paper_authors: Olivier Daoust, Hasan Nayir, Irfan Azam, Antoine Lesage-Landry, Gunes Karabulut Kurt
for: 避免遥感器损坏和残骸的潜在威胁，提高遥感器的安全性。
methods: integrate sensing and communication techniques to detect space debris, using canonical polyadic (CP) tensor decomposition method to estimate the rank of the tensor that denotes the number of paths including line-of-sight and non-line-of-sight.
results: simulation results show that the proposed tensor-based scheme has higher probability of detection than conventional energy-based detection scheme for space debris detection.Abstract
Thousands of satellites, asteroids, and rocket bodies break, collide, or degrade, resulting in large amounts of space debris in low Earth orbit. The presence of space debris poses a serious threat to satellite mega-constellations and to future space missions. Debris can be avoided if detected within the safety range of a satellite. In this paper, an integrated sensing and communication technique is proposed to detect space debris for satellite mega-constellations. The canonical polyadic (CP) tensor decomposition method is used to estimate the rank of the tensor that denotes the number of paths including line-of-sight and non-line-of-sight by exploiting the sparsity of THz channel with limited scattering. The analysis reveals that the reflected signals of the THz can be utilized for the detection of space debris. The CP decomposition is cast as an optimization problem and solved using the alternating least square (ALS) algorithm. Simulation results show that the probability of detection of the proposed tensor-based scheme is higher than the conventional energy-based detection scheme for the space debris detection.
摘要
众多卫星、小行星和火箭体坍塌、相撞或衰变，导致低地球轨道中有很多空间垃圾。空间垃圾对卫星巨合群和未来空间任务构成了严重的威胁。如果探测到空间垃圾在卫星的安全范围内，可以避免垃圾的损害。在这篇论文中，我们提出了一种集成探测和通信技术，用于检测卫星巨合群中的空间垃圾。我们使用了多重线性（CP）张量分解方法来估算卫星检测到的信号的rank，通过利用THz频道的稀热扩散来减少检测的复杂性。分析表明，THz信号的反射可以用于检测空间垃圾。CP分解被表示为一个优化问题，并使用了变分最小二乘（ALS）算法来解决。实验结果表明，提议的张量基本方法的检测可能性比传统的能量基本方法高。
Movable-Antenna Array-Enabled Wireless Communication with CoMP Reception
results: 这种方法可以实现高效的无线通信，并且比过去的参考模型表现出更好的性能。将MA阵列的位置优化可以获得更高的受到信号噪音比，并且可以实现更好的均衡多点接收。Abstract
We consider the movable antenna (MA) array-enabled wireless communication with coordinate multi-point (CoMP) reception, where multiple destinations adopt the maximal ratio combination technique to jointly decode the common message sent from the transmitter equipped with the MA array. Our goal is to maximize the effective received signal-to-noise ratio, by jointly optimizing the transmit beamforming and the positions of the MA array. Although the formulated problem is highly non-convex, we reveal that it is fundamental to maximize the principal eigenvalue of a hermite channel matrix which is a function of the positions of the MA array. The corresponding sub-problem is still non-convex, for which we develop a computationally efficient algorithm. Afterwards, the optimal transmit beamforming is determined with a closed-form solution. In addition, the theoretical performance upper bound is analyzed. Since the MA array brings an additional spatial degree of freedom by flexibly adjusting all antennas' positions, it achieves significant performance gain compared to competitive benchmarks.
摘要
我们考虑了可移动天线（MA）数组启用的无线通信，使多个目标使用最大比率组合技术同时解码发送者配备MA数组的共同消息。我们的目标是 Maximizing the effective received signal-to-noise ratio，通过同时优化发射扫描和MA数组的位置来实现。虽然问题是非常不对称，但我们发现，最大化 hermite channel 矩阵的主要特征值是 MA 数组位置的函数。相应的子问题仍然是非对称的，我们开发了 computationally efficient 算法。然后，最佳发射扫描是通过关闭式解决方案确定的。此外，我们还分析了理论性能Upper bound。由于 MA 数组通过自由调整所有天线的位置，增加了空间学度的自由度，因此实现了比竞争benchmarks更高的性能。
Robust Multidimentional Chinese Remainder Theorem for Integer Vector Reconstruction
for: 该 paper targets the problem of robustly reconstructing an integer vector from its erroneous remainders in multidimensional (MD) signal processing.
