Title: Zero-Energy RIS-Assisted Communications With Noise Modulation and Interference-Based Energy Harvesting Show Chinese title

Title: 零能RIS辅助通信与噪声调制和干扰式能量收集

Abstract: To advance towards carbon-neutrality and improve the limited {performance} of conventional passive wireless communications, in this paper, we investigate the integration of noise modulation with zero-energy reconfigurable intelligent surfaces (RISs). In particular, the RIS reconfigurable elements (REs) are divided into two groups: one for beamforming the desired signals in reflection mode and another for harvesting energy from interference signals in an absorption mode, providing the power required for RIS operation. Since the harvested energy is a random variable, a random number of REs can beamform the signals, while the remainder blindly reflects them. We present a closed-form solution and a search algorithm for REs allocation, jointly optimizing both the energy harvesting (EH) and communication performance. Considering the repetition coding technique and discrete phase shifts, we derive analytical expressions for the energy constrained success rate, bit error rate, optimal threshold, mutual information, {and energy efficiency}. Numerical and simulation results confirm the effectiveness of the algorithm and expressions, demonstrating the superiority of the proposed integration over conventional noise-modulation systems. It is shown that by properly allocating the REs, both the EH and communication performance can be improved in low to moderate interference scenarios, while the latter is restricted in the high-interference regime. Show Chinese abstract

Abstract: 为了迈向碳中和并改善传统被动无线通信的局限性{性能}，在本文中，我们研究了噪声调制与零能耗可重构智能表面（RIS）的集成。 特别是，RIS 的可重构单元（REs）被分为两组：一组用于反射模式下波束成形所需信号，另一组用于吸收模式下从干扰信号中收集能量，从而为 RIS 运行提供所需的功率。 由于收集的能量是一个随机变量，因此可以有随机数量的 REs 进行信号波束成形，而其余的则盲目地反射信号。 我们提出了一个闭式解和一种搜索算法来分配 REs，联合优化能量采集（EH）和通信性能。 考虑到重复编码技术和离散相移，我们推导了能量受限的成功率、比特误码率、最优阈值、互信息以及{和能源效率}的分析表达式。 数值和仿真结果验证了该算法和公式的有效性，展示了所提出集成方法相对于传统噪声调制系统的优越性。 研究表明，通过合理分配 REs，在低到中等干扰场景下，既可以提高能量采集和通信性能，而在高干扰情况下，后者受到限制。