{"title":"Joint Client Association and UAV Scheduling in Cache-Enabled UAV-Assisted Vehicular Networks","authors":"Shichao Zhu, Lin Gui, Qi Zhang, Xiupu Lang","doi":"10.1109/VTC2021-Spring51267.2021.9448868","DOIUrl":"https://doi.org/10.1109/VTC2021-Spring51267.2021.9448868","url":null,"abstract":"In the case of explosive content requests being generated by numerous vehicles in rush hour, the cellular downlink resources become insufficient. This paper considers two supplementary schemes for exploiting the uplink resources: One is letting vehicles cache the browsed contents so that the vehicles can share contents with one another; and the other is dispatching a cache-enabled UAV to transmit contents to the vehicles nearby. We formulate a joint optimization problem for maximizing the average data rate of vehicles, and then decompose it into the subproblems of client association and UAV scheduling. The client association aims at matching the vehicles to the resources, and the UAV scheduling is to update the UAV’s caching and trajectory to adapt to the environment changing. The two subproblems focus respectively on the current condition and the long term profit, and are solved respectively by a matching-based algorithm and a deep reinforcement learning-based algorithm. Our simulation results based on a real-world traffic data set demonstrate the advantages of the proposed approaches.","PeriodicalId":194840,"journal":{"name":"2021 IEEE 93rd Vehicular Technology Conference (VTC2021-Spring)","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124380412","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}
{"title":"Efficient Power Allocation for Cognitive Radio NOMA using Game-Theoretic Based Pricing Strategy","authors":"Shaima' S. Abidrabbu, H. Arslan","doi":"10.1109/VTC2021-Spring51267.2021.9448851","DOIUrl":"https://doi.org/10.1109/VTC2021-Spring51267.2021.9448851","url":null,"abstract":"Cognitive radio-based non-orthogonal multiple access (CR-NOMA) is considered to be one of the promising multiple accessing technique candidates for 5G and beyond networks. These networks are facing a lot of challenges to achieve high spectral efficiency, low latency, and massive connectivity. Interference management and efficient power allocation are highly interesting among the researchers to investigate in CR-NOMA networks. This paper studies the power allocation of underlay CR-NOMA network using game theory approach by conducting the pricing technique to achieve efficient power allocation and minimum interference. In particular, the game is formulated, and its solution is achieved by exploring the suboptimal solution represented by the Pareto-efficiency of the Nash equilibrium point. The simulation results show the superiority of the proposed scheme in achieving higher spectral efficiency, fairness index, and sum utilities of secondary users compared to existing schemes.","PeriodicalId":194840,"journal":{"name":"2021 IEEE 93rd Vehicular Technology Conference (VTC2021-Spring)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125609205","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}
Fuad Mousse Abinader Jr., C. Rom, K. Pedersen, Sofonias Hailu, Niko Kolehmainen
{"title":"System-Level Analysis of mmWave 5G Systems with Different Multi-Panel Antenna Device Models","authors":"Fuad Mousse Abinader Jr., C. Rom, K. Pedersen, Sofonias Hailu, Niko Kolehmainen","doi":"10.1109/VTC2021-Spring51267.2021.9449044","DOIUrl":"https://doi.org/10.1109/VTC2021-Spring51267.2021.9449044","url":null,"abstract":"5G New Radio (NR) incorporates numerous beam-based novel features such as beam management procedures for selecting the best serving gNB beam, recovery from beam failures, beam-based inter-cell mobility support and advanced UEs with multiple directional panels. In this paper, we study the joint performance of all these techniques for a macro cellular scenario at 28 GHz with special emphasis on how the UE antenna design influences the system-level performance. It is shown that the full benefits of 5G can be delivered with the introduction of multiple directional antenna panels at the UE side. We also introduce a mechanism for controlling the UE antenna panel switching. Our results from advanced dynamic system-level simulations indicate excellent performance with handover failure rates on the order of 0.01-0.03%, and beam failure rates at 0.04%, for UE speeds as high as 60 km/h. The median SINR gain of using four directional antenna panels at the UE equals 6 dB as compared to Omni UEs.","PeriodicalId":194840,"journal":{"name":"2021 IEEE 93rd Vehicular Technology Conference (VTC2021-Spring)","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125782677","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}
