Co-channel interference is interference caused by radio technology. As soon as two transmitters transmit on the same frequency
, such interference can occur. This also applies if both transmitting frequencies are modulated with the same signal. In such a case, interference forms between the modulated carrier frequencies. Since the transmitters are stationary and thus fixed, this co-channel interference can only be prevented by reducing the transmission power
andthus the range
. In modern radio systems, multipath propagation is used, whereby the energy of the radio frequencies arriving at different times is cumulated.