eess.SP - 2023-11-28

RIS-Enhanced MIMO Channels in Urban Environments: Experimental Insights

  • paper_url: http://arxiv.org/abs/2311.16985
  • repo_url: None
  • paper_authors: James Rains, Anvar Tukmanov, Qammer Abbasi, Muhammad Imran
  • for: 该研究是为了检验智能广播环境 paradigm 是否可以明显提高当代城市macrocell 性能。
  • methods: 该研究使用了可重新配置智能表面 (RIS) 对实际的 sub-6 GHz MIMO 频率域通道进行影响。研究使用了一种自然 inspirited 的扫描算法来最大化用户位置的通道增益,发现在某些情况下可以提高通道容量50%。
  • results: 分析表明,在这些设置下,RIS的引入可能会影响频率域通道的空间特性。研究组提供了 RIS 原型图文、Gerber文件和源代码,以便未来的无线通信研究人员进行实验。
    Abstract Can the smart radio environment paradigm measurably enhance the performance of contemporary urban macrocells? In this study, we explore the impact of reconfigurable intelligent surfaces (RISs) on a real-world sub-6 GHz MIMO channel. A rooftop-mounted macrocell antenna has been adapted to enable frequency domain channel measurements to be ascertained. A nature-inspired beam search algorithm has been employed to maximize channel gain at user positions, revealing a potential 50% increase in channel capacity in certain circumstances. Analysis reveals, however, that the spatial characteristics of the channel can be adversely affected through the introduction of a RIS in these settings. The RIS prototype schematics, Gerber files, and source code have been made available to aid in future experimental efforts of the wireless research community.
    摘要 可以吗?我们在这个研究中研究了使用可编程智能表面(RIS)对现代城市macrocell的性能是否可以有明显提高?我们使用了一个顶楼安装的 macrocell天线,并使用频域频率测量来确定频率域通道的性能。我们采用了一种基于自然的搜索算法,以最大化用户位置的通道增益,发现在某些情况下,通道容量可以提高50%。然而,分析表明,在这些设置下,RIS的空间特性可能会受到负面影响。我们已经提供了RIS原型图文、Gerber文件和源代码,以帮助未来的无线通信研究人员进行实验。

HARQ Retransmissions in C-V2X: A BSM Latency Analysis

  • paper_url: http://arxiv.org/abs/2311.16983
  • repo_url: None
  • paper_authors: Abdurrahman Fouda, Randall Berry, Ivan Vukovic
  • For: The paper studies the transmission latency and reliability of periodic basic safety messages (BSMs) in cellular vehicular-to-everything (C-V2X) systems with hybrid automatic repeat request (HARQ) retransmissions and semi-persistent scheduling (SPS) in C-V2X transmission mode 4.* Methods: The paper uses extensive system-level simulations that closely follow the SPS process to evaluate the BSM transmission latency and reliability with HARQ retransmissions. Additionally, the paper provides an analytical model for the tail behavior of the BSM latency distribution with HARQ retransmissions.* Results: The study reveals the impact of several deployment settings (e.g., bandwidth configurations and vehicle density) on the BSM transmission latency and reliability with HARQ retransmissions in C-V2X systems.Here’s the simplified Chinese text format you requested:* For: 研究Periodic Basic Safety Messages (BSMs)在Cellular Vehicular-to-Everything (C-V2X)系统中Hybrid Automatic Repeat Request (HARQ)重传和Semipersistent Scheduling (SPS)的传输延迟和可靠性。* Methods: 使用 extensible system-level simulations closely follow SPS process 评估BSM传输延迟和可靠性。同时提供了BSM延迟分布的尾部行为的analytical模型。* Results: 研究发现不同部署设置(如频道配置和车辆密度)对BSM传输延迟和可靠性带来的影响。
    Abstract Cellular vehicular-to-everything (C-V2X) systems offer the potential for improving road safety, in part through the exchange of periodic basic safety messages (BSMs) between nearby vehicles. The reliability and latency of these messages is a key metric. Hybrid automatic repeat request (HARQ) retransmissions are one technique used to this end. However, HARQ may come at the expense of consuming the limited available wireless resources, especially in highly congested scenarios. This paper studies BSM transmission latency and reliability when HARQ retransmissions are used with the semi-persistent scheduling (SPS) in C-V2X transmission mode 4. We do so through extensive system-level simulations that closely follow the SPS process. Furthermore, we provide an analytical model for the tail behavior of the BSM latency distribution with HARQ retransmissions that is a good approximation to the simulation results. Our study reveals the impact of several deployment settings (e.g., bandwidth configurations and vehicle density).
    摘要 mobile cellular vehicular-to-everything (C-V2X) 系统可能提高公路安全性,其中包括透过附近车辆之间交换时间讯息 (BSM) 的交换。这些讯息的可靠性和延迟时间是重要的指标。混合自动重复请求 (HARQ) 是一种用于提高这些讯息的可靠性和快速传输的技术。但是,HARQ 可能会占用有限的无线资源,特别是在高度拥堵的enario中。这篇文章研究了 C-V2X 传输模式4中BSM 传输延迟和可靠性,以及使用 HARQ 重复请求和半定期分配 (SPS)。我们透过严格遵循 SPS 过程的系统级别的模拟,并提供了BSM 延迟分布的尾部行为的分析模型,这是对模拟结果的好近似。我们的研究显示了不同的部署设定(例如带宽配置和车辆密度)对 C-V2X 传输的影响。

