eess.SP - 2023-09-13

Space-Time Adaptive Processing in Connected and Automated Vehicular Radar Platoons

  • paper_url: http://arxiv.org/abs/2309.07355
  • repo_url: None
  • paper_authors: Zahra Esmaeilbeig, Kumar Vijay Mishra, Mojtaba Soltanalian
  • for: 这个研究是为了开发一个适用于自动驾驶汽车(CAV)雷达系统的空间时间自适应处理(STAP)框架。
  • methods: 这个研究使用了时分多普逻(TDM)来实现发送器调度,以提高目标探测性能。
  • results: numerical experiments confirm that the optimized TDM is successful in enhancing the target detection performance.
    Abstract In this study, we develop a holistic framework for space-time adaptive processing (STAP) in connected and automated vehicle (CAV) radar systems. We investigate a CAV system consisting of multiple vehicles that transmit frequency-modulated continuous-waveforms (FMCW), thereby functioning as a multistatic radar. Direct application of STAP in a network of radar systems such as in a CAV may lead to excess interference. We exploit time division multiplexing (TDM) to perform transmitter scheduling over FMCW pulses to achieve high detection performance. The TDM design problem is formulated as a quadratic assignment problem which is tackled by power method-like iterations and applying the Hungarian algorithm for linear assignment in each iteration. Numerical experiments confirm that the optimized TDM is successful in enhancing the target detection performance.
    摘要 在本研究中,我们开发了一个整体框架 для空间时间适应处理(STAP)在连接自动汽车(CAV)雷达系统中。我们研究了一个包含多个车辆发射频分Modulated continuous-waveform(FMCW)的CAV系统,这些车辆functioning as a multistatic radar。直接在CAV系统中应用STAP可能会导致过度干扰。我们利用时分多路多播(TDM)来实现发射器调度,以实现高的检测性能。TDM设计问题被формализова为一个 quadratic assignment problem,这个问题被解决通过power method-like iterations和应用hungarian algorithm来实现线性分配。数值实验证明优化的TDM能够提高目标检测性能。

  • paper_url: http://arxiv.org/abs/2309.07299
  • repo_url: None
  • paper_authors: Alexander Vavoulas, Nicholas Vaiopoulos, Harilaos G. Sandalidis, Konstantinos K. Delibasis
  • for: 研究用户RandomLocation在半径形覆盖区域中的无线通信链接性能。
  • methods: 使用方差天线和高速铁路网络等实际场景,研究用户RandomLocation对无线通信链接性能的影响。
  • results: 研究发现,用户RandomLocation会对无线通信链接性能产生很大的影响,并提供了 relevante distance metrics和频繁TerminalLocation对连接性能的影响的分析。
    Abstract Wireless transmitters (Txs) radiating directionally downwards often generate circular footprints on the ground. In certain scenarios, using elliptical cells can offer increased flexibility for providing user coverage, owing to the unique network characteristics. For instance, an elliptical footprint can be produced when a practical directional antenna with unequal azimuth and elevation half-power beamwidths is used in high-speed railway networks. Another common scenario involves the production of an elliptical footprint when an airborne Tx radiates at an angle by tilting its directional antenna by a few degrees. This paper aims to investigate, for the first time, the association between the random user location within an elliptical coverage area and the performance of a wireless communication link by considering these scenarios. We assume an unmanned aerial vehicle (UAV) as a Tx, although a tall cellular base station tower could also be employed without losing generality. To better understand the impact of random location, we derive relevant distance metrics and investigate the outage probability of the link for the two scenarios, taking both random terminal location and fading impairments into account. The findings may provide valuable insights into the performance of similar wireless systems.
    摘要 无线发送器(Tx)通常在下方方向性发射,可能生成圆形覆盖区 на 地面。在某些情况下,使用椭圆细胞可以提供更多的用户覆盖,由于无线网络特有的特点。例如,在高速铁路网络中使用实用方向性扬声器时,可以生成椭圆覆盖区。另一种常见的enario是通过倾斜irectional扬声器几度来生成椭圆覆盖区。这篇论文旨在,对于首次研究用户随机位置在椭圆覆盖区内的无线通信链的相关性,investigate 具体情况。我们假设用无人机(UAV)作为发送器,可以使用高Cellular 基站塔也可以无损generality。为了更好地理解随机位置的影响,我们 derive 相关的距离指标,并对两种情况的频繁受到干扰的情况进行研究。我们的发现可能为类似无线系统的性能提供有价值的洞察。

