eNB with external LNA

Using an external LNA has different impacts on:

1) received signal level. It may cause saturation of received signal. To avoid that:

connect a UE (very close to eNB) and start uplink transfert.
adjust rx_gain based on "t spl" output:

(enb) t spl Press [return] to stop the trace --TX 1----- dBFS --RX 1----- RMS MAX SAT RMS MAX -23.1 -4.5 0 -47.4 -35.9 -23.1 -5.4 0 -47.4 -35.6 -23.1 -5.5 0 -47.4 -35.9

ideally, RMS should be around -15 and MAX should be around -3, when the UE is transmitting.

2) measured EPRE by eNB. This is less critical, it is used only for logging. To have correct EPRE measurement in eNB log, you can set the rx_epre_offset parameter to the gain of your LNA.