Pub Date : 2022-09-01DOI: 10.1109/VTC2022-Fall57202.2022.10012847
Shashwat Mishra, Lou Salaün, J. Gorce, Chung Shue Chen
We develop a framework for maximizing the number of transmitted packets for devices in a Narrowband Internet of Things (NB-IoT) network using non-orthogonal multiple access (NOMA) in the downlink. The base station (BS) chooses one of the multiple available physical resource blocks (PRBs) that are well separated in frequency for a device, giving them the advantage of exploiting frequency diversity. The scheduling strategy focuses on the two-fold problem involving efficient device clustering and optimum power allocation. This problem is a mixed-integer non-convex problem. We propose a bipartite graph matching approach, termed minimum weight full matching with pruning (MWFMP), to address the problem over multiple PRBs and solve it under the quality-of-service (QoS), allowable PRB, power budget, and interference constraints. Additionally, we provide a comparison with a greedy heuristic, the multi-PRB stratified device allocation (MPSDA), where we extend our previous work for a single PRB connectivity problem. Furthermore, we compare our algorithms to orthogonal multiple access (OMA) scheduling, which is prevalent in legacy LTE networks. We show that our algorithms steadily outperform the connectivity performance offered by OMA.
{"title":"Maximizing Downlink User Connection Density in NOMA-aided NB-IoT Networks Through a Graph Matching Approach","authors":"Shashwat Mishra, Lou Salaün, J. Gorce, Chung Shue Chen","doi":"10.1109/VTC2022-Fall57202.2022.10012847","DOIUrl":"https://doi.org/10.1109/VTC2022-Fall57202.2022.10012847","url":null,"abstract":"We develop a framework for maximizing the number of transmitted packets for devices in a Narrowband Internet of Things (NB-IoT) network using non-orthogonal multiple access (NOMA) in the downlink. The base station (BS) chooses one of the multiple available physical resource blocks (PRBs) that are well separated in frequency for a device, giving them the advantage of exploiting frequency diversity. The scheduling strategy focuses on the two-fold problem involving efficient device clustering and optimum power allocation. This problem is a mixed-integer non-convex problem. We propose a bipartite graph matching approach, termed minimum weight full matching with pruning (MWFMP), to address the problem over multiple PRBs and solve it under the quality-of-service (QoS), allowable PRB, power budget, and interference constraints. Additionally, we provide a comparison with a greedy heuristic, the multi-PRB stratified device allocation (MPSDA), where we extend our previous work for a single PRB connectivity problem. Furthermore, we compare our algorithms to orthogonal multiple access (OMA) scheduling, which is prevalent in legacy LTE networks. We show that our algorithms steadily outperform the connectivity performance offered by OMA.","PeriodicalId":326047,"journal":{"name":"2022 IEEE 96th Vehicular Technology Conference (VTC2022-Fall)","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127443992","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-01DOI: 10.1109/VTC2022-Fall57202.2022.10012894
Yuan Ren, Kaiyu Qian, Xuewei Zhang, Fan Jiang, G. Lu
In this paper, the non-orthogonal multiple access (NOMA) and simultaneous wireless information and power transfer (SWIPT) are applied to wireless caching networks (WCN). Particularly, in the content pushing stage, base station sends the most popular contents to helpers with NOMA and the helpers harvest energy from the received signals. Then, the helpers send the requested files to the users with NOMA in the content delivery stage. In the content pushing stage, we minimize the maximum delay of the helpers by jointly optimizing the power allocation and time switching factors. Due to the non-convexity of the problem, the bisection method and two-layer iterative algorithm are devised to solve the problem. In the content delivery stage, the energy efficiency (EE) optimization problem is formulated under the quality-of-service, energy harvesting, and transmit power constraints. By using the nonlinear fractional programming theory and the Lagrange dual method, the original optimization problem is solved and the optimal power and time allocation coefficients are obtained. Simulation results show that the proposed algorithm reduces the delay of the helpers and improves the EE performance of helpers compared to the benchmark schemes.
