Novel Iterative Clipping and Error Filtering Methods for Efficient PAPR Reduction in 5G and beyond

Abstract

The physical-layer radio access of 5G New Radio (NR) and other modern wireless networks builds on the cyclic prefix (CP) orthogonal frequency-division multiplexing (OFDM), known to suffer from the high peak-to-average power ratio (PAPR) challenge. In this article, novel PAPR reduction methods are developed, referred to as the iterative clipping and weighted error filtering (ICWEF) approach. To this end, clipping noise is separated from the data signal in frequency domain and properly tailored frequency-selective clipping noise filtering is adopted to control the tradeoff between PAPR reduction and transmitted signal quality. Furthermore, as 5G NR networks support adopting different OFDM numerologies at different bandwidth parts within one channel bandwidth, the ICWEF approach is also extended to take into account and suppress the resulting inter-numerology interference - something that most existing state-of-the-art methods do not consider. To facilitate comprehensive performance evaluations, a software-defined radio based prototyping testbed including a high-power base station power amplifier is also developed and used for assessing the performance of PAPR reduction solutions. The proposed ICWEF-based PAPR reduction concept is thereon thoroughly validated with extensive numerical and experimental results and shown to outperform the existing state-of-the-art reference solutions.