MC-CDMA System Performance for Different Frequency Selective Channels

Multi-carrier CDMA (MC-CDMA) is a promising multiple access scheme for the fourth generation mobile radio systems which aim to support services with wide range of data rates up to 100 Mbps. MC-CDMA exploits frequency diversity by transmitting chips of a bit over multiple subcarriers, making the communication system more robust to diverse frequency selective fading of the outdoor environment. Up to now, performance of multicarrier systems has been investigated mainly for indoor environment that is characterised by small delay spreads and low mobile speeds. We investigated performance of MC-CDMA system for outdoor environment. MMSEC combining technique was used. The results show that the system parameters, like Pn code length (i.e., number of subcarriers) and size of S-P conversion, can be varied in order to provide optimal system performance. Furthermore, in the case of no movement, an increase in the spectral efficiency can be attained by selecting the frequency band in a hybrid FDMA/MC-CDMA system depending on the frequency selectivity and the data rate.