methods: 作者通过分析数据模调对雷达探测性能的影响， derivation of the ambiguity function（AF）of the OTFS waveform， and characterization of the radar global accuracy。
results: 作者通过分析数据分布对AF的行为进行了准确的approximation，并证明OTFS波形在雷达性能方面的全球性能与OFDM波形相当。Abstract
Orthogonal time frequency space (OTFS) modulation has recently been identified as a suitable waveform for joint radar and communication systems. Focusing on the effect of data modulation on the radar sensing performance, we derive the ambiguity function (AF) of the OTFS waveform and characterize the radar global accuracy. We evaluate the behavior of the AF with respect to the distribution of the modulated data and derive an accurate approximation for the mean and variance of the AF, thus, approximating its distribution by a Rice distribution. Finally, we evaluate the global radar performance of the OTFS waveform with the OFDM waveform.
摘要
Orthogonal time frequency space (OTFS) 模ulation 已经被认为是合适的探测和通信系统之waveform。我们专注于数据模ulation对探测性能的影响， derivation ambiguity function (AF) 的OTFS 波形，并Characterize 激光全球精度。我们分析了对于数据分布的影响，并 derive 精度和方差的准确估计，因此可以简化 AF 的分布为Rice distribution。最后，我们评估了 OTFS 波形和 OFDM 波形之间的全球激光性能。Note: Please note that the translation is in Simplified Chinese, which is the standard form of Chinese used in mainland China and Singapore. If you need Traditional Chinese, please let me know.
Linear Least Squares Estimation of Fiber-Longitudinal Optical Power Profile
results: 实验结果表明，该方法可以准确地估算光纤中的力度分布，RMS 误差为 0.18 dB。此外，该方法还能够成功地检测到小于 0.77 dB 的损失缺陷。Abstract
This paper presents a linear least squares method for fiber-longitudinal power profile estimation (PPE), which estimates an optical signal power distribution throughout a fiber-optic link at a coherent receiver. The method finds the global optimum in least square estimation of longitudinal power profiles, thus closely matching true optical power profiles and locating loss anomalies in a link with high spatial resolution. Experimental results show that the method achieves accurate PPE with an RMS error from OTDR of 0.18 dB. Consequently, it successfully identifies a loss anomaly as small as 0.77 dB, demonstrating the potential of a coherent receiver in locating even splice and connector losses. The method is also evaluated under a WDM condition with optimal system fiber launch power, highlighting its feasibility for use in operations. Furthermore, a fundamental limit for stable estimation and spatial resolution of least-squares-based PPE is quantitatively discussed in relation to the ill-posedness of PPE by evaluating the condition number of a nonlinear perturbation matrix.
摘要
Translation notes:* "fiber-longitudinal" is translated as "长itudinal" (cháng yǐng) to emphasize the direction of the power profile estimation.* "optical signal power distribution" is translated as "光学信号电压分布" (guāng yǐng xìn yuè diàn yuè fēn bù) to emphasize the distribution of the optical signal power.* "coherent receiver" is translated as "同步接收器" (tóng xù jì huò) to emphasize the type of receiver used in the method.* "loss anomalies" is translated as "损失异常" (shèng shí yì cháng) to emphasize the type of anomalies detected by the method.* "high spatial resolution" is translated as "高空间分辨率" (gāo kōng jìan fēn biéng rù) to emphasize the accuracy of the method in locating the loss anomalies.* "WDM condition" is translated as "WDM条件" (WDM tiáo jiàn) to emphasize the specific condition under which the method is evaluated.* "optimal system fiber launch power" is translated as "最佳系统纤维发射功率" (zuì jì system fàng xiàng yì yì) to emphasize the importance of the launch power in the method.
