Pub Date : 2022-09-01DOI: 10.1109/VTC2022-Fall57202.2022.10012788
Nalin Jayaweera, Dileepa Marasinghe, Nandana Rajatheva, Sami-Jukka Hakola, T. Koskela, Oskari Tervo, J. Karjalainen, E. Tiirola, J. Hulkkonen
The mmWave communication up to 71 GHz is already specified in 3rd generation partnership project (3GPP)5G New Radio (NR), and communication in sub-THz bands is being studied for 6G widely in the academia and industry. Operation with very narrow beamwidths and much higher bandwidths in contrast to Frequency Range 1 (sub-6 GHz) can cater to the high data rate requirements at the expense of extra signal processing burden to overcome the unfavourable conditions such as high attenuation and scattering in the presence of obstacles. Such severe signal power attenuation caused by an obstacle may degrade the network performance due to link failures occurring as a result of line-of-sight (LoS) to non-LoS (NLoS) transitions. These limitations raise the necessity of a sensing system to collect situational awareness data to assist the wireless communication network. This work proposes a method to improve the LoS detection and user localization accuracy using multiple light detection and ranging (LiDAR) sensors co-located in access points (APs). We also propose an approach to predict the LoS transitions based on static LiDAR maps and the proposed method detected the LoS transition 400ms before its occurrence.
{"title":"LiDAR aided Wireless Networks - LoS Detection and Prediction based on Static Maps","authors":"Nalin Jayaweera, Dileepa Marasinghe, Nandana Rajatheva, Sami-Jukka Hakola, T. Koskela, Oskari Tervo, J. Karjalainen, E. Tiirola, J. Hulkkonen","doi":"10.1109/VTC2022-Fall57202.2022.10012788","DOIUrl":"https://doi.org/10.1109/VTC2022-Fall57202.2022.10012788","url":null,"abstract":"The mmWave communication up to 71 GHz is already specified in 3rd generation partnership project (3GPP)5G New Radio (NR), and communication in sub-THz bands is being studied for 6G widely in the academia and industry. Operation with very narrow beamwidths and much higher bandwidths in contrast to Frequency Range 1 (sub-6 GHz) can cater to the high data rate requirements at the expense of extra signal processing burden to overcome the unfavourable conditions such as high attenuation and scattering in the presence of obstacles. Such severe signal power attenuation caused by an obstacle may degrade the network performance due to link failures occurring as a result of line-of-sight (LoS) to non-LoS (NLoS) transitions. These limitations raise the necessity of a sensing system to collect situational awareness data to assist the wireless communication network. This work proposes a method to improve the LoS detection and user localization accuracy using multiple light detection and ranging (LiDAR) sensors co-located in access points (APs). We also propose an approach to predict the LoS transitions based on static LiDAR maps and the proposed method detected the LoS transition 400ms before its occurrence.","PeriodicalId":326047,"journal":{"name":"2022 IEEE 96th Vehicular Technology Conference (VTC2022-Fall)","volume":"2 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":"129245754","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-Fall57202.2022.10012883
Yutao Shi, Ping Wang, Xinhong Wang
Autonomous valet parking (AVP) is a popular application scenario for autonomous driving in the future. For AVP path planning, the original hybrid A-star ($mathrm{A}^{*}$) algorithm has problems of large search costs, searching towards wrong directions and generating unreasonable parking paths. To solve these problems and generate a better path, a path planning method is proposed for typical AVP scenarios. The method divides path planning into global part and local part. The global path is planned based on graph search and state lattice algorithm. Then the hybrid $mathrm{A}^{*}$ algorithm and Reeds-Shepp curve are modified to complete the local path planning, and finally a complete path that can be executed by the vehicle is generated. Then, a controller for path tracking based on model predictive control (MPC) is designed to overcome the shortcomings of traditional proportional integral derivative (PID) control such as overshoot and difficulty in precise control. Finally, the feasibility of the path planning and tracking method is verified by simulation using MATLAB and the vehicle simulation software CarSim. The results show that the planning efficiency and rationality are improved by implementing the proposed method, and the parking process can be done well with a small tracking error.
