Pub Date : 2024-10-22DOI: 10.1016/j.phycom.2024.102529
zhaoxia Zhou , yixuan Lu , jingbo Xia
In order to overcome the disadvantages of single sensor localization in complex indoor environments, this paper proposes a design scheme for the ultra-wide band (UWB) and LiDAR co-location fusion system. To attain the ideal positioning effect of this system, a segmented point fusion approach based on Euclid's theorem is put forward to optimize the conventional extended Kalman filter and unscented Kalman filter algorithms. It can effectively reduce the positioning error of UWB in non-line-of-sight environments and under the multipath effect, and also assist LiDAR in correcting trajectory drift in sparsely textured scenes. Through both simulations and experiments, the feasibility of the proposed algorithm in the UWB/LiDAR positioning system is verified. The results reveal that the positioning error of the enhanced multi-sensor fusion algorithm is reduced by 22% compared with the original algorithm and 25.7% compared with the single sensor positioning method.
{"title":"Research on the fusion positioning system of UWB/LiDAR based on the algorithm of SPF and KF","authors":"zhaoxia Zhou , yixuan Lu , jingbo Xia","doi":"10.1016/j.phycom.2024.102529","DOIUrl":"10.1016/j.phycom.2024.102529","url":null,"abstract":"<div><div>In order to overcome the disadvantages of single sensor localization in complex indoor environments, this paper proposes a design scheme for the ultra-wide band (UWB) and LiDAR co-location fusion system. To attain the ideal positioning effect of this system, a segmented point fusion approach based on Euclid's theorem is put forward to optimize the conventional extended Kalman filter and unscented Kalman filter algorithms. It can effectively reduce the positioning error of UWB in non-line-of-sight environments and under the multipath effect, and also assist LiDAR in correcting trajectory drift in sparsely textured scenes. Through both simulations and experiments, the feasibility of the proposed algorithm in the UWB/LiDAR positioning system is verified. The results reveal that the positioning error of the enhanced multi-sensor fusion algorithm is reduced by 22% compared with the original algorithm and 25.7% compared with the single sensor positioning method.</div></div>","PeriodicalId":48707,"journal":{"name":"Physical Communication","volume":"67 ","pages":"Article 102529"},"PeriodicalIF":2.0,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142560987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-10-21DOI: 10.1016/j.phycom.2024.102527
Rashmi H, Ashvini Chaturvedi, John D’Souza
Simultaneously Transmitting and Reflecting (STAR) Reconfigurable Intelligent Surface (RIS) demonstrates the ability to split incoming electromagnetic beams to transmit and reflect signals in a concurrent manner. Thus, compared to conventional RIS, service area coverage is extended on deploying STAR-RIS. This paper presents a geometry-based stochastic channel model (GBSM) of STAR-RIS-assisted outdoor wireless channel. For the considered semi-urban environment, STAR-RIS operates in energy-splitting mode. Channel between a base station (BS) and users located on the reflect/transmit (R/T) side of STAR-RIS is characterised using a GBSM. An elliptical model incorporates the inevitable presence of scatterers in the considered semi-urban segment. Statistical properties of the wireless channel under test are analysed using space–time cross-correlation function (ST-CCF) and temporal auto-correlation function (ACF). Further, to gain holistic insight about the wireless channel behaviour, normalised Doppler power spectral density (ND-PSD) is estimated for semi-urban segment having three distinct underlying hypothesis as: (i) Wireless channel is governed by Rayleigh fading model, (ii) Wireless Channel is equipped with conventional RIS and (iii) STAR-RIS is an integral part of the considered wireless channel. Simulation results confirm that STAR-RIS performs at par with RIS, however, facilitating an additional degree of coverage. It is observed that temporal ACF and ST-CCF improves with an increase in the number of elements in STAR-RIS.