{"title":"Near-field localization using machine learning: an empirical study","authors":"M. Laakso, R. Wichman","doi":"10.1109/VTC2021-Spring51267.2021.9449002","DOIUrl":"https://doi.org/10.1109/VTC2021-Spring51267.2021.9449002","url":null,"abstract":"Estimation methods for passive near-field localization have been studied to an appreciable extent in signal processing research. Such localization methods find use in various applications, for instance in medical imaging. However, methods based on the standard near-field signal model can be inaccurate in real-world applications, due to deficiencies of the model itself and hardware imperfections. It is expected that deep neural network (DNN) based estimation methods trained on the nonideal sensor array signals could outperform the model-driven alternatives. In this work, a DNN based estimator is trained and validated on a set of real world measured data. The series of measurements was conducted with an inexpensive custom built multichannel software-defined radio (SDR) receiver, which makes the nonidealities more prominent. The results show that a DNN based localization estimator clearly outperforms the compared model-driven method.","PeriodicalId":194840,"journal":{"name":"2021 IEEE 93rd Vehicular Technology Conference (VTC2021-Spring)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127968386","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}
{"title":"A Task Assignment Scheme for Parked-Vehicle Assisted Edge Computing in IoV","authors":"Qingxia Peng, Yunjian Jia, Liang Liang, Zhengchuan Chen","doi":"10.1109/VTC2021-Spring51267.2021.9448735","DOIUrl":"https://doi.org/10.1109/VTC2021-Spring51267.2021.9448735","url":null,"abstract":"Vehicular edge computing (VEC) has been envisioned as an important application of edge computing in vehicular networks. Parked vehicles with embedded computation resources could be exploited as a supplement for VEC. They cooperate with edge severs to process offloading tasks at the vehicular network edge, leading to a new paradigm called parked-vehicle assisted edge computing (PVEC) in the Internet of Vehicles (IoV). However, recent researchers mostly focus on how to optimize the total cost of requesting vehicle (RV), and rarely pay attention to the optimization of the utility of PVs that provide services, including the reward from RV and the overhead of executing task. In this paper, we study a task assignment problem with computing delay constraints for PVEC in IoV. Specially, extra performance loss caused by offloading subtasks to PVs is taken into the cost function of RV. The optimal task assignment problem is formulated and solved with the Stackelberg game framework and a ternary search-based algorithm to minimize the cost of RV and maximize the utility of PVs. Finally, extensive numerical results are provided to demonstrate that our scheme is more efficient in deducing the total cost of RV and increasing the reward for PVs than other two existing schemes.","PeriodicalId":194840,"journal":{"name":"2021 IEEE 93rd Vehicular Technology Conference (VTC2021-Spring)","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115782313","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}
{"title":"QoS Optimization for Distributed Edge Computing System: A Multi-agent State-based Learning Approach","authors":"Fenghui Zhang, M. Wang, Liqing Shan, Xiangqing Wang, Maosheng Fu, Xiancun Zhou","doi":"10.1109/VTC2021-Spring51267.2021.9449000","DOIUrl":"https://doi.org/10.1109/VTC2021-Spring51267.2021.9449000","url":null,"abstract":"Placement of edge computing servers at the edge of the network can reduce task transmission delay. Connecting them into a system can provide services for a wider range. However, due to the mobility of the crowd and mobile devices, the number of tasks offloaded to each edge server may be quite different, which will seriously affect the QoS of the system. To this end, we investigate the QoS improvement of the distributed edge computing system from the game-theoretic perspective and propose a multi-agent state-based learning algorithm. Firstly, by modeling the cost of an edge computing server as the deviation between its execution time and the system average execution time, we formulate the QoS improvement of the system as a state-based game where each agent competes to maximize its own utility. Then, we propose a multi-agent state-based learning algorithm to obtain the pure Nash equilibrium strategy of each agent. Finally, compared with the existing approaches, the experiments show that the proposed algorithm can improve the QoS of the distributed edge computing system.","PeriodicalId":194840,"journal":{"name":"2021 IEEE 93rd Vehicular Technology Conference (VTC2021-Spring)","volume":"131 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115879794","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}
{"title":"Location-Free Beam Prediction in mmWave Systems","authors":"Tushara Ponnada, H. Al-Tous, O. Tirkkonen","doi":"10.1109/VTC2021-Spring51267.2021.9448938","DOIUrl":"https://doi.org/10.1109/VTC2021-Spring51267.2021.9448938","url":null,"abstract":"Channel charting is a method for creating radio-maps of a cell that capture the neighborhood relationships between User Equipments (UEs) in the cell based on machine learning techniques. In this paper, we leverage channel charting for predicting the best Base Station (BS) beam to serve a given UE in a massive-MIMO 5G network. Because of the autonomous beamforming at the UE in 5G networks, the BS cannot determine the best beam for transmission to a UE by measuring the UE transmissions in all the BS beams. To address this issue, we propose a framework to predict the best BS beam for a mobile UE in the next transmission instant by utilizing the channel charts of the cell that the UE is currently in. We evaluate the prediction accuracy of the framework using simulated channels from QuaDRiGa channel generator. We compare the performance of channel chart and physical location based predictors. While the prediction accuracy attained using channel charting is less than that of the prediction using physical locations, there remain several ways to improve the performance.","PeriodicalId":194840,"journal":{"name":"2021 IEEE 93rd Vehicular Technology Conference (VTC2021-Spring)","volume":"432 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132328874","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}
