Interference Canceller for DS/CDMA using Carrier Phase Information

A Direct-Sequence/Code Division Multiple Access (DS/CDMA) system is considered to be the system where the interference from other users limits the channel capacity rather than the receiver noise. Therefore, a lot of interference cancellers have been proposed. However, most of them were for the base stations. This paper has proposed an easy interference canceller for lightly equipped systems or terminals, and theoretical analysis has been carried out. The canceller calculates the interference due to other users following the minimum mean square criterion under the assumption that the carrier phase of each signal is known and that the synchronization is established. The estimated interference noise is combined and subtracted from the interference contaminated desired signal. Computer simulations coincide with the analysis revealing two times improvement in signal-to-noise ratio when processing gain is 31 and Eb/No is 20[dB].