Pub Date : 2024-12-16DOI: 10.1109/OJVT.2024.3512052
Edward Au
{"title":"Editorial: Message From the Editor-in-Chief","authors":"Edward Au","doi":"10.1109/OJVT.2024.3512052","DOIUrl":"https://doi.org/10.1109/OJVT.2024.3512052","url":null,"abstract":"","PeriodicalId":34270,"journal":{"name":"IEEE Open Journal of Vehicular Technology","volume":"6 ","pages":"viii-viii"},"PeriodicalIF":5.3,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10803008","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142825779","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-16DOI: 10.1109/OJVT.2024.3518621
Rafael P. Torres;Jesús R. Pérez
This paper presents a novel lower boundary for the coherence block (ChB) length in time-variant wireless channels. A rigorous estimation of the ChB length is important for the proper design of systems based on time division duplex-orthogonal frequency division multiplexing (TDD-OFDM). ChB length is especially relevant in the case of massive multiple input-multiple output (m-MIMO) systems, as it determines the overhead due to the massive channel estimation and, consequently, the spectral efficiency that can be achieved. The proposed boundary is based on a tractable propagation model, is related to easily obtainable channel parameters, and applicable to radio channels with temporal variation due to both the movement of the users and the movement of objects that surround them; including vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I) and industrial Machine-to-Machine (M2M) communications.
{"title":"A Lower Boundary on the Length of the Coherence Block in Vehicular Communications Channels","authors":"Rafael P. Torres;Jesús R. Pérez","doi":"10.1109/OJVT.2024.3518621","DOIUrl":"https://doi.org/10.1109/OJVT.2024.3518621","url":null,"abstract":"This paper presents a novel lower boundary for the coherence block (ChB) length in time-variant wireless channels. A rigorous estimation of the ChB length is important for the proper design of systems based on time division duplex-orthogonal frequency division multiplexing (TDD-OFDM). ChB length is especially relevant in the case of massive multiple input-multiple output (m-MIMO) systems, as it determines the overhead due to the massive channel estimation and, consequently, the spectral efficiency that can be achieved. The proposed boundary is based on a tractable propagation model, is related to easily obtainable channel parameters, and applicable to radio channels with temporal variation due to both the movement of the users and the movement of objects that surround them; including vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I) and industrial Machine-to-Machine (M2M) communications.","PeriodicalId":34270,"journal":{"name":"IEEE Open Journal of Vehicular Technology","volume":"6 ","pages":"256-264"},"PeriodicalIF":5.3,"publicationDate":"2024-12-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10804205","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142905784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-12DOI: 10.1109/OJVT.2024.3490477
{"title":"IEEE Open Journal of Vehicular Technology Information for Authors","authors":"","doi":"10.1109/OJVT.2024.3490477","DOIUrl":"https://doi.org/10.1109/OJVT.2024.3490477","url":null,"abstract":"","PeriodicalId":34270,"journal":{"name":"IEEE Open Journal of Vehicular Technology","volume":"6 ","pages":"C4-C4"},"PeriodicalIF":5.3,"publicationDate":"2024-12-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10795781","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142810414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vehicular Ad Hoc Networks (VANET) represent an immense technological advancement enhancing connectivity among Vehicular Technology including vehicles and roadside infrastructure to ensure road safety and improve forthcoming transportation services. The effectiveness of safety applications depends on the reliability and consistency of periodically broadcasted real-time environmental and vehicle state information. However, insider threats arise when nodes with valid access credentials disseminate maliciously incorrect information. Existing misbehavior detection solutions are often static and lack the adaptability required for the dynamic nature of vehicular networks, leaving a gap in addressing sophisticated attacks such as Denial of Service (DoS), data replay, and Sybil attacks. To fill this gap, we propose a context-aware, data-driven misbehavior detection framework that allows each vehicle to perform plausibility and consistency checks on received messages. The Adaptive Misbehavior Detection Framework addresses critical security challenges within localized vehicles by incorporating dynamically computed parameters and confidence intervals to assess message integrity. To determine the presence of misbehavior, a weighted average approach effectively reduces the possibility of false positives. Simulation results demonstrate that our proposed mechanism significantly enhances detection performance against key misbehavior types, including false information dissemination, DoS, disruptive, and variants of Sybil attacks variants, outperforming existing benchmarks with the VeReMi extension dataset.
