Physical Communication最新文献_第10页

Adaptive access strategy for satellite-terrestrial optical networks based on particle swarm optimization algorithm

IF 2 4区计算机科学

Physical Communication Pub Date : 2025-01-03 DOI: 10.1016/j.phycom.2025.102600

Pengzhen Guo , Zixu Zhao , Yeqi Zhang , Qingbo Yang , Lifang Li , Liying Tan , Jing Ma

{"title":"Adaptive access strategy for satellite-terrestrial optical networks based on particle swarm optimization algorithm","authors":"Pengzhen Guo , Zixu Zhao , Yeqi Zhang , Qingbo Yang , Lifang Li , Liying Tan , Jing Ma","doi":"10.1016/j.phycom.2025.102600","DOIUrl":"10.1016/j.phycom.2025.102600","url":null,"abstract":"<div><div>Satellite-to-terrestrial laser communications offer high bandwidth and security, making the integration of satellites and terrestrial infrastructure into a high-speed communications network critical. In satellite-terrestrial optical networks (STON), frequent link handovers necessitate an efficient access process to establish high-capacity and reliable laser links. We propose a novel and efficient optical network satellite adaptive access (ONSAA) strategy to reduce satellite access frequency while enhancing network capacity. For the first time, this strategy integrates the unique Pointing, Acquisition, and Tracking (PAT) process of satellite laser communication. The satellite access process is divided into two parts: satellite selection and the PAT process. Optimizing these two components independently can improve overall network performance. To optimize satellite selection, We apply a particle swarm optimization (PSO) algorithm, which effectively balances the capacity and dynamics of STON. Additionally, we propose a multi-scans method for the PAT process to increase satellite access success rates, thereby reducing the frequency of access requests. This method also minimizes docking delay, which in turn extends the link transmission time for successful connections between the optical ground station (OGS) and the satellite network. Docking delay refers to the time required to successfully access the satellite. Simulation results demonstrate that this strategy reduces the number of accesses and enhancing network capacity, while the optimized PAT process ensure fast and reliable connections presenting a promising solution for future STON applications.</div></div>","PeriodicalId":48707,"journal":{"name":"Physical Communication","volume":"69 ","pages":"Article 102600"},"PeriodicalIF":2.0,"publicationDate":"2025-01-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143105023","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}

引用次数: 0

Channel estimation and symbol detection for AFDM over doubly selective fading channels

IF 2 4区计算机科学

Physical Communication Pub Date : 2025-01-02 DOI: 10.1016/j.phycom.2024.102597

Pengfei Huang , Qiang Li , Dong Huang , Junfeng Wang

{"title":"Channel estimation and symbol detection for AFDM over doubly selective fading channels","authors":"Pengfei Huang , Qiang Li , Dong Huang , Junfeng Wang","doi":"10.1016/j.phycom.2024.102597","DOIUrl":"10.1016/j.phycom.2024.102597","url":null,"abstract":"<div><div>In this paper, two receiver designs, each incorporating channel estimation and symbol detection, are presented for affine frequency division multiplexing (AFDM) over doubly selective fading channels. The first design unlocks the potential of deep learning in AFDM receivers. We first construct deep neural networks (DNNs), then train them offline by using training data, and finally deploy them online at the receiver to output transmitted information bits. This DNN receiver fails to achieve satisfactory bit error rate (BER) performance when there is no guard interval (GI) between the pilot and data. To solve this problem, we design a GI-free iterative AFDM receiver, which first performs coarse channel estimation and symbol detection, then implements interference cancellation by using the detected symbols, and finally proceeds channel estimation, symbol detection, and interference cancellation in an iterative manner until reaching a stop criterion. Moreover, a performance-enhancing method is proposed for the GI-free iterative AFDM receiver. In this enhanced scheme, the data interfered by the pilot is estimated by maximum-likelihood detection. Simulation results show that the DNN receiver is more robust than the existing scheme in the presence of pilot-data interference, and the performance-enhancing GI-free iterative receiver demonstrates excellent BER performance, achieving a gap of less than 0.5 dB compared to the scenario of perfect channel estimation, at a BER level of <span><math><mrow><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mo>−</mo><mn>3</mn></mrow></msup></mrow></math></span>.</div></div>","PeriodicalId":48707,"journal":{"name":"Physical Communication","volume":"69 ","pages":"Article 102597"},"PeriodicalIF":2.0,"publicationDate":"2025-01-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143105021","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}