methods: 该 paper 使用了robust MD Chinese remainder theorem (CRT)，which is recently proposed for a special class of moduli, but with a strict constraint on the moduli. The paper investigates the robust MD-CRT for a general set of moduli and presents a necessary and sufficient condition on the difference between paired remainder errors, as well as a simple sufficient condition on the remainder error bound.
results: 该 paper presents a closed-form reconstruction algorithm and generalizes the results of the robust MD-CRT from integer vectors/matrices to real ones. The paper validates the robust MD-CRT for general moduli through numerical simulations and applies it to MD sinusoidal frequency estimation based on multiple sub-Nyquist samplers.Abstract
The problem of robustly reconstructing an integer vector from its erroneous remainders appears in many applications in the field of multidimensional (MD) signal processing. To address this problem, a robust MD Chinese remainder theorem (CRT) was recently proposed for a special class of moduli, where the remaining integer matrices left-divided by a greatest common left divisor (gcld) of all the moduli are pairwise commutative and coprime. The strict constraint on the moduli limits the usefulness of the robust MD-CRT in practice. In this paper, we investigate the robust MD-CRT for a general set of moduli. We first introduce a necessary and sufficient condition on the difference between paired remainder errors, followed by a simple sufficient condition on the remainder error bound, for the robust MD-CRT for general moduli, where the conditions are associated with (the minimum distances of) these lattices generated by gcld's of paired moduli, and a closed-form reconstruction algorithm is presented. We then generalize the above results of the robust MD-CRT from integer vectors/matrices to real ones. Finally, we validate the robust MD-CRT for general moduli by employing numerical simulations, and apply it to MD sinusoidal frequency estimation based on multiple sub-Nyquist samplers.
摘要
“多维度（MD）信号处理中，有问题 robustly 从其不准确余值中重建整数 вектор。为解决这问题，一种 robust MD Chinese remainder theorem（CRT）最近被提出，但这问题的紧张限制了实际应用。本文研究robust MD-CRT 的一般模仿，包括对于一般模仿的必要和充分条件、对于不同对象的充分条件、以及一个关于这些体积生成的最小距离的封闭式重建算法。然后，我们将这些结果扩展到实数 вектор/矩阵上。最后，我们透过数字实验验证robust MD-CRT 的可靠性，并将其应用到多 sub-Nyquist 探针中的 MD 谐波频率估计。”
A Zero-Forcing Approach for the RIS-Aided MIMO Broadcast Channel
paper_authors: Dominik Semmler, Michael Joham, Wolfgang Utschick
for: 这 paper 是为了最大化多用户智能面带有多输入多输出广播通道的含义 спектраль效率 (SE) 的算法。
methods: 这 paper 使用了零做法，包括用户分配，以确保计算独立于智能面元素的数量。特别是， paper 提出了两种算法，利用基站和智能面之间的直线结构来提高 SE 性能。
results: simulations 表明，这些算法可以与其他线性 precoding 算法相比，具有更高的 SE 性能，但具有较低的复杂性。Abstract
We present efficient algorithms for the sum-spectral efficiency (SE) maximization of the multi-user reconfigurable intelligent surface (RIS)-aided multiple-input multiple-output (MIMO) broadcast channel based on a zero-forcing approach. These methods conduct a user allocation for which the computation is independent of the number of elements at the RIS, that is usually large. Specifically, two algorithms are given that exploit the line-of-sight (LOS) structure between the base station (BS) and the RIS. Simulations show superior SE performance compared to other linear precoding algorithms but with lower complexity.