Beamforming Design and Performance Evaluation for RIS-aided Localization using LEO Satellite Signals

  • paper_url: http://arxiv.org/abs/2309.07296
  • repo_url: None
  • paper_authors: Lei Wang, Pinjun Zheng, Xing Liu, Tarig Ballal, Tareq Y. Al-Naffouri
  • for: 本研究探讨了使用低地球轨道卫星信号和可变智能表面(RIS)实现的位置呈现方法。
  • methods: 本文使用了克拉默-瑞恩约束来 derivation of the Cramér-Rao bound of the considered localization problem,并提出了一种最优的RIS扫描设计,以最小化 derive bound。
  • results: numerical results demonstrate that the proposed beamforming scheme outperforms benchmark alternatives, and shows that the combination of LEO satellites and RISs has the potential to achieve localization accuracy at the meter or even sub-meter level.
    Abstract The growing availability of low-Earth orbit (LEO) satellites, coupled with the anticipated widespread deployment of reconfigurable intelligent surfaces (RISs), opens up promising prospects for new localization paradigms. This paper studies RIS-aided localization using LEO satellite signals. The Cram\'er-Rao bound of the considered localization problem is derived, based on which an optimal RIS beamforming design that minimizes the derived bound is proposed. Numerical results demonstrate the superiority of the proposed beamforming scheme over benchmark alternatives, while also revealing that the synergy between LEO satellites and RISs holds the promise of achieving localization accuracy at the meter or even sub-meter level.
    摘要 随着低地球轨道卫星(LEO)的可用性增加,以及预计的广泛部署智能表面(RIS),开启了新的地点化方案的可能性。本文研究了RIS帮助地点化使用LEO卫星信号。基于考虑的地点化问题的卡尔-拉奥 bounds,提出了最优的RIS扫描设计,以iminimize der bound。 numerically results表明提案的扫描方案比参照方案更优,而且还表明了LEO卫星和RIS的共同作用可以达到米级或以下的地点化精度。

Adaptive KalmanNet: Data-Driven Kalman Filter with Fast Adaptation

  • paper_url: http://arxiv.org/abs/2309.07016
  • repo_url: https://github.com/kalmannet/adaptive-knet-icassp24
  • paper_authors: Xiaoyong Ni, Guy Revach, Nir Shlezinger
  • for: 提高Partially known state space (SS)模型下的跟踪性能
  • methods: 结合Classical Kalman filter (KF)和深度神经网络 (DNN)
  • results: 能够适应SS模型变化而无需重新训练
    Abstract Combining the classical Kalman filter (KF) with a deep neural network (DNN) enables tracking in partially known state space (SS) models. A major limitation of current DNN-aided designs stems from the need to train them to filter data originating from a specific distribution and underlying SS model. Consequently, changes in the model parameters may require lengthy retraining. While the KF adapts through parameter tuning, the black-box nature of DNNs makes identifying tunable components difficult. Hence, we propose Adaptive KalmanNet (AKNet), a DNN-aided KF that can adapt to changes in the SS model without retraining. Inspired by recent advances in large language model fine-tuning paradigms, AKNet uses a compact hypernetwork to generate context-dependent modulation weights. Numerical evaluation shows that AKNet provides consistent state estimation performance across a continuous range of noise distributions, even when trained using data from limited noise settings.
    摘要 通过结合古典卡尔曼畸(KF)和深度神经网络(DNN),可以实现部分知道状态空间(SS)模型中的跟踪。现有的DNN帮助设计受到特定分布和下辖SS模型的训练所限制,因此,对模型参数的变化可能需要重新训练。而KF可以通过参数调整适应,但是DNN的黑obox性使得找到可调Component困难。因此,我们提出了适应型卡尔曼网(AKNet),一种可以在不需要重新训练的情况下适应SS模型变化。受到 latest Advances in large language model fine-tuning paradigms 的启发,AKNet使用了一个紧凑的 hypernetwork 生成状态dependent的权重模ulation。numerical evaluation表明,AKNet在不同噪音分布下提供了一致的状态估计性能,即使用limited noise Settingstrained。

