Transmit power in usrp 2920

[ElectricalEngineeringStudent]

Is there a way to adjust the transmit power of a USRP 2920 when sending a signal? And if yes, how do you do this?

[ElectricalEngineeringStudent]

Also, I am using Labview. to transmit a signal from one USRP to another USRP.

[Sarah_Y · Accepted solution]

You can adjust the transmit power by changing the gain setting control from the niUSRP Configure Signal.vi in the LabVIEW driver:

If you are looking to do a continuous transmission, the niUSRP EX Tx Continuous Async.vi example is a good starting place.  This gain setting can be set from 0 (no gain) to 31.5 dB in 0.5 dB steps.

You mentioned that you are transmitting from one USRP to another.  Use caution when doing this because it is easy to damage the RF front end by inputting too much power.  I would recommend setting the TX gain to 0 and adjusting the RX gain to avoid damaging your hardware.

[ElectricalEngineeringStudent]

Oh okay!! Thank you so much! 

Also, do you know how to calculate the power spectral density of the noise? Along with the bandwidth of the channel?

I am trying to calculate the capacity of the channel. Hence, why I need these parameters.

[Haniff]

Hello,

I am going to measure the actual transmission power of a USRP using a signal analyzer. But before that, I would like to make sure that my setup is safe and will not harm the analyzer.

To connect the output of the USRP to the input of the analyzer, I use an SMA-to-SMA cable that came in the USRP package. The RF input of the analyzer is 50 ohm and can accept up to +30dBm input signal (0 VDC, DC coupled). When conencting the cable, I will also use the 30dB attenuator to attenuate the output power of the USRP. Is this setup safe for the signal analyzer?

Thank you,

Hanif

[fromm8]

Hi Haniff

According to this the connector should be SMA and the impedance 50Ω, so it is fine. Then, the maximum output power is:

So you should be carefull with that.

Regards

Frank R.