摘要
我们提出了高效的算法，用于多用户智能表面受助多输入多输出广播频道上的总spectral efficiency（SE）最大化，基于零强制方法。这些方法在RIS中元素数量约为大的情况下，实现了用户分配，计算独立于RIS元素数量。 Specifically，我们提出了两种算法，利用基站（BS）与RIS之间的直线结构。模拟结果表明，我们的算法在其他线性 precoding 算法比较高，但具有较低的复杂度。
AIaaS for ORAN-based 6G Networks: Multi-time scale slice resource management with DRL
for: 本研究旨在Addressing slice resource management for 6G networks at different time scales, using an open radio access network (ORAN) architecture and artificial intelligence (AI) techniques.
results: 提议的算法可以分析最大资源利用率，以取得决策在 интер-slice 级别。内 slice 智能代理工作在非实时层次，重新配置资源在不同的slice中。 results 表明，该方法可以提高 eMBB、URLLC 和 mMTC 等slice类型的性能。Abstract
This paper addresses how to handle slice resources for 6G networks at different time scales in an architecture based on an open radio access network (ORAN). The proposed solution includes artificial intelligence (AI) at the edge of the network and applies two control-level loops to obtain optimal performance compared to other techniques. The ORAN facilitates programmable network architectures to support such multi-time scale management using AI approaches. The proposed algorithms analyze the maximum utilization of resources from slice performance to take decisions at the inter-slice level. Inter-slice intelligent agents work at a non-real-time level to reconfigure resources within various slices. Further than meeting the slice requirements, the intra-slice objective must also include the minimization of maximum resource utilization. This enables smart utilization of the resources within each slice without affecting slice performance. Here, each xApp that is an intra-slice agent aims at meeting the optimal QoS of the users, but at the same time, some inter-slice objectives should be included to coordinate intra- and inter-slice agents. This is done without penalizing the main intra-slice objective. All intelligent agents use deep reinforcement learning (DRL) algorithms to meet their objectives. We have presented results for enhanced mobile broadband (eMBB), ultra-reliable low latency (URLLC), and massive machine type communication (mMTC) slice categories.
摘要
To optimize resource utilization, the proposed algorithms analyze the maximum utilization of resources from a slice performance perspective and make decisions at the inter-slice level. Inter-slice intelligent agents work at a non-real-time level to reconfigure resources within various slices. Additionally, the intra-slice objective should minimize maximum resource utilization to ensure smart resource utilization within each slice without affecting slice performance.Each xApp, or intra-slice agent, aims to meet the optimal quality of service (QoS) of users while coordinating with inter-slice objectives. This is achieved without penalizing the main intra-slice objective. All intelligent agents use deep reinforcement learning (DRL) algorithms to meet their objectives.The paper presents results for enhanced mobile broadband (eMBB), ultra-reliable low latency (URLLC), and massive machine type communication (mMTC) slice categories, demonstrating the effectiveness of the proposed solution.
RIS-Parametrized Rich-Scattering Environments: Physics-Compliant Models, Channel Estimation, and Optimization
results: 论文提出了一种 physics-compliant 模型，可以用来 parametrically 模拟 RIS-parametrized 吸收物 scattering 环境，并且可以在不知道实验环境的情况下优化 RIS 配置。Abstract
The tunability of radio environments with reconfigurable intelligent surfaces (RISs) enables the paradigm of smart radio environments in which wireless system engineers are no longer limited to only controlling the radiated signals but can in addition also optimize the wireless channels. Many practical radio environments include complex scattering objects, especially indoor and factory settings. Multipath propagation therein creates seemingly intractable coupling effects between RIS elements, leading to the following questions: How can a RIS-parametrized rich-scattering environment be modelled in a physics-compliant manner? Can the parameters of such a model be estimated for a specific but unknown experimental environment? And how can the RIS configuration be optimized given a calibrated physics-compliant model? This chapter summarizes the current state of the art in this field, highlighting the recently unlocked potential of frugal physical-model-based open-loop control of RIS-parametrized rich-scattering radio environments.
摘要
《受控Radio环境中的智能表面（RIS）的可调性，使得无线系统工程师不再只能控制发射的信号，还可以优化无线通道。实际的无线环境中存在复杂的散射物，特别是室内和工厂环境。多路射传输使得RIS元素之间存在许多难以解决的干扰效应，这引出了以下问题：如何在物理相容的方式模拟RIS参数化的 ricH-scattering 环境？可以估算特定而不确定的实验环境中RIS参数的模型吗？如何基于加工物理相容的模型来优化RIS配置？本章简要总结当前领域的最新进展，强调最近解锁了基于减少物理模型的开 loop控制RIS参数化 ricH-scattering 无线环境的潜力。》Note: "ricH-scattering" is a term used to describe the complex scattering behavior of signals in environments with many reflective objects, such as indoor and factory settings.
