A method and system for detecting PIM signals in a wireless communication base station are disclosed. According to one aspect, a method includes receiving radio frequency, RF, signals over a frequency band spanning a plurality of frequencies of signals transmitted by at least a first transmitter external to the base station and at least a second transmitter. The method includes determining frequencies at which signals are present among the received radio frequency signals. PIM signal frequencies are calculated based on the determined frequencies at which signals are present. The method includes determining whether the calculated PIM signal frequencies interfere with selected uplink channels.