Abstract: Multi-carrier is a fascinating choice for modern wireless communication system as it diminishes the issues of Inter Symbol Interference (ISI) and utilize frequency diversity. Minimum Mean Square Error (MMSE) Multi User Detection (MUD) technique is utilised for Multi Carrier-Code Division Multiple Access (MC-CDMA) which is a novel digital modulation technique under multipath fading environment. Multipath fading increases Bit Error Rate (BER) of a communication system due to which system performance degrades. MMSE algorithm is simulated in MATLAB and compares with different detections techniques such as Successive Interferences Cancellation (SIC), Parallel Interferences Cancellation (PIC), decorrelator and matched filter.