VLSI Implementation of an Adaptive Multiuser Detector for Multirate WCDMA Systems

A multirate receiver for WCDMA systems based on the adaptive signature method was designed and implemented. We employed an adaptive signature algorithm to consider two well-known multirate schemes, namely, the low rate and the high rate detector for variable spreading factor systems. In monorate scenarios, numerical experimentations showed that the adaptive signature method outperforms the Rake receiver and reaches the performances of the soft 4-stage multistage parallel interference cancellation receiver. In multirate scenarios, the performance comparison of two multirate schemes in floating-point and fixed-point was analyzed. Reusing the existing hardware architecture previously developed for monorate systems, we targeted the hardware implementation of these two multirate schemes on FPGA components.