Pub Date : 2023-11-07DOI: 10.1109/TGCN.2023.3330791
Dongji Li;Shaoyi Xu;Chengyu Zhao;Yuanjie Wang;Rongtao Xu;Bo Ai
Owing to the striking features, such as controllable mobility, low cost, and so on, unmanned aerial vehicles (UAVs) are deemed to be the promising solution to complete data collection tasks of Internet of Things devices (IoTDs). The limited onboard energy, however, undeniably impedes the progress of collecting data. Furthermore, this task is complicated further due to the various amount of data generated by the different types of IoTDs. The goal of this paper is to design an applicable data collection scheme for IoT networks using a laser-powered UAV to maximize system energy efficiency. We propose an improved clustering algorithm called logarithm kernel-based mean shift (LKMS) inspired by the idea behind the mean shift algorithm. Based on the LKMS, we propose a novel algorithm to determine the optimal visiting order and enter points (EPs) of IoTD clusters, paving the way for the following optimization. To manage to solve the variables-coupling and non-convex formulated problem, we artificially divide the entire flying procedure into two phases, the flying and charging (FC) phase as well as the collecting data (CD) phase, depending on whether the UAV is harvesting energy. The block coordinate descent (BCD) and the successive convex approximation (SCA) methods are used to decouple the variables and solve the non-convex subproblems. Simulation results validate the effectiveness of our proposed scheme.
{"title":"Data Collection in Laser-Powered UAV-Assisted IoT Networks: Phased Scheme Design Based on Improved Clustering Algorithm","authors":"Dongji Li;Shaoyi Xu;Chengyu Zhao;Yuanjie Wang;Rongtao Xu;Bo Ai","doi":"10.1109/TGCN.2023.3330791","DOIUrl":"10.1109/TGCN.2023.3330791","url":null,"abstract":"Owing to the striking features, such as controllable mobility, low cost, and so on, unmanned aerial vehicles (UAVs) are deemed to be the promising solution to complete data collection tasks of Internet of Things devices (IoTDs). The limited onboard energy, however, undeniably impedes the progress of collecting data. Furthermore, this task is complicated further due to the various amount of data generated by the different types of IoTDs. The goal of this paper is to design an applicable data collection scheme for IoT networks using a laser-powered UAV to maximize system energy efficiency. We propose an improved clustering algorithm called logarithm kernel-based mean shift (LKMS) inspired by the idea behind the mean shift algorithm. Based on the LKMS, we propose a novel algorithm to determine the optimal visiting order and enter points (EPs) of IoTD clusters, paving the way for the following optimization. To manage to solve the variables-coupling and non-convex formulated problem, we artificially divide the entire flying procedure into two phases, the flying and charging (FC) phase as well as the collecting data (CD) phase, depending on whether the UAV is harvesting energy. The block coordinate descent (BCD) and the successive convex approximation (SCA) methods are used to decouple the variables and solve the non-convex subproblems. Simulation results validate the effectiveness of our proposed scheme.","PeriodicalId":13052,"journal":{"name":"IEEE Transactions on Green Communications and Networking","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2023-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135508593","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-07DOI: 10.1109/TGCN.2023.3330481
Li Ping Qian;Suru Zhou;Mengru Wu;Yuan Wu
Non-orthogonal multiple access (NOMA) and energy-harvesting (EH) relay have been envisioned as promising technologies in Narrowband Internet of Things (NB-IoT) networks to efficiently improve the spectral-energy efficiency of networks and the massive connectivity of devices. However, the successive interference cancellation (SIC) ordering of NOMA has become a bottleneck affecting the performance of uplink transmission in NB-IoT networks. Also, while using NOMA, the data rate based fairness across NB-IoT devices cannot be ensured due to the difference between individual channels. To address these issues, this paper investigates the integration of NOMA and EH relay into the NB-IoT network. Correspondingly, we aim to maximize the data rate based proportional fairness across all NB-IoT devices by jointly optimizing the resource allocation and SIC ordering. We first prove the NP-hardness of this joint optimization problem and then tackle this mathematically intractable problem by decomposing it into resource allocation and SIC ordering problems. To solve the resource allocation problem, we exploit the convexity of the problem through transformation and reparameterization and then derive the optimal solution based on its Lagrangian function. We also propose a low-complexity SIC ordering algorithm by leveraging tabu search to obtain the sub-optimal SIC ordering. Simulation results validate the effectiveness of the proposed algorithm and the superiority of NOMA compared to frequency division multiple access (FDMA).