  • paper_url: http://arxiv.org/abs/2309.06911
  • repo_url: None
  • paper_authors: Gilles Callebaut, Liang Liu, Thomas Eriksson, Liesbet Van der Perre, Ove Edfors, Christian Fager
  • for: 本研究的目的是为6G无线网络的发展提供基础设施。
  • methods: 本文提出了6G无线网络的研究方向和技术方法,包括新的应用和网络能效提高。
  • results: 本文描述了6G无线网络的测试基础设施的需求和趋势,以及其发展的方法。
    Abstract The proof of the pudding is in the eating - that is why 6G testbeds are essential in the progress towards the next generation of wireless networks. Theoretical research towards 6G wireless networks is proposing advanced technologies to serve new applications and drastically improve the energy performance of the network. Testbeds are indispensable to validate these new technologies under more realistic conditions. This paper clarifies the requirements for 6G radio testbeds, reveals trends, and introduces approaches towards their development.
    摘要 “Proof of the pudding is in the eating”,这句话告诉我们,在下一代无线网络的发展过程中,6G测试床是非常重要的。理论研究表明,6G无线网络将拥有新的应用和巨大提高网络能效性。但是,为了 validate these new technologies,我们需要在更真实的环境中进行测试。本文阐述了6G无线电测试床的需求,探讨了趋势,并介绍了其开发方法。

Intelligent Reflective Surface Assist Integrated Sensing and Wireless Power Transfer

  • paper_url: http://arxiv.org/abs/2309.06909
  • repo_url: None
  • paper_authors: Zheng Li, Zhengyu Zhu, Zheng Chu, Yingying Guan, De Mi, Fan Liu, Lie-Liang Yang
  • for: 本研究旨在探讨一种智能反射 superficie(IRS)协助的 интеGRATED 感知和无线电力传输(ISWPT)系统,其中发送器在交通基础设施网络上发送信号感知多个目标并同时传输多个能量收集设备(EHDs)。
  • methods: 本研究提出了一种joint 优化系统性能的方法,通过减少能量收集和感知之间的性能质量负担,并通过对射频相位调整和射频平面调整进行优化。
  • results: 研究结果验证了提出的算法,并 demonstarted IRS 可以帮助提高 ISWPT 系统的性能。
    Abstract Wireless sensing and wireless energy are enablers to pave the way for smart transportation and a greener future. In this paper, an intelligent reflecting surface (IRS) assisted integrated sensing and wireless power transfer (ISWPT) system is investigated, where the transmitter in transportation infrastructure networks sends signals to sense multiple targets and simultaneously to multiple energy harvesting devices (EHDs) to power them. In light of the performance tradeoff between energy harvesting and sensing, we propose to jointly optimize the system performance via optimizing the beamforming and IRS phase shift. However, the coupling of optimization variables makes the formulated problem non-convex. Thus, an alternative optimization approach is introduced and based on which two algorithms are proposed to solve the problem. Specifically, the first one involves a semi-definite program technique, while the second one features a low-complexity optimization algorithm based on successive convex approximation and majorization minimization. Our simulation results validate the proposed algorithms and demonstrate the advantages of using IRS to assist wireless power transfer in ISWPT systems.
    摘要 无线感知和无线能源是智能交通和绿色未来的推动者。本文研究了一种帮助器(IRS)协助的 интеGRATED 无线传输和感知系统,其中传输器在交通基础设施网络上发射信号感知多个目标并同时传输多个能量收集设备(EHD)以供电。为了解决能收集和感知性能之间的性能质量负担,我们提议同时优化系统性能via 磁场调制和IRS阶段偏移。但是,优化变量的协同关系使得问题变得非对称。因此,我们引入了一种代替优化方法,并基于这种方法提出了两种算法来解决问题。 Specifically, the first one involves a semi-definite program technique, while the second one features a low-complexity optimization algorithm based on successive convex approximation and majorization minimization. Our simulation results validate the proposed algorithms and demonstrate the advantages of using IRS to assist wireless power transfer in ISWPT systems.Note: Please note that the translation is in Simplified Chinese, which is the standard writing system used in mainland China. If you need the translation in Traditional Chinese, please let me know.

TTD Configurations for Near-Field Beamforming: Parallel, Serial, or Hybrid?