{"title":"Geometry-based stochastic channel modeling of a semi-urban environment using simultaneously transmitting and reflecting reconfigurable intelligentsurface","authors":"Rashmi H, Ashvini Chaturvedi, John D’Souza","doi":"10.1016/j.phycom.2024.102527","DOIUrl":"10.1016/j.phycom.2024.102527","url":null,"abstract":"<div><div>Simultaneously Transmitting and Reflecting (STAR) Reconfigurable Intelligent Surface (RIS) demonstrates the ability to split incoming electromagnetic beams to transmit and reflect signals in a concurrent manner. Thus, compared to conventional RIS, service area coverage is extended on deploying STAR-RIS. This paper presents a geometry-based stochastic channel model (GBSM) of STAR-RIS-assisted outdoor wireless channel. For the considered semi-urban environment, STAR-RIS operates in energy-splitting mode. Channel between a base station (BS) and users <span><math><mrow><mo>(</mo><msub><mrow><mtext>U</mtext></mrow><mrow><mtext>R</mtext></mrow></msub><mo>/</mo><msub><mrow><mtext>U</mtext></mrow><mrow><mtext>T</mtext></mrow></msub><mo>)</mo></mrow></math></span> located on the reflect/transmit (R/T) side of STAR-RIS is characterised using a GBSM. An elliptical model incorporates the inevitable presence of scatterers in the considered semi-urban segment. Statistical properties of the wireless channel under test are analysed using space–time cross-correlation function (ST-CCF) and temporal auto-correlation function (ACF). Further, to gain holistic insight about the wireless channel behaviour, normalised Doppler power spectral density (ND-PSD) is estimated for semi-urban segment having three distinct underlying hypothesis as: (i) Wireless channel is governed by Rayleigh fading model, (ii) Wireless Channel is equipped with conventional RIS and (iii) STAR-RIS is an integral part of the considered wireless channel. Simulation results confirm that STAR-RIS performs at par with RIS, however, facilitating an additional degree of coverage. It is observed that temporal ACF and ST-CCF improves with an increase in the number of elements in STAR-RIS.</div></div>","PeriodicalId":48707,"journal":{"name":"Physical Communication","volume":"67 ","pages":"Article 102527"},"PeriodicalIF":2.0,"publicationDate":"2024-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-10-19DOI: 10.1016/j.phycom.2024.102528
Hager S. Fouda, Samar I. Farghaly, Heba S. Dawood
In this paper, a blind centralized cooperative spectrum sensing (CSS) with soft decision fusion is considered. The fusion center (FC) constructs the energy vector from the collaborating secondary nodes. The energy feature is assumed to be an efficient measure, as it is widely used and directly correlates with the strength of the received signal. The K-means clustering algorithm is employed to extract descriptive statistical features about the distributions of the absence and presence of the primary user (PU) signal, such as the mean and non-centrality parameter. In the framework of this statistical analysis, the signal-to-noise ratio (SNR) at each node is easily estimated and examined. Equal, selective, and weighted combining techniques are applied to develop three joint likelihood ratio test (JLRT)-based algorithms. These algorithms are implemented in the context of simple hypothesis testing, where the distribution of the data is fully specified. Furthermore, they are justified by the Neyman-Pearson theorem, which constructs the most powerful test for a given significance level. The proposed selective and weighted JLRT approaches are based on the estimated SNRs at each sensor, reflecting their reliability. Several comparison scenarios between the proposed algorithms, K-means, fuzzy c-means (FCM), and OR-rule are simulated over Rayleigh fading channel with low average SNR and few samples. The simulation results reveal that the proposed tests outperform other CSS techniques. Additionally, asymptotic theoretical expressions for probability of detection and the probability of false alarm are derived, which show high agreement with the simulated results.