非正交多址接入（NOMA）和能量收集（EH）中继被认为是窄带物联网（NB-IoT）网络中很有前景的技术，可有效提高网络的频谱能效和设备的海量连接。然而，NOMA 的连续干扰消除（SIC）排序已成为影响 NB-IoT 网络上行链路传输性能的瓶颈。此外，在使用 NOMA 时，由于各个信道之间的差异，无法确保 NB-IoT 设备之间基于数据速率的公平性。为了解决这些问题，本文研究了如何将 NOMA 和 EH 中继集成到 NB-IoT 网络中。相应地，我们的目标是通过联合优化资源分配和 SIC 排序，最大限度地提高所有 NB-IoT 设备的数据传输速率。我们首先证明了这一联合优化问题的 NP 难度，然后通过将其分解为资源分配和 SIC 排序问题来解决这一数学上难以解决的问题。为了解决资源分配问题，我们通过变换和重参数化利用了问题的凸性，然后根据其拉格朗日函数推导出最优解。我们还提出了一种低复杂度的 SIC 排序算法，利用塔布搜索获得次优 SIC 排序。仿真结果验证了所提算法的有效性，以及 NOMA 与频分多址（FDMA）相比的优越性。
{"title":"Joint Optimization of Resource Allocation and SIC Ordering in Energy-Harvesting Relay-Aided NOMA NB-IoT Networks","authors":"Li Ping Qian;Suru Zhou;Mengru Wu;Yuan Wu","doi":"10.1109/TGCN.2023.3330481","DOIUrl":"10.1109/TGCN.2023.3330481","url":null,"abstract":"Non-orthogonal multiple access (NOMA) and energy-harvesting (EH) relay have been envisioned as promising technologies in Narrowband Internet of Things (NB-IoT) networks to efficiently improve the spectral-energy efficiency of networks and the massive connectivity of devices. However, the successive interference cancellation (SIC) ordering of NOMA has become a bottleneck affecting the performance of uplink transmission in NB-IoT networks. Also, while using NOMA, the data rate based fairness across NB-IoT devices cannot be ensured due to the difference between individual channels. To address these issues, this paper investigates the integration of NOMA and EH relay into the NB-IoT network. Correspondingly, we aim to maximize the data rate based proportional fairness across all NB-IoT devices by jointly optimizing the resource allocation and SIC ordering. We first prove the NP-hardness of this joint optimization problem and then tackle this mathematically intractable problem by decomposing it into resource allocation and SIC ordering problems. To solve the resource allocation problem, we exploit the convexity of the problem through transformation and reparameterization and then derive the optimal solution based on its Lagrangian function. We also propose a low-complexity SIC ordering algorithm by leveraging tabu search to obtain the sub-optimal SIC ordering. Simulation results validate the effectiveness of the proposed algorithm and the superiority of NOMA compared to frequency division multiple access (FDMA).","PeriodicalId":13052,"journal":{"name":"IEEE Transactions on Green Communications and Networking","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2023-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135507439","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-06DOI: 10.1109/TGCN.2023.3330247
Wenhan Xu;Jiadong Yu;Yuan Wu;Danny H. K. Tsang
The explosive development of the Internet of Things (IoT) has led to increased interest in mobile edge computing (MEC), which provides computational resources at network edges to accommodate computation-intensive and latency-sensitive applications. Intelligent reflecting surfaces (IRSs) have gained attention as a solution to overcome blockage problems during the offloading uplink transmission in MEC systems. This paper explores IRS-aided multi-cell networks that enable servers to serve neighboring cells and cooperate to handle resource exhaustion. We aim to minimize the joint energy and latency cost by jointly optimizing the computation tasks, edge computing resources, user beamforming, and IRS phase shifts. The problem is decomposed into two subproblems—the MEC subproblem and the IRS communication subproblem—using the block coordinate descent (BCD) technique. The MEC subproblem is reformulated as a nonconvex quadratic constrained problem (QCP), while the IRS communication subproblem is transformed into a weight-sum-rate problem with auxiliary variables. We propose an efficient algorithm to alternately optimize the MEC resources and IRS communication variables. Numerical results show that our algorithm outperforms benchmarks and that multi-cell MEC systems achieve additional performance gains when supported by IRS.
