[srslte-users] TX Power and Signal Power received at UE

[mark h]

Ruben,
I have been using a B210's and Lime USB's and have been seeing similar
numbers. I may be incorrect, but I believe the Peak Output Power of the
b210 and lime are around -30dbm. So If you spread it over 2.5Mhz your
observed peak power will be less. I had the same issue and am ordering some
power amplifiers. Attached is are screenshots of ENB and UE (B210) signal
measured at 2 meters. Does it look similar to your setup?

Hardware:
Pi-4
Ettus B210
2.4Ghz antennas

On Wed, May 27, 2020 at 1:00 AM Rúben Queirós <up201504489 at fe.up.pt> wrote:

> Good Afternoon,
>
> First of all thank you for developing srsLTE. I'm currently researching
> to my MSc degree and i'm using srsLTE to evaluate the performance of
> different SDR hardwares namely, BladeRFx40, BladeRF micro 2.0 and USRP
> B210 The antennas used are TriBand from Nuand. For the UE i'm using a
> commercial Samsung J7 that connects sucessfully to the srseNB and
> srsEPC.
>
> I've been using the software for a couple months already and i'm running
> out of options so i'm writing you this e-mail hoping that you can help
> me with my problem.
>
> Im transmitting in Band 3, 7 and 20, Central frequencies, switching
> between NRBs ( from 15 up to 50 sucessfully ) and according to some LTE
> Throughput Calculators, the results are way lower than the expected at
> Low range ( 1 Meter between the eNB station and UE ). After logging the
> Signal Power Received at the UE, i realised the signal power is way
> weaker than it should be.
>
> Assuming the information in
> https://www.pasternack.com/t-calculator-friis.aspx is correct, and
> considering no antenna gains in RX or TX, i should be expecting
>
>
> Tx Power   1m ( range)    2600 MHz       1800 MHz        800 MHz
> 8dBm       Blade Micro  -32,75 dBm      -29,55 dBm      -22,51 dBm
> 6dBm       Blade x40    -34,75 dBm      -31,55 dBm      -24,51 dBm
> 10dBm      USRP B210    -30,75 dBm      -27,55 dBm      -20,51 dBm
>
> However the values im getting are between -70 to -95 dBm. This tests
> were done with LOS between the eNB and the UE and i've noticed the
> software always sets the TX Gain of the RF hardware to the max, yet it
> is still a weak signal.
> I will attach an example of an enb.conf used in one of this tests. If it
> is not enough to detect the problem, i also attach the other logs i
> capture for the same test performed.
>
> Thank you in advance!
> Ruben Queirós_______________________________________________
> srslte-users mailing list
> srslte-users at lists.softwareradiosystems.com
> http://www.softwareradiosystems.com/mailman/listinfo/srslte-users
>
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