{"title":"LA-DETECTS: Local and Adaptive Data-Centric Misbehavior Detection Framework for Vehicular Technology Security","authors":"Rukhsar Sultana;Jyoti Grover;Meenakshi Tripathi;Prinkle Sharma","doi":"10.1109/OJVT.2024.3513152","DOIUrl":"https://doi.org/10.1109/OJVT.2024.3513152","url":null,"abstract":"Vehicular Ad Hoc Networks (VANET) represent an immense technological advancement enhancing connectivity among Vehicular Technology including vehicles and roadside infrastructure to ensure road safety and improve forthcoming transportation services. The effectiveness of safety applications depends on the reliability and consistency of periodically broadcasted real-time environmental and vehicle state information. However, insider threats arise when nodes with valid access credentials disseminate maliciously incorrect information. Existing misbehavior detection solutions are often static and lack the adaptability required for the dynamic nature of vehicular networks, leaving a gap in addressing sophisticated attacks such as Denial of Service (DoS), data replay, and Sybil attacks. To fill this gap, we propose a context-aware, data-driven misbehavior detection framework that allows each vehicle to perform plausibility and consistency checks on received messages. The Adaptive Misbehavior Detection Framework addresses critical security challenges within localized vehicles by incorporating dynamically computed parameters and confidence intervals to assess message integrity. To determine the presence of misbehavior, a weighted average approach effectively reduces the possibility of false positives. Simulation results demonstrate that our proposed mechanism significantly enhances detection performance against key misbehavior types, including false information dissemination, DoS, disruptive, and variants of Sybil attacks variants, outperforming existing benchmarks with the VeReMi extension dataset.","PeriodicalId":34270,"journal":{"name":"IEEE Open Journal of Vehicular Technology","volume":"6 ","pages":"145-169"},"PeriodicalIF":5.3,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10782992","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142858977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-09DOI: 10.1109/OJVT.2024.3514217
Iqra Farhat;Umar Rashid;Omer Waqar
Cloud Radio Access Networks (CRAN) face a critical challenge due to the limited capacity of fronthaul links overwhelmed by massive data transmissions. This paper proposes a novel CRAN design that effectively tackles this challenge. Our approach combines three key elements: (1) Massive MIMO at the baseband unit to leverage large array gain and interference suppression; (2) a novel simultaneous transmitting and reflecting (STAR) reconfigurable intelligent surface (RIS) that can both transmit and reflect signals concurrently, improving fronthaul capacity through energy splitting technique by enabling communication with remote radio heads serving multiple user equipments; and (3) a data compression technique by optimizing the quantization noise covariance matrix across remote radio heads, significantly reducing the fronthaul traffic load. We formulate a problem to maximize the overall network sum-rate by jointly optimizing transmit power, fronthaul capacity, beamforming vectors at RRHs, data compression, and STAR-RIS transmission-reflection coefficients. To address the nonconvexity of the resulting joint optimization problem, successive convexification along with alternating optimization technique are used to develop an iterative algorithm. Simulations demonstrate that our STAR-RIS-aided CRAN design surpasses conventional reflecting-only RIS aided CRAN by providing full-space coverage and thus offering more degrees-of-freedom compared to traditional RIS.