{"title":"An Autonomous Valet Parking Algorithm for Path Planning and Tracking","authors":"Yutao Shi, Ping Wang, Xinhong Wang","doi":"10.1109/VTC2022-Fall57202.2022.10012883","DOIUrl":"https://doi.org/10.1109/VTC2022-Fall57202.2022.10012883","url":null,"abstract":"Autonomous valet parking (AVP) is a popular application scenario for autonomous driving in the future. For AVP path planning, the original hybrid A-star ($mathrm{A}^{*}$) algorithm has problems of large search costs, searching towards wrong directions and generating unreasonable parking paths. To solve these problems and generate a better path, a path planning method is proposed for typical AVP scenarios. The method divides path planning into global part and local part. The global path is planned based on graph search and state lattice algorithm. Then the hybrid $mathrm{A}^{*}$ algorithm and Reeds-Shepp curve are modified to complete the local path planning, and finally a complete path that can be executed by the vehicle is generated. Then, a controller for path tracking based on model predictive control (MPC) is designed to overcome the shortcomings of traditional proportional integral derivative (PID) control such as overshoot and difficulty in precise control. Finally, the feasibility of the path planning and tracking method is verified by simulation using MATLAB and the vehicle simulation software CarSim. The results show that the planning efficiency and rationality are improved by implementing the proposed method, and the parking process can be done well with a small tracking error.","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":"125503504","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-Fall57202.2022.10013065
Xinyu Qi, A. Hu
As the inherent attribute of equipment circuit hardware, Radio Frequency Fingerprints (RFFs) is hardly-forged and has become one of the most powerful guarantees of physical layer security. Most existing RFF-based methods ignore the temporal relation and are designed under an ideal dataset with a large number of samples and complete signal records, thus they tend to be less versatile in real-world scenarios. To address this problem, we propose a novel time representation method for wireless signal pictorialization called modified gramian angular fields (MGAF), which depicts the characteristics of the signal along the time axis through the transformation of coordinate system and a representation of trigonometric difference. After that, a channel-selectable convolution neural network (CNN) is used to extract high-dimensional feature vectors as the RFFs for further identification. The entire experiments are conducted with purposely poorly designed datasets. The results shows the accuracy can reach at 94.82% with only three half-sine waves and 99.26% with a quarter of the preamble at the SNR level of 30 dB.
射频指纹（RFF）作为设备电路硬件的固有属性，几乎无法伪造，已成为物理层安全的最有力保障之一。现有的基于射频指纹的方法大多忽略了时间关系，并且是在具有大量样本和完整信号记录的理想数据集下设计的，因此在实际应用中往往不那么通用。针对这一问题，我们提出了一种用于无线信号图像化的新型时间表示方法，即修正格兰角场（MGAF），它通过坐标系变换和三角函数差表示，沿时间轴描述信号的特征。然后，使用通道可选卷积神经网络（CNN）提取高维特征向量作为 RFF，以便进一步识别。整个实验都是在故意设计较差的数据集上进行的。结果表明，在信噪比为 30 dB 的情况下，仅使用三个半正弦波的识别准确率可达 94.82%，使用四分之一前导码的识别准确率可达 99.26%。
{"title":"Embrace Imperfect Datasets: New Time Representation for RFF Identification","authors":"Xinyu Qi, A. Hu","doi":"10.1109/VTC2022-Fall57202.2022.10013065","DOIUrl":"https://doi.org/10.1109/VTC2022-Fall57202.2022.10013065","url":null,"abstract":"As the inherent attribute of equipment circuit hardware, Radio Frequency Fingerprints (RFFs) is hardly-forged and has become one of the most powerful guarantees of physical layer security. Most existing RFF-based methods ignore the temporal relation and are designed under an ideal dataset with a large number of samples and complete signal records, thus they tend to be less versatile in real-world scenarios. To address this problem, we propose a novel time representation method for wireless signal pictorialization called modified gramian angular fields (MGAF), which depicts the characteristics of the signal along the time axis through the transformation of coordinate system and a representation of trigonometric difference. After that, a channel-selectable convolution neural network (CNN) is used to extract high-dimensional feature vectors as the RFFs for further identification. The entire experiments are conducted with purposely poorly designed datasets. The results shows the accuracy can reach at 94.82% with only three half-sine waves and 99.26% with a quarter of the preamble at the SNR level of 30 dB.","PeriodicalId":326047,"journal":{"name":"2022 IEEE 96th Vehicular Technology Conference (VTC2022-Fall)","volume":"66 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":"126626090","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-Fall57202.2022.10012713