{"title":"Weighted joint LRTs for cooperative spectrum sensing using K-means clustering","authors":"Hager S. Fouda, Samar I. Farghaly, Heba S. Dawood","doi":"10.1016/j.phycom.2024.102528","DOIUrl":"10.1016/j.phycom.2024.102528","url":null,"abstract":"<div><div>In this paper, a blind centralized cooperative spectrum sensing (CSS) with soft decision fusion is considered. The fusion center (FC) constructs the energy vector from the collaborating secondary nodes. The energy feature is assumed to be an efficient measure, as it is widely used and directly correlates with the strength of the received signal. The K-means clustering algorithm is employed to extract descriptive statistical features about the distributions of the absence and presence of the primary user (PU) signal, such as the mean and non-centrality parameter. In the framework of this statistical analysis, the signal-to-noise ratio (SNR) at each node is easily estimated and examined. Equal, selective, and weighted combining techniques are applied to develop three joint likelihood ratio test (JLRT)-based algorithms. These algorithms are implemented in the context of simple hypothesis testing, where the distribution of the data is fully specified. Furthermore, they are justified by the Neyman-Pearson theorem, which constructs the most powerful test for a given significance level. The proposed selective and weighted JLRT approaches are based on the estimated SNRs at each sensor, reflecting their reliability. Several comparison scenarios between the proposed algorithms, K-means, fuzzy c-means (FCM), and OR-rule are simulated over Rayleigh fading channel with low average SNR and few samples. The simulation results reveal that the proposed tests outperform other CSS techniques. Additionally, asymptotic theoretical expressions for probability of detection and the probability of false alarm are derived, which show high agreement with the simulated results.</div></div>","PeriodicalId":48707,"journal":{"name":"Physical Communication","volume":"67 ","pages":"Article 102528"},"PeriodicalIF":2.0,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142572016","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-10-19DOI: 10.1016/j.phycom.2024.102519
Rana Sedghi, Masoumeh Azghani
Recently, the emerging intelligent reflecting surfaces (IRS) has been leveraged to establish a smart and controllable wireless environment. This paper addresses the challenge of maximizing spectral efficiency in an IRS-aided downlink multi-user system while facing jammer attacks. The optimization problem focuses on improving the available transmission rate and limiting the impact of malicious jammer signals. The efficiency of the IRS in anti-jamming communications is achieved by determining the optimal phase shifts of the IRS elements and the optimal beamforming at the base station (BS). The optimization problem is non-convex. To tackle this non-convexity, an alternating optimization algorithm is proposed, dividing the main problem into two sub-problems which are solved using the semi-definite relaxation (SDR) and Gaussian randomization techniques. The simulation results confirm the enhanced spectral efficiency achieved by the proposed anti-jamming method in an IRS-assisted system. The optimal adjustment of the phase shifts in the IRS elements has resulted in a significant enhancement of about 25% in spectral efficiency compared to the random IRS phase case.
{"title":"IRS assisted anti jamming and beamforming technique","authors":"Rana Sedghi, Masoumeh Azghani","doi":"10.1016/j.phycom.2024.102519","DOIUrl":"10.1016/j.phycom.2024.102519","url":null,"abstract":"<div><div>Recently, the emerging intelligent reflecting surfaces (IRS) has been leveraged to establish a smart and controllable wireless environment. This paper addresses the challenge of maximizing spectral efficiency in an IRS-aided downlink multi-user system while facing jammer attacks. The optimization problem focuses on improving the available transmission rate and limiting the impact of malicious jammer signals. The efficiency of the IRS in anti-jamming communications is achieved by determining the optimal phase shifts of the IRS elements and the optimal beamforming at the base station (BS). The optimization problem is non-convex. To tackle this non-convexity, an alternating optimization algorithm is proposed, dividing the main problem into two sub-problems which are solved using the semi-definite relaxation (SDR) and Gaussian randomization techniques. The simulation results confirm the enhanced spectral efficiency achieved by the proposed anti-jamming method in an IRS-assisted system. The optimal adjustment of the phase shifts in the IRS elements has resulted in a significant enhancement of about 25% in spectral efficiency compared to the random IRS phase case.</div></div>","PeriodicalId":48707,"journal":{"name":"Physical Communication","volume":"67 ","pages":"Article 102519"},"PeriodicalIF":2.0,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529652","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-10-19DOI: 10.1016/j.phycom.2024.102525
Bin Zheng , Yin-Chang Yu , Jin-Yuan Wang , Changfeng Ding
Unlike terrestrial handover schemes, the handover schemes in 5G satellite–terrestrial integrated network (STIN) face several challenges, such as large propagation delay, complex channel environment, and fast satellite movement. Therefore, the handover schemes designed in the 5G terrestrial network is not suitable for the 5G STIN. In view of this, this paper considers the inter-beam handover problem for the 5G STIN with a low earth orbit satellite and a ground user. We establish the satellite channel model, which includes path loss, rain attenuation, and multi-beam antenna gain. To model the mobile feature of the user, we consider a two-dimensional random walk model. Then, we propose A5 event-based conditional handover (CHO) scheme, time factor-based CHO scheme, and load factor-based CHO scheme to achieve efficient inter-beam handover. Considering that there may be multiple beams that meet the triggering condition in each handover scheme, we also propose three kinds of beam selection schemes, namely random beam selection scheme, maximum power-based beam selection scheme, and minimum distance-based beam selection scheme. To evaluate the performance of the proposed handover schemes, key performance indicators, such as handover frequency, ping-pong handover rate, unnecessary handover rate, handover failure rate, and average transmission rate are analyzed. Simulation results verify the superiority of the proposed handover schemes by comparing them with the benchmark scheme.
