Multi-user gain in a quasi-DPSK multi-carrier CDMA downlink channel

This paper describes a multi-carrier code division multiple access downlink system which may be of use in mobile radio communication applications. A novel form of differential phase shift keying where the phase shift keying is applied in the transmitter after all the user symbols have been combined. This produces a performance improvement when there is more than one user present. Results of simulations using models of typical urban mobile radio channels are presented and comparison is made with a number of similar downlink systems