Haiyang Ding, M. Elkashlan, Hancheng Yang, Haipeng Li, Kewei Xin
Cascaded fading plays a vital role in backscatter communications but its effect on the transmission robustness of symbiotic backscatter system has not been well understood yet. In this paper, we investigate this effect under three symbiotic mechanisms, namely commensal, parasitic and competitive schemes. Our analysis indicates that: 1) For the commensal scheme, cascaded backscatter fading incurs an inferior outage performance of the backscatter system in comparison with the counterpart over single-hop backscatter fading; 2) For the parasitic scheme, cascaded backscatter fading leads to a superior outage performance of the primary system in comparison with the counterpart over single-hop backscatter fading; 3) For the backscatter system, regardless of single-hop or cascaded backscatter fading, the exact outage probability of the parasitic scheme overlaps with the asymptotic of the commensal scheme; 4) For the competitive scheme, as the decoding threshold of the primary system approaches zero, the asymptotic outage performance of the primary system in cascaded and single-hop backscatter fading tend to be the same; and 5) Unlike single-hop backscatter fading, as the decoding threshold of backscatter signal approaches zero, the outage probability of the competitive and parasitic schemes for the backscatter system in cascaded backscatter fading approaches that of the competitive scheme for the primary system.
{"title":"Symbiotic Backscatter System over Cascaded Fading Channels","authors":"Haiyang Ding, M. Elkashlan, Hancheng Yang, Haipeng Li, Kewei Xin","doi":"10.1109/VTC2022-Fall57202.2022.10012713","DOIUrl":"https://doi.org/10.1109/VTC2022-Fall57202.2022.10012713","url":null,"abstract":"Cascaded fading plays a vital role in backscatter communications but its effect on the transmission robustness of symbiotic backscatter system has not been well understood yet. In this paper, we investigate this effect under three symbiotic mechanisms, namely commensal, parasitic and competitive schemes. Our analysis indicates that: 1) For the commensal scheme, cascaded backscatter fading incurs an inferior outage performance of the backscatter system in comparison with the counterpart over single-hop backscatter fading; 2) For the parasitic scheme, cascaded backscatter fading leads to a superior outage performance of the primary system in comparison with the counterpart over single-hop backscatter fading; 3) For the backscatter system, regardless of single-hop or cascaded backscatter fading, the exact outage probability of the parasitic scheme overlaps with the asymptotic of the commensal scheme; 4) For the competitive scheme, as the decoding threshold of the primary system approaches zero, the asymptotic outage performance of the primary system in cascaded and single-hop backscatter fading tend to be the same; and 5) Unlike single-hop backscatter fading, as the decoding threshold of backscatter signal approaches zero, the outage probability of the competitive and parasitic schemes for the backscatter system in cascaded backscatter fading approaches that of the competitive scheme for the primary system.","PeriodicalId":326047,"journal":{"name":"2022 IEEE 96th Vehicular Technology Conference (VTC2022-Fall)","volume":"40 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":"123365213","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-Fall57202.2022.10012938
Doaa Rjoub, Ahmad Alsharoa, Ala’eddin Masadeh
Every year, wildfires burn out countless hectares of lands, resulting in ecological, environmental, and economic damage. This paper presents an energy management system that consists of an unmanned aerial vehicle (UAV) equipped with air quality and light detection and ranging (LiDAR) sensors for monitoring forests and recognizing flames early. We develop a novel approach for autonomous patrolling system. This approach has the advantage of effectively detecting wildfire incidents, while optimizing the energy consumption of the UAV’s battery to cover large areas. When a wildfire is detected, the UAV is able to transmit real-time data, such as sensor readings and LiDAR data, to the nearby communication tower. We formulate an optimization problem that minimizes the overall UAV’s energy consumption due to patrolling. Based on the pollutant dispersion mode, we propose a novel UAV patrolling solution based on genetic algorithm with the goal of maximizing the patrolling coverage of the UAV taking into account the UAV’s battery constraints. More specifically, we optimize the UAV’s flight path using a plume dispersion model to find the concentration of common gases of wildfire. Finally, simulations are presented to show the efficiency and validity of the solution.