{"title":"Joint Power and Time Allocation in NOMA-SWIPT Enabled Wireless Caching Networks","authors":"Yuan Ren, Kaiyu Qian, Xuewei Zhang, Fan Jiang, G. Lu","doi":"10.1109/VTC2022-Fall57202.2022.10012894","DOIUrl":"https://doi.org/10.1109/VTC2022-Fall57202.2022.10012894","url":null,"abstract":"In this paper, the non-orthogonal multiple access (NOMA) and simultaneous wireless information and power transfer (SWIPT) are applied to wireless caching networks (WCN). Particularly, in the content pushing stage, base station sends the most popular contents to helpers with NOMA and the helpers harvest energy from the received signals. Then, the helpers send the requested files to the users with NOMA in the content delivery stage. In the content pushing stage, we minimize the maximum delay of the helpers by jointly optimizing the power allocation and time switching factors. Due to the non-convexity of the problem, the bisection method and two-layer iterative algorithm are devised to solve the problem. In the content delivery stage, the energy efficiency (EE) optimization problem is formulated under the quality-of-service, energy harvesting, and transmit power constraints. By using the nonlinear fractional programming theory and the Lagrange dual method, the original optimization problem is solved and the optimal power and time allocation coefficients are obtained. Simulation results show that the proposed algorithm reduces the delay of the helpers and improves the EE performance of helpers compared to the benchmark schemes.","PeriodicalId":326047,"journal":{"name":"2022 IEEE 96th Vehicular Technology Conference (VTC2022-Fall)","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129980635","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-01DOI: 10.1109/VTC2022-Fall57202.2022.10012731
Haide Wang, Pengyi Jia, Xianbin Wang
Timestamping accuracy is of the utmost importance to achieve accurate time synchronization of large-scale connected systems. However, the heterogeneity and complexity inherent to Internet of Things (IoT) systems lead to multi-source timestamping uncertainties and significantly deteriorate performance of traditional inflexible synchronization methods. In this paper, a situation-aware hybrid time synchronization protocol is designed based on multi-source timestamping uncertainty modeling and integrated time information exchange mechanism for heterogeneous IoT systems. More specifically, the multi-source timestamping error inherent to the overall synchronization process are accurately modeled by exploring the impact of the multi-faceted operating conditions. By analyzing the real-time timestamping uncertainties, a hybrid time synchronization scheme is actualized, which can achieve optimal synchronization strategy for clock parameters estimation. In addition, an integrated time information exchange mechanism is designed to reduce timestamping redundancy during time synchronization. Simulation results show that the proposed scheme can enhance the synchronization accuracy for heterogeneous operating scenarios.
{"title":"Situation-Aware Hybrid Time Synchronization Based on Multi-Source Timestamping Uncertainty Modeling","authors":"Haide Wang, Pengyi Jia, Xianbin Wang","doi":"10.1109/VTC2022-Fall57202.2022.10012731","DOIUrl":"https://doi.org/10.1109/VTC2022-Fall57202.2022.10012731","url":null,"abstract":"Timestamping accuracy is of the utmost importance to achieve accurate time synchronization of large-scale connected systems. However, the heterogeneity and complexity inherent to Internet of Things (IoT) systems lead to multi-source timestamping uncertainties and significantly deteriorate performance of traditional inflexible synchronization methods. In this paper, a situation-aware hybrid time synchronization protocol is designed based on multi-source timestamping uncertainty modeling and integrated time information exchange mechanism for heterogeneous IoT systems. More specifically, the multi-source timestamping error inherent to the overall synchronization process are accurately modeled by exploring the impact of the multi-faceted operating conditions. By analyzing the real-time timestamping uncertainties, a hybrid time synchronization scheme is actualized, which can achieve optimal synchronization strategy for clock parameters estimation. In addition, an integrated time information exchange mechanism is designed to reduce timestamping redundancy during time synchronization. Simulation results show that the proposed scheme can enhance the synchronization accuracy for heterogeneous operating scenarios.","PeriodicalId":326047,"journal":{"name":"2022 IEEE 96th Vehicular Technology Conference (VTC2022-Fall)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131061876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-01DOI: 10.1109/VTC2022-Fall57202.2022.10012827
T. Guo
This paper studies a use case for quickly connecting users with an aerial bass station (BS) in emergency by leveraging digital twin (DT) and robust reinforcement learning (RL). Scattered communities of users are assigned a limited number of channels, and the flying BS is autonomously and optimally placed according to predefined criteria. Q-learning, a common type of RL, is employed as a solution to optimization of BS placement. Two optimization objectives are considered to maximize the per-user data rate in the worst condition and minimize the total BS transmitted power, respectively. To overcome resource limitations of the aerial BS, the RL training with many iterations is done in the DT virtual space connected to the physical space via an aerial BS. In particular, a practically sound max-min technique is proposed to handle the measurement and prediction uncertainties. It is shown that, even if the models used in DT are imperfect and measurements are inaccurate, nearly-optimal results can be obtained in DT. Compared to RL training 100% in the physical space, a huge number of BS moves can be avoided and a significant amount of time and energy can be saved. The assessment results suggest that model and measurement errors, especially when applying DT, should be seriously considered, and the robust optimization technique has potential to handle the uncertainties.
