Performance of multi-rate broad band CDMA in a fading channel using multi-user/multi-path interference approximation

Future mobile communication systems should be able to support a wide range of services with different bit rates. Spread spectrum CDMA techniques have attracted much attention to be employed in such a system. Different techniques of CDMA could be used to map low, medium and high bit rate data into the same allocated bandwidth, including pure or broad-band CDMA, FDM/FH/CDMA, TDM/TH/CDMA or a hybrid of these systems. This paper investigates multi-rate broad band CDMA using multi-user interference statistics for both Gaussian and Rayleigh fading channels. Approximation of multi-user interference, in general, helps in theoretical approaches to error performance evaluation and, in particular, is quite useful for a simulation approach in a fading channel. Some results of a multi-rate broad-band CDMA with 2 services (low and high bit rates) is presented