results: 研究结果显示，相比之前的一些传统方法，该系统可以更好地均衡三个功能，并且在允许的约束下可以获得更大的性能空间。Abstract
The wireless domain is witnessing a flourishing of integrated systems, e.g. (a) integrated sensing and communications, and (b) simultaneous wireless information and power transfer, due to their potential to use resources (spectrum, power) judiciously. Inspired by this trend, we investigate integrated sensing, communications and powering (ISCAP), through the design of a wideband OFDM signal to power a sensor while simultaneously performing target-sensing and communication. To characterize the ISCAP performance region, we assume symbols with non-zero mean asymmetric Gaussian distribution (i.e., the input distribution), and optimize its mean and variance at each subcarrier to maximize the harvested power, subject to constraints on the achievable rate (communications) and the average side-to-peak-lobe difference (sensing). The resulting input distribution, through simulations, achieves a larger performance region than that of (i) a symmetric complex Gaussian input distribution with identical mean and variance for the real and imaginary parts, (ii) a zero-mean symmetric complex Gaussian input distribution, and (iii) the superposed power-splitting communication and sensing signal (the coexisting solution). In particular, the optimized input distribution balances the three functions by exhibiting the following features: (a) symbols in subcarriers with strong communication channels have high variance to satisfy the rate constraint, while the other symbols are dominated by the mean, forming a relatively uniform sum of mean and variance across subcarriers for sensing; (b) with looser communication and sensing constraints, large absolute means appear on subcarriers with stronger powering channels for higher harvested power. As a final note, the results highlight the great potential of the co-designed ISCAP system for further efficiency enhancement.
摘要
无线领域目前正在蓬勃发展集成系统，例如（a）集成感知和通信，以及（b）同时进行无线信息和能量传输，这些系统的潜在使用资源（频率、功率）的方式被认为是可以很好地利用。受到这种趋势的启发，我们研究集成感知通信和能源供应（ISCAP），通过设计宽带OFDM信号来为感知器提供能源，同时进行目标检测和通信。为了描述ISCAP性能区域，我们假设输入信号具有非零均值抽象 Gaussian 分布（即输入分布），并优化其均值和方差在每个子帧中以最大化收集的能量，并遵循通信可达率和检测平均偏差的限制。得到的输入分布，通过仿真结果表明，在性能区域中获得更大的空间，比（i）同样的均值和方差的 сим 复杂 Gaussian 输入分布（ii）零均值的 сим 复杂 Gaussian 输入分布，以及（iii）杂合通信和检测信号的电力分配方案（共存解）。特别是，优化的输入分布均衡了三个功能，其特点包括：（a）在强通信频道上的子帧中，具有高方差以满足可达率限制，而其他子帧则受到mean的控制，形成一个相对均匀的含义和方差的总和 across subcarriers for sensing;（b）在通信和检测限制更加宽松的情况下，大的绝对均值出现在强电力传输频道上，以提高收集的能量。最后，结果表明了可以通过合理的设计来进一步提高集成ISCAP系统的效率。
Robust Waveform Design for Integrated Sensing and Communication
results: simulation results表明，使用Robust waveform设计可以确保实际操作中的通信性能达到规定的水平，而 Nominal waveform设计则无法确保这一点。这 validate了 Robust waveform设计的价值。Abstract
Integrated sensing and communication (ISAC), which enables hardware, resources (e.g., spectra), and waveforms sharing, is becoming a key feature in future-generation communication systems. This paper investigates robust waveform design for ISAC systems when the underlying true communication channels (e.g. time-selective ones) are not accurately known. With uncertainties in nominal communication channel models, the nominally-estimated communication performance may be not achievable in practice; i.e., the communication performance of ISAC systems cannot be guaranteed. Therefore, we formulate robust waveform design problems by studying the worst-case channels and prove that the robustly-estimated performance is guaranteed to be attainable in real-world operation. As a consequence, the reliability of ISAC systems in terms of communication performance is improved. The robust waveform design problems are shown to be non-convex, non-differentiable, and high-dimensional, which cannot be solved using existing optimization techniques. Therefore, we develop a computationally-efficient and globally-optimal algorithm to solve them. Simulation results show that the robustly-estimated communication performance can be ensured to be practically reachable while the nominally-estimated performance cannot, which validates the value of robust design.
