1. adjacent channel interference: if different systems work at adjacent frequencies, adjacent channel interference will occur due to adjacent channel leakage at the transmitter and adjacent channel selectivity at the receiver.
2. Stray radiation: Due to the nonlinearity of the power amplifier, mixer and filter in the transmitter, radiation signal components will be generated in a large range outside the working frequency band, including thermal noise, harmonics, parasitic radiation, frequency conversion products and intermodulation products. When the interference signals generated by these transmitters fall within the working frequency band of the receiver of the interfered system, the background noise of the receiver will increase, thus reducing the sensitivity.
3. Intermodulation interference: mainly caused by the nonlinearity of the receiver, the consequence is to improve the noise floor and reduce the receiving sensitivity. Types include intermodulation caused by multiple interference sources, intermodulation caused by emission components and interference sources.
4. Blocking interference: Blocking interference is not in the receiving frequency band of the interfered system, but because the interference signal is too strong and beyond the linear range of the receiver, the receiver is saturated and cannot work. In order to prevent the receiver from being overloaded, the power of the received signal must be lower than its compression point 1dB.