version: "1.0.1" name: matlab-set-up-usrp-radio description: > Set up and verify a connection to an NI USRP radio (USRP E320, N300, N310, N320, N321, X300, X310, or X410) using Wireless Testbench. Use when connecting a USRP for the first time, configuring radio hardware, troubleshooting connection failures, or verifying a radio setup. Covers host inspection (OS, NIC type/speed/MTU), device discovery (findsdru, probesdru), UHD version checking, programmatic radio configuration, and basebandTransceiver verification. Also use when the user mentions USRP setup, radio not found, connection errors, dropped samples, or network configuration for SDR hardware. license: MathWorks BSD-3-Clause compatibility: ">=R2026a" metadata: author: MathWorks version: "1.0"

Set Up USRP Radio with Wireless Testbench

Connect, configure, and verify a supported NI USRP radio for use with Wireless Testbench in MATLAB.

Required References — Load Immediately

• references/troubleshooting.md — diagnostic checklist, Mender updates, network path isolation

When to Use

• Connecting a USRP radio to a host computer for the first time
• Configuring network settings (NIC, IP address, MTU) for USRP streaming
• Running radioSetupWizard or radioConfigurations
• Troubleshooting "radio not found", connection errors, or dropped samples
• Verifying a radio setup works end-to-end

When Not to Use

These workflows each require a working radio connection first — use this skill for that setup step.

• FPGA targeting or HDL workflows — check for a dedicated skill, or see Target NI USRP Radios
• Generating or transmitting waveforms — check for a dedicated skill, or see Transmit and Capture
• Intelligent capture (preamble/energy detection) — check for a dedicated skill, or see Spectrum Monitoring
• Multi-device synchronization — check for a dedicated skill, or see Radio Management
• comm.SDRuReceiver or comm.SDRuTransmitter path — this skill covers the modern Wireless Testbench path
• Installing MATLAB or toolboxes — do not use or recommend mpm (MATLAB Package Manager). This skill assumes MATLAB and the Wireless Testbench support package are already installed.

Workflow

Follow these steps in order. Inspect the host and radio before creating any radio configuration. Every check catches a different class of failure.

Step 0: Verify Support Package

addons = matlab.addons.installedAddons;
if ~any(addons.Identifier == "NI_USRP")
    error("Install 'Wireless Testbench Support Package for NI USRP Radios' via Add-On Explorer.")
end

If missing, the user must install it via Add-On Explorer before proceeding.

Step 1: Inspect Host

Before touching the radio, gather host system information. This determines whether the hardware is capable of 10 GbE streaming.

Detect OS and Platform

if ispc
    platform = "Windows";
elseif ismac
    platform = "macOS";
else
    platform = "Linux";
end
fprintf("Platform: %s, MATLAB %s\n", platform, version)

Inspect Network Interfaces (Linux)

% List all network interfaces with speed, MTU, and driver info
[~, interfaces] = system('ip -o link show | grep -v "lo:"');
disp(interfaces)

Then for each interface that could connect to the USRP, check NIC details:

% Replace <iface> with the actual interface name (for example, enp1s0f0)
[~, nicDetails] = system('ethtool <iface> 2>/dev/null | head -30');
disp(nicDetails)
 
% Check if it's a USB dongle
[~, usbInfo] = system('readlink -f /sys/class/net/<iface>/device 2>/dev/null');
disp(usbInfo)  % If path contains "usb", it's a USB adapter

Inspect Network Interfaces (Windows)

[~, interfaces] = system('powershell "Get-NetAdapter | Format-Table Name, InterfaceDescription, LinkSpeed, MacAddress"');
disp(interfaces)

What to Look For

Link Speed by Device

MTU and Jumbo Frames

X410 Note

The X410 has a QSFP28 connector but Wireless Testbench does not support native 100 GbE QSFP. You must use a QSFP → 4 × 10 GbE SFP+ breakout cable — each lane appears as a separate 10 GbE SFP+ port (Port 0–3).

E320 Note

The MATLAB installation includes the 1G FPGA variant by default. A standard 1 GbE NIC (PCIe or onboard) is correct for default operation. The E320 also has an SFP+ port — switch to the XG variant through sdruload for 10 GbE streaming (requires a 10 GbE NIC and SFP+ module).

