Parallel interference cancellation applied to an asynchronous MC-CDMA system

Multicarrier code-division multiple-access (MC-CDMA) is a strong candidate for the transmission technology of fourth generation cellular communication systems. In contrast to this the third generation cellular system UMTS employs direct-sequence CDMA (DS-CDMA) technology for both uplink and downlink. Hence interference cancellation is an appropriate method to combat multiple access interference. In an uplink MC-CDMA system with many asynchronous active users, the implementation of interference cancellation is a very difficult task, since the blockwise FFT computation in the receiver enables the synchronization on a single user only. With the implemented signal processing, the application of parallel interference cancellation in a multi-user MC-CDMA receiver is possible with moderate computational complexity, leading to an amazing increase in bit error performance.