Performances of multicarrier system with time and frequency domain spreading for wireless communications

This paper evaluates the performances of the multi-carrier system with both time and frequency domain spreading for indoor and outdoor wireless environments. The salient feature of the two-way spreading is to enable the achievement both of the time and frequency diversity gains under time varying fading channels. This paper recommends employing the multi-carrier - direct sequence - code division multiplexing access with frequency spread coding (MC-DS-CDMA/FSC) method and the orthogonal frequency division multiple access with time and frequency code division multiplexing (OFDMA-TFCDM) method to implement two-way spreading for downlink and uplink transmission, respectively. The various computer simulation results confirm that these two methods could provide the better transmission quality than the conventional methods under indoor and outdoor wireless communication environments.