Testbed Configuration for Minimizing PAPR in GFDM Systems through a Novel Companding Approach

Generalized frequency division multiplexing (GFDM) has emerged as a quintessential waveform candidate poised to meet the stringent requirements of next-generation wireless communication frameworks, addressing pivotal 5G physical layer challenges through its flexible, adaptive structure and spectral efficiency. Despite its numerous advantages, GFDM, akin to other multi-carrier schemes, is afflicted by an inherent high peak-to-average power ratio (PAPR), which can degrade power efficiency and impair system performance under high-power amplifier constraints. In this paper, we rigorously derive the complementary cumulative distribution function (CCDF) for GFDM systems, elucidating its intricate dependence on the design and characteristics of pulse-shaping filters, which are instrumental in managing spectral and temporal properties. Furthermore, we introduce an optimized non-linear companding scheme, specifically calibrated to enhance PAPR performance in GFDM systems by tailoring key parameters to achieve a balance between signal integrity and power efficiency. Extensive simulations demonstrate that the proposed approach, in conjunction with refined pulse-shaping filter configurations, yields substantial enhancements in PAPR reduction, outperforming conventional methods within the GFDM framework. To substantiate the theoretical and simulated outcomes, we have developed an experimental testbed leveraging the universal software radio peripheral (USRP) and LabVIEW environment, providing empirical validation and underscoring the real-world applicability of our proposed technique.