{"title":"Robust Q-learning for Fast And Optimal Flying Base Station Placement Aided By Digital Twin For Emergency Use","authors":"T. Guo","doi":"10.1109/VTC2022-Fall57202.2022.10012827","DOIUrl":"https://doi.org/10.1109/VTC2022-Fall57202.2022.10012827","url":null,"abstract":"This paper studies a use case for quickly connecting users with an aerial bass station (BS) in emergency by leveraging digital twin (DT) and robust reinforcement learning (RL). Scattered communities of users are assigned a limited number of channels, and the flying BS is autonomously and optimally placed according to predefined criteria. Q-learning, a common type of RL, is employed as a solution to optimization of BS placement. Two optimization objectives are considered to maximize the per-user data rate in the worst condition and minimize the total BS transmitted power, respectively. To overcome resource limitations of the aerial BS, the RL training with many iterations is done in the DT virtual space connected to the physical space via an aerial BS. In particular, a practically sound max-min technique is proposed to handle the measurement and prediction uncertainties. It is shown that, even if the models used in DT are imperfect and measurements are inaccurate, nearly-optimal results can be obtained in DT. Compared to RL training 100% in the physical space, a huge number of BS moves can be avoided and a significant amount of time and energy can be saved. The assessment results suggest that model and measurement errors, especially when applying DT, should be seriously considered, and the robust optimization technique has potential to handle the uncertainties.","PeriodicalId":326047,"journal":{"name":"2022 IEEE 96th Vehicular Technology Conference (VTC2022-Fall)","volume":"97 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130724775","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Flocking control is a significant problem in multi-agent systems such as multi-agent unmanned aerial vehicles and multi-agent autonomous underwater vehicles, which enhances the cooperativity and safety of agents. In contrast to traditional methods, multi-agent reinforcement learning (MARL) solves the problem of flocking control more flexibly. However, methods based on MARL suffer from sample inefficiency, since they require a huge number of experiences to be collected from interactions between agents and the environment. We propose a novel method Pretraining with Demonstrations for MARL (PwD-MARL), which can utilize non-expert demonstrations collected in advance with traditional methods to pretrain agents. During the process of pretraining, agents learn policies from demonstrations by MARL and behavior cloning simultaneously, and are prevented from overfitting demonstrations. By pretraining with non-expert demonstrations, PwD-MARL improves sample efficiency in the process of online MARL with a warm start. Experiments show that PwD-MARL improves sample efficiency and policy performance in the problem of flocking control, even with bad or few demonstrations.