{"title":"Enhanced Fronthaul Capacity in CRANs: Sum-Rate Maximization via Joint Optimal Design of STAR-RIS, Massive MIMO and Data Compression","authors":"Iqra Farhat;Umar Rashid;Omer Waqar","doi":"10.1109/OJVT.2024.3514217","DOIUrl":"https://doi.org/10.1109/OJVT.2024.3514217","url":null,"abstract":"Cloud Radio Access Networks (CRAN) face a critical challenge due to the limited capacity of fronthaul links overwhelmed by massive data transmissions. This paper proposes a novel CRAN design that effectively tackles this challenge. Our approach combines three key elements: (1) Massive MIMO at the baseband unit to leverage large array gain and interference suppression; (2) a novel simultaneous transmitting and reflecting (STAR) reconfigurable intelligent surface (RIS) that can both transmit and reflect signals concurrently, improving fronthaul capacity through energy splitting technique by enabling communication with remote radio heads serving multiple user equipments; and (3) a data compression technique by optimizing the quantization noise covariance matrix across remote radio heads, significantly reducing the fronthaul traffic load. We formulate a problem to maximize the overall network sum-rate by jointly optimizing transmit power, fronthaul capacity, beamforming vectors at RRHs, data compression, and STAR-RIS transmission-reflection coefficients. To address the nonconvexity of the resulting joint optimization problem, successive convexification along with alternating optimization technique are used to develop an iterative algorithm. Simulations demonstrate that our STAR-RIS-aided CRAN design surpasses conventional reflecting-only RIS aided CRAN by providing full-space coverage and thus offering more degrees-of-freedom compared to traditional RIS.","PeriodicalId":34270,"journal":{"name":"IEEE Open Journal of Vehicular Technology","volume":"6 ","pages":"202-215"},"PeriodicalIF":5.3,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10787117","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142890354","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-09DOI: 10.1109/OJVT.2024.3513460
Víctor P. Gil Jiménez;Ángel Navia Vázquez
In this paper, a novel decoding kernel method based on Successive Parzen Windows Interference Cancellation (SPWIC) is proposed for the Non-Orthogonal Multiple Access (NOMA) uplink. The procedure leverages on the diversity in both angle and received power at a 3D antenna combined with a Parzen Windows based decoding to achieve better interference cancellation, providing the decoding process with robustness against multi-user interference and user discrimination. This is specially convenient in vehicular scenarios in crowded cities. We have evaluated SPWIC in various scenarios and concluded that it outperforms the standard Successive Interference Cancellation (SIC) approach even in Multiple-Input Multiple-Output (MIMO) cases such that up to 9 users can be allocated on the same resources -as long as they are not too close to each other-. Although it is proposed for mmWave, it can be directly adapted to lower frequencies.
{"title":"Uplink Non-Orthogonal Multiple Access (NOMA) Decoding Based on Successive Parzen Windows Interference Cancellation","authors":"Víctor P. Gil Jiménez;Ángel Navia Vázquez","doi":"10.1109/OJVT.2024.3513460","DOIUrl":"https://doi.org/10.1109/OJVT.2024.3513460","url":null,"abstract":"In this paper, a novel decoding kernel method based on Successive Parzen Windows Interference Cancellation (SPWIC) is proposed for the Non-Orthogonal Multiple Access (NOMA) uplink. The procedure leverages on the diversity in both angle and received power at a 3D antenna combined with a Parzen Windows based decoding to achieve better interference cancellation, providing the decoding process with robustness against multi-user interference and user discrimination. This is specially convenient in vehicular scenarios in crowded cities. We have evaluated SPWIC in various scenarios and concluded that it outperforms the standard Successive Interference Cancellation (SIC) approach even in Multiple-Input Multiple-Output (MIMO) cases such that up to 9 users can be allocated on the same resources -as long as they are not too close to each other-. Although it is proposed for mmWave, it can be directly adapted to lower frequencies.","PeriodicalId":34270,"journal":{"name":"IEEE Open Journal of Vehicular Technology","volume":"6 ","pages":"265-275"},"PeriodicalIF":5.3,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10786369","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142918336","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-09DOI: 10.1109/OJVT.2024.3514749
Salah Berra;Abderrazak Benchabane;Sourav Chakraborty;Kazuki Maruta;Rui Dinis;Marko Beko
