User Guide

Chapter 5: eNodeB configuration 8
5.3 TX/RX gain setting
TX and RX antenna gain values must be customized in order to avoid saturation when set too
high or Bler when set too low. Those two values actually depend on your setup:
• Conducted vs wireless conditions
• Physical RF attenuator used
• Combiner/divider used
TX and RX gain values are defined in RF configuration file located under
/root/enb/config/rf driver directory.
To know which files is used by LTE service, just look at enb.cfg file.
Example:
include "rf_driver/1chan.cfg",
5.3.1 Wired test
When the device under test is connected through RF cable to the eNodeb, the recommended
RX and TX antenna gain values are :
tx_gain: 60.0, /* TX gain (in dB) */
rx_gain: 0.0, /* RX gain (in dB) */
If physical RF attenuators (or RF combiners) are used, additional gain must be added to
these default values equivalent to the path loss introduced
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Note: max SDR input is -10 dBm, max SDR output is 5dBm (depending on the frequency).
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5.3.2 Wireless test
In Wireless test conditions (i.e when LTE antenna are used), the recommended RX and TX
antenna gain values are :
tx_gain: 90.0, /* TX gain (in dB) */
rx_gain: 60.0, /* RX gain (in dB) */