Check MTU and Kernel Buffer Sizes (Linux)

[~, mtu] = system('cat /sys/class/net/<iface>/mtu');
fprintf("MTU: %s", mtu)
 
[~, rmem] = system('sysctl net.core.rmem_max');
[~, wmem] = system('sysctl net.core.wmem_max');
fprintf("%s%s", rmem, wmem)

USB dongle warning: USB-to-Ethernet adapters are unreliable for USRP streaming, even USB 3.0 models. They cause dropped samples, timeouts, and intermittent failures. If a USB dongle is detected, warn the user strongly and recommend a dedicated PCIe NIC. If the user must use a dongle (for example, laptop), suggest:

• Connect laptop to power supply (USB power management throttles adapters)
• Try alternative adapter models
• Reduce sample rate to lower bandwidth demands

Detect bridge and virtual interfaces: If the host runs Hyper-V, Docker, libvirt, or NIC teaming, the USRP-facing NIC may be enslaved to a bridge. See references/bridge-detection.md for detection commands (Linux and Windows). If a bridge is found, set static IP and MTU on the bridge interface, not the physical NIC.

Step 2: Discover and Inspect Radio

Before running discovery, confirm with the user that the radio is powered on, cabled, and the Ethernet link LED is lit. E320 and N3xx devices take 30–60 seconds to boot after power-on — findsdru returns empty until the device finishes booting. If findsdru returns empty and the user needs cabling help, point them to the archived doc for their release: https://www.mathworks.com/help/releases/<release>/wireless-testbench/ug/resolve-issues-with-connecting-radio-to-host.html (derive <release> from version('-release')).

Use findsdru to discover devices — this is the only recommended MATLAB function for radio discovery. Do not use uhd_find_devices.

radios = findsdru

Returns a structure array with fields: Platform, IPAddress, SerialNum, Status. A Status of 'Success' means the device is reachable.

Multiple Devices Found

If numel(radios) > 1, list all discovered devices and ask the user which one to set up.

if numel(radios) > 1
    fprintf("Found %d devices:\n", numel(radios));
    for i = 1:numel(radios)
        fprintf("  [%d] %s at %s (Serial: %s) — %s\n", ...
            i, radios(i).Platform, radios(i).IPAddress, radios(i).SerialNum, radios(i).Status);
    end
end

Ask the user which device to configure. This skill sets up one radio at a time. For multi-device synchronization (shared clock, coordinated capture), a separate workflow is needed after each device is individually configured.

Target device not in results: If the user identifies a specific device (for example, "my E320") but that device does not appear in findsdru output, do not select a different device from the list. The target device is unreachable — skip directly to troubleshooting (Step 6) focused on why that specific device is not discovered. Common causes: wrong subnet on the NIC facing that device, dongle or NIC not configured, device still booting, or cabling issue. Never assume a discovered device "is" the user's target under a different name — each USRP model reports its actual platform string.

If no radio is found at all, the NIC is likely misconfigured (wrong subnet, interface down, or firewall). Go back to Step 1 and check specifically: is the interface up? Is there a static IP on the same subnet as the USRP (for example, 192.168.10.x)? Then retry findsdru. If it still fails, go to Step 6 (Troubleshooting).

Inspect the selected radio in detail:

% Use the IP address of the device the user selected
selectedRadio = radios(idx);  % idx = user's choice (e.g., 1)
info = probesdru(selectedRadio.IPAddress)

This returns motherboard, daughterboard, firmware, FPGA image, and the device-side UHD version.

Check UHD version match:

hostUHD = getSDRuDriverVersion

Compare the host UHD version with the device UHD version from the probesdru output. Version mismatch is a common failure. Each MATLAB release includes a specific UHD version. If mismatched, the radio configuration step (Step 4) attempts to update device firmware.

Default USRP IP addresses (factory defaults, all models):

Step 3: Fix Host Issues

Based on Step 1 findings, fix any issues before proceeding to radio configuration.

Do not execute these commands directly — they require sudo (root privileges). Present them to the user and ask them to run the commands themselves. If the radio is already reachable through findsdru and no streaming issues are expected yet, skip to Step 4 and address host fixes later if dropped samples occur.

Linux — set static IP, MTU, and buffers:

# Set static IP on the same subnet as the USRP (replace <iface>)
sudo ip addr add 192.168.10.1/24 dev <iface>
sudo ip link set <iface> up
 
# Enable jumbo frames (REQUIRED for 10 GbE only — skip for 1 GbE)
sudo ip link set <iface> mtu 9000
 
# Increase kernel network buffers (REQUIRED for streaming)
sudo sysctl -w net.core.rmem_max=33554432
sudo sysctl -w net.core.wmem_max=33554432

For 1 GbE connections (for example, E320), leave MTU at the default 1500 — do not enable jumbo frames.

