MC-CDMA using overloaded minimum TSC spreading codes

In this paper we investigate the performance of multicarrier code-division multiple-access (MC-CDMA) using overloaded minimum total squared correlation (TSC) spreading codes in indoor channel environment. Since we use overloaded spreading codes, a number of MC-CDMA sub-channels were not being used for data transmission. These empty sub-channels were utilized as comb-type pilot. For interpolating the channel characteristics of the other sub-channels we applied linear interpolator to maintain low complexity. The validity of the system is confirmed by comparing it with the original MC-CDMA system using Walsh-Hadamard spreading codes, employing equal gain combining (EGC) and maximum ratio combining (MRC) at the receiver. The simulation result shows that although the spreading codes of interest are not orthogonal codes, for a low number of users the system under investigation performed better than MC-CDMA using either EGC or MRC.