  • paper_url: http://arxiv.org/abs/2309.06861
  • repo_url: None
  • paper_authors: Zhaolin Wang, Xidong Mu, Yuanwei Liu, Robert Schober
  • For: The paper is written for hybrid beamforming architectures in wideband near-field communications, specifically addressing the spatial-wideband effect and the maximum time delay requirements of true-time delayers (TTDs).* Methods: The paper investigates two TTD configurations: serial and hybrid serial-parallel, and proposes a power equalization approach to address the cumulative insertion loss. It also studies the wideband near-field beamforming design for different configurations to maximize spectral efficiency in both single-user and multi-user systems.* Results: The paper derives a closed-form solution for the beamforming design in single-user systems and develops a penalty-based iterative algorithm for multi-user systems. Numerical results show that the proposed designs can significantly reduce the maximum time delays required for TTDs and that the hybrid configuration excels in single-user systems, while the serial configuration is preferred in multi-user systems.Here is the result in Simplified Chinese text:* For: 这篇论文是为宽频近场通信中的混合扫描 Architecture 而写的,具体来说是解决宽频近场通信中的空间宽频效应和真实时延器(TTD)的最大时延问题。* Methods: 论文 investigate了两种 TTD 配置:串行和混合串行平行,并提出了一种能量均衡approach来 Addressing the cumulative insertion loss. 它还研究了不同配置下的宽频近场扫描设计,以最大化单个用户和多个用户系统中的spectral efficiency。* Results: 论文 derive了一个关于单用户系统的closed-form解决方案,并开发了一种 penalty-based iterative algorithm来 Addressing the multi-user system. 数字结果表明,提posed设计可以减少 TTD 的最大时延 requirement,并且混合配置在单用户系统中表现出色,而串行配置在多用户系统中表现更好。
    Abstract True-time delayers (TTDs) are popular components for hybrid beamforming architectures to combat the spatial-wideband effect in wideband near-field communications. A serial and a hybrid serial-parallel TTD configuration are investigated for hybrid beamforming architectures. Compared to the conventional parallel configuration, the serial configuration exhibits a cumulative time delay through multiple TTDs, which potentially alleviates the maximum delay requirements on the TTDs. However, independent control of individual TTDs becomes impossible in the serial configuration. In this context, a hybrid TTD configuration is proposed as a compromise solution. Furthermore, a power equalization approach is proposed to address the cumulative insertion loss of the serial and hybrid TTD configurations. Moreover, the wideband near-field beamforming design for different configurations is studied for maximizing the spectral efficiency in both single-user and multiple-user systems. 1) For single-user systems, a closed-form solution for the beamforming design is derived. The preferred user locations and the required maximum time delay of each TTD configuration are characterized. 2) For multi-user systems, a penalty-based iterative algorithm is developed to obtain a stationary point of the spectral efficiency maximization problem for each TTD configuration. In addition, a mixed-forward-and-backward (MFB) implementation is proposed to enhance the performance of the serial configuration. Our numerical results confirm the effectiveness of the proposed designs and unveil that i) compared to the conventional parallel configuration, both the serial and hybrid configurations can significantly reduce the maximum time delays required for the TTDs and ii) the hybrid configuration excels in single-user systems, while the serial configuration is preferred in multi-user systems.
    摘要 true-time delayers (TTDs) 是各种混合扫描镜谱架构中的受欢迎组件,以避免频宽频段效应在宽频近场通信中。我们 investigate 了串行和混合串行平行 TTD 配置在混合扫描镜谱架构中。相比传统并行配置,串行配置会带来累加时延,从而减轻 TTD 的最大延迟要求。然而,在串行配置中独立控制个别 TTD 是不可能的。为此,我们提出了混合 TTD 配置作为妥协解决方案。此外,我们还提出了一种电力均衡方法,以解决串行和混合 TTD 配置中的累加插入损耗。此外,我们还研究了不同配置下的宽频近场扫描设计,以最大化单个用户和多个用户系统中的 spectral efficiency。1)对单用户系统,我们 derive 了一个关闭式解决方案,用于扫描设计。我们还Characterize 了最佳用户位置和每个 TTD 配置的最大时延要求。2)对多用户系统,我们提出了一种罚 penalty-based 迭代算法,以获得每个 TTD 配置的 spectral efficiency 的最大化站点。此外,我们还提出了一种混合前后 (MFB) 实现,以提高串行配置的性能。我们的数字结果表明,我们的设计方案具有有效性,并且发现:i)与传统并行配置相比, both 串行和混合配置可以减少 TTD 的最大时延要求。ii)在单用户系统中,混合配置 excel,而在多用户系统中,串行配置是更好的选择。

