A Novel Limiter with Application in Crest Factor Reduction Techniques for Wireless Communications

Crest factor reduction (CFR) techniques based on limiting and filtering can improve the efficiency of radio frequency power amplifiers for wireless communication systems. In previously published CFR based on hard clipping limiters, the reduction in peak to average power ratio (PAPR) is critically compromised by peak reconstruction during the filtering of out-of-band distortions. This work proposes a novel limiter suitable for CFR applications. The proposed limiter substantially attenuates the phenomenon of peak reconstruction, especially because it achieves the maximum output amplitude at a single input amplitude level and, beyond threshold, any input amplitude increase is associated to an output amplitude decrease. Simulation results based on a 3GPP WCDMA test signal are reported to illustrate the superior performance of a CFR technique that employs the proposed limiter instead of the hard clipping limiter. In particular, to comply with an error vector magnitude (EVM) specification of 17.5%, a further 0.5 dB in PAPR reduction is possible when the CFR uses the proposed limiter.