The waveforms being employed by fourthgeneration (4G) and candidate fifth-generation (5G) radio access and wireless backhaul technologies are based on modulation techniques that allow significantly increased spectral efficiency and capacity, and enable new spectrum sharing scenarios. However, the use of high peak-to-average power ratio (PAPRs) modulations requires inefficient operation of the power amplifier (PA) to fulfill stringent spectral mask and modulation accuracy requirements. With digital linearization techniques such as crest factor reduction (CFR) and digital predistortion (DPD), the classical linearity versus power efficiency tradeoff can be mitigated and the network capital and operational expenditures (CAPEX and OPEX) may be reduced. This article describes the architecture and linearization strategies employed by SHAPER (Solutions for wideband Highly lineAr and efficient PowER amplification), a demonstration platform for fast prototyping and experimental validation of CFR and DPD techniques for multiple waveform types and application environments.

Peer Reviewed