The problem motivates this paper is that securing the critical data of 5G based wireless IoT network is of significant importance. Wireless 5G IoT systems consist of a large number of devices (low-cost legitimate users), which are of low complexity and under strict energy constraints. Physical layer security (PLS) schemes, along with energy harvesting, have emerged as a potential candidate that provides an effective solution to address this issue. During the data collection process of IoT, PHY security techniques can exploit the characteristics of the wireless channel to ensure secure communication. This paper focuses on optimizing the secrecy rate for simultaneous wireless information and power transfer (SWIPT) IoT system, considering that the malicious eavesdroppers can intercept the data. In particular, the main aim is to optimize the secrecy rate of the system under signal to interference noise ratio (SINR), energy harvesting (EH), and total transmits power constraints. We model our design as an optimization problem that advocates the use of additional noise to ensure secure communication and guarantees efficient wireless energy transfer. The primary problem is non-convex due to complex objective functions in terms of transmit beamforming matrix and power splitting ratios. We have considered both the perfect channel state information (CSI) and the imperfect CSI scenarios. To circumvent the non-convexity of the primary problem in perfect CSI case, we proposed a solution based on the concave-convex procedure (CCCP) iterative algorithm, which results in a maximum local solution for the secrecy rate. In the imperfect CSI scenario, we facilitate the use of S-procedure and present a solution based on the iterative successive convex approximation (SCA) approach. Simulation results present the validations of the proposed algorithms. The results provide an insightful view that the proposed iterative method based on the CCCP algorithm achieves higher secrecy rates and lower computational complexity in comparison to the other algorithms.

问题的动机在于，保护基于5G的无线IoT网络的关键数据至关重要。无线5G IoT系统由大量设备（低成本的合法用户）组成，这些设备的复杂度低且受到严格的能源限制。物理层安全性（PLS）方案以及能量收集已成为潜在的候选方案，可以为解决此问题提供有效的解决方案。在物联网的数据收集过程中，PHY安全技术可以利用无线通道的特性来确保安全的通信。考虑到恶意的窃听者可以拦截数据，本文重点在于优化同时进行无线信息和电力传输（SWIPT）IoT系统的保密率。尤其是，主要目的是在信噪比（SINR），能量收集（EH）和总发射功率约束下优化系统的保密率。我们将设计建模为一个优化问题，该问题提倡使用附加噪声来确保安全的通信并确保有效的无线能量传输。首要问题是由于在发射波束成形矩阵和功率分配比方面的复杂目标函数而导致的非凸性。我们已经考虑了完美的信道状态信息（CSI）和不完善的CSI方案。为了避免在理想CSI情况下主要问题的非凸性，我们提出了一种基于凹凸过程（CCCP）迭代算法的解决方案，该解决方案可以最大程度地提高机密性。在不完善的CSI方案中，我们促进了S过程的使用，并提出了基于迭代连续凸逼近（SCA）方法的解决方案。仿真结果表明了所提出算法的有效性。结果提供了有见解的观点，即与其他算法相比，基于CCCP算法的迭代方法实现了更高的保密率和更低的计算复杂度。