Pub Date : 2024-11-25DOI: 10.1109/LCOMM.2024.3505896
Longshen Chen;Jia Zhu;Yulong Zou;Yulei Lou;Yizhi Li
In this letter, we study a dual-function radar-communication unmanned aerial vehicle (DFRC-UAV)- enabled integrated sensing and communications (ISAC) system, and propose a simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS) assisted DFRC-UAV-enabled ISAC scheme called SRaDUI, where a DFRC-UAV simultaneously senses ground targets and multicasts information to users assisted by a STAR-RIS. To improve the multicast capacity, we formulate an achievable rate maximization problem by jointly designing the scheduling of targets, the covariance matrices of the transmitted symbol vectors, the STAR-RIS coefficients, and the DFRC-UAV trajectory. To address this non-convex problem, we propose an alternating optimization (AO) based iterative algorithm, decomposing the original problem into a series of subproblems, which can be solved alternately to obtain suboptimal solutions based on the semidefinite relaxation (SDR) and successive convex approximation (SCA). Numerical results demonstrate the superiority of the proposed SRaDUI scheme and the effectiveness of the designed iterative algorithm.
{"title":"STAR-RIS-Assisted Multicast Communications in DFRC-UAV-Enabled ISAC Systems","authors":"Longshen Chen;Jia Zhu;Yulong Zou;Yulei Lou;Yizhi Li","doi":"10.1109/LCOMM.2024.3505896","DOIUrl":"https://doi.org/10.1109/LCOMM.2024.3505896","url":null,"abstract":"In this letter, we study a dual-function radar-communication unmanned aerial vehicle (DFRC-UAV)- enabled integrated sensing and communications (ISAC) system, and propose a simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS) assisted DFRC-UAV-enabled ISAC scheme called SRaDUI, where a DFRC-UAV simultaneously senses ground targets and multicasts information to users assisted by a STAR-RIS. To improve the multicast capacity, we formulate an achievable rate maximization problem by jointly designing the scheduling of targets, the covariance matrices of the transmitted symbol vectors, the STAR-RIS coefficients, and the DFRC-UAV trajectory. To address this non-convex problem, we propose an alternating optimization (AO) based iterative algorithm, decomposing the original problem into a series of subproblems, which can be solved alternately to obtain suboptimal solutions based on the semidefinite relaxation (SDR) and successive convex approximation (SCA). Numerical results demonstrate the superiority of the proposed SRaDUI scheme and the effectiveness of the designed iterative algorithm.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"29 1","pages":"170-174"},"PeriodicalIF":3.7,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-11-22DOI: 10.1109/LCOMM.2024.3504725
Zizhou Zheng;Huan Huang;Hongliang Zhang;A. Lee Swindlehurst
Dual-polarized (DP) multiple-input-multiple-output (MIMO) systems have been widely adopted in commercial mobile wireless communications. Such systems achieve multiplexing and diversity gain by exploiting the polarization dimension. However, existing studies have shown that the capacity of DP MIMO may not surpass that of single-polarized (SP) MIMO systems due to the cross-polarization coupling induced by the propagation environment. In this letter, we employ reconfigurable intelligent surfaces (RISs) to address this issue and investigate how large the surface should be to ensure a better performance for DP MIMO. Specifically, we first derive the capacities of DP and SP MIMO systems with an RIS, and then study the influence of the RIS size on the system capacity. Our analyses reveal how to deploy the RIS in a DP MIMO scenario.
{"title":"RIS-Aided Dual-Polarized MIMO: How Large a Surface Is Needed to Beat Single Polarization?","authors":"Zizhou Zheng;Huan Huang;Hongliang Zhang;A. Lee Swindlehurst","doi":"10.1109/LCOMM.2024.3504725","DOIUrl":"https://doi.org/10.1109/LCOMM.2024.3504725","url":null,"abstract":"Dual-polarized (DP) multiple-input-multiple-output (MIMO) systems have been widely adopted in commercial mobile wireless communications. Such systems achieve multiplexing and diversity gain by exploiting the polarization dimension. However, existing studies have shown that the capacity of DP MIMO may not surpass that of single-polarized (SP) MIMO systems due to the cross-polarization coupling induced by the propagation environment. In this letter, we employ reconfigurable intelligent surfaces (RISs) to address this issue and investigate how large the surface should be to ensure a better performance for DP MIMO. Specifically, we first derive the capacities of DP and SP MIMO systems with an RIS, and then study the influence of the RIS size on the system capacity. Our analyses reveal how to deploy the RIS in a DP MIMO scenario.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"29 1","pages":"150-154"},"PeriodicalIF":3.7,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-11-22DOI: 10.1109/LCOMM.2024.3504957
Yang Yu;Xiaoqing Tang
This letter introduces weighted sum power (WSP), a new performance metric for wireless resource allocation during cooperative spectrum sharing in cognitive radio networks, where the primary and secondary nodes have different priorities and quality of service (QoS) requirements. Compared to using energy efficiency (EE) and weighted sum energy efficiency (WSEE) as performance metrics and optimization objectives of wireless resource allocation towards green communication, the linear character of WSP can reduce the complexity of optimization problems. Meanwhile, the weights assigned to different nodes are beneficial for managing their power budget. Using WSP as the optimization objective, a suboptimal resource allocation scheme is proposed, leveraging linear programming and Newton’s method. Simulations verify that the proposed scheme provides near-optimal performance with low computation time. Furthermore, the initial approximate value selection in Newton’s method is also optimized to accelerate the proposed scheme.
