智能超表面辅助通感一体化信号处理与硬件试验

Signal Processing and Hardware Experiment for RIS-aided ISAC

通感一体化是是6G的主流趋势之一,毫米波、太赫兹等高频段具有丰富的频谱资源,是通感一体化颇具潜力的频段。然而,高频通感一体化面临覆盖受限的难题。RIS是极具潜力的解决方案,目前关于RIS辅助通感一体化的文献主要集中在波束赋形优化方面,而如何设计有效的信号处理方法从RIS重塑的回波信号中提取感知信息仍然是一个悬而未决的问题,对RIS辅助通感一体化软硬件架构更是处于空白。为此,设计了RIS辅助通感一体化系统的软硬件架构,在此基础上进行了RIS辅助盲区通信和目标感知硬件试验,并提出了DSP检测器,理论分析表明,在使用N个子载波的OFDM一体化波形时,其相比传统能量检测器有N倍的SNR增益。硬件试验结果表明,优化RIS码本设计可有效降低通信误比特率、提升目标检测概率,且远距离目标检测时所提DSP检测器的性能显著优于传统的能量检测器。

Integrated communication and sensing (ISAC) is one of the mainstream trends in 6G, and high-frequency bands such asmillimeter wave and terahertz have rich spectral resources, making it a promising frequency band for ISAC. However, highfrequencyISAC faces the challenge of limited coverage. Reconfigurable intelligent surface (RIS) is a highly promisingsolution. The current literature on RIS-assisted ISAC mainly focuses on beamforming optimization, while how to designeffective signal processing methods to extract sensing information from the echo signals reshaped by RIS is still an unresolvedissue, and the software and hardware architecture of RIS-assisted ISAC is also in its infancy. For this purpose, the softwareand hardware architecture of the RIS-assisted ISAC is designed. Based on this, RIS-assisted blind spot communication andtarget sensing hardware experiments are conducted nad a DSP detector is proposed. The analytical result shows that whenusing an OFDM integrated waveform with N subcarriers, it has an SNR gain of N times compared to the traditional energydetectors. The hardware experiment results show that optimizing the RIS codebook design can effectively reduce the error bitrate of communications and improve target detection probability. Moreover, the performance of the proposed DSP detector issignificantly better than the traditional energy detector for long-distance target detection.