引用次数: 0

SCMA-Q-learning with overload control for random access in LEO satellite mMTC networks

IF 2 4区计算机科学

Physical Communication Pub Date : 2024-12-31 DOI: 10.1016/j.phycom.2024.102584

Zeyu Wu , Guoliang Jing , Jie Ding , Xu Zhao

引用次数: 0

Optical true time delay based hybrid beamforming for RIS-aided mmWave multi-user MISO systems

IF 2 4区计算机科学

Physical Communication Pub Date : 2024-12-30 DOI: 10.1016/j.phycom.2024.102596

Huan Huang , Jun Li , Yitian Wang , Ran Zhou , Chongfu Zhang

{"title":"Optical true time delay based hybrid beamforming for RIS-aided mmWave multi-user MISO systems","authors":"Huan Huang , Jun Li , Yitian Wang , Ran Zhou , Chongfu Zhang","doi":"10.1016/j.phycom.2024.102596","DOIUrl":"10.1016/j.phycom.2024.102596","url":null,"abstract":"<div><div>Reconfigurable intelligent surfaces (RISs) have emerged as a promising wireless technology for the 6th generation (6G) wireless systems. Herein, we investigate the joint passive- and hybrid- beamforming (JPHBF) optimization problem in RIS-aided millimeter-wave (mmWave) multi-user MISO (MU-MISO) systems. Furthermore, we introduced codebooks into analog- and passive- beamforming design for low training and feedback overheads. We proposed optical true time delay (OTTD)-based sub-connected hybrid beamforming (SC-HBF) with a low hardware cost and low channel estimation overheads. Compared to the traditional SC-HBF implementation, only about half of the optical true time delay pool based phase control units (OTTDP-PCUs) are required. We design the codebook-based passive- and analog- beamforming (PABF) under the constraints improved by the use of about half of the OTTDP-PCUs and the passive nature of RISs. The results show that the use of multiple RISs significantly improves the sum rate, specifically an improvement of approximately 284.5% at 25 dBm total transmit power. Although only about half of the OTTDP-PCUs are used, the proposed OTTD-based SC-HBF achieves near-optimal sum rates. Moreover, we presented a design example of the optical wavelength matrix used to map the OTTDP-PCUs.</div></div>","PeriodicalId":48707,"journal":{"name":"Physical Communication","volume":"69 ","pages":"Article 102596"},"PeriodicalIF":2.0,"publicationDate":"2024-12-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143105022","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"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}

引用次数: 0

Knowledge graph enhanced recommendation for semantic structure construction and feedback in online learning

IF 2 4区计算机科学

Physical Communication Pub Date : 2024-12-28 DOI: 10.1016/j.phycom.2024.102590

Wei Wu, Shuangqi Yang, Feng Tian, Xin Wei, Yagang Pan

引用次数: 0

Secrecy performance of RIS-assisted wireless-powered systems with artificial-jamming generation

IF 2 4区计算机科学

Physical Communication Pub Date : 2024-12-27 DOI: 10.1016/j.phycom.2024.102592

Vo Ta Ty , Pham Ngoc Son , Tran Trung Duy

{"title":"Secrecy performance of RIS-assisted wireless-powered systems with artificial-jamming generation","authors":"Vo Ta Ty , Pham Ngoc Son , Tran Trung Duy","doi":"10.1016/j.phycom.2024.102592","DOIUrl":"10.1016/j.phycom.2024.102592","url":null,"abstract":"<div><div>This paper proposes a reconfigurable intelligent surface (RIS)-aided communication systems, where energy harvesting (EH) and artificial jamming techniques are used. In the proposed system, a source harvests energy from a base station, and uses the harvested energy to send data to a destination via the RIS, under presence of an eavesdropper. A jammer is employed to generate noises on the eavesdropper. For performance evaluation, we derive expressions of outage probability (OP), intercept probability (IP), average secrecy capacity (ASC) and secrecy outage probability (SOP) for the proposed system under Rayleigh fading environment. Simulation results are provided to confirm the accuracy of the analytical expressions. We also evaluate the performance of a corresponding system without using the jammer. The results show that the proposed system obtains much better performance than the non-jammer one. Moreover, the performance of the proposed system can be enhanced by increasing the number of reflecting elements at the RIS, increasing the transmit power of the source and jammer nodes, and optimizing the fraction of time allocated for the EH phase. On the contrary, IP of the non-jammer system is very high, and its ASC and SOP performance converge to saturation points at high signal-to-noise ratio (SNR) levels.</div></div>","PeriodicalId":48707,"journal":{"name":"Physical Communication","volume":"69 ","pages":"Article 102592"},"PeriodicalIF":2.0,"publicationDate":"2024-12-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143105339","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}