Massive multiple-input multiple-output (MIMO) systems are critical technologies for the next generation of networks. In this field of research, new forms of deployment are emerging, such as extremely large-scale MIMO (XL-MIMO), in which the antenna array at the base station (BS) is of extreme dimensions. As a result, spatial non-stationary features emerge as users view just a section of the antenna array, known as the visibility regions (VRs). The XL-MIMO systems can achieve higher spectral efficiency, improve cell coverage, and provide significantly higher data rates than standard MIMO systems. It is a promising technology for future sixth-generation (6G) networks. However, due to the large number of antennas, linear precoding algorithms such as Zero-Forcing (ZF) and regularized Zero-Forcing (RZF) methods suffer from unacceptable computational complexity, primarily due to the required matrix inversion. This work aims to develop low-complexity precoding techniques for the downlink XL-MIMO system. These low-complexity linear precoding methods are based on Gauss-Seidel (GS) and Successive Over-Relaxation (SOR) techniques, which avoid calculating the complex matrix inversion and lead to stable linear precoding performance. To further enhance linear precoding performance, we incorporate the Chebyshev acceleration method with the SOR and GS methods, referred to as the Cheby-SOR and Cheby-GS methods. As these proposed methods require optimizing parameters, we create a deep unfolded network (DUN) to optimize the algorithm parameters. Our performance results demonstrate that the proposed method significantly reduces computational complexity from to $mathcal {O}(K^{2})$ , where $K$ represents the number of users. Moreover, our approach outperforms the original algorithms, requiring only a few iterations to achieve the RZF bit error rate (BER) performance.
{"title":"A Low Complexity Linear Precoding Method for Extremely Large-Scale MIMO Systems","authors":"Salah Berra;Abderrazak Benchabane;Sourav Chakraborty;Kazuki Maruta;Rui Dinis;Marko Beko","doi":"10.1109/OJVT.2024.3514749","DOIUrl":"https://doi.org/10.1109/OJVT.2024.3514749","url":null,"abstract":"Massive multiple-input multiple-output (MIMO) systems are critical technologies for the next generation of networks. In this field of research, new forms of deployment are emerging, such as extremely large-scale MIMO (XL-MIMO), in which the antenna array at the base station (BS) is of extreme dimensions. As a result, spatial non-stationary features emerge as users view just a section of the antenna array, known as the visibility regions (VRs). The XL-MIMO systems can achieve higher spectral efficiency, improve cell coverage, and provide significantly higher data rates than standard MIMO systems. It is a promising technology for future sixth-generation (6G) networks. However, due to the large number of antennas, linear precoding algorithms such as Zero-Forcing (ZF) and regularized Zero-Forcing (RZF) methods suffer from unacceptable computational complexity, primarily due to the required matrix inversion. This work aims to develop low-complexity precoding techniques for the downlink XL-MIMO system. These low-complexity linear precoding methods are based on Gauss-Seidel (GS) and Successive Over-Relaxation (SOR) techniques, which avoid calculating the complex matrix inversion and lead to stable linear precoding performance. To further enhance linear precoding performance, we incorporate the Chebyshev acceleration method with the SOR and GS methods, referred to as the Cheby-SOR and Cheby-GS methods. As these proposed methods require optimizing parameters, we create a deep unfolded network (DUN) to optimize the algorithm parameters. Our performance results demonstrate that the proposed method significantly reduces computational complexity from to \u0000<inline-formula><tex-math>$mathcal {O}(K^{2})$</tex-math></inline-formula>\u0000, where \u0000<inline-formula><tex-math>$K$</tex-math></inline-formula>\u0000 represents the number of users. Moreover, our approach outperforms the original algorithms, requiring only a few iterations to achieve the RZF bit error rate (BER) performance.","PeriodicalId":34270,"journal":{"name":"IEEE Open Journal of Vehicular Technology","volume":"6 ","pages":"240-255"},"PeriodicalIF":5.3,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10787224","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142905783","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-02DOI: 10.1109/OJVT.2024.3509646
Geoffrey Eappen;Jorge Luis Gonzalez;Vibhum Singh;Rakesh Palisetty;Alireza Haqiqtnejad;Liz Martinez Marrero;Jevgenij Krivochiza;Jorge Querol;Nicola Maturo;Juan Carlos Merlano Duncan;Eva Lagunas;Stefano Andrenacci;Symeon Chatzinotas
