The combination of Orthogonal Frequency Division Multiplexing (OFDM) and Code Division Multiple Access (CDMA) is generally termed Multi-carrier CDMA (MC-CDMA). For future high-data-rate wireless applications, MC-CDMA has emerged as the most promising multiple access scheme due to its numerous advantages in both uplink and downlink communications. Carrier Interferometry (CI) code used as a spreading sequence for its inherently strong orthogonality nature; of length N can supports 2N users. In present work, a communication system which can support up to $3N$ number of users with variable data...