摘要
Future 通信系统中的一个关键特性是集成感知和通信（ISAC），它允许硬件、资源（例如谱）和波形共享。本文研究未知通信道模型下的ISAC系统robust波形设计问题。由于实际通信道模型不准确，则 nominally-estimated 通信性能可能不能实现。因此，我们将robust波形设计问题转化为研究最差通信道和证明robustly-estimated 通信性能是实际操作中可以实现的。这使得ISAC系统的通信性能可以提高。robust波形设计问题是非对称、不导数、高维的，不能使用现有的优化技术解决。因此，我们开发了一种 computationally-efficient 和 globally-optimal 算法来解决它们。 simulation results 表明，robustly-estimated 通信性能可以在实际操作中实现，而 nominally-estimated 通信性能无法实现，这证明了robust设计的价值。
A Portable Ultrasound Imaging Pipeline Implementation with GPU Acceleration on Nvidia CLARA AGX
paper_authors: A. N. Madhavanunni, V. Arun Kumar, Mahesh Raveendranatha Panicker
for: 这个论文旨在描述一个使用GPU加速的手持式超音波图像处理推断，并且针对Nvidia CLARA AGX开发板进行实现。
methods: 这个实现方案使用了非定向扫描波传输，并且使用Nvidia CLARA AGX开发板进行加速。GPU加速的传统延迟和总和（DAS）探针 former 以及两种适应非线性探针 former 和两种福洛-基于技术被实现。
results: 这个实现方案在实验中证明了它的可行性和图像质量，并且在不同的探针格尺度下进行了执行速度的测试，发现GPU加速可以提供高达180倍的速度提升。Abstract
In this paper, we present a GPU-accelerated prototype implementation of a portable ultrasound imaging pipeline on an Nvidia CLARA AGX development kit. The raw data is acquired with nonsteered plane wave transmit using a programmable handheld open platform that supports 128-channel transmit and 64-channel receive. The received signals are transferred to the Nvidia CLARA AGX developer platform through a host system for accelerated imaging. GPU-accelerated implementation of the conventional delay and sum (DAS) beamformer along with two adaptive nonlinear beamformers and two Fourier-based techniques was performed. The feasibility of the complete pipeline and its imaging performance was evaluated with in-vitro phantom imaging experiments and the efficacy is demonstrated with preliminary in-vivo scans. The image quality quantified by the standard contrast and resolution metrics was comparable with that of the CPU implementation. The execution speed of the implemented beamformers was also investigated for different sizes of imaging grids and a significant speedup as high as 180 times that of the CPU implementation was observed. Since the proposed pipeline involves Nvidia CLARA AGX, there is always the potential for easy incorporation of online/active learning approaches.
摘要
在这篇论文中，我们提出了一种基于GPU的手持式超声图像处理框架的抽象实现。使用可编程的手持式开放平台，收集到的原始数据被转移到Nvidia CLARA AGX开发器平台上进行加速图像处理。我们实现了GPU加速的传统延迟和积（DAS）扩展器以及两种适应非线性扩展器和两种福洛尔基于技术。我们进行了卷积物理镜像实验和先行尝试的生物体内扫描，并证明了图像质量指标和CPU实现的相似性。此外，我们还研究了不同大小的扫描网格的执行速度，并发现GPU实现的扩展器速度可以达到CPU实现的180倍。由于提出的管道使用Nvidia CLARA AGX，因此总是可以轻松地将在线/活动学习策略 incorporated。
Energy-Aware Adaptive Sampling for Self-Sustainability in Resource-Constrained IoT Devices
paper_authors: Marco Giordano, Silvano Cortesi, Prodromos-Vasileios Mekikis, Michele Crabolu, Giovanni Bellusci, Michele Magno
For: The paper is written for resource-constrained, battery-powered IoT devices that require self-sustainability through smart power management algorithms and energy harvesting solutions.* Methods: The paper proposes an energy-aware adaptive sampling rate algorithm based on a finite state machine (FSM) and inspired by TCP Reno’s additive increase and multiplicative decrease, which maximizes sensor sampling rates while ensuring power self-sustainability without risking battery depletion.* Results: The proposed algorithm enables self-sustainability while maximizing sampled locations per day, with results validated on data from three different European cities and consistently maintaining a minimum of 24 localizations per day and achieving peaks of up to 3000.Here is the same information in Simplified Chinese text:* For: 这篇论文是为了Resource-constrained, battery-powered IoT设备而写的，需要智能能源管理算法和能量收集解决方案实现自我可持续性。* Methods: 论文提出了一种基于finite state machine (FSM)的能源意识适应样本率算法，启发自TCP Reno的加法增长和乘法减少，以最大化传感器样本率，保证自我可持续性而不损害电池充电。* Results: 提议的算法可以实现自我可持续性，并且在三个不同的欧洲城市的数据上验证了结果， consistently maintaining a minimum of 24 localizations per day and achieving peaks of up to 3000。Abstract