In this paper, optimal linear precoding for the multibeam geostationary earth orbit (GEO) satellite with the multi-user (MU) multiple-input-multiple-output (MIMO) downlink scenario is addressed. Multiple-user interference is one of the major issues faced by the satellites serving the multiple users operating at the common time-frequency resource block in the downlink channel. To mitigate this issue, the optimal linear precoders are implemented at the gateways (GWs). The precoding computation is performed by utilizing the channel state information obtained at user terminals (UTs). The optimal linear precoders are derived considering beamformer update and power control with an iterative per-antenna power optimization algorithm with a limited required number of iterations. The efficacy of the proposed algorithm is validated using the In-Lab experiment for 16 × 16 precoding with multi-beam satellite for transmitting and receiving the precoded data with digital video broadcasting satellite-second generation extension (DVB-S2X) standard for the GW and the UTs. The software defined radio platforms are employed for emulating the GWs, UTs, and satellite links. The validation is supported by comparing the proposed optimal linear precoder with full frequency reuse (FFR), and minimum mean square error (MMSE) schemes. The experimental results demonstrate that with the optimal linear precoders it is possible to successfully cancel the inter-user interference in the simulated satellite FFR link. Thus, optimal linear precoding brings gains in terms of enhanced signal-to-noise-and-interference ratio, and increased system throughput and spectral efficiency.
{"title":"Optimal Linear Precoding Under Realistic Satellite Communications Scenarios","authors":"Geoffrey Eappen;Jorge Luis Gonzalez;Vibhum Singh;Rakesh Palisetty;Alireza Haqiqtnejad;Liz Martinez Marrero;Jevgenij Krivochiza;Jorge Querol;Nicola Maturo;Juan Carlos Merlano Duncan;Eva Lagunas;Stefano Andrenacci;Symeon Chatzinotas","doi":"10.1109/OJVT.2024.3509646","DOIUrl":"https://doi.org/10.1109/OJVT.2024.3509646","url":null,"abstract":"In this paper, optimal linear precoding for the multibeam geostationary earth orbit (GEO) satellite with the multi-user (MU) multiple-input-multiple-output (MIMO) downlink scenario is addressed. Multiple-user interference is one of the major issues faced by the satellites serving the multiple users operating at the common time-frequency resource block in the downlink channel. To mitigate this issue, the optimal linear precoders are implemented at the gateways (GWs). The precoding computation is performed by utilizing the channel state information obtained at user terminals (UTs). The optimal linear precoders are derived considering beamformer update and power control with an iterative per-antenna power optimization algorithm with a limited required number of iterations. The efficacy of the proposed algorithm is validated using the In-Lab experiment for 16 × 16 precoding with multi-beam satellite for transmitting and receiving the precoded data with digital video broadcasting satellite-second generation extension (DVB-S2X) standard for the GW and the UTs. The software defined radio platforms are employed for emulating the GWs, UTs, and satellite links. The validation is supported by comparing the proposed optimal linear precoder with full frequency reuse (FFR), and minimum mean square error (MMSE) schemes. The experimental results demonstrate that with the optimal linear precoders it is possible to successfully cancel the inter-user interference in the simulated satellite FFR link. Thus, optimal linear precoding brings gains in terms of enhanced signal-to-noise-and-interference ratio, and increased system throughput and spectral efficiency.","PeriodicalId":34270,"journal":{"name":"IEEE Open Journal of Vehicular Technology","volume":"6 ","pages":"81-91"},"PeriodicalIF":5.3,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10772061","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142825893","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-02DOI: 10.1109/OJVT.2024.3509736
Shakil Ahmed;Ahmed E. Kamal;Mohamed Y. Selim;Md Akbar Hossain;Saifur Rahman Sabuj
