TX Power and Signal Power Received at UE

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TX Power and Signal Power Received at UE

Post by RubenQueiros » Tue May 26, 2020 9:02 am

Good Afternoon,

First of all i've also written this e-mail to srsLTE mailing list because i'm not sure if this issue im having is related to the Hardware or to the Software!
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.

Thank you in advance!
Ruben Queirós

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