{"title":"Sample-Efficient Multi-Agent Reinforcement Learning with Demonstrations for Flocking Control","authors":"Yunbo Qiu, Yuzhu Zhan, Yue Jin, Jian Wang, Xudong Zhang","doi":"10.1109/VTC2022-Fall57202.2022.10012835","DOIUrl":"https://doi.org/10.1109/VTC2022-Fall57202.2022.10012835","url":null,"abstract":"Flocking control is a significant problem in multi-agent systems such as multi-agent unmanned aerial vehicles and multi-agent autonomous underwater vehicles, which enhances the cooperativity and safety of agents. In contrast to traditional methods, multi-agent reinforcement learning (MARL) solves the problem of flocking control more flexibly. However, methods based on MARL suffer from sample inefficiency, since they require a huge number of experiences to be collected from interactions between agents and the environment. We propose a novel method Pretraining with Demonstrations for MARL (PwD-MARL), which can utilize non-expert demonstrations collected in advance with traditional methods to pretrain agents. During the process of pretraining, agents learn policies from demonstrations by MARL and behavior cloning simultaneously, and are prevented from overfitting demonstrations. By pretraining with non-expert demonstrations, PwD-MARL improves sample efficiency in the process of online MARL with a warm start. Experiments show that PwD-MARL improves sample efficiency and policy performance in the problem of flocking control, even with bad or few demonstrations.","PeriodicalId":326047,"journal":{"name":"2022 IEEE 96th Vehicular Technology Conference (VTC2022-Fall)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130227845","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-01DOI: 10.1109/VTC2022-Fall57202.2022.10012985
Moisés Ramires, J. Torres-Sospedra, A. Moreira
The core of fingerprinting is based on the uniqueness of the RF signature in a given location over time. In the offline phase, the fingerprints -the set of RSSI values from different anchors-are collected at given locations generating a radio map. In the online phase, a matching algorithm retrieves the most similar fingerprints from the radio map and computes the position estimate for every operational fingerprint. However, computing the similarities to all the samples in the radio map may be inefficient and not scale in those cases where the radio map is large. Previous attempts to alleviate the computational load rely on the segmentation of the radio map through smart clustering in the offline stage, and a two-step estimation process in the online stage. However, most of the clustering models applied are generic without any consideration about signal propagation and relevant fingerprints are often filtered, resulting in a higher positioning error. This paper introduces Strongest AP Set (SAS), a clustering model conceived for RSSI-based fingerprinting. The results show that SAS is not only able to reduce the computational cost, but also to provide better accuracy than the full model without clustering.
{"title":"Accurate and Efficient Wi-Fi Fingerprinting-Based Indoor Positioning in Large Areas","authors":"Moisés Ramires, J. Torres-Sospedra, A. Moreira","doi":"10.1109/VTC2022-Fall57202.2022.10012985","DOIUrl":"https://doi.org/10.1109/VTC2022-Fall57202.2022.10012985","url":null,"abstract":"The core of fingerprinting is based on the uniqueness of the RF signature in a given location over time. In the offline phase, the fingerprints -the set of RSSI values from different anchors-are collected at given locations generating a radio map. In the online phase, a matching algorithm retrieves the most similar fingerprints from the radio map and computes the position estimate for every operational fingerprint. However, computing the similarities to all the samples in the radio map may be inefficient and not scale in those cases where the radio map is large. Previous attempts to alleviate the computational load rely on the segmentation of the radio map through smart clustering in the offline stage, and a two-step estimation process in the online stage. However, most of the clustering models applied are generic without any consideration about signal propagation and relevant fingerprints are often filtered, resulting in a higher positioning error. This paper introduces Strongest AP Set (SAS), a clustering model conceived for RSSI-based fingerprinting. The results show that SAS is not only able to reduce the computational cost, but also to provide better accuracy than the full model without clustering.","PeriodicalId":326047,"journal":{"name":"2022 IEEE 96th Vehicular Technology Conference (VTC2022-Fall)","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127618609","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-01DOI: 10.1109/VTC2022-Fall57202.2022.10012767
Mohd Hamza Naim Shaikh, S. Arzykulov, Abdulkadir Celik, A. Eltawil, G. Nauryzbayev
Reconfigurable intelligent surfaces (RISs) have sparked a renewed interest in the research community envisioning future wireless communication networks. In this study, we analyzed the performance of RIS-enabled non-orthogonal multiple access (NOMA) based device-to-device (D2D) wireless communication system, where the RIS is partitioned to serve a pair of D2D users. Specifically, closed-form expressions are derived for the upper and lower limits of spectral efficiency (SE) and energy efficiency (EE). In addition, the performance of the proposed NOMA-based system is also compared with its orthogonal counter-part. Extensive simulation is done to corroborate the analytical findings. The results demonstrate that RIS highly enhances the performance of a NOMA-based D2D network.
