RS-CDMA: a quasi-synchronous CDMA scheme to support uplink operation of mobile communication

A despreading scheme employing inverse filtering is introduced to exploit the frequency diversity of a multipath signal in such a way that the path with the strongest power is enhanced while the others are cancelled almost completely. Based on this scheme, a quasi-synchronous CDMA system, termed rotated spectrum code division multiple access (RS-CDMA), is proposed as an alternative to the previously proposed CTDMA to support uplink operation of mobile communications with good performance as well as high spectrum efficiency. The principle and simulation results of the performance are given.