{"title":"Inter-beam handover schemes for LEO satellites in 5G satellite–terrestrial integrated networks","authors":"Bin Zheng , Yin-Chang Yu , Jin-Yuan Wang , Changfeng Ding","doi":"10.1016/j.phycom.2024.102525","DOIUrl":"10.1016/j.phycom.2024.102525","url":null,"abstract":"<div><div>Unlike terrestrial handover schemes, the handover schemes in 5G satellite–terrestrial integrated network (STIN) face several challenges, such as large propagation delay, complex channel environment, and fast satellite movement. Therefore, the handover schemes designed in the 5G terrestrial network is not suitable for the 5G STIN. In view of this, this paper considers the inter-beam handover problem for the 5G STIN with a low earth orbit satellite and a ground user. We establish the satellite channel model, which includes path loss, rain attenuation, and multi-beam antenna gain. To model the mobile feature of the user, we consider a two-dimensional random walk model. Then, we propose A5 event-based conditional handover (CHO) scheme, time factor-based CHO scheme, and load factor-based CHO scheme to achieve efficient inter-beam handover. Considering that there may be multiple beams that meet the triggering condition in each handover scheme, we also propose three kinds of beam selection schemes, namely random beam selection scheme, maximum power-based beam selection scheme, and minimum distance-based beam selection scheme. To evaluate the performance of the proposed handover schemes, key performance indicators, such as handover frequency, ping-pong handover rate, unnecessary handover rate, handover failure rate, and average transmission rate are analyzed. Simulation results verify the superiority of the proposed handover schemes by comparing them with the benchmark scheme.</div></div>","PeriodicalId":48707,"journal":{"name":"Physical Communication","volume":"67 ","pages":"Article 102525"},"PeriodicalIF":2.0,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529653","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-10-19DOI: 10.1016/j.phycom.2024.102517
Yanshou Wang
{"title":"Retraction notice to \"Contactless human activity and sport action Identification based on UHF RFID Tag Wall and AI\"","authors":"Yanshou Wang","doi":"10.1016/j.phycom.2024.102517","DOIUrl":"10.1016/j.phycom.2024.102517","url":null,"abstract":"","PeriodicalId":48707,"journal":{"name":"Physical Communication","volume":"67 ","pages":"Article 102517"},"PeriodicalIF":2.0,"publicationDate":"2024-10-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142528681","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-10-18DOI: 10.1016/j.phycom.2024.102512
Zhoujie You , Wei Duan , Yan Jiang , Xiaohui Gu , Guoan Zhang
This paper studies the physical layer security (PLS) of a rate-splitting multiple access (RSMA) system over Nakagami-m fading channels. Unlike existing works, we focus on the eavesdropper (Eve) perspective, considering both passive and active jamming scenarios due to the uncertainty of Eve behavior. For a fair comparison, we introduce the concept of effective power (EP) for the overall PLS-RSMA system. In the passive eavesdropping case, EP is equivalent to the transmit power at the base station (BS), whereas in the active jamming case, EP is defined as the power gap between the BS and Eve. Considering the effects on the EP and Eve location, closed-form expressions of the security outage probability (SOP) are respectively derived for both considered scenarios. Simulation results corroborate our analysis, indicating that when EP is lower or Eve is farther from the BS, the probability of Eve attacking legitimate users is higher. On the contrary, a closer Eve tends to wiretap information directly from the BS. These findings provide valuable insights for predicting and implementing effective protection mechanisms for the PLS-RSMA system.
