The inventive idea is to send in the same cell on one channel several signals and to cause different radio frequency characteristics to the signals received on the same channel. The different characteristics of signals are brought about e.g. by modulating the signals in different ways or by sending the signals from different points, whereby the different signals will experience different radio channels. Owing to the different characteristics, the signals can be distinguished from one another by a joint detection, interference cancellation method. In the downlink direction from the base transceiver station to the mobile station and in the uplink direction from mobile station to the base transceiver station it is often advantageous to use different methods.