{"title":"Performance of RIS-empowered NOMA-based D2D Communication under Nakagami-m Fading","authors":"Mohd Hamza Naim Shaikh, S. Arzykulov, Abdulkadir Celik, A. Eltawil, G. Nauryzbayev","doi":"10.1109/VTC2022-Fall57202.2022.10012767","DOIUrl":"https://doi.org/10.1109/VTC2022-Fall57202.2022.10012767","url":null,"abstract":"Reconfigurable intelligent surfaces (RISs) have sparked a renewed interest in the research community envisioning future wireless communication networks. In this study, we analyzed the performance of RIS-enabled non-orthogonal multiple access (NOMA) based device-to-device (D2D) wireless communication system, where the RIS is partitioned to serve a pair of D2D users. Specifically, closed-form expressions are derived for the upper and lower limits of spectral efficiency (SE) and energy efficiency (EE). In addition, the performance of the proposed NOMA-based system is also compared with its orthogonal counter-part. Extensive simulation is done to corroborate the analytical findings. The results demonstrate that RIS highly enhances the performance of a NOMA-based D2D network.","PeriodicalId":326047,"journal":{"name":"2022 IEEE 96th Vehicular Technology Conference (VTC2022-Fall)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127855554","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-01DOI: 10.1109/VTC2022-Fall57202.2022.10012976
Sohan Gyawali, Takayuki Shimizu, Hongsheng Lu, Michael Clifford, J. Kenney, Y. Qian
An intelligent transportation system aims to provide various traffic safety and navigation services, and mainly relies on local perception and vehicular communication technologies. However, the vehicular communication technologies can be a target of wide range of attacks including position falsification, Sybil and denial-of-service (DoS) attacks which can lead to disastrous traffic accidents and jams. As a viable solution, misbehavior detection systems can be used in vehicular networks. Different from other works, in this paper, we propose a misbehavior detection system that utilizes both local perception and basic safety messages (BSM). Our work shows the methodology for generating realistic vehicular network data sets that include both local perception and BSM. In addition, we compare and show that the propose scheme is better compared to the previous scheme utilizing only beacon information for accurately identifying misbehavior in intelligent transportation system.
{"title":"Local perception and BSM based misbehavior detection in Intelligent Transportation System","authors":"Sohan Gyawali, Takayuki Shimizu, Hongsheng Lu, Michael Clifford, J. Kenney, Y. Qian","doi":"10.1109/VTC2022-Fall57202.2022.10012976","DOIUrl":"https://doi.org/10.1109/VTC2022-Fall57202.2022.10012976","url":null,"abstract":"An intelligent transportation system aims to provide various traffic safety and navigation services, and mainly relies on local perception and vehicular communication technologies. However, the vehicular communication technologies can be a target of wide range of attacks including position falsification, Sybil and denial-of-service (DoS) attacks which can lead to disastrous traffic accidents and jams. As a viable solution, misbehavior detection systems can be used in vehicular networks. Different from other works, in this paper, we propose a misbehavior detection system that utilizes both local perception and basic safety messages (BSM). Our work shows the methodology for generating realistic vehicular network data sets that include both local perception and BSM. In addition, we compare and show that the propose scheme is better compared to the previous scheme utilizing only beacon information for accurately identifying misbehavior in intelligent transportation system.","PeriodicalId":326047,"journal":{"name":"2022 IEEE 96th Vehicular Technology Conference (VTC2022-Fall)","volume":"107 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131320026","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-01DOI: 10.1109/VTC2022-Fall57202.2022.10012959
Kazuma Matsumoto, Takanori Hara, Y. Yuda, K. Higuchi
In this paper, we propose an autonomous decentralized user association method that maximizes the integrated system throughput, which is defined across multiple services. The quality of service (QoS) of each service is defined by the system throughput, which takes into account the trade-off between spectrum efficiency and fairness among users for each service. Then, the total quality of all services is defined by the integrated system throughput, which is calculated by the weighted generalized average of the system throughput levels of each service. The proposed method achieves the optimal user association that maximizes the integrated system throughput according to the distribution of base stations (BSs) and users in the system coverage based only on a small amount of control information broadcasted by each BS through autonomous decentralized control of each user terminal. Computer simulations assuming a heterogeneous network show that the proposed method increases the system throughput of each service and integrated system throughput compared to the cell range expansion (CRE) method, which is widely used in 4G and 5G mobile communication systems.
