Multicarrier techniques are of high interest in modern communication systems due to their spectral efficiency and simplicity of channel equalization even in the case of heavily frequency selective channels. Further advantages of MC techniques include, e.g., their insensitivity to timing errors as well as to limited narrowband interference. The combination with CDMA provides an interesting multiple access technique for multiple users. Multiaccess interference in highly loaded systems is a major factor for performance loss and diverse methods exist to mitigate it. This paper focuses on a fully loaded MCCDMA system with linear MMSE and nonlinear PIC receivers in a Rayleigh fading channel. We study the system performance with relatively low number of subchannels and compare it with the theoretically predicted performance when the number of subchannels tends towards infinity. QPSK and higher order QAM modulations are studied, and a scaling issue in the PIC receiver is identified for the latter. We come to the general conclusion that the higher the modulation order, the more subchannels we need to achieve performance close to that predicted by theory. We also conclude that in the (quasi-) synchronous uplink case, PIC performs similarly to downlink, offering a good improvement compared to the linear MMSE receiver.