A frequency-domain oversampling detector for zero-padded MC-CDMA systems

In conventional cyclic prefix (CP) based multicarrier code-division multiple-access (MC-DMA) systems, the major problem is the multiple-access interference (MAI) caused by frequency-selective fading, near-far effect and frequency offset. In order to eliminate MAI, we propose a linear minimum mean-square error (MMSE) detector for zero-padded (ZP) MC-CDMA systems based on frequency-domain oversampling and MMSE linear combining. The complexity of the detector can be reduced by reducing the oversampling factor according to the specific application. Simulation results show that the proposed detector significantly outperforms the conventional MMSE detector for CP based MC-CDMA in severe MAI environments.