本文研究了中上衰减信道上速率分割多路访问（RSMA）系统的物理层安全性（PLS）。与现有研究不同的是，由于夏娃行为的不确定性，我们将重点放在窃听者（夏娃）的角度，同时考虑被动和主动干扰场景。为了进行公平比较，我们为整个 PLS-RSMA 系统引入了有效功率 (EP) 的概念。在被动窃听情况下，EP 相当于基站 (BS) 的发射功率，而在主动干扰情况下，EP 被定义为 BS 与夏娃之间的功率差距。考虑到对 EP 和夏娃位置的影响，分别得出了两种情况下安全中断概率 (SOP) 的闭式表达式。仿真结果证实了我们的分析，表明当 EP 较低或 Eve 离 BS 较远时，Eve 攻击合法用户的概率较高。相反，距离较近的夏娃倾向于直接从 BS 窃听信息。这些发现为预测和实施 PLS-RSMA 系统的有效保护机制提供了宝贵的见解。
{"title":"PLS-RSMA system: An eavesdropping perspective","authors":"Zhoujie You , Wei Duan , Yan Jiang , Xiaohui Gu , Guoan Zhang","doi":"10.1016/j.phycom.2024.102512","DOIUrl":"10.1016/j.phycom.2024.102512","url":null,"abstract":"<div><div>This paper studies the physical layer security (PLS) of a rate-splitting multiple access (RSMA) system over Nakagami-<em>m</em> fading channels. Unlike existing works, we focus on the eavesdropper (Eve) perspective, considering both passive and active jamming scenarios due to the uncertainty of Eve behavior. For a fair comparison, we introduce the concept of effective power (EP) for the overall PLS-RSMA system. In the passive eavesdropping case, EP is equivalent to the transmit power at the base station (BS), whereas in the active jamming case, EP is defined as the power gap between the BS and Eve. Considering the effects on the EP and Eve location, closed-form expressions of the security outage probability (SOP) are respectively derived for both considered scenarios. Simulation results corroborate our analysis, indicating that when EP is lower or Eve is farther from the BS, the probability of Eve attacking legitimate users is higher. On the contrary, a closer Eve tends to wiretap information directly from the BS. These findings provide valuable insights for predicting and implementing effective protection mechanisms for the PLS-RSMA system.</div></div>","PeriodicalId":48707,"journal":{"name":"Physical Communication","volume":"67 ","pages":"Article 102512"},"PeriodicalIF":2.0,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529651","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-10-18DOI: 10.1016/j.phycom.2024.102524
M.A. Amirabadi , S.A. Nezamalhosseini
Visible Light Communication (VLC) offers a promising solution for future networks, leveraging existing lighting infrastructure in indoor environments. However, VLC requires a direct line of sight to function which can be limiting. Reconfigurable Intelligent Surface (RIS) is a new technology that can bend light and radio waves, addressing this limitation in VLC. RIS come in three types: passive which reflects signals, active that boosts and reflects signals, and Simultaneous Transmission and Reflection (STAR)-RIS which can both reflect and transmit signals simultaneously. STAR-RIS offers the most control over the signal. In this paper, we propose a new multi-user VLC system with a massive Multiple-Input, Multiple-Output Orthogonal Frequency-Division Multiplexing (MIMO-OFDM) architecture, leveraging STAR-RIS to optimize data rates and improve coverage, particularly in non-line-of-sight scenarios. We formulate a system model and solve a convex optimization problem to determine the optimal transmission and reflection coefficients for STAR-RIS elements, aiming to maximize the total sum rate for all users. By employing maximum ratio transmission precoding, we minimize interference among users and demonstrate significant performance gains. Simulation results show that our proposed energy splitting-based STAR-RIS configuration outperforms traditional mode selection and time switching approaches with fixed or random coefficients, yielding substantial improvements in data rates and user experience. This study offers the first detailed exploration of STAR-RIS in VLC systems, highlighting its potential for future high-speed, multi-user communication networks. Our findings set the stage for further research into optimizing VLC systems using STAR-RIS, particularly in complex environments with non-line-of-sight users and massive MIMO-OFDM configurations.
