Burst Mode

If an SDR receiver block or System object™ cannot keep up with the radio hardware, then the model or code is not processing data in real time. Burst mode enables you to buffer a set of contiguous samples without losing samples by setting the number of frames in a burst.

• Determine If You Need Burst Mode

• Enable Burst Mode

• Limitations

Determine If You Need Burst Mode

It is recommended that you enable burst mode when your application requires fresh samples from the hardware or guaranteed contiguous samples. To see if the received data is contiguous, enable the overflow indicator on the receiver block or object.

To determine if you need burst mode, see Detect Underruns and Overruns.

Enable Burst Mode

Use burst mode when your model loses samples because it cannot keep up with the real-time data received from the hardware. Burst mode enables you to buffer a minimum set of contiguous samples without losing samples. However, lost samples can still happen between bursts, especially with large burst sizes. If your model can keep up in real time, do not use burst mode. The default number of frames in a burst is 20.

Enable Burst Mode in Receiver Block

The Pluto Receiver block has an Enable burst mode parameter. When you select this parameter, the block produces a set of contiguous frames without an overrun to the radio hardware. Enable burst mode to simulate models that cannot run in real time. Specify the amount of contiguous data using the Frames in burst parameter.

Enable Burst Mode in Receiver System Object

The comm.SDRRxPluto System object has an EnableBurstMode property. When you set this property to true, the System object produces a set of contiguous frames without an overrun to the radio hardware. This setting can help simulate models that cannot run in real time. Specify the amount of contiguous data using the NumFramesInBurst property.

rx.EnableBurstMode=true

EnableBurstMode: true                            
NumFramesInBurst: 20                              

Limitations

Burst mode requires a fresh set of samples from the hardware. Therefore, when you call a receiver System object for the first time with burst mode enabled, the overflow output argument is 1. Likewise, the first time-step of a receiver block with burst mode enabled asserts the overflow port.