引用次数: 0

Aperture selection approaches for robust NLOS-UV communication in turbulent channels

IF 2 4区计算机科学

Physical Communication Pub Date : 2024-12-24 DOI: 10.1016/j.phycom.2024.102593

Sayed Hasan Hariq , Niyazi Odabaşıoğlu , Bahattin Karakaya

{"title":"Aperture selection approaches for robust NLOS-UV communication in turbulent channels","authors":"Sayed Hasan Hariq , Niyazi Odabaşıoğlu , Bahattin Karakaya","doi":"10.1016/j.phycom.2024.102593","DOIUrl":"10.1016/j.phycom.2024.102593","url":null,"abstract":"<div><div>In this research, we investigate aperture selection schemes for non-line-of-sight ultraviolet communication systems operating in log-normal atmospheric turbulence channels. The proposed approaches involve the selection of a single transmit and/or receive aperture from a pool of <span><math><mi>N</mi></math></span> transmit and/or <span><math><mi>M</mi></math></span> receive apertures for communication, based on maximizing the signal-to-noise ratio along the corresponding optical path. To further improve the performance of non-line-of-sight ultraviolet links, we incorporate an optically pre-amplified PIN photo-detector at the receiver and an optical booster amplifier at the transmitter. We consider all noise sources, including those arising from amplified spontaneous emission due to optical amplifiers. We derive closed-form outage and bit-error-rate expressions and conduct diversity gain analyses to assess the performance. Monte Carlo simulations are employed to validate the accuracy of our derivations. The results reveal that selection diversity schemes offer full diversity gain and outperform multiple-input-multiple-output non-line-of-sight ultraviolet systems without aperture selection. Our study demonstrates the efficacy of aperture selection as well as optical amplifiers in enhancing the reliability and performance of non-line-of-sight ultraviolet communication systems in turbulent atmospheric conditions.</div></div>","PeriodicalId":48707,"journal":{"name":"Physical Communication","volume":"69 ","pages":"Article 102593"},"PeriodicalIF":2.0,"publicationDate":"2024-12-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143105026","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}

引用次数: 0

Fairness driven TDMA with joint phase and beamforming optimization for ND-IRS assisted MU-MISO communication systems

IF 2 4区计算机科学

Physical Communication Pub Date : 2024-12-20 DOI: 10.1016/j.phycom.2024.102587

Amit Agarwal

{"title":"Fairness driven TDMA with joint phase and beamforming optimization for ND-IRS assisted MU-MISO communication systems","authors":"Amit Agarwal","doi":"10.1016/j.phycom.2024.102587","DOIUrl":"10.1016/j.phycom.2024.102587","url":null,"abstract":"<div><div>This paper investigates the optimization of rate performance in downlink intelligent reflecting surface (IRS)-assisted multi-user multiple-input single-output (MU-MISO) systems with a focus on fairness. The IRS operates in either diagonal (D) or non-diagonal (ND) configurations, with time allocation designed to maximize the minimum signal-to-noise ratio (SNR), effectively optimizing data rates for all users. The D-IRS configuration is commonly used due to its simplicity in implementation and control link load. However, ND-IRS allows signal reflection from different elements with adjustable phase shifts, enhancing system performance. The study examines how different IRS configurations and time allocation strategies influence data rates in a fairness-driven MU-MISO, time division multiple access (TDMA) transmission system. Using alternating optimization (AO) for the joint phase of the IRS and beamforming at the base station (BS), combined with fairness-based time allocation, the research explores the impact of transmit power, IRS elements, and user count on performance. Results show that ND-IRS with fairness-based time allocation consistently delivers the highest data rates across various scenarios. ND-IRS outperforms D-IRS, and random phase IRS setups, especially as transmit power and the number of IRS elements increase. Our results demonstrate that ND-IRS with fairness-based time allocation consistently achieves the highest data rates across various scenarios. For example, ND-IRS with fairness based time allocation performs better as compared to the equal time allocation scheme. Further, ND-IRS outperforms D-IRS with optimized phase as well as random phase IRS setups. Computer simulations confirm these findings.</div></div>","PeriodicalId":48707,"journal":{"name":"Physical Communication","volume":"69 ","pages":"Article 102587"},"PeriodicalIF":2.0,"publicationDate":"2024-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143104931","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}

