Pre-filtering techniques for MC-CDMA downlink transmissions

We consider the downlink of a multi-carrier code-division multiple-access (MC-CDMA) system operating in a time division duplexing (TDD) mode and propose a non-linear pre-filtering scheme based on Tomlinson-Harashima pre-coding. In designing the pre-filtering matrices we adopt a minimum mean square error (MMSE) approach under a constraint on the overall transmit power since multiple access interference and multipath distortions are pre-compensated at the base station, low-complex receivers can be employed at the mobile units. Compared to other existing solutions, the proposed scheme provides better error rate performance