matlab-transmit-capture-usrp

What it does

Instructs an agent to help users generate, transmit, and capture RF waveforms with NI USRP radios using Wireless Testbench. It covers default object choice (basebandTransceiver), configuring sample rate, center frequencies, and gains, preparing complex waveforms, performing both single-shot and continuous transmissions, and capturing IQ data with foreground or background modes. It also details using radio buffers vs direct-to-host captures, handling data types, and loopback testing.

How it works

• Create a radio object and a baseband object (default to basebandTransceiver). Optionally preload FPGA code.
• Configure direction-specific or standalone properties (SampleRate, TransmitCenterFrequency, CaptureCenterFrequency, TransmitRadioGain, CaptureRadioGain) as needed.
• Prepare a complex waveform vector or matrix; ensure values are within [-1, 1], with even-numbered rows, and correct data type. If using Preload, pass TransmitDataType to constructor.
• Transmit: use transmit(bbtrx, txWaveform, "once") for single-shot or transmit(bbtrx, txWaveform, "continuous") for ongoing transmission; stop with stopTransmission(bbtrx).
• Capture: use foreground capture with data, timestamp, droppedSamples = capture(bbtrx, duration). Choose between foreground and background capture, SaveLocation, and UseRadioBuffer to manage where data is stored. Cast data as needed (CaptureDataType defaults to int16, with guidance to cast to double if needed).
• Background capture: start with capture(..., Background=true), poll isCapturing(bbtrx) or use CompletionFcn, then retrieve via captureOutputs(bbtrx) or file path when SaveLocation is used.
• Use UseRadioBuffer true by default for reliability; set false for long captures exceeding onboard memory, and follow capacity guidance per device (E320/N-series ~2^29 samples, X300/X310 ~2^28, X410 ~2^30).
• Loopback: set TransmitCenterFrequency and CaptureCenterFrequency to the same value to enable internal coupling, and perform transmit then capture as described.

When to use it

• When transmitting a waveform over the air or capturing IQ data
• For loopback tests, multi-antenna configurations, continuous transmission, or long-duration captures
• When troubleshooting dropped samples, gain settings, or RF configurations
• When a user mentions transmit waveform, capture signal, IQ data, loopback, RF gain, sample rate, or antenna configuration

What it can touch

• MATLAB/MathWorks Wireless Testbench APIs and properties:
  • Object creation: basebandTransceiver(radio) and optional Preload=true, TransmitDataType
  • Properties: SampleRate, TransmitCenterFrequency, CaptureCenterFrequency, TransmitRadioGain, CaptureRadioGain, DropedSamplesAction, CaptureDataType, UseRadioBuffer, SaveLocation, Background, CompletionFcn
  • Functions: transmit, stopTransmission, capture, stopCapture, captureOutputs, radioConfigurations, isCapturing

Caveats

• Requires a saved radio configuration before use; if none, guide user to matlab-set-up-usrp-radio (implied by prerequisites).
• CaptureDataType defaults to int16; casting to double may be necessary for many signal-processing operations.
• Direct-to-host captures depend on sustained network throughput and may require reducing sample rate, antennas, or using radioSetupWizard to optimize host network settings.
• Some workflows (FPGA targeting, intelligent capture with preamble/energy detection) are noted as NOT for this skill; refer to related skills.