Study of BSM Inter-Packet Gap Tails in C-V2X Networks

  • paper_url: http://arxiv.org/abs/2311.16904
  • repo_url: None
  • paper_authors: Abdurrahman Fouda, Randall Berry, Ivan Vukovic
  • For: This paper investigates the tail behavior of inter-packet gaps (IPGs) and information age (IA) distributions in C-V2X mode 4, a decentralized resource allocation method based on semi-persistent scheduling (SPS).* Methods: The study employs high-fidelity system-level simulations to evaluate the performance of interleaved one-shot SPS transmissions and proposes an accurate analytical model to characterize the IPG tail behavior of C-V2X BSM transmissions.* Results: The numerical results demonstrate significant improvement in the IPG and IA tail distributions in various simulation scenarios, and the proposed analytical model validates the results by matching the asymptotic slopes of IPG distribution in different BSM transmission modes.
    Abstract Cellular vehicle-to-everything (C-V2X) enables safety-critical connected vehicular service by exchanging basic safety messages (BSMs) among nearby vehicular users (VUEs). Timely transmission of BSMs is crucial to avoid stale information at VUEs. However, successive packet losses can lead to large inter-packet gaps (IPGs), reducing the BSMs' reliability. This paper investigates the tail behavior of IPG and information age (IA) distributions in C-V2X mode 4, a decentralized resource allocation method based on semi-persistent scheduling (SPS). We study the improvements and trade-offs introduced by SAE one-shot transmission to decrease the number of successive BSM losses at destination VUEs. The study employs high-fidelity system-level simulations that closely follow the SPS process of CV2X mode 4 to evaluate the performance of interleaved one-shot SPS transmissions. The numerical results demonstrate significant improvement in the IPG and IA tail distributions in various simulation scenarios. Additionally, we propose an accurate analytical model to characterize the IPG tail behavior of C-V2X BSM transmissions. The proposed model is validated by comparing its results with those obtained using the system-level simulations. Our validation shows that the proposed model generates analytical results that coincide with the asymptotic slopes of IPG distribution in different BSM transmission modes.
    摘要 mobile vehicle-to-everything (C-V2X) 可以提供安全关联的连接车辆服务,通过在附近车辆用户 (VUEs) 之间交换基本安全消息 (BSMs)。在时刻传输 BSMs 是关键,以避免 VUEs 上的旧消息。然而,连续的包失失可能会导致大的间隔包 (IPGs),从而降低 BSMs 的可靠性。本文研究 C-V2X 模式 4 中 IPG 和信息年龄 (IA) 分布的尾部特性。我们研究了 SAE 一击传输是否可以降低目标 VUEs 上连续 BSM losses。我们使用高精度系统水平的 Simulations 来评估 C-V2X 模式 4 中一击 SPS 传输的性能。 numerics 结果显示,在不同的 simulate enario 中,一击 SPS 传输可以提供显著改善 IPG 和 IA 尾部分布。此外,我们提出了一个准确的分析模型,用于描述 C-V2X BSM 传输中 IPG 尾部特性。该模型通过与系统水平 Simulations 的结果进行比较,并证明了其可以准确地描述 IPG 尾部分布的各种模式。

Localization of a Passive Source with a Sensor Network based Experimental Molecular Communication Platform