{"title":"Energy-Latency Aware Intelligent Reflecting Surface Aided Multi-Cell Mobile Edge Computing","authors":"Wenhan Xu;Jiadong Yu;Yuan Wu;Danny H. K. Tsang","doi":"10.1109/TGCN.2023.3330247","DOIUrl":"10.1109/TGCN.2023.3330247","url":null,"abstract":"The explosive development of the Internet of Things (IoT) has led to increased interest in mobile edge computing (MEC), which provides computational resources at network edges to accommodate computation-intensive and latency-sensitive applications. Intelligent reflecting surfaces (IRSs) have gained attention as a solution to overcome blockage problems during the offloading uplink transmission in MEC systems. This paper explores IRS-aided multi-cell networks that enable servers to serve neighboring cells and cooperate to handle resource exhaustion. We aim to minimize the joint energy and latency cost by jointly optimizing the computation tasks, edge computing resources, user beamforming, and IRS phase shifts. The problem is decomposed into two subproblems—the MEC subproblem and the IRS communication subproblem—using the block coordinate descent (BCD) technique. The MEC subproblem is reformulated as a nonconvex quadratic constrained problem (QCP), while the IRS communication subproblem is transformed into a weight-sum-rate problem with auxiliary variables. We propose an efficient algorithm to alternately optimize the MEC resources and IRS communication variables. Numerical results show that our algorithm outperforms benchmarks and that multi-cell MEC systems achieve additional performance gains when supported by IRS.","PeriodicalId":13052,"journal":{"name":"IEEE Transactions on Green Communications and Networking","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2023-11-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135502759","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-03DOI: 10.1109/TGCN.2023.3330018
Muhammad Awais;Haris Pervaiz;Muhammad Ali Jamshed;Wenjuan Yu;Qiang Ni
The development of futuristic wireless infrastructure necessitates low power consumption, high reliability, and massive connectivity. One of the most promising solutions to address these requirements is the integration of aerial base station (ABS) based communication systems that employ both in the air (aerial) and on the ground (terrestrial) components. This integration enhances line of sight connections, enabling the fulfillment of escalating quality-of-service (QoS) demands. This article examines the problem of resource allocation in ABS assisted multi-hop wireless networks. We investigate a joint optimization problem that involves subcarrier (SC) assignment, power allocation, and blocklength allocation, subject to delay, reliability, and QoS constraints to improve the sum-rate under the finite blocklength (FBL) regime. We propose an approach for SC allocation and selection of cooperative ABSs based on matching theory. Subsequently, we employ an alternating optimization method to propose a novel bisection-based low-complexity adaptation (BLCA) algorithm to optimize the resource allocation policy. This algorithm includes a two-step projected gradient descent-based strategy to optimize the power allocation on each SC using dynamic and geometric programming. Furthermore, we examine flexible blocklength and power allocation use cases under the next generation of multiple access techniques. Monte-Carlo simulations validate that the proposed algorithmic solution significantly achieves a near-optimal solution while requiring 1600 times less computational cost compared to benchmarks in its counterparts.