As the demand for high-speed data transmission grows with the expected emergence of 6G networks and the proliferation of wireless devices, more than traditional wireless infrastructure may be required. Small cell networks (ScNs) integrated with reconfigurable intelligent surfaces (RISs) and multiple-inputmultiple-output (MIMO) have emerged as promising solutions to address this issue. However, ScNs have resource allocation limitations, and traditional RISs can only reflect signals in a limited propagation space of 1800 with fixed reflection properties. This paper proposes a novel approach to overcome these challenges by introducing actively simultaneously transmitting and reflecting (ASTAR)-RISs. Unlike conventional RIS, ASTAR-RISs actively amplify and transmit signals, effectively mitigating the limited propagation challenge and improving signal strength, especially in dense ScNs. This approach enhances the quality of service in complex channel environments by amplifying, on top of reflection, from the macro base station (mBS), improving the overall signal strength, and providing 3600 flexible propagation space. Furthermore, ASTAR-RIS enables dynamic beam management, significantly improving signal coverage and interference management, which are crucial in dense deployments. In this work, we propose a network architecture where distributed ASTAR-RIS units are deployed to assist small cell mBSs by optimizing signal coverage and enhancing communication performance. ASTAR-RISs dynamically control signal reflection and amplification, complementing the functionality of traditional small-cell BSs in dense network environments. Using the MIMO technique, we design phase shifts for ASTAR elements and develop optimal hybrid beamforming for users at the mBS. We dynamically control the ON/OFF status of the ASTAR-RIS based on active or idle status. We propose an efficient model that ensures fairness of signal-to-noise ratio (SNR) for all users and minimizes overall power consumption while meeting user SNR and phase shift constraints. To this end, we integrate robust beamforming and power allocation strategies, ensuring the system maintains reliable performance even under imperfect channel state information (CSI). We formulate a max-min optimization problem that optimizes the SNR and power consumption, subject to the ON/OFF status, phase shift, and power budget of the ASTAR-RIS. Our proposed method uses an alternating optimization algorithm to optimize the phase shift matrix at the ASTAR-RIS and the hybrid beamforming at the mBS. The approach includes two transmission schemes, and the phase optimization problem is solved using a successive convex approximation method that offers a closed-form solution at each step. Additionally, we use the dual method to determine the optimal ON/OFF status of the ASTAR-RIS. Comprehensive simulations validate the robustness and scalability of our proposed solution, particularly under varying network densities and CSI uncertaint
{"title":"Optimizing Small Cell Performance: A New MIMO Paradigm With Distributed ASTAR-RISs","authors":"Shakil Ahmed;Ahmed E. Kamal;Mohamed Y. Selim;Md Akbar Hossain;Saifur Rahman Sabuj","doi":"10.1109/OJVT.2024.3509736","DOIUrl":"https://doi.org/10.1109/OJVT.2024.3509736","url":null,"abstract":"As the demand for high-speed data transmission grows with the expected emergence of 6G networks and the proliferation of wireless devices, more than traditional wireless infrastructure may be required. Small cell networks (ScNs) integrated with reconfigurable intelligent surfaces (RISs) and multiple-inputmultiple-output (MIMO) have emerged as promising solutions to address this issue. However, ScNs have resource allocation limitations, and traditional RISs can only reflect signals in a limited propagation space of 1800 with fixed reflection properties. This paper proposes a novel approach to overcome these challenges by introducing actively simultaneously transmitting and reflecting (ASTAR)-RISs. Unlike conventional RIS, ASTAR-RISs actively amplify and transmit signals, effectively mitigating the limited propagation challenge and improving signal strength, especially in dense ScNs. This approach enhances the quality of service in complex channel environments by amplifying, on top of reflection, from the macro base station (mBS), improving the overall signal strength, and providing 3600 flexible propagation space. Furthermore, ASTAR-RIS enables dynamic beam management, significantly improving signal coverage and interference management, which are crucial in dense deployments. In this work, we propose a network architecture where distributed ASTAR-RIS units are deployed to assist small cell mBSs by optimizing signal coverage and enhancing communication performance. ASTAR-RISs dynamically control signal reflection and amplification, complementing the functionality of traditional small-cell BSs in dense network environments. Using the MIMO technique, we design phase shifts for ASTAR elements and develop optimal hybrid beamforming for users at the mBS. We dynamically control the ON/OFF status of the ASTAR-RIS based on active or idle status. We propose an efficient model that ensures fairness of signal-to-noise ratio (SNR) for all users and minimizes overall power consumption while meeting user SNR and phase shift constraints. To this end, we integrate robust beamforming and power allocation strategies, ensuring the system maintains reliable