Abstract: A transmitter which transmits at least first and second burst sequences, through at least first and second channels of a radio link including a different repeater in each of the respective channels, is disclosed. A carrier signal is gated into each burst sequence in time division fashion by gating signals. By the use of gating signals reproduced from received bursts, a receiver detects an interference signal introduced from at least the first channel into the second by removing from the received bursts and interference signal that difference in frequency and/or phase which is liable to occur between the first and second bursts in the repeaters. To this end, continuous signals are controlled by the received bursts and the reproduced gating signals so as to have frequencies and phases different by the difference and are used to frequency convert the received first bursts and the received interference signal into a burst and an interference component signal.