Crest factor reduction through in-band and out-of-band distortion optimization

A new crest factor reduction (CFR) technique is presented to reduce the peak to average ratio (PAR) of a wide-band code division multiple access (WCDMA) signal. Simple CFR techniques hard limit the desired signal to reduce the amplitude peaks and filtering is used to remove the out-of-band distortion. Here the trade-off between allowing out-of-band distortion and the error vector magnitude (EVM) is investigated for different levels of PAR reduction. It is demonstrated that there is an optimum clipping level for a desired PAR when trading off adjacent channel power ratio (ACPR) and EVM.