{"title":"Early Wildfire Detection using UAVs Integrated with Air Quality and LiDAR Sensors","authors":"Doaa Rjoub, Ahmad Alsharoa, Ala’eddin Masadeh","doi":"10.1109/VTC2022-Fall57202.2022.10012938","DOIUrl":"https://doi.org/10.1109/VTC2022-Fall57202.2022.10012938","url":null,"abstract":"Every year, wildfires burn out countless hectares of lands, resulting in ecological, environmental, and economic damage. This paper presents an energy management system that consists of an unmanned aerial vehicle (UAV) equipped with air quality and light detection and ranging (LiDAR) sensors for monitoring forests and recognizing flames early. We develop a novel approach for autonomous patrolling system. This approach has the advantage of effectively detecting wildfire incidents, while optimizing the energy consumption of the UAV’s battery to cover large areas. When a wildfire is detected, the UAV is able to transmit real-time data, such as sensor readings and LiDAR data, to the nearby communication tower. We formulate an optimization problem that minimizes the overall UAV’s energy consumption due to patrolling. Based on the pollutant dispersion mode, we propose a novel UAV patrolling solution based on genetic algorithm with the goal of maximizing the patrolling coverage of the UAV taking into account the UAV’s battery constraints. More specifically, we optimize the UAV’s flight path using a plume dispersion model to find the concentration of common gases of wildfire. Finally, simulations are presented to show the efficiency and validity of the solution.","PeriodicalId":326047,"journal":{"name":"2022 IEEE 96th Vehicular Technology Conference (VTC2022-Fall)","volume":"13 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":"122254163","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-Fall57202.2022.10012745
Iman Valiulahi, C. Masouros, Abdelhamid Salem
This work studies resource allocation policies for a multi-antenna access point that is powered by a combination of harvested energy and the power grid, communicating with multiple single-antenna users. We propose a non-convex problem to directly solve the throughput maximization problem. Though the problem is challenging to solve, we first propose an iterative algorithm based on the first-order Taylor expansion and block coordinate descent for the scenario that full channel state information (CSI) and energy arrival information (EAI) are assumed to be known. Then, inspired by this scenario, we study a case in which statistical CSI and EAI are only required. Simulation results demonstrate that the energy-performance trade-off as well as the performance of the statistical case is comparable to the full CSI and EAI scenario, which supports the practical aspect of the proposed policies.
{"title":"Resource Allocation Policies for Hybrid Power-Grid and Harvested Energy Communication Systems","authors":"Iman Valiulahi, C. Masouros, Abdelhamid Salem","doi":"10.1109/VTC2022-Fall57202.2022.10012745","DOIUrl":"https://doi.org/10.1109/VTC2022-Fall57202.2022.10012745","url":null,"abstract":"This work studies resource allocation policies for a multi-antenna access point that is powered by a combination of harvested energy and the power grid, communicating with multiple single-antenna users. We propose a non-convex problem to directly solve the throughput maximization problem. Though the problem is challenging to solve, we first propose an iterative algorithm based on the first-order Taylor expansion and block coordinate descent for the scenario that full channel state information (CSI) and energy arrival information (EAI) are assumed to be known. Then, inspired by this scenario, we study a case in which statistical CSI and EAI are only required. Simulation results demonstrate that the energy-performance trade-off as well as the performance of the statistical case is comparable to the full CSI and EAI scenario, which supports the practical aspect of the proposed policies.","PeriodicalId":326047,"journal":{"name":"2022 IEEE 96th Vehicular Technology Conference (VTC2022-Fall)","volume":"30 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":"116255151","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-Fall57202.2022.10012869
S. S. Hosseini, B. Champagne, Xiaohua Chang
We study the problem of direction of arrival (DoA) estimation for cell-free massive MIMO (m-MIMO) systems operating over extremely high frequency (EHF) and terahertz (THF) bands, where the wireless channel can effectively be modeled by a line-of-sight path. For this model, a low-complexity deep neural network (DNN)-based method is proposed to estimate the DoA of a radio wave impinging on an access point (AP) equipped with an antenna array. To train the DNN, a special feature set is proposed obtained from the first superdiagonal entries of the spatial correlation matrix. This selection of features makes it possible to employ a DNN with only a few low-dimensional layers, which considerably speeds up training and processing. More importantly, it is shown that the trained DNN is robust against quantization noise in the array snapshot data. This property makes the centralized implementation of the proposed DNN-based method feasible, which is particularly well-suited for cell-free m-MIMO. Through extensive simulations, the new method is shown to achieve an estimation performance that nearly matches or exceeds that of classical bechmark methods, but with considerably reduced complexity.
