Abstract: A DS-CDMA system comprises at least one transmitter and at least one receiver operating on a dedicated signal channel which is used by other DS-CDMA operators in a non-synchronous way. A receiver for use in such a DS-CDMA system includes a data aided multiuser interference canceller (38) comprising a feedforward filter (48) connected to a subtracting stage (50). A decision stage (52) is connected to an output of the subtracting stage (50). Decisions from the decision stage (52) are stored in a memory which also stores preliminary decisions made on the signal applied to the feedforward filter (48) by a simple receiver (46). These decisions are applied to a feedback filter (58) the output of which is connected to the subtracting stage (50) thereby removing the effects of pre-cursive and post-cursive interference. The input to, and output from, the decision stage 52 are compared and the difference is used for adjusting the tap weights of the feedforward and feedback filters (48,58).