In the ever-growing Internet of Things (IoT) landscape, smart power management algorithms combined with energy harvesting solutions are crucial to obtain self-sustainability. This paper presents an energy-aware adaptive sampling rate algorithm designed for embedded deployment in resource-constrained, battery-powered IoT devices. The algorithm, based on a finite state machine (FSM) and inspired by Transmission Control Protocol (TCP) Reno's additive increase and multiplicative decrease, maximizes sensor sampling rates, ensuring power self-sustainability without risking battery depletion. Moreover, we characterized our solar cell with data acquired over 48 days and used the model created to obtain energy data from an open-source world-wide dataset. To validate our approach, we introduce the EcoTrack device, a versatile device with global navigation satellite system (GNSS) capabilities and Long-Term Evolution Machine Type Communication (LTE-M) connectivity, supporting MQTT protocol for cloud data relay. This multi-purpose device can be used, for instance, as a health and safety wearable, remote hazard monitoring system, or as a global asset tracker. The results, validated on data from three different European cities, show that the proposed algorithm enables self-sustainability while maximizing sampled locations per day. In experiments conducted with a 3000 mAh battery capacity, the algorithm consistently maintained a minimum of 24 localizations per day and achieved peaks of up to 3000.
摘要
在日益扩大的互联网物联网（IoT）场景中，智能电力管理算法和能量收集解决方案是获得自我可持续性的关键。这篇论文介绍了一种能源意识的自适应采样率算法，用于在有限资源的、电池动力的 IoT设备中进行静态部署。该算法基于金字塔状态机（FSM），并受到传输控制协议（TCP）reno的加法增加和乘数减少的启发，以最大化传感器采样率，确保无需电池耗尽。此外，我们对solar cell进行了48天的数据收集和分析，并使用了来自开源的全球数据集来获得能量数据。为验证我们的方法，我们引入了EcoTrack设备，这是一种多功能设备，具有全球定位系统（GNSS）能力和长期演进机型通信（LTE-M）连接，支持MQTT协议将数据传输到云端。这种多功能设备可以在各种应用场景中使用，例如健康和安全护身符、远程危险监测系统或全球资产跟踪系统。实验结果，基于三个欧洲城市的数据，显示了提议的算法可以保证自我可持续性，同时最大化采样位置数。在使用3000mAh电池容量的实验中，算法一直保持了每天至少24个地点的采样，并达到了3000的峰值。
Age Optimum Sampling in Non-Stationary Environment
results: 实验结果表明，我们提出的算法可以快速检测延迟变化，并且由提posed策略获得的AoI相对较低。Abstract
In this work, we consider a status update system with a sensor and a receiver. The status update information is sampled by the sensor and then forwarded to the receiver through a channel with non-stationary delay distribution. The data freshness at the receiver is quantified by the Age-of-Information (AoI). The goal is to design an online sampling strategy that can minimize the average AoI when the non-stationary delay distribution is unknown. Assuming that channel delay distribution may change over time, to minimize the average AoI, we propose a joint stochastic approximation and non-parametric change point detection algorithm that can: (1) learn the optimum update threshold when the delay distribution remains static; (2) detect the change in transmission delay distribution quickly and then restart the learning process. Simulation results show that the proposed algorithm can quickly detect the delay changes, and the average AoI obtained by the proposed policy converges to the minimum AoI.
