is first applied to coding means 332 wherein the desired coding to ensure the protection of the data against transmission errors is performed and said coded signal is applied to a multiplexer 338 said data may comprise for example said frame or a description of the frame structure of the frame to be transmitted next the signal 352 combined in this manner is further applied to second interleaving means 336 in the interleaving means the interleaving is performed using substantially equal interleaving length as in connection with the first interleaving the transmitter may comprise the multiplexer 338 wherein additional data such as power regulation data 330 or reference symbols 328 is combined to the interleaved signal for coherent reception when a cdma transmitter is involved the combined signal 340 is further applied to a means 342 wherein the signal is multiplied by a spreading code characteristic of the connection whereby the signal spreads to the frequency band used the signal multiplied in this manner is further applied to radio frequency parts wherein the signal is converted to the radio frequency and amplified to be transmitted by an antenna 346 the transmitter of the system of the invention further comprises control means 354 controlling the operation of the above parts and said means can be implemented by means of a microprocessor or control logic for example let us.