To make persistent, add to /etc/sysctl.conf and configure the interface in /etc/network/interfaces or NetworkManager.

Windows — adjust adapter settings (10 GbE):

• Open Device Manager → Network Adapters → your NIC → Advanced
• Set Jumbo Frame/Packet to 9014 bytes
• Increase Receive Buffers and Transmit Buffers to maximum (adapter-dependent — check valid range first)
• Disable interrupt moderation if available

Windows — adjust adapter settings (1 GbE, for example E320):

• Set MTU to 1498 (required for UHD 4.6 on Windows — do not use 9000)
• Leave Jumbo Frame/Packet disabled (1514 bytes)
• Increase Receive Buffers to maximum (varies by adapter: Intel may support 2048+, Realtek often caps at 512)
• Disable power saving: Disable-NetAdapterPowerManagement -Name "<adapter>"
• Disable all protocols except TCP/IPv4 on the radio NIC
• Disable Windows Firewall on the radio NIC interface

All Windows NIC configuration commands (New-NetIPAddress, netsh, Set-NetAdapterAdvancedProperty) require an elevated (Administrator) terminal. MATLAB system() calls cannot elevate — the user must run these from an admin prompt.

After fixing, rerun Step 2 (findsdru) to confirm the radio is now reachable. If the radio is still not found or shows USRPDriverNotCompatible, go to Step 6 (Troubleshooting).

Step 4: Create Radio Configuration

A saved radio configuration is required before using basebandTransceiver or basebandReceiver.

First, check for existing configurations that might already match the radio:

configs = radioConfigurations;
if ~isempty(configs)
    for i = 1:numel(configs)
        fprintf("  '%s' — %s at %s\n", configs(i).Name, configs(i).Hardware, configs(i).IPAddress);
    end
end

If any existing configuration matches the device (same IP, same model), ask the user if they want to reuse it before creating a new one. Do not silently reuse or overwrite — the user may have specific settings in their existing configuration.

Determine the correct SFP+ port index: Devices with multiple SFP+ ports (X310, X410) expose multiple IP addresses in probesdru output (for example, ip-addr0, ip-addr1, ip-addr2, ip-addr3). Compare the IP found by findsdru against the probesdru port list to determine which port index (0, 1, 2, 3) the radio was discovered on. Use that index for the HostIPx/DeviceIPx pair below — using the wrong port index causes misleading errors.

Option A: Programmatic (preferred when agent is driving)

Use the internal DeviceStore API to create a configuration without the GUI. You MUST use the `getUsrp<Model>Params()` function matching the user's selected device — do not copy example names blindly. Read the `probesdru` output carefully before setting any fields — do not assume values. Default params assume UBX-160 daughterboards; if probesdru reports a different board (e.g., OBX, TwinRX) or "Unknown", ask the user what is installed. For unsupported/unknown boards, configure as if UBX-160 — streaming still works but is untested. For TwinRX, skip transmit verification (RX-only board).

% Get default parameters — MUST match the selected radio's model:
%   E320 → getUsrpE320Params()    N310 → getUsrpN310Params()
%   X310 → getUsrpX310Params()    X410 → getUsrpX410Params()
%   N320 → getUsrpN320Params()    N300 → getUsrpN300Params()
params = wt.internal.hardware.DefaultDevices.getUsrpE320Params();  % ← match user's device
params.Name = "MyE320";  % ← user-chosen config name
% Use actual IPs from findsdru (Step 2) and host NIC inspection (Step 1)
% IMPORTANT: Use the correct port index (0 or 1) matching the SFP+ port
% where the radio was discovered. For single-port setups, port 0 is typical.
params.Network.DeviceIP0 = selectedRadio.IPAddress;
params.Network.HostIP0 = "<host-ip-from-step-1>";
 
% Save the configuration
store = wt.internal.hardware.DeviceStore();
store.setDeviceParameters("MyE320", params);  % ← same as params.Name
 
% Verify it was saved
configs = radioConfigurations;
disp(configs)

CRITICAL: If multiple radios were discovered, configure only the one the user selected. Do not use IPs, model names, or parameters from other discovered devices.

Recovery from bad store writes: The wt.radio.* classes cache state. If you write a bad configuration (for example, wrong daughterboard string), the corrupted values persist in memory. To recover:

clear all
rehash toolboxcache

Then recreate the configuration from scratch.

