Abstract: Multi-access interference (MAI) is the major factor degradingthe CDMAsystemperformance and capacity. According to the characteristics ofMAI in CDMA systems, a multi-user detector is designed by a newhard-decision parallel decision algorithmforMAI cancellation. Analysis and simulation results showthat this detector performs better and has larger capacity to restrain near-far impact than the conventional ones, and hence has good potential for practical application.