Uplink capacity of a code division multiple access (CDMA) system is limited by the mutual interference among users. It is well known that interference cancellation can significantly increase the CDMA uplink capacity. In this paper, we present a new interference cancellation scheme based on non-parametric channel estimation and waveform reconstruction. Compared with the traditional parametric scheme, the new scheme can effectively solve the model mismatch problem caused by a multipath channel. We also propose channel estimation cleaning methods to further improve the performance.