It is shown that the Multi-Address Interference(MAI) can be effectively reduced when Double Waveforms(DW) are used with chip code in the asynchronous DS-CDMA system. A novel method to reduce the MAI based on Waveform Sets(WS) is proposed. For any number of users, each user can choose single waveform from the WS that can be designed with only two or three kinds of seven conventional waveforms, and can obtain better Signal to Interference plus Noise Ratio(SINR) and Bit Error Rate(BER) performance than DW meth...