{"title":"A Low-Complexity DNN-Based DoA Estimation Method for EHF and THF Cell-Free Massive MIMO","authors":"S. S. Hosseini, B. Champagne, Xiaohua Chang","doi":"10.1109/VTC2022-Fall57202.2022.10012869","DOIUrl":"https://doi.org/10.1109/VTC2022-Fall57202.2022.10012869","url":null,"abstract":"We study the problem of direction of arrival (DoA) estimation for cell-free massive MIMO (m-MIMO) systems operating over extremely high frequency (EHF) and terahertz (THF) bands, where the wireless channel can effectively be modeled by a line-of-sight path. For this model, a low-complexity deep neural network (DNN)-based method is proposed to estimate the DoA of a radio wave impinging on an access point (AP) equipped with an antenna array. To train the DNN, a special feature set is proposed obtained from the first superdiagonal entries of the spatial correlation matrix. This selection of features makes it possible to employ a DNN with only a few low-dimensional layers, which considerably speeds up training and processing. More importantly, it is shown that the trained DNN is robust against quantization noise in the array snapshot data. This property makes the centralized implementation of the proposed DNN-based method feasible, which is particularly well-suited for cell-free m-MIMO. Through extensive simulations, the new method is shown to achieve an estimation performance that nearly matches or exceeds that of classical bechmark methods, but with considerably reduced complexity.","PeriodicalId":326047,"journal":{"name":"2022 IEEE 96th Vehicular Technology Conference (VTC2022-Fall)","volume":"30 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":"115245356","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-Fall57202.2022.10012851
T. Guo
Aimed at boosting spectrum utilization towards B5G/6G evolution, this paper studies an overlying network that is built by using “dummy” aerial relays and shares the frequency band with a primary network, where the low-cost relays without using sophisticated transmit beamforming generate interference to the primary network. The main objectives are, by using collaborative transmitter precoding, i) to increase Signal-to-Leakage Ratio (SLR) which is the ratio of signal power at the intended receiver to interference power at an unintended receiver, and ii) to reduce the overlying network’s total transmit power. A performance trade-off framework based on robust optimization is proposed to balance these two contradicting objectives, with consideration of the relays’ asynchronicity and channel measurement errors. It is found that the relays’ amplification is a sensitive parameter that can be tuned together with the transmitter precoder in optimization. To overcome the problem of unknown uncertainty set in the max-min optimization, a practical technique based on multiple measurements, semi-analytical robust design, is proposed and tested. Performance evaluation results suggest the proposed overlying network is promising toward the two objectives.
