Multi-user performance of CDMA in the presence of phase noise

Phase noise can be the major source of performance degradation in low cost low bit-rate digital systems operating in the millimeter wavelength band. The use of CDMA with a differential modulation at the chip level will permit an improvement in system performance and a simpler demodulation. However, the enhancement of CDMA multi-user interference arising from the differential receiver has to be considered. In this study different approaches are considered and a possible solution is suggested to obtain a compromise between the effects of the phase noise and of the multi-user interference