摘要
在这个工作中，我们考虑了一个状态更新系统，该系统包括一个传感器和一个接收器。状态更新信息由传感器采样并传输到接收器，但是通信滞后分布是非站ARY的，即不固定的。接收器中的数据新鲜度被衡量为年龄信息（AoI）。目标是设计一种在线采样策略，以最小化接收器中的年龄信息平均值，当传输滞后分布未知时。假设通信滞后分布可能会随时间变化，我们提出了一种联合随机批量估计和非 Parametric 变化点检测算法，可以：（1）在延迟分布保持静止时学习最佳更新阈值；（2）快速检测传输延迟分布的变化，然后重新开始学习过程。 simulation 结果表明，我们提出的算法可以快速检测延迟变化，并且提出的策略的年龄信息平均值可以快速 converges 到最小值。
Intelligent-Reflecting-Surface-Assisted UAV Communications for 6G Networks
paper_authors: Zhaolong Ning, Tengfeng Li, Yu Wu, Xiaojie Wang, Qingqing Wu, Fei Richard Yu, Song Guo
for: 这篇论文主要写于6G移动网络中的智能反射表（IRS）和无人飞行器（UAV）技术的应用。
methods: 本论文提出了一种基于IRS和UAV的解决方案，以提高6G网络的覆盖和效率。
results: 该解决方案可以解决6G网络中的覆盖困难和资源约束问题，同时也可以提高网络效率和用户体验。Abstract
In 6th-Generation (6G) mobile networks, Intelligent Reflective Surfaces (IRSs) and Unmanned Aerial Vehicles (UAVs) have emerged as promising technologies to address the coverage difficulties and resource constraints faced by terrestrial networks. UAVs, with their mobility and low costs, offer diverse connectivity options for mobile users and a novel deployment paradigm for 6G networks. However, the limited battery capacity of UAVs, dynamic and unpredictable channel environments, and communication resource constraints result in poor performance of traditional UAV-based networks. IRSs can not only reconstruct the wireless environment in a unique way, but also achieve wireless network relay in a cost-effective manner. Hence, it receives significant attention as a promising solution to solve the above challenges. In this article, we conduct a comprehensive survey on IRS-assisted UAV communications for 6G networks. First, primary issues, key technologies, and application scenarios of IRS-assisted UAV communications for 6G networks are introduced. Then, we put forward specific solutions to the issues of IRS-assisted UAV communications. Finally, we discuss some open issues and future research directions to guide researchers in related fields.
摘要
在6代手机网络（6G）中，智能反射表面（IRS）和无人机（UAV）已经出现为解决地面网络覆盖困难和资源约束所提出的技术。无人机，通过其 mobilidad和低成本，为移动用户提供多样的连接选择和6G网络的新部署方式。然而，无人机的电池容量有限，通信环境动态和随机，以及通信资源限制，导致传统的无人机基站网络的性能差。IRS可以不仅重构无线环境，还可以实现无线网络转发在成本效果的方式。因此，它在6G网络中获得了广泛关注。在本文中，我们进行了6G网络中IRS协助无人机通信的全面调查。首先，我们介绍了6G网络中IRS协助无人机通信的主要问题、关键技术和应用场景。然后，我们提出了解决IRS协助无人机通信的具体问题的解决方案。最后，我们讨论了一些未解决的问题和未来研究方向，以便引导相关领域的研究人员。
Structured Two-Stage True-Time-Delay Array Codebook Design for Multi-User Data Communication
results: 研究人员通过分析closed-form两个阶段的设计方法，发现该方法可以实现所需的带分带特定的扩散谱，并且在多用户通信网络中表现出优秀的性能。Abstract
Wideband millimeter-wave and terahertz (THz) systems can facilitate simultaneous data communication with multiple spatially separated users. It is desirable to orthogonalize users across sub-bands by deploying frequency-dependent beams with a sub-band-specific spatial response. True-Time-Delay (TTD) antenna arrays are a promising wideband architecture to implement sub-band-specific dispersion of beams across space using a single radio frequency (RF) chain. This paper proposes a structured design of analog TTD codebooks to generate beams that exhibit quantized sub-band-to-angle mapping. We introduce a structured Staircase TTD codebook and analyze the frequency-spatial behaviour of the resulting beam patterns. We develop the closed-form two-stage design of the proposed codebook to achieve the desired sub-band-specific beams and evaluate their performance in multi-user communication networks.
