spectrum measurements and didn’t observe any signature of PIM, but the ‘Calculated PIM’ shows different measurements, why is that?

spectrum measurements and didn’t observe any signature of PIM, but the ‘Calculated PIM’ shows different measurements, why is that?

PIM is best recognized by one of two things; 1) above average noise floor relative to Boltzman’s constant equation, plus instrument noise figure, and 2) LTE single carrier PIM shows a very distinct slope across the top of the uplink in-band spectrum. Both of these occurrences can easily be seen to correlate with significant increases in uplink noise floors relative to increases in transmit power, example when using OCNS (Orthogonal Channel Noise Simulator) or AILG (Air Interface Load Generator) test commands used on the transmitters. In the Calculated PIM table, the cautionary Yes and No are just indications that there is overlap with the noted Radio RX frequency ranges.