High-performance cVEP-BCI under minimal calibration
results: 实现了最高的信息传输率（ITR）250 bits per minute（bpm），与当前的稳态视觉诱发potential-based BCIs（SSVEP-BCIs）相当。Abstract
The ultimate goal of brain-computer interfaces (BCIs) based on visual modulation paradigms is to achieve high-speed performance without the burden of extensive calibration. Code-modulated visual evoked potential-based BCIs (cVEP-BCIs) modulated by broadband white noise (WN) offer various advantages, including increased communication speed, expanded encoding target capabilities, and enhanced coding flexibility. However, the complexity of the spatial-temporal patterns under broadband stimuli necessitates extensive calibration for effective target identification in cVEP-BCIs. Consequently, the information transfer rate (ITR) of cVEP-BCI under limited calibration usually stays around 100 bits per minute (bpm), significantly lagging behind state-of-the-art steady-state visual evoked potential-based BCIs (SSVEP-BCIs), which achieve rates above 200 bpm. To enhance the performance of cVEP-BCIs with minimal calibration, we devised an efficient calibration stage involving a brief single-target flickering, lasting less than a minute, to extract generalizable spatial-temporal patterns. Leveraging the calibration data, we developed two complementary methods to construct cVEP temporal patterns: the linear modeling method based on the stimulus sequence and the transfer learning techniques using cross-subject data. As a result, we achieved the highest ITR of 250 bpm under a minute of calibration, which has been shown to be comparable to the state-of-the-art SSVEP paradigms. In summary, our work significantly improved the cVEP performance under few-shot learning, which is expected to expand the practicality and usability of cVEP-BCIs.
摘要
BCIs based on visual modulation paradigms 的最终目标是实现高速性表现，无需耗费庞大的调整。基于宽频白噪（WN）的 cVEP-BCI 具有许多优点，包括提高的交通速率、扩展的编码目标能力和提高的编码flexibility。然而，在宽频刺激下，需要进行广泛的调整以便有效地识别目标。因此， cVEP-BCI 的信息传输率（ITR）在有限的调整下通常在 100 位/分钟（bpm），远远落后于当前的稳态 visual evoked potential（SSVEP）基于 BCIs，它们的 ITR 超过 200 bpm。为了提高 cVEP-BCI 的性能，我们设计了一个高效的快速单目标抖摆calibration阶段，持续时间低于 1 分钟，以EXTRACT GENERALIZABLE SPATIAL-TEMPORAL PATTERNS。通过利用 calibration 数据，我们开发了两种COMPLEMENTARY METHODS TO CONSTRUCT cVEP temporal patterns：基于刺激序列的直线模型方法和使用交叉主题数据的转移学习技术。因此，我们实现了最高的 ITR 250 bpm ，在有限的 calibration 下，这个成果已经被证明可以与当前 SSVEP 方法相比。总之，我们的工作在几个shot学习中提高了 cVEP 性能，这可能扩大 BCIs 的实用性和可用性。
Joint Design of ISAC Waveform under PAPR Constraints
results: 实验结果表明，提出的双功能波形可以提供良好的通信质量服务（QoS）和感知性能。Abstract
In this paper, we formulate the precoding problem of integrated sensing and communication (ISAC) waveform as a non-convex quadratically constrainted quadratic program (QCQP), in which the weighted sum of communication multi-user interference (MUI) and the gap between dual-use waveform and ideal radar waveform is minimized with peak-to-average power ratio (PAPR) constraints. We propose an efficient algorithm based on alternating direction method of multipliers (ADMM), which is able to decouple multiple variables and provide a closed-form solution for each subproblem. In addition, to improve the sensing performance in both spatial and temporal domains, we propose a new criteria to design the ideal radar waveform, in which the beam pattern is made similar to the ideal one and the integrated sidelobe level of the ambiguity function in each target direction is minimized in the region of interest. The limited memory Broyden-Fletcher-Goldfarb-Shanno (L-BFGS) algorithm is applied to the design of the ideal radar waveform which works as a reference in the design of the dual-function waveform. Numerical results indicate that the designed dual-function waveform is capable of offering good communication quality of service (QoS) and sensing performance.
