SDR Receiver Sample Times

You can set the sample time of the E3xx 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 automatic output sample time of the receiver block corresponds to the value Samples per frame parameter divided by Baseband sample rate (Hz) parameter. To change the sample rate on the receiver block, on the Advanced tab of the block mask, select Override automatic sample time, then set the value with the Sample time parameter. 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('E3xx');
    [data,validData,overflow] = 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);
    specAnalyzer(data);

See Also

Functions

Blocks

Objects


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