{"title":"Energy-Aware Resource Optimization for Improved URLLC in Multi-Hop Integrated Aerial Terrestrial Networks","authors":"Muhammad Awais;Haris Pervaiz;Muhammad Ali Jamshed;Wenjuan Yu;Qiang Ni","doi":"10.1109/TGCN.2023.3330018","DOIUrl":"10.1109/TGCN.2023.3330018","url":null,"abstract":"The development of futuristic wireless infrastructure necessitates low power consumption, high reliability, and massive connectivity. One of the most promising solutions to address these requirements is the integration of aerial base station (ABS) based communication systems that employ both in the air (aerial) and on the ground (terrestrial) components. This integration enhances line of sight connections, enabling the fulfillment of escalating quality-of-service (QoS) demands. This article examines the problem of resource allocation in ABS assisted multi-hop wireless networks. We investigate a joint optimization problem that involves subcarrier (SC) assignment, power allocation, and blocklength allocation, subject to delay, reliability, and QoS constraints to improve the sum-rate under the finite blocklength (FBL) regime. We propose an approach for SC allocation and selection of cooperative ABSs based on matching theory. Subsequently, we employ an alternating optimization method to propose a novel bisection-based low-complexity adaptation (BLCA) algorithm to optimize the resource allocation policy. This algorithm includes a two-step projected gradient descent-based strategy to optimize the power allocation on each SC using dynamic and geometric programming. Furthermore, we examine flexible blocklength and power allocation use cases under the next generation of multiple access techniques. Monte-Carlo simulations validate that the proposed algorithmic solution significantly achieves a near-optimal solution while requiring 1600 times less computational cost compared to benchmarks in its counterparts.","PeriodicalId":13052,"journal":{"name":"IEEE Transactions on Green Communications and Networking","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2023-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134982408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-11-01DOI: 10.1109/TGCN.2023.3329127
Tao Zhou;Kui Xu;Guojie Hu;Xiaochen Xia;Wei Xie;Chunguo Li
Potential eavesdropping and malicious jamming attacks pose an enormous threat to wireless communication. In this paper, a novel architecture of reconfigurable intelligent surface (RIS)–simultaneously transmitting and reflecting (STAR)-RIS is utilized to assist both anti-jamming and anti-eavesdropping transmissions. We aim to minimize the access point (AP) transmit power while ensuring that both secure communication requirements and user service requirements are met. Since the channel status information (CSI) of illegal nodes (eavesdropper and jammer) is difficult to obtain accurately and the beamforming strategy of a jammer is unknown, we consider a robust beamforming design with imperfect CSI for illegal channels and an unknown jamming strategy. Outage-constrained power minimization problems are formulated for three different protocols of the STAR-RIS, namely, energy splitting (ES), mode switching (MS) and time switching (TS). For each protocol, the alternate optimization (AO)-based method is proposed to jointly optimize the active beamforming (ABF) of the AP and the passive beamforming (PBF) of the STAR-RIS to solve these nonconvex and highly coupled problems. Simulation results show the effectiveness of the proposed methods. Compared with the conventional RIS, the STAR-RIS has significantly more potential in terms of anti-jamming and eavesdropping suppression.
{"title":"Robust Beamforming Design for STAR-RIS-Assisted Anti-Jamming and Secure Transmission","authors":"Tao Zhou;Kui Xu;Guojie Hu;Xiaochen Xia;Wei Xie;Chunguo Li","doi":"10.1109/TGCN.2023.3329127","DOIUrl":"10.1109/TGCN.2023.3329127","url":null,"abstract":"Potential eavesdropping and malicious jamming attacks pose an enormous threat to wireless communication. In this paper, a novel architecture of reconfigurable intelligent surface (RIS)–simultaneously transmitting and reflecting (STAR)-RIS is utilized to assist both anti-jamming and anti-eavesdropping transmissions. We aim to minimize the access point (AP) transmit power while ensuring that both secure communication requirements and user service requirements are met. Since the channel status information (CSI) of illegal nodes (eavesdropper and jammer) is difficult to obtain accurately and the beamforming strategy of a jammer is unknown, we consider a robust beamforming design with imperfect CSI for illegal channels and an unknown jamming strategy. Outage-constrained power minimization problems are formulated for three different protocols of the STAR-RIS, namely, energy splitting (ES), mode switching (MS) and time switching (TS). For each protocol, the alternate optimization (AO)-based method is proposed to jointly optimize the active beamforming (ABF) of the AP and the passive beamforming (PBF) of the STAR-RIS to solve these nonconvex and highly coupled problems. Simulation results show the effectiveness of the proposed methods. Compared with the conventional RIS, the STAR-RIS has significantly more potential in terms of anti-jamming and eavesdropping suppression.","PeriodicalId":13052,"journal":{"name":"IEEE Transactions on Green Communications and Networking","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135362622","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-30DOI: 10.1109/TGCN.2023.3328387
Jung-Chieh Chen
This study proposes a joint design approach for hybrid beamforming and reflecting beamforming in an intelligent reflecting surface (IRS)-assisted millimeter-wave massive multiuser multiple-input single-output system. The goal is to maximize energy efficiency using energy- and hardware-efficient hybrid beamforming architectures at the base station and low-resolution (e.g., 1–2 bits) phase shifters at the IRS. However, the problem of maximizing energy efficiency is complicated by the high coupling of design variables. To address this, we use a zero-force (ZF) beamforming technique as the digital component of hybrid beamforming and develop a probability learning algorithm based on a cross-entropy optimization (CEO) framework to determine the weights of the analog part of hybrid beamforming as well as IRS phase shifts simultaneously. Additionally, we seek to maximize spatial reuse benefits by increasing the size of the IRS while selecting only a limited number of IRS elements to improve spectral and energy efficiency while minimizing power consumption. This involves joint optimization of hybrid beamforming, IRS element selection, and phase shifts associated with the chosen IRS elements. Solving this problem is challenging, but the proposed ZF-assisted CEO algorithm can still be applied with slight modifications. Simulation results demonstrate that our algorithms achieve significantly better energy efficiency than competitors while maintaining reasonable spectral efficiency.