{"title":"Sum rate optimization in STAR-RIS assisted multiuser massive MIMO-OFDM VLC systems","authors":"M.A. Amirabadi , S.A. Nezamalhosseini","doi":"10.1016/j.phycom.2024.102524","DOIUrl":"10.1016/j.phycom.2024.102524","url":null,"abstract":"<div><div>Visible Light Communication (VLC) offers a promising solution for future networks, leveraging existing lighting infrastructure in indoor environments. However, VLC requires a direct line of sight to function which can be limiting. Reconfigurable Intelligent Surface (RIS) is a new technology that can bend light and radio waves, addressing this limitation in VLC. RIS come in three types: passive which reflects signals, active that boosts and reflects signals, and Simultaneous Transmission and Reflection (STAR)-RIS which can both reflect and transmit signals simultaneously. STAR-RIS offers the most control over the signal. In this paper, we propose a new multi-user VLC system with a massive Multiple-Input, Multiple-Output Orthogonal Frequency-Division Multiplexing (MIMO-OFDM) architecture, leveraging STAR-RIS to optimize data rates and improve coverage, particularly in non-line-of-sight scenarios. We formulate a system model and solve a convex optimization problem to determine the optimal transmission and reflection coefficients for STAR-RIS elements, aiming to maximize the total sum rate for all users. By employing maximum ratio transmission precoding, we minimize interference among users and demonstrate significant performance gains. Simulation results show that our proposed energy splitting-based STAR-RIS configuration outperforms traditional mode selection and time switching approaches with fixed or random coefficients, yielding substantial improvements in data rates and user experience. This study offers the first detailed exploration of STAR-RIS in VLC systems, highlighting its potential for future high-speed, multi-user communication networks. Our findings set the stage for further research into optimizing VLC systems using STAR-RIS, particularly in complex environments with non-line-of-sight users and massive MIMO-OFDM configurations.</div></div>","PeriodicalId":48707,"journal":{"name":"Physical Communication","volume":"67 ","pages":"Article 102524"},"PeriodicalIF":2.0,"publicationDate":"2024-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-10-17DOI: 10.1016/j.phycom.2024.102522
Hui Chen , Yuhui Zhou , Shufen Chen , Xilai Wang , Peiqing Guo , Gaojian Huang , Xingwang Li
Different from linear arrays that can resolve only one angular component, two-dimensional (2-D) array patterns enable to remove the cone of uncertainty and right/left ambiguities generated in a linear array. Motivated by this, a novel structure of 2-D time-modulated planar arrays (TMPAs) is developed to synthesize directional modulation (DM) symbols in this paper. The proposed 2-D TMPA DM transmitter can synthesize multicarrier DM symbols with suppressing the mirror harmonic frequencies and provide a higher power efficiency. This is demonstrated by way of simulations of a multi-beam 8*8 element planar antenna array and its security performance is shown via the bit error rate (BER) metric.
{"title":"Time-modulated planar arrays enabled directional modulation symbol synthesis","authors":"Hui Chen , Yuhui Zhou , Shufen Chen , Xilai Wang , Peiqing Guo , Gaojian Huang , Xingwang Li","doi":"10.1016/j.phycom.2024.102522","DOIUrl":"10.1016/j.phycom.2024.102522","url":null,"abstract":"<div><div>Different from linear arrays that can resolve only one angular component, two-dimensional (2-D) array patterns enable to remove the cone of uncertainty and right/left ambiguities generated in a linear array. Motivated by this, a novel structure of 2-D time-modulated planar arrays (TMPAs) is developed to synthesize directional modulation (DM) symbols in this paper. The proposed 2-D TMPA DM transmitter can synthesize multicarrier DM symbols with suppressing the mirror harmonic frequencies and provide a higher power efficiency. This is demonstrated by way of simulations of a multi-beam 8*8 element planar antenna array and its security performance is shown via the bit error rate (BER) metric.</div></div>","PeriodicalId":48707,"journal":{"name":"Physical Communication","volume":"67 ","pages":"Article 102522"},"PeriodicalIF":2.0,"publicationDate":"2024-10-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142529649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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 : 2024-10-17DOI: 10.1016/j.phycom.2024.102523
Sen Wang , Baowang Lian , Musen Liu , Junyao Zhang , Varun G. Menon , Xingwang Li
In this work, we delve into the covertness performance of the reconfigurable intelligent surface (RIS) symbiotic ambient backscatter communication (AmBC) systems, where the RIS is partitioned into two zones to serve covert and public users. To impede with the monitor’s detection, the source deliberately transmits both information and interference signals. Specifically, we derive closed-form expressions for the detection error probability (DEP) and outage probabilities. Subsequently, the effective covert rate (ECR) is maximized by optimizing the power allocation factor and the number of each zone reflective elements. Finally, we investigate the energy efficiency (EE) of the considered system. Simulation results validate the accuracy of the analysis, underscoring that the RIS-segmented symbiotic AmBC systems can achieve better covertness by improving the interference cancellation capability and dividing the optimal RIS zones.
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