  • paper_url: http://arxiv.org/abs/2311.16848
  • repo_url: None
  • paper_authors: Fatih Gulec, Damla Yagmur Koda, Baris Atakan, Andrew W. Eckford
  • for: 本研究目的是为了在无知源排放的空气污染物监测中估计分子传输器(TX)的位置。
  • methods: 本研究使用了一种新的实验平台,包括一个集成的感知网络(SN)与蒸发的酒精分子作为被动TX。在SNCLA中,使用了一个高斯气泡模型来 derivate位置估计器。通过测量信号的SN来计算或估计参数,如传输质量、风速、检测时间和实际浓度,以用于位置估计器的输入。
  • results: 数值计算结果表明,SNCLA在强风的情况下表现更好。实验数据显示,沸腾分子不会在SN中均匀传播,风速存在影响。此外,基于实验数据的统计分析表明,感知信号采集到的信号采样遵循Log-normal分布,而附加噪声采用Student’s t-分布,与文献中的Gaussian假设不同。
    Abstract In a practical molecular communication scenario such as monitoring air pollutants released from an unknown source, it is essential to estimate the location of the molecular transmitter (TX). This paper presents a novel Sensor Network-based Localization Algorithm (SNCLA) for passive transmission by using a novel experimental platform which mainly comprises a clustered sensor network (SN) with $24$ sensor nodes and evaporating ethanol molecules as the passive TX. In SNCLA, a Gaussian plume model is employed to derive the location estimator. The parameters such as transmitted mass, wind velocity, detection time, and actual concentration are calculated or estimated from the measured signals via the SN to be employed as the input for the location estimator. The numerical results show that the performance of SNCLA is better for stronger winds in the medium. Our findings show that evaporated molecules do not propagate homogeneously through the SN due to the presence of the wind. In addition, our statistical analysis based on the measured experimental data shows that the sensed signals by the SN have a log-normal distribution, while the additive noise follows a Student's t-distribution in contrast to the Gaussian assumption in the literature.
    摘要 在实际分子通信场景中,如监测未知源释放的空气污染物,估计分子传输器(TX)的位置是非常重要。这篇论文提出了一种新的感知网络地图算法(SNCLA),使用了一个主要由24个感知节点组成的分布式感知网络(SN)和蒸发乙醇分子作为被动TX。在SNCLA中,我们采用了 Gaussian 气泡模型来 derivate 位置估计器。通过测量信号的SN来计算或估算传输 Parameters 如传输质量、风速、检测时间和实际浓度,并将其作为输入参数提供给位置估计器。数值结果表明,SNCLA在强风的情况下表现更好。我们的实验数据分析表明,在SN中传输分子不具备均匀分布,因为存在风速的影响。此外,我们的统计分析表明,通过感知网络探测到的信号呈 log-normal 分布,而附加的噪声遵循 Student's t-distribution 而非文献中的 Gaussian 假设。

