Issue with 2 Adalm-PlutoSDR communication

Hi! I'm working on a project using two ADALM-PLUTO SDRs and the MathWorks example "Image Transmission Using 802.11 Waveform and SDR". I’m trying to transmit from one PC to another (each with its own Pluto), but the receiver doesn’t seem to capture any data.

I’ve also tried a simple transmission (like sending a basic message, not an image) using the same waveform and still no reception on the second device.

my questions are:

• Does this example actually support two physical PlutoSDRs, or is it intended for loopback with a single SDR?
• If yes, what are the minimal changes/settings needed to make it work across two separate SDRs and MATLAB sessions?
• Are there any known sync/calibration steps needed?

ps: Both devices use the same frequency (2.4 GHz), sample rate, and are connected correctly. No transmission errors, but no reception either.

Thanks in advance!

Answer 1

[Shivangi]

Hi Simina Viorica,

I understand that the issue is that when using two ADALM-PLUTO SDRs on separate PCs with the MathWorks "Image Transmission Using 802.11 Waveform and SDR" example, the receiver does not capture any data.

The example is intended for a single PlutoSDR device, where the transmitRepeat functionality is used to loop the transmission back into its own receiver. Both the documentation and the visual example describe a single-radio configuration. (https://www.mathworks.com/help/wlan/ug/image-transmission-reception-using-802-11-waveform-sdr.html)

It can work with two PlutoSDRs on separate PCs, but you need to modify it. Key steps:

• Assign separate RadioIDs to each SDR (usb:0, usb:1)
• Use “sdrtx” on the sender, “sdrrx” on the receiver
• Set same frequency, sample rate, and gain
• Use transmit() (not transmitRepeat) on Tx side
• Start Rx before Tx, using capture() to receive the waveform

Sync/calibration is needed because devices are not time/frequency synchronized:

• Receiver must handle Carrier Frequency Offset (CFO) and timing offset (the example already includes this)
• Gain settings matter — adjust Tx/Rx gain to avoid weak signal or overload
• Ensure Rx captures the full frame, including preamble

Hope this solves your query!

[Lakshay]

Hi, I am currently facing the same problem,(with CFO), is there any chance that you might able to help me with that?