{"title":"Autonomous Decentralized User Association Method to Maximize Integrated System Throughput for Multi-service Coexistence","authors":"Kazuma Matsumoto, Takanori Hara, Y. Yuda, K. Higuchi","doi":"10.1109/VTC2022-Fall57202.2022.10012959","DOIUrl":"https://doi.org/10.1109/VTC2022-Fall57202.2022.10012959","url":null,"abstract":"In this paper, we propose an autonomous decentralized user association method that maximizes the integrated system throughput, which is defined across multiple services. The quality of service (QoS) of each service is defined by the system throughput, which takes into account the trade-off between spectrum efficiency and fairness among users for each service. Then, the total quality of all services is defined by the integrated system throughput, which is calculated by the weighted generalized average of the system throughput levels of each service. The proposed method achieves the optimal user association that maximizes the integrated system throughput according to the distribution of base stations (BSs) and users in the system coverage based only on a small amount of control information broadcasted by each BS through autonomous decentralized control of each user terminal. Computer simulations assuming a heterogeneous network show that the proposed method increases the system throughput of each service and integrated system throughput compared to the cell range expansion (CRE) method, which is widely used in 4G and 5G mobile communication systems.","PeriodicalId":326047,"journal":{"name":"2022 IEEE 96th Vehicular Technology Conference (VTC2022-Fall)","volume":"136 9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131333900","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-01DOI: 10.1109/VTC2022-Fall57202.2022.10012844
S. Yadav, A. Yadav, D. Gurjar, Anshul Pandey
This paper examines physical layer security of a secure reconfigurable intelligent surfaces (RIS) enabled wireless communication system. Particularly, we explore a wiretap communication system wherein a source node transmits its confidential information to the legitimate destination node using an RIS-based relay terminal, and at the same time, a passive eavesdropper overhears this information from both source and RIS. Under this system setup, we first derive the closed-form expressions of the cumulative distribution function and probability density function of the end-to-end signal-to-noise ratios (SNRs) at the destination and eavesdropper by adopting the method of moments. Utilizing these distributions, we further deduce the exact expression of the secrecy outage probability (SOP) under Rayleigh fading channels. Moreover, to obtain the system’s secrecy diversity order, we present the asymptotic SOP analysis under two scenarios, viz., 1) high SNR regime, and 2) when average channel gains of main link go to infinity and average channel gains pertaining to wiretap links are fixed. It is revealed that the secrecy diversity order reduces to zero under high SNR regime, whereas a secrecy diversity order of 0. 805N can be achievable for large values of average channel gains of main link, where N is the number of RIS elements. Finally, the theoretical findings are validated via numerical and simulation studies. Our results show the impact of various involved parameters on the system’s SOP performance.
{"title":"Physical Layer Security Performance Analysis of RIS-Assisted Wireless Communication Systems","authors":"S. Yadav, A. Yadav, D. Gurjar, Anshul Pandey","doi":"10.1109/VTC2022-Fall57202.2022.10012844","DOIUrl":"https://doi.org/10.1109/VTC2022-Fall57202.2022.10012844","url":null,"abstract":"This paper examines physical layer security of a secure reconfigurable intelligent surfaces (RIS) enabled wireless communication system. Particularly, we explore a wiretap communication system wherein a source node transmits its confidential information to the legitimate destination node using an RIS-based relay terminal, and at the same time, a passive eavesdropper overhears this information from both source and RIS. Under this system setup, we first derive the closed-form expressions of the cumulative distribution function and probability density function of the end-to-end signal-to-noise ratios (SNRs) at the destination and eavesdropper by adopting the method of moments. Utilizing these distributions, we further deduce the exact expression of the secrecy outage probability (SOP) under Rayleigh fading channels. Moreover, to obtain the system’s secrecy diversity order, we present the asymptotic SOP analysis under two scenarios, viz., 1) high SNR regime, and 2) when average channel gains of main link go to infinity and average channel gains pertaining to wiretap links are fixed. It is revealed that the secrecy diversity order reduces to zero under high SNR regime, whereas a secrecy diversity order of 0. 805N can be achievable for large values of average channel gains of main link, where N is the number of RIS elements. Finally, the theoretical findings are validated via numerical and simulation studies. Our results show the impact of various involved parameters on the system’s SOP performance.","PeriodicalId":326047,"journal":{"name":"2022 IEEE 96th Vehicular Technology Conference (VTC2022-Fall)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2022-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129195390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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