SDR Receiver Sample Times

You can set the sample time of the E310 receiver block and receiver System object™ available in the Communications Toolbox™ Support Package for USRP®[1] Embedded Series Radio.

Consider changing the default sample time only when deploying a hardware-software co-design implementation.

Set Sample Times in Receiver Block

The output sample time of the receiver block is a function of the Baseband sample rate and Samples per frame parameters. However, the receiver block does not output a sample time automatically. To enable a sample rate on the receiver block data output, add a Signal Specification block.

  1. Add a Signal Specification block to a model that contains a receiver block. Connect the data output of the receiver block to the input of the Signal Specification block.

  2. Open the Signal Specification block mask.

  3. In the Sample time parameter, enter the desired sample period. For example, for a baseband sample rate of 1 MHz, and a frame size of 4000, the sample period should be 4000/1e6.

Set Sample Rate in Receiver System Object

The receiver sample period is the time interval between successive output samples of the receiver System object. The receiver determines the radio hardware frequency sample times using the BasebandSampleRate property. Set the sample rate for any downstream processing using the BasebandSampleRate property.

  1. Create a receiver System object and get data from it. For example:

    rx = sdrrx('E310');
    [data,dataLen] = rx();
  2. Examine only one channel and assign a sample rate.

    data = data(:,1);
    SampleRate = rx.BasebandSampleRate;
  3. Examine the received signal spectrum using a spectrum analyzer.

    specAnalyzer = dsp.SpectrumAnalyzer('SampleRate',SampleRate);

See Also



System Objects

[1] USRP, USRP2, UHD, and Ettus Research are trademarks of National Instruments Corp.