On The Overlay of Intelligent FDSS (MC-CDMA) on AMPS System (Downlink and Uplink Analysis)

The overlay of an intelligent Frequency Diversity Spread Spectrum System (FDSS) on the Advanced Mobile Phone Service system (AMPS) is studied. The worst-case condition is considered for the downlink analysis. Moreover, the effect of sidelobes outside the FDSS principal spectrum is considered. The downlink and uplink capacity of both systems are given using a model of 25 cells. Results show that the uplink is the link that limits the capacity of the mixed system and that it is affected highly by the increment of the AMPS transmitted signal. An original AMPS system with 24 channels per cell can be substituted by a mixed system, which has an AMPS system capacity of 12 channels per cell and an FDSS system capacity of 181 users per cell. Key-Words: AMPS, FDSS, Multicarrier CDMA, Overlay, Down and uplink capacities.