{"title":"Energy-Efficient Hybrid Beamforming Design for Intelligent Reflecting Surface-Assisted mmWave Massive MU-MISO Systems","authors":"Jung-Chieh Chen","doi":"10.1109/TGCN.2023.3328387","DOIUrl":"10.1109/TGCN.2023.3328387","url":null,"abstract":"This study proposes a joint design approach for hybrid beamforming and reflecting beamforming in an intelligent reflecting surface (IRS)-assisted millimeter-wave massive multiuser multiple-input single-output system. The goal is to maximize energy efficiency using energy- and hardware-efficient hybrid beamforming architectures at the base station and low-resolution (e.g., 1–2 bits) phase shifters at the IRS. However, the problem of maximizing energy efficiency is complicated by the high coupling of design variables. To address this, we use a zero-force (ZF) beamforming technique as the digital component of hybrid beamforming and develop a probability learning algorithm based on a cross-entropy optimization (CEO) framework to determine the weights of the analog part of hybrid beamforming as well as IRS phase shifts simultaneously. Additionally, we seek to maximize spatial reuse benefits by increasing the size of the IRS while selecting only a limited number of IRS elements to improve spectral and energy efficiency while minimizing power consumption. This involves joint optimization of hybrid beamforming, IRS element selection, and phase shifts associated with the chosen IRS elements. Solving this problem is challenging, but the proposed ZF-assisted CEO algorithm can still be applied with slight modifications. Simulation results demonstrate that our algorithms achieve significantly better energy efficiency than competitors while maintaining reasonable spectral efficiency.","PeriodicalId":13052,"journal":{"name":"IEEE Transactions on Green Communications and Networking","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2023-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135260735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To design and construct future wireless-friendly buildings, the wireless-friendliness of buildings, i.e., building wireless performance (BWP), must be evaluated to provide quantitative guidance for future building design. However, the BWP evaluation approach for indoor device-to-device (D2D) networks, which are expected to be widely employed, is absent from the existing theoretical systems of BWP evaluation. Accordingly, this paper presents the first systematic BWP evaluation approach for indoor D2D networks. We create a BWP evaluation metric, blockage gain, by simultaneously considering the impacts of building layouts and building materials. The blockage gain is defined as the spatially averaged coverage probability (SACP) improvement due to the out-of-room interference blockage by the room walls. We derive the theoretical upper and lower bounds of the SACP in the general scenario, and we obtain the empirical formulas of the SACP and the blockage gain by the derived upper and lower bounds. The empirical formulas indicate that the impacts of building layouts and building materials can be decoupled. Moreover, the results show that well-designed rooms can improve the SACP of the indoor D2D network by at least 0.1. This work can provide guidance for architects to design wireless-friendly buildings for indoor D2D networks.
