A Fixed-point Implementation of Successive Interference Canceller for WCDMA

Paper in proceeding, 2003

Multiuser detectors (MUD) can significantly increase the spectral efficiency of Code Division Multiple Access (CDMA) systems. In this paper, we present a symbol-level fixed-point Successive Interference Canceller (SIC) that is feasible to implement in Rapid Single Flux Quantum (RSFQ) superconducting electronics. A design procedure for finding the precision of the fixed-point SIC is introduced. A set of quantizers is found out with this procedure. By applying those quantizers, the simulation results show that a fixed-point multistage SIC performs the same as a floating-point decorrelator, which increases system capacity by a factor of four for the uplink model used in this paper.