The document provides an overview of Multi-Carrier Code Division Multiple Access (MC-CDMA) systems and discusses previous research in this area. It then proposes a new complex orthogonal wavelet packet based MC-CDMA system to investigate its bit error rate performance over different modulation techniques on an AWGN channel. The key aspects covered are: 1) MC-CDMA allows multiple users to transmit simultaneously by spreading user symbols across several subcarriers using different code values. 2) Previous research explored combining MC-CDMA with techniques like space-time coding and discrete wavelet transforms to improve performance. 3) The proposed system uses wavelet packet modulation waveforms instead of sinusoidal ones to eliminate guard intervals