • Hi Travis,

    This is my program that is used for transmitting and receiving the RF signals by Adalm Pluto.

    fsampling = 7.5e6;
    rxPluto = sdrrx('Pluto','BasebandSampleRate', 7.5e6, 'CenterFrequency',2402225000, 'RadioID','usb:1'); %2402225000, 2411600000, 2411756000
    rxPluto.ShowAdvancedProperties = true;
    rxPluto.SamplesPerFrame = 24700;
    rxPluto.GainSource = 'AGC Fast Attack';
    rxPluto.Gain = 70;
    rxPluto.EnableQuadratureCorrection = true;
    rxPluto.FrequencyCorrection = 0;
    txPluto = sdrtx('Pluto','BasebandSampleRate', 7.5e6, 'CenterFrequency',2402225000,'RadioID','usb:1'); % 241256250
    txPluto.ShowAdvancedProperties = true;
    txPluto.FrequencyCorrection = 0;
    % txPluto.BISTLoopbackMode = true;
    txPluto.Gain = -20;
    info(txPluto);

    % info(txPluto);

    Ts = 1/fsampling;
    fc= 1e5;%mc*(1/Tb); % carrier frequency for bit 10
    Ac = 1;
    fi1=0; % carrier phase for bit 1
    fi2=pi; % carrier phase for bit 0

    N = 100; % transmit 128 bits payload + 4 bytes preamble
    x_input = randi([0,1], N, 1) ;
    Tb = 10*1e-6;
    t2=Ts:Ts:Tb;
    for (n=1:1:N)
    if (x_input(n)==1)
    x_mod0=Ac*cos(2*pi*fc*t2+fi1);%modulation signal with carrier signal 1
    else
    x_mod0=Ac*cos(2*pi*fc*t2+fi2);%modulation signal with carrier signal 2
    end
    x_mod = [x_mod x_mod0];
    end
    modSignal=(complex(x_mod)');

    transmitRepeat(txPluto, modSignal); %doawnload basedband signal to radio and transmit.
    received_signal = rxPluto();
    received_signal = (received_signal);
    r_n = real(received_signal)';
    figure(1);
    plot( r_n );

  • adding mod = [] and running your code with Pluto connected RX to TX with a cable I get:

    -Travis

    1. It is not always happen, it happen sometimes.
  • I've run it a dozen times without issue. The only probably issue I could see is that you start the capture before the transmitter is fully initialized. In that case just add a small delay before running the RX code.

    -Travis

  • I try to connect Tx and Rx by cable,  I saw that some time the received signal is attenuated  10 times compare with the normal case. Therefore I think that the Tx gain is not stable?

  • I saw that some time the received signal is attenuated  10 times compare with the normal case.

    You are using the device with the AGC enabled, so there is no guarantee it always evolves to the same point. If you want it constant put the RX in manual gain mode.

    -Travis

  • I were tried to use tbe manual gain mode, but it is still happen. Do you think that the bandwidth of signal may cause the problem? I am using bandwidth 100KHz

  • Can you provide plots that show this deviation?

    -Travis