{"title":"Integration of Aerial-Relay-Based Network With Terrestrial Network Towards B5G/6G Evolution","authors":"T. Guo","doi":"10.1109/VTC2022-Fall57202.2022.10012851","DOIUrl":"https://doi.org/10.1109/VTC2022-Fall57202.2022.10012851","url":null,"abstract":"Aimed at boosting spectrum utilization towards B5G/6G evolution, this paper studies an overlying network that is built by using “dummy” aerial relays and shares the frequency band with a primary network, where the low-cost relays without using sophisticated transmit beamforming generate interference to the primary network. The main objectives are, by using collaborative transmitter precoding, i) to increase Signal-to-Leakage Ratio (SLR) which is the ratio of signal power at the intended receiver to interference power at an unintended receiver, and ii) to reduce the overlying network’s total transmit power. A performance trade-off framework based on robust optimization is proposed to balance these two contradicting objectives, with consideration of the relays’ asynchronicity and channel measurement errors. It is found that the relays’ amplification is a sensitive parameter that can be tuned together with the transmitter precoder in optimization. To overcome the problem of unknown uncertainty set in the max-min optimization, a practical technique based on multiple measurements, semi-analytical robust design, is proposed and tested. Performance evaluation results suggest the proposed overlying network is promising toward the two objectives.","PeriodicalId":326047,"journal":{"name":"2022 IEEE 96th Vehicular Technology Conference (VTC2022-Fall)","volume":"123 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":"120966376","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-Fall57202.2022.10012810
H. Matsuno, Tatsuya Nagao, Takuya Ohto, Takahiro Hayashi, Michihiro Harada
Intelligent reflecting surfaces (IRSs) have recently been attracting attention as solutions for coverage hole problems in mobile communication areas. To utilize the IRS for mobile networks, the reflecting signal strength of IRS is evaluated in advance to estimate the improvement of coverage and interference with other wireless systems. In order to evaluate an actual IRS precisely, the reflecting phase and amplitude should be evaluated considering the mutual coupling effect. In addition, a large measurement system is required to satisfy the far-field conditions of IRS. This makes the evaluation of large IRS difficult. To solve this problem, we propose a practical evaluation method of a large IRS by synthesizing RCS patterns of small IRSs (sub-IRS). To verify the validity, we also formulate mutual coupling effects on the IRS. Through numerical evaluation, the influence of mutual coupling between each sub-IRS is reduced by increasing the size of the sub-IRS. In addition, through evaluation with the electromagnetic simulator, the RCS pattern of the proposed method reproduced that of a large IRS.
{"title":"Practical Evaluation Method for Large IRS: RCS Pattern Synthesis of Sub-IRS with Mutual Coupling","authors":"H. Matsuno, Tatsuya Nagao, Takuya Ohto, Takahiro Hayashi, Michihiro Harada","doi":"10.1109/VTC2022-Fall57202.2022.10012810","DOIUrl":"https://doi.org/10.1109/VTC2022-Fall57202.2022.10012810","url":null,"abstract":"Intelligent reflecting surfaces (IRSs) have recently been attracting attention as solutions for coverage hole problems in mobile communication areas. To utilize the IRS for mobile networks, the reflecting signal strength of IRS is evaluated in advance to estimate the improvement of coverage and interference with other wireless systems. In order to evaluate an actual IRS precisely, the reflecting phase and amplitude should be evaluated considering the mutual coupling effect. In addition, a large measurement system is required to satisfy the far-field conditions of IRS. This makes the evaluation of large IRS difficult. To solve this problem, we propose a practical evaluation method of a large IRS by synthesizing RCS patterns of small IRSs (sub-IRS). To verify the validity, we also formulate mutual coupling effects on the IRS. Through numerical evaluation, the influence of mutual coupling between each sub-IRS is reduced by increasing the size of the sub-IRS. In addition, through evaluation with the electromagnetic simulator, the RCS pattern of the proposed method reproduced that of a large IRS.","PeriodicalId":326047,"journal":{"name":"2022 IEEE 96th Vehicular Technology Conference (VTC2022-Fall)","volume":"71 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":"114272954","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-Fall57202.2022.10012832
Miguel A. Bellido-Manganell, U. Fiebig, M. Walter
This paper presents a statistical analysis of the main components of the aircraft-to-aircraft channel based on the wideband channel measurements conducted between two aircraft in the VHF/UHF band at 250 MHz. We consider multiple flight segments where the aircraft flew at diverse altitudes and used different antennas for transmission and for reception, alternating between a top and a bottom antenna. In each scenario of interest, we analyse the power and the small-scale fading of the envelope of the direct line-of-sight component and of the specular reflection component off a lake. For both components, we compare the measured average power with the theoretical free-space path loss, and the measured small-scale fading with multiple well-known statistical distributions. The results show that the envelope of both components is strongly affected by the geometry, the location of the antennas, and by the aircraft fuselage itself. The different scenarios yield significant variations in the average power and in the distribution of the small-scale fading. A Rician distribution shows the best fit for the line-of-sight component envelope. The component reflected off the lake can be modeled by a Rician distribution when it is not obstructed or strongly affected by the aircraft fuselage, and by a Nakagami distribution otherwise. The parameters of the best-fitting distributions, including the Rician K-factor, are provided for the different scenarios.
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