A Wearable Ultra-Low-Power sEMG-Triggered Ultrasound System for Long-Term Muscle Activity Monitoring

  • paper_url: http://arxiv.org/abs/2309.06851
  • repo_url: None
  • paper_authors: Sebastian Frey, Victor Kartsch, Christoph Leitner, Andrea Cossettini, Sergei Vostrikov, Simone Benatti, Luca Benini
    for:This paper aims to develop a wearable solution that integrates surface electromyography (sEMG) and ultrasound (US) to monitor muscle activity with low power consumption.methods:The proposed approach utilizes an EMG-driven wake-up approach to achieve ultra-low power consumption, where the US probe is kept in a sleep state when there is no muscle activity. sEMG data are processed on the probe to identify muscle activity and generate a trigger to wake-up the US counterpart.results:The proposed approach enables more than 59% energy saving compared to operating both sEMG and US continuously, with a full-system average power consumption of 12.2 mW.
    Abstract Surface electromyography (sEMG) is a well-established approach to monitor muscular activity on wearable and resource-constrained devices. However, when measuring deeper muscles, its low signal-to-noise ratio (SNR), high signal attenuation, and crosstalk degrade sensing performance. Ultrasound (US) complements sEMG effectively with its higher SNR at high penetration depths. In fact, combining US and sEMG improves the accuracy of muscle dynamic assessment, compared to using only one modality. However, the power envelope of US hardware is considerably higher than that of sEMG, thus inflating energy consumption and reducing the battery life. This work proposes a wearable solution that integrates both modalities and utilizes an EMG-driven wake-up approach to achieve ultra-low power consumption as needed for wearable long-term monitoring. We integrate two wearable state-of-the-art (SoA) US and ExG biosignal acquisition devices to acquire time-synchronized measurements of the short head of the biceps. To minimize power consumption, the US probe is kept in a sleep state when there is no muscle activity. sEMG data are processed on the probe (filtering, envelope extraction and thresholding) to identify muscle activity and generate a trigger to wake-up the US counterpart. The US acquisition starts before muscle fascicles displacement thanks to a triggering time faster than the electromechanical delay (30-100 ms) between the neuromuscular junction stimulation and the muscle contraction. Assuming a muscle contraction of 200 ms at a contraction rate of 1 Hz, the proposed approach enables more than 59% energy saving (with a full-system average power consumption of 12.2 mW) as compared to operating both sEMG and US continuously.
    摘要 表面电MYography (sEMG) 是一种已知的方法,用于在穿戴式和资源受限的设备上监测肌肉活动。然而,当测量深部肌肉时,其信号噪声比 (SNR) 低、信号强度减弱和交叠问题会降低感测性能。ultrasound (US) 可以帮助 sEMG 提高肌动评估的准确性,但 US 硬件的能量总量远高于 sEMG 的,从而导致能源消耗过高,降低电池寿命。这项工作提议了一种携带两种模式的穿戴设备,并使用 EMG 驱动的唤醒方法来实现低功耗consumption。我们将两种现代 SoA US 和 ExG 维度诊断设备集成,以同步获取Short head of the biceps 的时间测量。为了降低能源消耗,US 探针在没有肌动活动时被保持在睡眠状态。sEMG 数据在探针上进行处理(滤波、封顶EXTRACTION 和阈值处理),以识别肌动活动并生成触发器,唤醒 US 对应部分。US 获取在肌肉脱静前开始,因为诊断神经筋接触点刺激和肌肉收缩之间的电romechanical delay (30-100 ms) 。假设每分钟一次肌肉收缩 200 ms,则提议的方法可以比continuously 操作 sEMG 和 US 的能源消耗减少超过 59% (全系统平均功耗为 12.2 mW)。