A Short Overview of 6G V2X Communication Standards

  • paper_url: http://arxiv.org/abs/2311.16810
  • repo_url: None
  • paper_authors: Donglin Wang, Yann Nana Nganso, Hans D. Schotten
    for:* 6G V2X communication system is designed to support the needs of linked autonomous cars and improve user experiences, air quality, road safety, and transportation settings.methods:* The paper compares the applications of various communication technologies, including Wi-Fi, LTE, 5G, and 6G, and focuses on new technologies for 6G V2X, such as brain-vehicle interface, blockchain-based V2X, and Machine Learning (ML).results:* The paper discusses the security challenges of 6G V2X and addresses the strengths, open challenges, development, and improving areas of further study in this field.Here is the same information in Simplified Chinese text:for:* 6G V2X通信系统是为了支持未来链接自驾车的需求,提高用户体验、空气质量、路 Safety 和交通设定。methods:* 本文比较不同通信技术的应用,包括 Wi-Fi、LTE、5G 和 6G,并专注在6G V2X新技术上,如脑车接口、区块基础 V2X 和机器学习(ML)。results:* 本文讨论6G V2X安全挑战,并评估这个领域的优点、开放挑战、发展和进一步研究领域。
    Abstract We are on the verge of a new age of linked autonomous cars with unheard-of user experiences, dramatically improved air quality and road safety, extremely varied transportation settings, and a plethora of cutting-edge apps. A substantially improved Vehicle-to-Everything (V2X) communication network that can simultaneously support massive hyper-fast, ultra-reliable, and low-latency information exchange is necessary to achieve this ambitious goal. These needs of the upcoming V2X are expected to be satisfied by the Sixth Generation (6G) communication system. In this article, we start by introducing the history of V2X communications by giving details on the current, developing, and future developments. We compare the applications of communication technologies such as Wi-Fi, LTE, 5G, and 6G. we focus on the new technologies for 6G V2X which are brain-vehicle interface, blocked-based V2X, and Machine Learning (ML). To achieve this, we provide a summary of the most recent ML developments in 6G vehicle networks. we discuss the security challenges of 6G V2X. We address the strengths, open challenges, development, and improving areas of further study in this field.
    摘要 我们正在reshold of a new era of interconnected autonomous cars with unprecedented user experiences, significantly improved air quality and road safety, and a wide range of cutting-edge apps. To achieve this ambitious goal, we need a substantially improved Vehicle-to-Everything (V2X) communication network that can simultaneously support massive hyper-fast, ultra-reliable, and low-latency information exchange. These needs are expected to be met by the Sixth Generation (6G) communication system.In this article, we will start by introducing the history of V2X communications, including the current, developing, and future developments. We will compare the applications of communication technologies such as Wi-Fi, LTE, 5G, and 6G. We will focus on the new technologies for 6G V2X, including brain-vehicle interface, blockchain-based V2X, and Machine Learning (ML). To achieve this, we will provide a summary of the most recent ML developments in 6G vehicle networks.We will also discuss the security challenges of 6G V2X and address the strengths, open challenges, development, and improving areas of further study in this field.Here is the translation in Simplified Chinese:我们正在reshold of a new era of interconnected autonomous cars with unprecedented user experiences, significantly improved air quality and road safety, and a wide range of cutting-edge apps. To achieve this ambitious goal, we need a substantially improved Vehicle-to-Everything (V2X) communication network that can simultaneously support massive hyper-fast, ultra-reliable, and low-latency information exchange. These needs are expected to be met by the Sixth Generation (6G) communication system.在这篇文章中,我们将开始介绍V2X通信的历史,包括当前、发展和未来的发展。我们将比较不同的通信技术,如Wi-Fi、LTE、5G和6G的应用。我们将专注于6G V2X新技术,包括脑 Vehicle 接口、区块链基础V2X和机器学习(ML)。为了实现这一目标,我们将提供6G车辆网络最新的ML发展情况。我们还将讨论6G V2X安全挑战,并评估这一领域的优点、开放挑战、发展和进一步研究领域。

A Novel 3D Non-stationary Localization-assisted ISAC Channel Model

  • paper_url: http://arxiv.org/abs/2311.16798
  • repo_url: None
  • paper_authors: Runruo Yang, Yang Wu, Jie Huang, Cheng-Xiang Wang
  • for: 本研究旨在提出一种基于三维非站立射线扩散(3D Non-Stationary Localization-Assisted ISAC)的 sixth generation(6G)无线通信系统应用场景。
  • methods: 本文提出了一种基于粒子滤波器的三维非站立射线扩散(3D Non-Stationary Localization-Assisted ISAC)通道模型,通过利用反射测量技术,掌握了通道中第一次反射 scatterer 和最后一次反射 scatterer 的位置。
  • results: 对比RT结果,本文的通道模型的 simulated 结果与实际场景中的通道性能具有良好的一致性,证明了模型的正确性。通过利用扩散参数,本文的通道模型能更好地映射实际环境。
    Abstract Integrated sensing and communication (ISAC) has attracted wide attention as an emerging application scenario for the sixth generation (6G) wireless communication system. In this paper, a novel three-dimensional (3D) non-stationary localization-assisted ISAC geometry-based stochastic model (GBSM) is proposed. The locations of the first-bounce scatterer and last-bounce scatterer in the communication channel can be estimated by the particle filter with the assistance of backscattering sensing. The important channel statistical properties of the proposed channel model are simulated and compared with the ray tracing (RT) results, including the delay spread, azimuth angle of departure/arrival (AAoD/AAoA) spread, and elevation angle of departure/arrival (EAoD/EAoA) spread. The simulation results of the proposed channel model show a good agreement with the RT results, which proves the correctness of the proposed channel model. Utilizing the localization parameters of scatterers, the proposed ISAC channel model can better map the real environment.
    摘要 sixth generation(6G)无线通信系统中的集成感知通信(ISAC)应用场景已经吸引了广泛的关注。本文提出了一种新的三维非站ARY(3D)非站ARY抽象模型(GBSM)。通过粒子滤波器的帮助,该模型可以估算第一次反射物和最后一次反射物在通信频道中的位置。该模型的通道统计性质,包括延迟跨度、发射角度/接收角度(AAoD/AAoA)的扩散、和发射高度/接收高度(EAoD/EAoA)的扩散,通过与射线追踪(RT)结果进行比较,并与RT结果达到了良好的一致性,这证明了该模型的正确性。通过抽象粒子的位置,该模型可以更好地映射实际环境。