Ying Guo, Gongpu Wang, Guoqing Li, Minzheng Jia, B. Ai
{"title":"Energy Efficiency Gains for Wireless Communication Systems Aided by Ambient Backscatter","authors":"Ying Guo, Gongpu Wang, Guoqing Li, Minzheng Jia, B. Ai","doi":"10.1109/VTC2021-Spring51267.2021.9448658","DOIUrl":"https://doi.org/10.1109/VTC2021-Spring51267.2021.9448658","url":null,"abstract":"Ambient backscatter is a new green technology that can enable batteryless tags or sensors to communicate with each other. In this paper, we combine ambient backscatter technology into traditional point-to-point wireless communication systems, and investigate its capacity and energy efficiency. Specifically, we build up the mathematical model for the new system with a sensor aided by ambient backscatter, derive its channel capacity, define the energy efficiency gain, and compare the capacity and energy efficiency performance of both traditional systems and backscatter aided systems. Simulations are then provided to corroborate our proposed studies.","PeriodicalId":194840,"journal":{"name":"2021 IEEE 93rd Vehicular Technology Conference (VTC2021-Spring)","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126578284","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}
{"title":"Beam Management Based Multi-cell Interference Suppression for Millimeter Wave Communications","authors":"Yaxin Song, Shaoyi Xu","doi":"10.1109/VTC2021-Spring51267.2021.9448763","DOIUrl":"https://doi.org/10.1109/VTC2021-Spring51267.2021.9448763","url":null,"abstract":"Millimeter wave (mmWave) communications is a promising solution for next-generation systems with a higher data rate. However, due to the narrow beamwidth characteristic of mmWave, inter-cell interference (ICI) is mainly caused by beams used by neighboring cells. In this paper, we aim to maximize the achievable sum rate of users at a mmWave cell in the downlink communication scenario of multi-cell systems. Since the formulated problem is a mixed-integer nonlinear programming problem, we decompose the problem into two subproblems, where one is solved by a multi-cell least beam interference (MLBI) algorithm to mitigate such ICI. And another is to guarantee edge users’ (UEes’) Quality of Service (QoS) and improve the achievable rate through a multi-user multi-beam prioritized power allocation (MPPA) algorithm. Finally, simulations and analyses are conducted to verify the efficiency of the proposed algorithms.","PeriodicalId":194840,"journal":{"name":"2021 IEEE 93rd Vehicular Technology Conference (VTC2021-Spring)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125196982","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}
{"title":"Simultaneous Wireless Power Transfer and Modulation Classification","authors":"Rahul Gupta, I. Krikidis","doi":"10.1109/VTC2021-Spring51267.2021.9448896","DOIUrl":"https://doi.org/10.1109/VTC2021-Spring51267.2021.9448896","url":null,"abstract":"This work proposes a new simultaneous wireless power transfer and modulation classification (SWPTMC) scheme appropriate for internet of things (IoT) applications. The problem of SWPTMC is investigated for various modulation formats, i.e., quadrature phase-shift-keying (QPSK), π/4-QPSK, offset QPSK (OQPSK), 16-pulse amplitude modulation (16-PAM), 16-quadrature amplitude modulation (16-QAM), and minimum shift keying (MSK). We propose three receiver architectures, i.e., an integrated receiver, a separate receiver with power splitting (PS), and a separate receiver with energy harvesting (EH)-based classification; all the architectures are studied under a non-linear model with a certain sensitivity and saturation level. Also, we derive the average harvested power over a Rayleigh fading channel for the different modulation formats. Two different approaches are used for the blind modulation classification (MC) algorithm: one for the intermediate frequency signal and the other for the baseband signal. Both the MC algorithms are based on the higher-order cumulants and cyclic cumulants of the received signal. The cyclic cumulants use the non-zero cycle frequency position, while the cumulants use threshold values for classifying modulation formats. Monte Carlo simulations are used to evaluate the performance of the proposed SWPTMC schemes. The results show that we can simultaneously harvest power without much affecting the classifier performance. Moreover, with an integrated receiver, we can simultaneously perform MC and harvest power without the requirement of PS circuit.","PeriodicalId":194840,"journal":{"name":"2021 IEEE 93rd Vehicular Technology Conference (VTC2021-Spring)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131003764","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}