Low-complexity hardware and algorithm for joint communication and sensing

  • paper_url: http://arxiv.org/abs/2309.06850
  • repo_url: None
  • paper_authors: Andrea Bedin, Shaghayegh Shahcheraghi, Traian E. Abrudan, Arash Asadi
    for:* 这篇论文旨在描述一种基于joint communication and sensing(JCAS)的算法,用于6G系统中提供快速、可靠的通信和精准的物理环境感知。methods:* 该算法使用了一种新的宽频分布式扫描架构,其结合了宽频分布式扫描和高频级数字扫描,以便精准地估算时射(ToA)和方向射(AoA)。results:* 对比2D多信号分类(2D-MUSIC)算法,该方法可以实现相似的性能,而且需要远少于总汇准采样率和复杂性。
    Abstract Joint Communication and Sensing (JCAS) is foreseen as one very distinctive feature of the emerging 6G systems providing, in addition to fast end reliable communication, the ability to obtain an accurate perception of the physical environment. In this paper, we propose a JCAS algorithm that exploits a novel beamforming architecture, which features a combination of wideband analog and narrowband digital beamforming. This allows accurate estimation of Time of Arrival (ToA), exploiting the large bandwidth and Angle of Arrival (AoA), exploiting the high-rank digital beamforming. In our proposal, we separately estimate the ToA and AoA. The association between ToA and AoA is solved by acquiring multiple non-coherent frames and adding up the signal from each frame such that a specific component is combined coherently before the AoA estimation. Consequently, this removes the need to use 2D and 3D joint estimation methods, thus significantly lowering complexity. The resolution performance of the method is compared with that of 2D MUltiple SIgnal Classification (2D-MUSIC) algorithm, using a fully-digital wideband beamforming architecture. The results show that the proposed method can achieve performance similar to a fully-digital high-bandwidth system, while requiring a fraction of the total aggregate sampling rate and having much lower complexity.
    摘要 joint communication and sensing (JCAS) 是6G系统的一个特点,它提供了快速、可靠的通信以及精准地理环境的感知。在这篇论文中,我们提出了一种JCAS算法,利用了一种新的ibeamforming架构,这种架构组合了宽频Analog和窄频数字ibeamforming。这allowaccurately estimating Time of Arrival (ToA), exploiting the large bandwidth and Angle of Arrival (AoA), exploiting the high-rank digital beamforming。在我们的提议中,我们分别估算了ToA和AoA。将ToA和AoA相关联的问题解决通过在每帧中获取多个非协调的帧,并将每帧的信号相加,以便在AoA估算中具有一个固定的组合。这样,我们可以简化复杂性,而不需要使用2D和3D的共同估算方法。我们对方法的分辨率性能进行了比较,使用了一种完全数字宽频ibeamforming架构,与2D MUltiple SIgnal Classification (2D-MUSIC)算法进行比较。结果表明,我们的方法可以达到与高频率数字系统相同的性能,而且需要的总总采样率和复杂性比较低。

Reliability-Latency-Rate Tradeoff in Low-Latency Communications with Finite-Blocklength Coding