{"title":"Evaluation of Building Wireless Performance for Indoor Device-to-Device Networks","authors":"Jixuan Lin;Haonan Hu;Yixin Huang;Jiliang Zhang;Jie Zhang","doi":"10.1109/TGCN.2023.3325341","DOIUrl":"10.1109/TGCN.2023.3325341","url":null,"abstract":"To design and construct future wireless-friendly buildings, the wireless-friendliness of buildings, i.e., building wireless performance (BWP), must be evaluated to provide quantitative guidance for future building design. However, the BWP evaluation approach for indoor device-to-device (D2D) networks, which are expected to be widely employed, is absent from the existing theoretical systems of BWP evaluation. Accordingly, this paper presents the first systematic BWP evaluation approach for indoor D2D networks. We create a BWP evaluation metric, blockage gain, by simultaneously considering the impacts of building layouts and building materials. The blockage gain is defined as the spatially averaged coverage probability (SACP) improvement due to the out-of-room interference blockage by the room walls. We derive the theoretical upper and lower bounds of the SACP in the general scenario, and we obtain the empirical formulas of the SACP and the blockage gain by the derived upper and lower bounds. The empirical formulas indicate that the impacts of building layouts and building materials can be decoupled. Moreover, the results show that well-designed rooms can improve the SACP of the indoor D2D network by at least 0.1. This work can provide guidance for architects to design wireless-friendly buildings for indoor D2D networks.","PeriodicalId":13052,"journal":{"name":"IEEE Transactions on Green Communications and Networking","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2023-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135057942","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-17DOI: 10.1109/TGCN.2023.3325385
Jun-Bo Wang;Bingshan Wang;Changfeng Ding;Min Lin;Jiangzhou Wang
Intelligent Reflecting Surface (IRS) is a promising approach to effectively improve the propagation environment, which includes a controller and numerous reflecting elements. In this paper, we consider an IRS-assisted mobile edge computing (MEC) system, which has a base station (BS), multiple single-antenna user terminals (UTs), and an IRS. Aiming at minimizing the system energy consumption, the transmission power of UTs, the BS receiving beamforming vector, the BS computing resources allocation, and the IRS effective phase shifts are jointly optimized. As these four variables are coupled together and the problem is non-convex, block coordinate descent method is adopted to decompose the optimization problem into four subproblems. In order to address the transmission power subproblem, quadratic transform based fractional programming, Lagrange dual transformation, and difference of convex function algorithm are used. Quadratic transformation and Lagrange dual transformation are also used to optimize the phase shift matrix and the receiving beamforming vector, while the quadratic transform in the multidimensional and complex case is used additionally in the IRS phase-shift subproblem to tackle the fractional term. Meanwhile, the computation resource allocation is derived in a closed-form expression. Simulation results confirm that for the IRS-assisted MEC system, the proposed optimization method is effective.
{"title":"Joint Optimization of Transmission and Computing Resource in Intelligent Reflecting Surface-Assisted Mobile-Edge Computing System","authors":"Jun-Bo Wang;Bingshan Wang;Changfeng Ding;Min Lin;Jiangzhou Wang","doi":"10.1109/TGCN.2023.3325385","DOIUrl":"10.1109/TGCN.2023.3325385","url":null,"abstract":"Intelligent Reflecting Surface (IRS) is a promising approach to effectively improve the propagation environment, which includes a controller and numerous reflecting elements. In this paper, we consider an IRS-assisted mobile edge computing (MEC) system, which has a base station (BS), multiple single-antenna user terminals (UTs), and an IRS. Aiming at minimizing the system energy consumption, the transmission power of UTs, the BS receiving beamforming vector, the BS computing resources allocation, and the IRS effective phase shifts are jointly optimized. As these four variables are coupled together and the problem is non-convex, block coordinate descent method is adopted to decompose the optimization problem into four subproblems. In order to address the transmission power subproblem, quadratic transform based fractional programming, Lagrange dual transformation, and difference of convex function algorithm are used. Quadratic transformation and Lagrange dual transformation are also used to optimize the phase shift matrix and the receiving beamforming vector, while the quadratic transform in the multidimensional and complex case is used additionally in the IRS phase-shift subproblem to tackle the fractional term. Meanwhile, the computation resource allocation is derived in a closed-form expression. Simulation results confirm that for the IRS-assisted MEC system, the proposed optimization method is effective.","PeriodicalId":13052,"journal":{"name":"IEEE Transactions on Green Communications and Networking","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135001865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2023-10-17DOI: 10.1109/TGCN.2023.3325377
Jie Li;Zhengyu Song;Tianwei Hou;Jiazi Gao;Anna Li;Zhiqing Tang
In recent years, the reconfigurable intelligent surface (RIS) has garnered considerable interest for its remarkable advancements in spectral efficiency (SE) and energy efficiency (EE). To further enhance the performance of cellular networks, we propose a novel RIS-aided multi-input multi-output (MIMO) non-orthogonal multiple access (NOMA) architecture. To mitigate both inter-cell and inter-cluster interferences, we introduce a signal-cancellation-based (SCB) design specifically tailored for the RISs. By strategically deploying the RIS in suitable locations and adjusting the reflection coefficient (RC) of its elements, we achieve effective interference mitigation. The passive beamforming at the RISs is meticulously designed, and we assess how many RIS elements are necessary to implement the SCB design. To gain insights into system performance, we analyze the outage probability and the ergodic rate, providing valuable information on the high signal-to-noise ratio slopes and diversity orders for the users in the network. The numerical results reveal: 1) in comparison to the zero-forcing and maximum-ratio-transmission precoding matrices, the identity precoding matrix at the BS offers superior performance; 2) an optimal number of RIS elements exists in order to maximize both SE and EE.