摘要
在本文中，我们将 интеграted sensing and communication（ISAC）波形的预处理问题设为非对称quadratically constrained quadratic program（QCQP），其中Weighted sum of communication multi-user interference（MUI）和理想 radar 波形与实际 radar 波形之间的差异是最小化的，同时受限于峰值至平均功率比（PAPR）的约束。我们提出了一种高效的 alternating direction method of multipliers（ADMM）算法，可以分解多个变量并提供每个子问题的关闭式解。此外，为了提高探测性能在空间和时域两个领域，我们提出了一新的标准来设计理想 radar 波形，其中扫描方式与理想波形类似，并在兴趣区域内尽量减少了各个方向的混合副幅水平。我们使用了有限记忆 Broyden-Fletcher-Goldfarb-Shanno（L-BFGS）算法来设计理想 radar 波形，该波形作为双功能波形的参照。numerical results表明，设计的双功能波形能够提供良好的通信质量服务（QoS）和探测性能。
Asymptotic CRB Analysis of Random RIS-Assisted Large-Scale Localization Systems
results: 我们发现，在提posed 随机配置 RIS 系统中， asymptotic 公式可以准确地 approximate exact CRB。numerical 结果表明，随机配置 RIS 对 CRB 的影响是非常显著的。Abstract
This paper studies the performance of a randomly RIS-assisted multi-target localization system, in which the configurations of the RIS are randomly set to avoid high-complexity optimization. We first focus on the scenario where the number of RIS elements is significantly large, and then obtain the scaling law of Cram\'er-Rao bound (CRB) under certain conditions, which shows that CRB decreases in the third or fourth order as the RIS dimension increases. Second, we extend our analysis to large systems where both the number of targets and sensors is substantial. Under this setting, we explore two common RIS models: the constant module model and the discrete amplitude model, and illustrate how the random RIS configuration impacts the value of CRB. Numerical results demonstrate that asymptotic formulas provide a good approximation to the exact CRB in the proposed randomly configured RIS systems.
摘要
这篇论文研究了随机RIS协助的多Target定位系统的性能，其中RIS配置随机设置以避免高复杂性优化。我们首先关注了RIS元素数量相对较多的场景，然后获得CRB下降的幂级关系，显示CRB在RIS维度增加的第三或第四阶幂下降。其次，我们扩展我们的分析至大规模系统，其中目标和感知器的数量都是substantial。在这种设置下，我们探讨了两种常见RIS模型：常数模块模型和随机振荡模型，并解释了随机RIS配置对CRB的影响。数值结果表明，幂级公式可以准确地 aproximate exact CRB在我们提议的随机配置RIS系统中。
On the Effective throughput of Shadowed Beaulieu-Xie fading channel
for: investigate data rate performance across various fading scenarios
methods: PDF-based approach, low-SNR and high-SNR approximation
results: effective throughput and impact of system parameters and delay parameter on effective throughputAbstract
Given the imperative for advanced wireless networks in the next generation and the rise of real-time applications within wireless communication, there is a notable focus on investigating data rate performance across various fading scenarios. This research delved into analyzing the effective throughput of the shadowed Beaulieu-Xie (SBX) composite fading channel using the PDF-based approach. To get the simplified relationship between the performance parameter and channel parameters, the low-SNR and the high-SNR approximation of the effective rate are also provided. The proposed formulations are evaluated for different values of system parameters to study their impact on the effective throughput. Also, the impact of the delay parameter on the EC is investigated. Monte-Carlo simulations are used to verify the facticity of the deduced equations.
摘要
随着下一代无线网络的需求和实时应用在无线通信中的增长，研究数据传输速率在不同的抑噪场景下的性能已经得到了广泛的关注。本研究利用PDF基本方法对shadowed Beaulieu-Xie（SBX）复杂抑噪通道的有效传输率进行分析。为了获得简化关系 между性能参数和通道参数，本研究还提供了低SNR和高SNR的近似值。通过不同系统参数的调整，研究对效果传输率的影响。此外，延迟参数对EC的影响也被调查。使用Monte Carlo仿真来验证推导出的公式。