A General 3D Non-Stationary 5G Wireless Channel Model

  • paper_url: http://arxiv.org/abs/2311.16783
  • repo_url: None
  • paper_authors: Shangbin Wu, Cheng-Xiang Wang, el-Hadi M. Aggoune, Mohammed M. Alwakeel, Xiao-Hu You
  • for: 这个论文旨在提出一个统一的几何基础模型(GBSM),用于描述 fifth generation(5G)无线通信系统中的小规模折叠抑降 channel 特性。
  • methods: 该模型基于 WINNER II 和 Saleh-Valenzuela(SV)通道模型,考虑了数组-时间集群演化,并可以根据模型参数适当调整,以获得不同场景的简化通道模型。
  • results: 论文通过对提案的通道模型的统计性质进行研究,以证明其能够准确捕捉不同场景的通道特性,并与某些通道测量数据 exhibit excellent fitting。
    Abstract A novel unified framework of geometry-based stochastic models (GBSMs) for the fifth generation (5G) wireless communication systems is proposed in this paper. The proposed general 5G channel model aims at capturing small-scale fading channel characteristics of key 5G communication scenarios, such as massive multiple-input multiple-output (MIMO), high-speed train (HST), vehicle-to-vehicle (V2V), and millimeter wave (mmWave) communication scenarios. It is a three-dimensional (3D) non-stationary channel model based on the WINNER II and Saleh-Valenzuela (SV) channel models considering array-time cluster evolution. Moreover, it can easily be reduced to various simplified channel models by properly adjusting model parameters. Statistical properties of the proposed general 5G small-scale fading channel model are investigated to demonstrate its capability of capturing channel characteristics of various scenarios, with excellent fitting to some corresponding channel measurements.
    摘要 “本文提出了一个统一的几何基础的数学模型(GBSM)框架,用于第五代(5G)无线通信系统。提议的通用5G通道模型针对5G通信场景中的小规模折射通道特性,如大规模多input多output(MIMO)、高速列车(HST)、车辆间通信(V2V)和毫米波(mmWave)通信场景进行捕捉。这是一个三维非站ARY(3D)不稳定通道模型,基于WINNER II和Saleh-Valenzuela(SV)通道模型,考虑阵列时间对应演化。此外,它可以轻松地将通道模型简化为不同的实际化通道模型,通过适当地调整模型参数。本文 investigate了提议的通用5G小规模折射通道模型的Statistical Property,以示其能够对各种场景的通道特性进行捕捉,具有优秀的适合性。”Note: Simplified Chinese is also known as "Mandarin" or "Standard Chinese".

