In this paper, new multiple access schemes based on the combination of Code Division Multiple Access (CDMA) and Multicarrier (MC) modulation (also known as OFDM) are reviewed. A description of a simulation platform developed to analyse the performance of such systems in the presence of timing errors is included. It is shown that the MC-CDMA system is very sensitive to a clock frequency offset, and the system performance rapidly degrades for an increasing number of carriers. It is also shown that the timing jitter gives rise to a performance degradation that is essentially independent of the number of carriers.