摘要
宽带毫米波和tera赫兹（THz）系统可以实现同时数据通信多个空间分隔的用户。希望对sub-band进行正交化用户，通过部署频率 dependent的束缚来实现。快时延迟（TTD）天线阵列是一种广泛应用的宽带体系，可以通过单个电磁波（RF）链实现sub-band特定的束缚分布在空间中。本文提出了一种结构化的analog TTD编码ebook的设计，以生成具有量化sub-band-to-angle映射的束缚。我们介绍了一种结构化的梯形 TTD编码ebook，并分析了其在resulting beam pattern中的频率空间行为。我们还开发了closed-form two-stage设计的提议，以实现所要的desired sub-band特定的束缚，并评估其在多用户通信网络中的性能。
SWIPT in Mixed Near- and Far-Field Channels: Joint Beam Scheduling and Power Allocation
results: 作者提出了一种高效的算法，可以在多个EH和ID接收器的情况下获得一个近似解，使用了变量排除法和 successive convex approximation 方法。作者还通过对特殊情况的研究，获得了有用的洞察。数值结果显示，作者的提议的共同设计在比较其他参照方案无法优化的情况下显著超越。Abstract
Extremely large-scale array (XL-array) has emerged as a promising technology to enhance the spectrum efficiency and spatial resolution in future wireless networks by exploiting massive number of antennas for generating pencil-like beamforming. This also leads to a fundamental paradigm shift from conventional far-field communications towards the new near-field communications. In contrast to the existing works that mostly considered simultaneous wireless information and power transfer (SWIPT) in the far field, we consider in this paper a new and practical scenario, called mixed near- and far-field SWIPT, where energy harvesting (EH) and information decoding (ID) receivers are located in the near- and far-field regions of the XL-array base station (BS), respectively. Specifically, we formulate an optimization problem to maximize the weighted sum-power harvested at all EH receivers by jointly designing the BS beam scheduling and power allocation, under the constraints on the maximum sum-rate and BS transmit power. First, for the general case with multiple EH and ID receivers, we propose an efficient algorithm to obtain a suboptimal solution by utilizing the binary variable elimination and successive convex approximation methods. To obtain useful insights, we then study the joint design for special cases. In particular, we show that when there are multiple EH receivers and one ID receiver, in most cases, the optimal design is allocating a portion of power to the ID receiver for satisfying the rate constraint, while the remaining power is allocated to one EH receiver with the highest EH capability. This is in sharp contrast to the conventional far-field SWIPT case, for which all powers should be allocated to ID receivers. Numerical results show that our proposed joint design significantly outperforms other benchmark schemes without the optimization of beam scheduling and/or power allocation.
摘要
很大规模的数组（XL-数组）已经成为未来无线网络中提高频谱效率和空间分辨率的有前途技术，通过利用庞大的天线数量生成射频束形成。这也导致了传统远场通信的基本思想的变革，转移到新的近场通信。与现有工作一样，我们在这篇论文中考虑了同时进行无线信息和能量传输（SWIPT）的远场和近场两种情况。在这种情况下，我们将BS的扫描方向和功率分配进行优化，以最大化所有能量收集器（EH）的总功率。特别是，我们提出了一个优化问题，以最大化所有EH收集器的总功率，并且受到BS发射功率的最大化和最小化率限制。首先，我们对多个EH和ID收集器的总 случа进行了有效的解决方案，通过利用二进制变量消除和束缚函数方法。为了获得有用的结论，我们还研究了特殊情况下的共同设计。结果显示，当有多个EH收集器和一个ID收集器时，优化设计通常是将一部分功率分配给ID收集器，以满足速率约束，而剩余的功率分配给EH收集器中功率最高的一个。这与远场SWIPT情况不同，在那里，所有功率都应该分配给ID收集器。numerical results表明，我们的提议的共同设计明显超越了不包括扫描方向和/或功率分配优化的参考方案。