Active RIS Enhanced Spectrum Sensing for Cognitive Radio Networks

  • paper_url: http://arxiv.org/abs/2311.16568
  • repo_url: None
  • paper_authors: Jungang Ge, Ying-Chang Liang, Sumei Sun, Yonghong Zeng
  • for: 提高二级用户 spectrum sensing 性能在弱主信号下
  • methods: 使用活动再配置智能表面帮助进行信号检测,并优化反射率矩阵来提高检测概率
  • results: 对比传统的被动RIS,活动RIS在较弱干扰下可以提高检测精度,但在强干扰下被动RIS可以更好地减少干扰In English:
  • for: Improving secondary user spectrum sensing performance in weak primary signal environments
  • methods: Using an active reconfigurable intelligent surface to assist with signal detection, and optimizing the reflecting coefficient matrix to improve detection probability
  • results: Compared to traditional passive RIS, the active RIS can improve detection accuracy in weak interference environments, but the passive RIS can better mitigate interference in strong interference scenarios
    Abstract In opportunistic cognitive radio networks, when the primary signal is very weak compared to the background noise, the secondary user requires long sensing time to achieve a reliable spectrum sensing performance, leading to little remaining time for the secondary transmission. To tackle this issue, we propose an active reconfigurable intelligent surface (RIS) assisted spectrum sensing system, where the received signal strength from the interested primary user can be enhanced and underlying interference within the background noise can be mitigated as well. In comparison with the passive RIS, the active RIS can not only adapt the phase shift of each reflecting element but also amplify the incident signals. Notably, we study the reflecting coefficient matrix (RCM) optimization problem to improve the detection probability given a maximum tolerable false alarm probability and limited sensing time. Then, we show that the formulated problem can be equivalently transformed to a weighted mean square error minimization problem using the principle of the well-known weighted minimum mean square error (WMMSE) algorithm, and an iterative optimization approach is proposed to obtain the optimal RCM. In addition, to fairly compare passive RIS and active RIS, we study the required power budget of the RIS to achieve a target detection probability under a special case where the direct links are neglected and the RIS-related channels are line-of-sight. Via extensive simulations, the effectiveness of the WMMSE-based RCM optimization approach is demonstrated. Furthermore, the results reveal that the active RIS can outperform the passive RIS when the underlying interference within the background noise is relatively weak, whereas the passive RIS performs better in strong interference scenarios because the same power budget can support a vast number of passive reflecting elements for interference mitigation.
    摘要 在机会性广播网络中,当主要信号强度非常低时,次要用户需要长时间进行可靠的spectrum sensing,这会导致剩下的时间非常少 для次要传输。为解决这个问题,我们提议使用活动可 configurable智能表面(RIS)帮助spectrum sensing系统,可以增强接收到 interessprimary user的信号强度,同时抑制后台干扰。相比 passive RIS,活动 RIS可以不仅调整反射元素的相位,还可以增强 incident signals。特别是,我们研究了反射系数矩阵(RCM)优化问题,以提高检测概率,并限制检测时间。我们发现,这个问题可以转化为一个加重平均方差Error minimization problem,并使用已知的Weighted Minimum Mean Square Error(WMMSE)算法的原理进行解决。我们还提出了一种Iterative optimization approach来获得最优的RCM。此外,为公正地比较passive RIS和活动 RIS,我们研究了通过RIS来 achieve a target detection probability under a special case where the direct links are neglected and the RIS-related channels are line-of-sight。通过广泛的 simulations,我们证明了WMMSE-based RCM optimization approach的效果。此外,结果还显示了活动 RIS在弱型干扰下可以超越 passive RIS,而passive RIS在强型干扰下表现更好,因为同样的功率预算可以支持一大量的Passive reflecting elements for interference mitigation。

Energy Efficiency Optimization in Active Reconfigurable Intelligent Surface-Aided Integrated Sensing and Communication Systems

  • paper_url: http://arxiv.org/abs/2311.16433
  • repo_url: None
  • paper_authors: Junjie Ye, Mohamed Rihan, Peichang Zhang, Lei Huang, Stefano Buzzi, Zhen Chen
  • for: 提高 интеграцион感知通信系统的能效性 (EE)
  • methods: 使用活动智能表面 (RIS) 帮助提高 ISAC 系统的 EE,并且利用增强功率的扩展来提高系统的 spectral efficiency
  • results: 比对于普通 RIS 和频率效率优化情况, 提出的方法可以获得显著的 EE 提升
    Abstract Energy efficiency (EE) is a challenging task in integrated sensing and communication (ISAC) systems, where high spectral efficiency and low energy consumption appear as conflicting requirements. Although passive reconfigurable intelligent surface (RIS) has emerged as a promising technology for enhancing the EE of the ISAC system, the multiplicative fading feature hinders its effectiveness. This paper proposes the use of active RIS with its amplification gains to assist the ISAC system for EE improvement. Specifically, we formulate an EE optimization problem in an active RIS-aided ISAC system under system power budgets, considering constraints on user communication quality of service and sensing signal-to-noise ratio (SNR). A novel alternating optimization algorithm is developed to address the highly non-convex problem by leveraging a combination of the generalized Rayleigh quotient optimization approach, semidefinite relaxation (SDR), and the majorization-minimization (MM) framework. Furthermore, to accelerate the algorithm and reduce computational complexity, we derive a semi-closed form for eigenvalue determination. Numerical results demonstrate the effectiveness of the proposed approach, showcasing significant improvements in EE compared to both passive RIS and spectrum efficiency optimization cases.
    摘要 “能效率(EE)在 интеграрованных感知通信(ISAC)系统中是一个挑战,因为高 spectral efficiency 和低能耗之间存在矛盾。虽然被动式重配置智能表面(RIS)已经出现为ISAC系统中提高EE的技术,但是multiplicative fading特征限制了其效iveness。本文提出使用活动RIS,其增益可以帮助ISAC系统提高EE。Specifically,我们形ulated了一个EE优化问题在一个活动RIS-assisted ISAC系统中,considering系统功率预算、用户通信质量服务要求和探测信号噪声比(SNR)的限制。我们开发了一种新的交互式优化算法,利用一种combined generalized Rayleigh quotient optimization approach、semidefinite relaxation(SDR)和主要化-最小化(MM)框架。此外,为了加速算法和减少计算复杂度,我们 derive了一种半闭形式的eigenvalue determination。数值结果表明提出的方法的有效性,显示与pasive RIS和spectrum efficiency optimization案例相比,具有显著的EE提高。”Note: The translation is in Simplified Chinese, which is one of the two standard versions of Chinese. The other version is Traditional Chinese.

