Uplink performance of a multicarrier-CDMA mobile radio system concept

Currently the air interface of future mobile radio systems is the topic of worldwide investigations. In this context CDMA (code division multiple access) seems to be a promising candidate as an element of the air interface of future mobile radio systems. The combination of OFDM (orthogonal frequency division multiplexing) and CDMA for mobile radio transmission has been proposed by several authors for the downlink. So far, the more elaborate uplink of such OFDM-CDMA mobile radio concepts has only been the topic of few publications, since channel estimation and data detection are more complex than in the downlink. The uplink of an OFDM-CDMA mobile radio concept is investigated. A pilot tone based channel estimation technique is proposed and several detection techniques suitable for the approach are described. Simulation results are shown for the case of a single receiver antenna as well as for dual receiver antenna diversity. The simulation results indicate that the proposed concept is well suited for future mobile radio systems