A Novel Filter Dependent CFR Scheme with Waterfilling Based Code Domain Compensation

Abstract

This paper proposes a novel crest factor reduction (CFR) algorithm applicable to currently deployed W-CDMA base stations. The peak-to-average ratio (PAR) reduction of the multiple carrier mixed signal, namely CFR, has been an issue in order to convey the benefit of using low-cost power amplifiers. The simple final clipping method (SFCM) as a conventional method has been widely utilized due to its simplicity and effectiveness. However, the SFCM degrades the adjacent channel leakage ratio (ACLR) characteristic as well as the signal quality indicated by either the error vector magnitude (EVM) or the peak code domain error (PCDE). Conventionally, in order to alleviate this undesired deterioration, extra channel filtering and signal quality enhancement followed by CFR might be processed in an open-loop style. Alternatively, to perform CFR by maintaining the PAR as low as possible subject to satisfying the prescribed ACLR and EVM/PCDE performance, this paper introduces the prediction filter dependent peak reduction (PFDPR) process collaboratively working with dynamic waterfilling-based code domain compensation (DWCDC). To verify the superiority of the proposed CFR algorithm, tentative simulations are conducted while maintaining the rules of legitimate W-CDMA base station test specifications.