A Deep Q-Learning based, Base-Station Connectivity-Aware, Decentralized Pheromone Mobility Model for Autonomous UAV Networks

  • paper_url: http://arxiv.org/abs/2311.16409
  • repo_url: None
  • paper_authors: Shreyas Devaraju, Alexander Ihler, Sunil Kumar
  • for: 这 paper 的目的是提出一种自适应协调方法来实现低 SWaP Fixed-wing UAV 网络中的高网络连接性和快速覆盖区域。
  • methods: 该 paper 使用了一种分布式蟒蠕(BS-CAP)移动模型,该模型可以在不知道网络的完整拓扑情况下,在分布式方式实现自适应协调。此外,paper 还提出了基于深度Q学习策略的BS-CAP模型(BSCAP-DQN)来进一步调整覆盖率和连接率的交互关系。
  • results: simulations 表明,提出的两种方法都可以有效地实现高网络连接性和快速覆盖区域,与现有方法相比有显著提高。
    Abstract UAV networks consisting of low SWaP (size, weight, and power), fixed-wing UAVs are used in many applications, including area monitoring, search and rescue, surveillance, and tracking. Performing these operations efficiently requires a scalable, decentralized, autonomous UAV network architecture with high network connectivity. Whereas fast area coverage is needed for quickly sensing the area, strong node degree and base station (BS) connectivity are needed for UAV control and coordination and for transmitting sensed information to the BS in real time. However, the area coverage and connectivity exhibit a fundamental trade-off: maintaining connectivity restricts the UAVs' ability to explore. In this paper, we first present a node degree and BS connectivity-aware distributed pheromone (BS-CAP) mobility model to autonomously coordinate the UAV movements in a decentralized UAV network. This model maintains a desired connectivity among 1-hop neighbors and to the BS while achieving fast area coverage. Next, we propose a deep Q-learning policy based BS-CAP model (BSCAP-DQN) to further tune and improve the coverage and connectivity trade-off. Since it is not practical to know the complete topology of such a network in real time, the proposed mobility models work online, are fully distributed, and rely on neighborhood information. Our simulations demonstrate that both proposed models achieve efficient area coverage and desired node degree and BS connectivity, improving significantly over existing schemes.
    摘要 无人机网络,由低SWaP(体积、重量和功率)、 fixes-wing无人机组成,在许多应用中使用,包括区域监测、搜寻救援、surveillance和跟踪。为了有效地完成这些任务,需要一个可拡展、分布式、自主无人机网络架构,高度连接。而为了快速探索区域,需要快速的区域覆盖,同时保持无人机之间的连接。然而,区域覆盖和连接却存在fundamental的负担假设:维护连接限制了无人机的探索能力。在这篇论文中,我们首先提出一种节点度和基站(BS)连接意识的分布式pheromone(BS-CAP) mobilility模型,以自主协调无人机运动在分布式无人机网络中。这个模型保持了1个邻居和BS之间的连接,同时实现快速的区域覆盖。接着,我们提议一种基于深度Q学习策略的BS-CAP模型(BSCAP-DQN),以进一步调整和改进覆盖和连接的负担假设。由于实时不可能知道这种网络的完整topology,我们的移动模型在线、分布式、基于邻居信息工作。我们的仿真结果表明,我们的两种提议模型可以有效地实现区域覆盖和desired节点度和BS连接,与现有方案相比有显著提高。