引用次数: 0

Improper Gaussian signaling for low-resolution active RIS-assisted rate-splitting multiple access multiuser MIMO system

IF 2 4区计算机科学

Physical Communication Pub Date : 2024-12-19 DOI: 10.1016/j.phycom.2024.102580

Hongwen Yu , Gege Hu , Ali Arshad Nasir , Zhichao Sheng , Syed Ali Hassan

{"title":"Improper Gaussian signaling for low-resolution active RIS-assisted rate-splitting multiple access multiuser MIMO system","authors":"Hongwen Yu , Gege Hu , Ali Arshad Nasir , Zhichao Sheng , Syed Ali Hassan","doi":"10.1016/j.phycom.2024.102580","DOIUrl":"10.1016/j.phycom.2024.102580","url":null,"abstract":"<div><div>This paper investigates a low-resolution active reconfigurable intelligent surface (aRIS)-assisted rate-splitting multiple access (RSMA) multiple-input multiple-output (MIMO) downlink system with improper Gaussian signaling (IGS). A max–min achievable log determinant (log-det) rate optimization problem is formulated by jointly optimizing the transmit beamforming, low-resolution aRIS’s power-amplified reconfigurable elements (aPREs), and rate-splitting (RS) vector. To address the nonsmooth optimization objective function, the formulated problem is decoupled into two subproblems, namely, transmit beamforming and RS vector optimization, and aPREs’ vector and RS vector optimization. For the large-scale mixed discrete-continuous problem imposed by the aPREs’ vector optimization, we introduce a novel penalized optimization framework that employs a cubic complexity quadratic solver for alternately optimizing the RS vector, transmit beamforming, and the aPREs’ vector. Simulation results show that the consideblack RSMA system outperforms the space-division multiple access (SDMA) scheme with respect to rate fairness, and the use of IGS is remarkably superior to the traditional proper Gaussian signaling (PGS) in improving the rate fairness among users.</div></div>","PeriodicalId":48707,"journal":{"name":"Physical Communication","volume":"69 ","pages":"Article 102580"},"PeriodicalIF":2.0,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143105025","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}

引用次数: 0

Unsupervised learning approach for distributed beamforming in cell-free integrated sensing and communication with dynamic balancing method

IF 2 4区计算机科学

Physical Communication Pub Date : 2024-12-19 DOI: 10.1016/j.phycom.2024.102591

Mohamed Elrashidy , Mudassir Masood , Ali Arshad Nasir

{"title":"Unsupervised learning approach for distributed beamforming in cell-free integrated sensing and communication with dynamic balancing method","authors":"Mohamed Elrashidy , Mudassir Masood , Ali Arshad Nasir","doi":"10.1016/j.phycom.2024.102591","DOIUrl":"10.1016/j.phycom.2024.102591","url":null,"abstract":"<div><div>Cell-free massive multiple input multiple output (MIMO) systems can provide reliable connectivity and increase user throughput and spectral efficiency of integrated sensing and communication (ISAC) systems. This can only be achieved through intelligent beamforming design. While many works have proposed optimization methods to design beamformers for cell-free systems, the underlying algorithms are computationally complex and potentially increase fronthaul link loads. To address this concern, we propose an unsupervised learning algorithm to jointly design the communication and sensing beamformers for cell-free ISAC system. Specifically, we adopt a teacher–student training model to guarantee a balanced maximization of sensing signal to noise ratio (SSNR) and signal to interference plus noise ratio (SINR), which represent the sensing and communication metrics, respectively. The proposed scheme is decentralized, which can reduce the load on the central processing unit (CPU) and the required fronthaul links. To avoid the tradeoff problem between sensing and communication counterparts of the cell-free system, we first train two identical models (teacher models) each biased towards one of the two tasks. A third identical model (a student model) is trained based on the maximum sensing and communication performance information obtained by the teacher models. The balancing factor of the student loss is dynamically adapted based on the student’s performance during training. While the results show that our proposed unsupervised DL approach yields a performance close to the model-driven solution, the proposed approach is more computationally efficient than the state of the art by at least three orders of magnitude.</div></div>","PeriodicalId":48707,"journal":{"name":"Physical Communication","volume":"69 ","pages":"Article 102591"},"PeriodicalIF":2.0,"publicationDate":"2024-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143105027","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}

引用次数: 0