Re: This flow graph is radiating negative Tx power

[Christophe Seguinot]

Hi

- What does "negative Tx power" means ?

A few suggestions:

• move to GNURadio >=3.8 (most of us uses GR 3.8 or 3.9 so it's difficult to help for outdated GR 3.7)
  
• QT GUI Sink : Bandwith should be equal to sample rate of the block incoming signal, i.e. samp_rate at the RRC Filter output (the FFT Sink does not work as a real spectrum analyzer)
  
• Did you measure the signal power using a spectrum analyzer ? When do so, the receiving antennna being close to the emitter antenna, you should get the -20 to -30 dB as compared to the emitted power (frequency close to 1GHz and 6dBi antennas (Indoor panel), this is depending on frequency and antenna gain). If your emitted power is +20 dBm, you should measure something in the range 0 dBm to -20 dBm. If not, there is something wrong in the transmission chain.
  
• Did you check your signal amplitude at USRP bloc input (The maximum value should be 1 Volt to get maximum RF  power which also depend on USRP settings
• Did you connected the antenna to the good channel Rx/Tx ?

Sincerely, Christophe

On 12/03/2021 15:08, AKINYELE ITAMAKINDE wrote:

Good day to  all community members.

Please, I need you to help correct this flow graph configuration. The Tx power radiating is too minimal. I have adjusted and also added some other blocks to boost the signal but all to no avail. The flow graph is been used for propagation channel measurement. I will like someone to take me through or send video and other link on how to solve this problem. The flow graph is attached.

 Thank you.

Akinyele.