{"title":"An RIS-Aided Interference Mitigation-Based Design for MIMO-NOMA in Cellular Networks","authors":"Jie Li;Zhengyu Song;Tianwei Hou;Jiazi Gao;Anna Li;Zhiqing Tang","doi":"10.1109/TGCN.2023.3325377","DOIUrl":"10.1109/TGCN.2023.3325377","url":null,"abstract":"In recent years, the reconfigurable intelligent surface (RIS) has garnered considerable interest for its remarkable advancements in spectral efficiency (SE) and energy efficiency (EE). To further enhance the performance of cellular networks, we propose a novel RIS-aided multi-input multi-output (MIMO) non-orthogonal multiple access (NOMA) architecture. To mitigate both inter-cell and inter-cluster interferences, we introduce a signal-cancellation-based (SCB) design specifically tailored for the RISs. By strategically deploying the RIS in suitable locations and adjusting the reflection coefficient (RC) of its elements, we achieve effective interference mitigation. The passive beamforming at the RISs is meticulously designed, and we assess how many RIS elements are necessary to implement the SCB design. To gain insights into system performance, we analyze the outage probability and the ergodic rate, providing valuable information on the high signal-to-noise ratio slopes and diversity orders for the users in the network. The numerical results reveal: 1) in comparison to the zero-forcing and maximum-ratio-transmission precoding matrices, the identity precoding matrix at the BS offers superior performance; 2) an optimal number of RIS elements exists in order to maximize both SE and EE.","PeriodicalId":13052,"journal":{"name":"IEEE Transactions on Green Communications and Networking","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2023-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135007185","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A low-power, low-latency, and long-range (LoRa) relay is developed using mixed-frequency underwater wireless communication systems (UWCSs) for LoRa wide-area network. First, the feasibility of utilizing LoRa in an underwater-to-above-water communication link is examined through theoretical and experimental approaches. In addition, the communication link quality is evaluated using the received signal strength indicator, signal-to-noise ratio, and packet delivery ratio at different depths, horizontal distances, and LoRa physical layer parameters. Finally, considering the experimentally observed challenges of UWCSs, the LoRa-based relay is designed, and its usability is validated by comparing the communication systems without and with the relay (from underwater to the water surface to the above-water) in terms of LoRa physical layer parameters, transmission range, and link quality indices. Moreover, the network latency and battery consumption of the whole system are studied without and with the relay using different LoRa physical layer parameters, and the optimum parameters are presented. The results show that the designed relay can improve communication performance without delay and power consumption concerns.
{"title":"Experimental and Simulation Study of a LoRaWAN-Assisted Relay for IoUT Communication","authors":"Javad Bolboli;Maaz Salman;Ramavath Prasad Naik;Wan-Young Chung","doi":"10.1109/TGCN.2023.3324638","DOIUrl":"10.1109/TGCN.2023.3324638","url":null,"abstract":"A low-power, low-latency, and long-range (LoRa) relay is developed using mixed-frequency underwater wireless communication systems (UWCSs) for LoRa wide-area network. First, the feasibility of utilizing LoRa in an underwater-to-above-water communication link is examined through theoretical and experimental approaches. In addition, the communication link quality is evaluated using the received signal strength indicator, signal-to-noise ratio, and packet delivery ratio at different depths, horizontal distances, and LoRa physical layer parameters. Finally, considering the experimentally observed challenges of UWCSs, the LoRa-based relay is designed, and its usability is validated by comparing the communication systems without and with the relay (from underwater to the water surface to the above-water) in terms of LoRa physical layer parameters, transmission range, and link quality indices. Moreover, the network latency and battery consumption of the whole system are studied without and with the relay using different LoRa physical layer parameters, and the optimum parameters are presented. The results show that the designed relay can improve communication performance without delay and power consumption concerns.","PeriodicalId":13052,"journal":{"name":"IEEE Transactions on Green Communications and Networking","volume":null,"pages":null},"PeriodicalIF":4.8,"publicationDate":"2023-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136374239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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