  • paper_url: http://arxiv.org/abs/2309.06769
  • repo_url: None
  • paper_authors: Lintao Li, Wei Chen, Petar Popovski, Khaled B. Letaief
  • For: 这篇论文主要研究了具有最小延迟要求的无线通信中的可靠性-延迟-率质量交易。它探讨了在有限块长编码(FBC)下的可靠性-延迟-率交易的基本质量,特别是错误概率、延迟违反概率(DVP)和服务率之间的交易。* Methods: 本论文使用了有效容量(EC)和正常近似来约束可靠性-延迟-率交易的质量。它还提出了一种EC-近似方法来评估受到质量约束的低延迟通信中的可靠性-延迟-率交易。* Results: 研究发现,在AWGN和RAYLEIGH抽象通道上,在允许的最大干扰电平下,可靠性-延迟-率交易存在一定的质量交易。此外,在 Nakagami-$m$ 抽象通道上,可靠性-延迟-率交易也存在一定的质量交易,但与AWGN和RAYLEIGH抽象通道相比,它的质量交易较差。在延迟传输中,如果延迟阈值大于通道准确时间,则可靠性-延迟-率交易存在一定的极限形式。
    Abstract Low-latency communication plays an increasingly important role in delay-sensitive applications by ensuring the real-time exchange of information. However, due to the constraints on the maximum instantaneous power, bounded latency is hard to be guaranteed. In this paper, we investigate the reliability-latency-rate tradeoff in low-latency communications with finite-blocklength coding (FBC). More specifically, we are interested in the fundamental tradeoff between error probability, delay-violation probability (DVP), and service rate. Based on the effective capacity (EC) and normal approximation, we present several gain-conservation inequalities to bound the reliability-latency-rate tradeoffs. In particular, we investigate the low-latency transmissions over an additive white Gaussian noise (AWGN) channel, over a Rayleigh fading channel, with frequency or spatial diversity, and over a Nakagami-$m$ fading channel. To analytically evaluate the quality-of-service-constrained low-latency communications with FBC, an EC-approximation method is further conceived to derive the closed-form expression of quality-of-service-constrained throughput. For delay-sensitive transmissions in which the latency threshold is greater than the channel coherence time, we find an asymptotic form of the tradeoff between the error probability and DVP over the AWGN and Rayleigh fading channels. Our results may provide some insights into the efficient scheduling of low-latency wireless communications in which statistical latency and reliability metrics are adopted.
    摘要 低延迟通信在延迟敏感应用中扮演着越来越重要的角色,确保了实时信息交换。然而,由于最大幂值功率的限制,保证 bounded latency 很难。在这篇论文中,我们研究了低延迟通信中的可靠性-延迟率-速率贸易。更Specifically,我们对 error probability、延迟违约概率(DVP)和服务率之间的基本贸易进行了研究。基于有效容量(EC)和正常approximation,我们提出了多种可靠性-延迟率-速率贸易的上限。具体来说,我们研究了在加itive white Gaussian noise(AWGN)频道、Rayleigh折射频道、频率或空间多普通频道以及Nakagami-$m$ 折射频道上的低延迟传输。为了分析受限于服务质量的低延迟通信,我们提出了EC-approximation方法来 derive closed-form表达式。对于延迟敏感传输,我们发现在AWGN和Rayleigh折射频道上,随着延迟阈值的增加,error probability和DVP之间存在一定的 asymptotic 关系。我们的结果可能提供一些关于有效地调度低延迟无线通信的经验。

Globally Optimal Beamforming Design for Integrated Sensing and Communication Systems

  • paper_url: http://arxiv.org/abs/2309.06674
  • repo_url: None
  • paper_authors: Zhiguo Wang, Jiageng Wu, Ya-Feng Liu, Fan Liu
  • for: 这paper是为了提出一种多输入多输出(MIMO)扫描和多用户通信的共同优化模型,以优化扫描和通信的性能。
  • methods: 该paper使用了 McCormick 环境 relaksation 和 semi-definite relaxation(SDR)技术来解决形ulated problem,并提出了一种高效的全局分支和约束 bounds 算法来解决这个问题。
  • results: 该paper提出的算法可以 garantía finding the global solution for the considered problem, 并且可以作为现有的本地或半优化算法的性能评估标准。
    Abstract In this paper, we propose a multi-input multi-output (MIMO) beamforming transmit optimization model for joint radar sensing and multi-user communications, where the design of the beamformers is formulated as an optimization problem whose objective is a weighted combination of the sum rate and the Cram\'{e}r-Rao bound (CRB), subject to the transmit power budget constraint. The formulated problem is challenging to obtain a global solution, because the sum rate maximization (SRM) problem itself (even without considering the sensing metric) is known to be NP-hard. In this paper, we propose an efficient global branch-and-bound algorithm for solving the formulated problem based on the McCormick envelope relaxation and the semidefinite relaxation (SDR) technique. The proposed algorithm is guaranteed to find the global solution for the considered problem, and thus serves as an important benchmark for performance evaluation of the existing local or suboptimal algorithms for solving the same problem.
    摘要 在这篇论文中,我们提出了一种多输入多输出(MIMO)发射优化模型,用于同时进行雷达探测和多用户通信。在这个模型中,发射器的设计被设置为优化问题的目标,其目标是一种加权的总质量和克拉默-拉奥 bound(CRB)的函数,同时满足发射功率预算限制。这个问题是NP-困难的,因此寻找全局解决方案是非常困难的。在这篇论文中,我们提出了一种高效的全局分支和约束算法,基于McCormick环境缓和SDR技术来解决这个问题。这种算法能够确保找到全局解决方案,因此可以作为现有的本地或部分优化算法的性能评估标准。