AD9361 Gain Control and RSSI User Guide documents shows below equation for RF Port to Received Signal Level Conversion.
dBFS(peak) = Pin(dBm) + Analog Gain(dB) -13dB + 4.1dB + PAR(dB) -ARC(dB) + Digital Gain
Also, from data sheet, ARC(dB) converts from average power to RMS power. Depending on the waveform, RMS and average are not the same value.
What's the value of ARC(dB) for LTE ?