5G backscatter communication presents an emerging energy-efficient IoT connectivity solution with enhanced availability and data rate advantages over traditional wireless networks. For 5G backscatter, synchronization is crucial as it ensures high-quality transmission. Popular synchronization methods employ autocorrelation and cross-correlation for accurate timing, yet they are constrained by resources. Traditional cross-correlation-based methods for resource utilization optimization also fail in 5G backscatter due to the presence of multiple templates for 5G. A synchronization strategy that supports high accuracy and low power would be highly attractive for wireless backscatter communication. We propose Symmetric Differential (SD)-based Sync, an accurate and resource-efficient synchronization method for 5G backscatter. We have observed that the envelope of the 5G Primary Synchronization Signal (PSS) exhibits a unique mirror symmetry, which enables us to employ differential techniques for low-power PSS detection. We extensively evaluated our design using a testbed of backscatter hardware, SDR gNodeB, and User Equipment (UE). Results show that our SD consumes 3,175 D flip-flops, which is 87x lower than NR fine timing (NFT), 181x lower than symmetry-based semi-template sync (SST), and 30x lower than symmetric autocorrelation (SA)-based sync.

翻译：5G反向散射通信提供了一种新兴的节能物联网连接方案，相较于传统无线网络具有更高的可用性和数据速率优势。在5G反向散射通信中，同步至关重要，因为它是确保高质量传输的基础。常用的同步方法采用自相关和互相关实现精确计时，但受限于资源。传统基于互相关的资源利用优化方法在5G反向散射场景中因存在多个5G模板而失效。一种兼具高精度与低功耗的同步策略对无线反向散射通信极具吸引力。我们提出基于对称差分（SD）的同步方法，这是一种面向5G反向散射的精确且资源高效的同步方案。研究发现5G主同步信号（PSS）的包络具有独特的镜像对称性，这使我们能够采用差分技术实现低功耗的PSS检测。我们利用反向散射硬件、SDR gNodeB和用户设备（UE）组成的测试平台对该设计进行了全面评估。结果表明，我们的SD方法仅消耗3,175个D触发器，比NR精确定时（NFT）低87倍，比基于对称半模板同步（SST）低181倍，比基于对称自相关（SA）同步低30倍。