CDMA is stands for Code Division Multiple Access, the narrowband message signal is multiplied by a very large bandwidth signal called spreading signal or code before modulation and transmission over the air. When suitable channel coding schemes are employed the working region corresponds usually to low or moderate SNR values, which reduces the interest of those techniques for the estimation and cancellation of non-linear distortion effects. The iterative receivers of DS-CDMA and MC-CDMA signals with low envelope fluctuation that jointly performs the detection and estimation and cancellation of non-linear distortion effects that are inherent to the transmitted signals. To improve the performance at low to moderate SNR, turbo receivers combined with threshold based cancellation of non-linear distortion effects.