Performance of a multi-rate FDM/FH/CDMA system in multi-path fading channels

In this paper a multi-service/multi-rate system using frequency division multiplexing/frequency hopping and code division multiple access (FDM/FH/CDMA) is investigated. In such a system low bit rate signals (e.g. voice) are spread over the whole allocated bandwidth while higher bit rate data are transmitted over narrow-band frequency slots which are either fixed (FDM) or hopping (FH). The error performance of a two service system (10 kbps voice and 500 kbps data) in two different environments (indoor-pico cell and outdoor-micro cell) is evaluated and compared with previous results of pure CDMA in which all signals with different bit rates are direct-sequence spread over the whole allocated bandwidth.