Option B: GUI wizard (when user is driving interactively)

radioSetupWizard

The wizard walks through device selection, IP configuration, connectivity test, firmware or FPGA update if needed, clock, time, and LO source configuration, and saves a named configuration. Use this when the user prefers a guided interactive experience or when firmware needs updating (the wizard handles firmware flashing). Note: After support package installation, a dialog box prompts the user to open the Radio Setup Wizard — tell the user to close it (the skill handles setup).

After either option, verify the configuration exists:

radio = radioConfigurations("MyN310");
disp(radio)

This returns a wt.radio.<Model> object (R2025a+) with properties and synchronization methods.

Step 5: Verify Connection

Create a basebandTransceiver to confirm the full pipeline works. The basebandTransceiver loads its own FPGA bitstream onto the device — do not use sdruload for streaming (that is the legacy comm.SDRuReceiver path). However, sdruload is still valid for FPGA image management on E320 (for example, switching between 1G and XG variants — see Set Up USRP E320 for 10GbE).

radio = radioConfigurations("MyN310");
 
bbtrx = basebandTransceiver(radio);
bbtrx.SampleRate = 5e6;  % Use a rate safe for 1 GbE; increase for 10 GbE
bbtrx.TransmitCenterFrequency = 2.4e9;
bbtrx.CaptureCenterFrequency = 2.4e9;
bbtrx.TransmitRadioGain = 10;
bbtrx.CaptureRadioGain = 30;
% Do not set TransmitAntennas/CaptureAntennas — defaults are device-specific
 
% Generate a test tone
numSamples = 10000;
t = (0:numSamples-1)' / bbtrx.SampleRate;
txWaveform = 0.8 * exp(1j*2*pi*1e6*t);
 
% Transmit and capture
transmit(bbtrx, txWaveform, "continuous");
[rxData, ~, droppedSamples] = capture(bbtrx, milliseconds(1));
stopTransmission(bbtrx);
 
if droppedSamples == 0
    disp("Verification passed: TX/RX working, no dropped samples.")
else
    warning("Dropped %d samples — check NIC MTU and buffer settings.", droppedSamples)
end
 
% Release the radio so it's available for the user's application code
clear bbtrx

If basebandTransceiver errors out or streaming consistently drops samples, go to Step 6 (Troubleshooting).

`UseRadioBuffer` option: By default, capture uses the radio's onboard memory buffer (UseRadioBuffer=true). This gives the most reliable streaming for captures that fit in onboard memory.

[rxData, ~, droppedSamples] = capture(bbtrx, seconds(5), UseRadioBuffer=false);

Set UseRadioBuffer=false when:

• Capture length exceeds radio onboard memory (varies by device, up to 2^30 samples) — this is the primary reason
• Using X310 with TwinRX capturing on more than 2 antennas

For dropped samples, UseRadioBuffer=false can help diagnose the source: compare drop counts with and without the buffer to isolate whether the issue is buffer-related or NIC-related. But it is not a fix — direct streaming is more demanding on the network, so fix the underlying NIC/MTU/buffer issues in Step 3.

Step 6: Troubleshooting

If any step fails, consult references/troubleshooting.md — it covers the full diagnostic checklist, manual Mender firmware updates, network path diagnostics, and bridge interference.

Key Functions

Conventions

• Inspect host first. Always check OS, NIC type/speed, MTU, and buffers before touching the radio.
• Stay in MATLAB. Use findsdru or probesdru for discovery — never call uhd_find_devices or other UHD CLI tools.
• Modern path for streaming. Use basebandTransceiver, basebandReceiver, or basebandTransmitter. These load their own FPGA bitstream. Do not use sdruload for streaming — that is the legacy comm.SDRu* path. sdruload remains valid for FPGA image management (for example, E320 variant switching).
• Programmatic config when agent-driven. Use DeviceStore to create configs without the GUI. Fall back to radioSetupWizard when the user prefers interactive setup or firmware needs updating.
• Check versions early. Compare getSDRuDriverVersion (host) with probesdru output (device) before proceeding.
• Diagnose before configuring. Complete all host and radio checks before creating a radio configuration or launching the wizard.
• Use release-specific doc URLs. When linking to MathWorks docs, use https://www.mathworks.com/help/releases/<release>/wireless-testbench/... (derive <release> from version('-release')). This ensures docs match the user's installed version.

Copyright 2026 The MathWorks, Inc.