High peak to average power ratio (PAPR) is viewed as a serious limitation of all multi-carrier systems. In this article, a companding transform with clipping technique is proposed for universal filtered multi-carrier (UFMC) system. The proposed companding transform successfully reduces the PAPR by expanding the small amplitude signals and compressing the peak amplitude signals. Moreover, the combination of companding and clipping further reduces the PAPR. Besides, the proposed scheme provides more flexibility by properly selecting companding parameters and clipping ratio (CR). Additionally, this article presents the performance evaluation of various nonlinear companding transforms (NCTs) of the UFMC system in terms of PAPR reduction, bit-error-rate, and reduced out-of-band emissions. Simulation results confirm that the proposed hybrid transform provides superior system performance when compared to other NCTs. The proposed hybrid transform with CR of 1.4 provides superior PAPR diminution of 8.5 dB and net gain of 8.9 dB when compared to other schemes. Finally, the proposed hybrid transform is validated by using wireless-open access-research platform over real time channel.

中文翻译：

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通用滤波多载波系统混合变换性能评估

高峰均功率比 (PAPR) 被视为所有多载波系统的严重限制。在本文中，针对通用滤波多载波 (UFMC) 系统提出了一种采用限幅技术的压扩变换。所提出的压缩扩展变换通过扩展小振幅信号和压缩峰值振幅信号成功地降低了 PAPR。此外，压缩扩展和削波的组合进一步降低了 PAPR。此外，提出的方案通过正确选择构成参数和剪辑比率（CR）提供了更大的灵活性。此外，本文还介绍了 UFMC 系统在 PAPR 降低、误码率和带外辐射降低方面的各种非线性压扩变换 (NCT) 的性能评估。仿真结果证实，与其他 NCT 相比，所提出的混合变换提供了卓越的系统性能。与其他方案相比，建议的 CR 为 1.4 的混合变换提供了 8.5 dB 的出色 PAPR 减少和 8.9 dB 的净增益。最后，通过使用实时信道上的无线开放访问研究平台验证了所提出的混合变换。