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transmitRepeat

Download waveform signal to radio and repeatedly transmit it over the air

Description

example

transmitRepeat(tx,wave) downloads the waveform signal wave to the radio hardware associated by the transmitter System object™, tx, and transmits it repeatedly over the air. The waveform signal is downloaded into the radio hardware memory and transmitted over the air repeatedly, without gaps, until the transmitter is released by calling release(tx).

Examples

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Make sure your radio hardware is configured for host-radio communication by following the steps in Guided Host-Radio Hardware Setup.

Create a transmitter System object for your radio hardware with specific properties. For example:

tx = sdrtx('AD936x');
tx.CenterFrequency = 2.415e9;
tx.BasebandSampleRate = 2e6;
tx.Gain = -5;

Generate a waveform for transmission.

sw = dsp.SineWave;
sw.Amplitude = 0.5;
sw.Frequency = 100e3;
sw.ComplexOutput = true;
sw.SampleRate = tx.BasebandSampleRate;
sw.SamplesPerFrame = 20000;
txWaveform = sw();  

Download the generated waveform to the radio and repeatedly transmit it over the air.

transmitRepeat(tx,txWaveform)
## Establishing connection to hardware. This process can take several seconds.
## Waveform transmission has started successfully and will repeat indefinitely. 
## Call the release method to stop the transmission.

Stop repeated transmission by releasing the transmitter.

release(tx);

Input Arguments

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Transmitter, specified as one of the following System objects:

To create a transmitter System object, use the sdrtx function.

Waveform signal sent to the radio hardware, specified as a complex matrix. The number of columns in the matrix depends on the number of channels in use, as specified by the ChannelMapping property of tx. Each column corresponds to a channel of complex data transmitted on one channel. For each channel, the minimum number of data samples is 4096. When only one channel is in use, the maximum number of data samples is 16 million, and the number of samples must be even. When both channels are in use, the maximum number of data samples is 8 million for each channel.

The complex data type of the waveform signal must be one of these data types:

  • 16-bit signed integers — Since the AD9361/AD9364 RF chip has a 12-bit DAC, only the 12 most significant bits of the I and Q samples are used.

  • Single-precision floating point — Complex values are scaled to the range of [–1, 1]. Since the AD9361/AD9364 RF chip has a 12-bit DAC, numbers of magnitude less than 0.0625 are lost.

  • Double-precision floating point — Complex values are scaled to the range of [–1, 1]. Since the AD9361/AD9364 RF chip has a 12-bit DAC, numbers of magnitude less than 0.0625 are lost.

Data Types: int16 | single | double
Complex Number Support: Yes

Introduced in R2014b