{"title":"Weighted Sum Power Minimization for Cooperative Spectrum Sharing in Cognitive Radio Networks","authors":"Yang Yu;Xiaoqing Tang","doi":"10.1109/LCOMM.2024.3504957","DOIUrl":"https://doi.org/10.1109/LCOMM.2024.3504957","url":null,"abstract":"This letter introduces weighted sum power (WSP), a new performance metric for wireless resource allocation during cooperative spectrum sharing in cognitive radio networks, where the primary and secondary nodes have different priorities and quality of service (QoS) requirements. Compared to using energy efficiency (EE) and weighted sum energy efficiency (WSEE) as performance metrics and optimization objectives of wireless resource allocation towards green communication, the linear character of WSP can reduce the complexity of optimization problems. Meanwhile, the weights assigned to different nodes are beneficial for managing their power budget. Using WSP as the optimization objective, a suboptimal resource allocation scheme is proposed, leveraging linear programming and Newton’s method. Simulations verify that the proposed scheme provides near-optimal performance with low computation time. Furthermore, the initial approximate value selection in Newton’s method is also optimized to accelerate the proposed scheme.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"29 1","pages":"160-164"},"PeriodicalIF":3.7,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938516","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Demodulation of visible light communication (VLC) signals using intensity modulation direct detection is limited by the noise inherent in the signal. To address this issue, we propose an enhanced machine learning (ML) image-based demodulator for on-off keying (OOK) modulated VLC signals. We designed and implemented a transmitter and receiver equipped with sensors to collect real-time environmental data. The transmission distance is varied, and the received waveform is converted into images. To minimize the computational load of the demodulator, we apply bicubic interpolation and image thresholding techniques to these images. Subsequently, we developed an ML-based demodulator using MobileNetV2 and trained the model with the collected dataset. To enhance the model’s versatility and accuracy, we used data augmentation techniques. Experimental results indicate that the proposed ML-driven demodulator significantly extends the communication range and increases noise tolerance, achieving a demodulation accuracy of 97.58%.
{"title":"Image-Based VLC Signal Demodulation Using Machine Learning","authors":"Kaleem Ullah;Maaz Salman;Javad Bolboli;Wan-Young Chung","doi":"10.1109/LCOMM.2024.3504524","DOIUrl":"https://doi.org/10.1109/LCOMM.2024.3504524","url":null,"abstract":"Demodulation of visible light communication (VLC) signals using intensity modulation direct detection is limited by the noise inherent in the signal. To address this issue, we propose an enhanced machine learning (ML) image-based demodulator for on-off keying (OOK) modulated VLC signals. We designed and implemented a transmitter and receiver equipped with sensors to collect real-time environmental data. The transmission distance is varied, and the received waveform is converted into images. To minimize the computational load of the demodulator, we apply bicubic interpolation and image thresholding techniques to these images. Subsequently, we developed an ML-based demodulator using MobileNetV2 and trained the model with the collected dataset. To enhance the model’s versatility and accuracy, we used data augmentation techniques. Experimental results indicate that the proposed ML-driven demodulator significantly extends the communication range and increases noise tolerance, achieving a demodulation accuracy of 97.58%.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"29 1","pages":"145-149"},"PeriodicalIF":3.7,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938512","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"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 : 2024-11-22DOI: 10.1109/LCOMM.2024.3504745
Alessandro Buratto;Andrea Munari;Leonardo Badia
Random access protocols are usually adopted in the Internet of Things to enable uncoordinated medium sharing. Tackling this setting, we explore the statistics of the packet inter-delivery times under slotted ALOHA contention, considering two backoff schemes (reactive vs. proactive). We further discuss the efficiency of these schemes in minimizing the average age of information. Finally, we investigate age minimization both as a centralized optimization and via game theory, obtaining numerical solutions for both cases. A reactive scheme applied in a centralized manner is found to be the most suitable to systems that require a bounded age, whereas a proactive solution applied distributedly is best used to minimize the average age.
{"title":"Strategic Backoff of Slotted ALOHA for Minimal Age of Information","authors":"Alessandro Buratto;Andrea Munari;Leonardo Badia","doi":"10.1109/LCOMM.2024.3504745","DOIUrl":"https://doi.org/10.1109/LCOMM.2024.3504745","url":null,"abstract":"Random access protocols are usually adopted in the Internet of Things to enable uncoordinated medium sharing. Tackling this setting, we explore the statistics of the packet inter-delivery times under slotted ALOHA contention, considering two backoff schemes (reactive vs. proactive). We further discuss the efficiency of these schemes in minimizing the average age of information. Finally, we investigate age minimization both as a centralized optimization and via game theory, obtaining numerical solutions for both cases. A reactive scheme applied in a centralized manner is found to be the most suitable to systems that require a bounded age, whereas a proactive solution applied distributedly is best used to minimize the average age.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"29 1","pages":"155-159"},"PeriodicalIF":3.7,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10764733","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-22DOI: 10.1109/LCOMM.2024.3505054
Ziang Liu;Ayush Bhandari;Bruno Clerckx
The success of full-stack full-duplex communication systems depends on how effectively one can achieve digital self-interference cancellation (SIC). Towards this end, in this letter, we consider unlimited sensing framework (USF) enabled full-duplex system. We show that by injecting folding non-linearities in the sensing pipeline, one can not only suppress self-interference but also recover the signal of interest (SoI). This approach leads to novel design of the receiver architecture that is complemented by a modulo-domain channel estimation method. We then demonstrate the advantages of $mathscr {M}_{lambda } $