performance even under imperfect channel state information (CSI). We formulate a max-min optimization problem that optimizes the SNR and power consumption, subject to the ON/OFF status, phase shift, and power budget of the ASTAR-RIS. Our proposed method uses an alternating optimization algorithm to optimize the phase shift matrix at the ASTAR-RIS and the hybrid beamforming at the mBS. The approach includes two transmission schemes, and the phase optimization problem is solved using a successive convex approximation method that offers a closed-form solution at each step. Additionally, we use the dual method to determine the optimal ON/OFF status of the ASTAR-RIS. Comprehensive simulations validate the robustness and scalability of our proposed solution, particularly under varying network densities and CSI uncertaint","PeriodicalId":34270,"journal":{"name":"IEEE Open Journal of Vehicular Technology","volume":"6 ","pages":"128-144"},"PeriodicalIF":5.3,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10772072","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142859068","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-02DOI: 10.1109/OJVT.2024.3509686
Afaq Ahmed;Iftikhar Ahmad;Habibur Rehman;Ammar Hasan
This paper proposes a conditioned adaptive barrier function-based integral super-twisting sliding mode controller for the hybrid energy storage system (HESS) with a field-oriented control of 3-phase induction motor for the electric vehicles (EVs). The conditioned approach ensures that the control input stays within bounds, the adaptive barrier adjusts the sliding mode controller (SMC) gains, and the super-twisting technique helps in reducing the chattering. Consequently, the overall system performance is improved. The HESS consists of a fuel cell, battery, and super-capacitor. A rule-based energy management system has been designed, defining different modes of operation for an efficient use of energy sources under different loading conditions. The designed energy management system accounts for the power inflow and the status of the energy sources. The proposed controller ensures smooth energy sources current tracking and stabilizes the DC bus voltage while controlling the motor speed and flux under various operating conditions. The controller's global asymptotic stability has been verified through Lyapunov stability analysis. Intensive computer simulations using Matlab/Simulink are performed to validate the proposed controller's performance and compare it with the conventional PI and SMC controllers. Finally, controller hardware-in-the-loop validation has been conducted for the real-time performance validation.
{"title":"Conditioned Adaptive Barrier Function Based Integral Super-Twisting Sliding Mode Control for Electric Vehicles With Hybrid Energy Storage System","authors":"Afaq Ahmed;Iftikhar Ahmad;Habibur Rehman;Ammar Hasan","doi":"10.1109/OJVT.2024.3509686","DOIUrl":"https://doi.org/10.1109/OJVT.2024.3509686","url":null,"abstract":"This paper proposes a conditioned adaptive barrier function-based integral super-twisting sliding mode controller for the hybrid energy storage system (HESS) with a field-oriented control of 3-phase induction motor for the electric vehicles (EVs). The conditioned approach ensures that the control input stays within bounds, the adaptive barrier adjusts the sliding mode controller (SMC) gains, and the super-twisting technique helps in reducing the chattering. Consequently, the overall system performance is improved. The HESS consists of a fuel cell, battery, and super-capacitor. A rule-based energy management system has been designed, defining different modes of operation for an efficient use of energy sources under different loading conditions. The designed energy management system accounts for the power inflow and the status of the energy sources. The proposed controller ensures smooth energy sources current tracking and stabilizes the DC bus voltage while controlling the motor speed and flux under various operating conditions. The controller's global asymptotic stability has been verified through Lyapunov stability analysis. Intensive computer simulations using Matlab/Simulink are performed to validate the proposed controller's performance and compare it with the conventional PI and SMC controllers. Finally, controller hardware-in-the-loop validation has been conducted for the real-time performance validation.","PeriodicalId":34270,"journal":{"name":"IEEE Open Journal of Vehicular Technology","volume":"6 ","pages":"92-108"},"PeriodicalIF":5.3,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10772067","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142844588","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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