A system for transmitting data between stations, such as base stations and subscriber stations in a wireless telecommunications system, employs variable set of interleaving parameters for its interleaving operations. By using different set of interleaving parameters with the interleavers, data which would otherwise be aligned when transmitted from a station to many stations, or from many stations to a station, will not be aligned after interleaving has been performed. This reduces the peak to average ratio required for a transmitter and/or can reduce interference experienced at receivers in the system. This is especially true if a significant proportion of the otherwise aligned signals are symbols which require zero energy to transmit.