What is repressive interference?

a necessary condition for suppressing interference in radio communication.

wireless interference is generally divided into co-frequency interference, adjacent channel interference, out-of-band interference, intermodulation interference and barrage jamming.

(1) Co-channel interference Any carrier frequency of a useless signal is the same as that of a useful signal, which causes interference to a receiver receiving a useful signal on the same channel.

(2) The interference caused by the adjacent channel interference station's adjacent channel power falling into the passband of the receiving adjacent channel receiver is called adjacent channel interference.

(3) Out-of-band interference The interference caused by harmonics or stray radiation of the transmitter in the passband of receiving useful signals is called out-of-band interference.

(4) Intermodulation interference is divided into transmitter intermodulation interference and receiver intermodulation interference. Transmitter intermodulation interference is the interference caused by multiple transmitter signals falling into another transmitter and modulating each other under the nonlinear effect of this final power amplifier, resulting in unnecessary combined frequencies, which is called transmitter intermodulation interference. The receiver intermodulation interference is the interference caused by the intermodulation frequency generated under the nonlinear circuit at the front end of the receiver when multiple strong signals enter the receiver at the same time, and the intermodulation frequency falls into the intermediate frequency band of the receiver, which is called receiver intermodulation interference.

(5) When barrage jamming receives a weak useful signal, it is interfered by strong interference signals on both sides of the receiving frequency and in the high-frequency loop band, which is called barrage jamming. Lightly, it will reduce the sensitivity of reception, and seriously, the signal will be interrupted.