A Grouping-based Scheduler for Efficient Channel Utilization under Age of Information Constraints
results: simulation 结果显示，提出的二步分组算法（TGA）可以减少通道使用率，与一个先前的工作相比，在许多情况下显著减少了channel使用率，并且与一个 derive 的下界相比，当有多个来源时，channel使用率为0.42%。Abstract
We consider a status information updating system where a fusion center collects the status information from a large number of sources and each of them has its own age of information (AoI) constraints. A novel grouping-based scheduler is proposed to solve this complex large-scale problem by dividing the sources into different scheduling groups. The problem is then transformed into deriving the optimal grouping scheme. A two-step grouping algorithm (TGA) is proposed: 1) Given AoI constraints, we first identify the sources with harmonic AoI constraints, then design a fast grouping method and an optimal scheduler for these sources. Under harmonic AoI constraints, each constraint is divisible by the smallest one and the sum of reciprocals of the constraints with the same value is divisible by the reciprocal of the smallest one. 2) For the other sources without such a special property, we pack the sources which can be scheduled together with minimum update rates into the same group. Simulations show the channel usage of the proposed TGA is significantly reduced as compared to a recent work and is 0.42% larger than a derived lower bound when the number of sources is large.
摘要
我团队考虑了一个状态信息更新系统，该系统中的拥有者中心从多个来源收集状态信息，每个来源都有自己的年龄信息（AoI）约束。我们提出了一种分组方式的计划器，用于解决这个复杂的大规模问题。问题转化为找到最佳分组方案。我们提出了两步分组算法（TGA）：1. 给定AoI约束，我们首先将来源分为具有幂等AoI约束的源组和其他无特殊性质的源组。在幂等AoI约束下，每个约束都是最小一个的分母，并且所有具有相同值的约束的 reciprocal 之和是最小一个的分母的reciprocal的分母。2. 对于其他无特殊性质的来源，我们将具有最小更新频率的来源打包在同一组中。实验表明，提案的TGA Channel使用率significantly reduced compared to recent work, and is 0.42% larger than a derived lower bound when the number of sources is large.
Age of Information Guaranteed Scheduling for Asynchronous Status Updates in Collaborative Perception
for: The paper is written for collaborative perception (CP) systems where a fusion center monitors various regions using multiple sources, and the center has different age of information (AoI) constraints for different regions.
methods: The paper proposes an algorithm called scheduling for CP with asynchronous status updates (SCPA) to minimize the number of required channels and subject to AoI constraints with asynchronous status updates.
results: According to numerical results, the number of channels required by SCPA can reach only 12% more than a derived lower bound.Abstract
We consider collaborative perception (CP) systems where a fusion center monitors various regions by multiple sources. The center has different age of information (AoI) constraints for different regions. Multi-view sensing data for a region generated by sources can be fused by the center for a reliable representation of the region. To ensure accurate perception, differences between generation time of asynchronous status updates for CP fusion should not exceed a certain threshold. An algorithm named scheduling for CP with asynchronous status updates (SCPA) is proposed to minimize the number of required channels and subject to AoI constraints with asynchronous status updates. SCPA first identifies a set of sources that can satisfy the constraints with minimum updating rates. It then chooses scheduling intervals and offsets for the sources such that the number of required channels is optimized. According to numerical results, the number of channels required by SCPA can reach only 12% more than a derived lower bound.
摘要
我们考虑了协同感知（CP）系统，其中统计中心监控多个区域，并且从多个来源获取多元观察数据。中心具有不同的资讯年龄（AoI）限制 для不同的区域。多元感知数据 для一个区域由来源生成，可以在中心进行融合，以获得区域的可靠表现。确保正确感知，协同感知融合中的不同时间生成的 asynchronous status updates 差异应小于一定阈值。一个名为协同感知 avec asynchronous status updates 的算法（SCPA）被提出，以最小化需要的通道数量，并且遵循 AoI 限制。SCPA 首先 identific 一群可以满足限制的来源，然后选择这些来源的调度间隔和偏移量，以便优化通道数量。根据数据显示，SCPA 可以对需要的通道数量进行最小化，与一个 derive 的下限相差只有12%。
Score-based Diffusion Models With Self-supervised Learning For Accelerated 3D Multi-contrast Cardiac Magnetic Resonance Imaging
paper_authors: Yuanyuan Liu, Zhuo-Xu Cui, Congcong Liu, Hairong Zheng, Haifeng Wang, Yihang Zhou, Yanjie Zhu for:这种研究旨在加速3D-MC-CMR成像过程，以提高其广泛应用的可行性。methods:研究人员提出了一种基于自我监督学习的新方法，使用得分基于扩散模型来加速3D-MC-CMR成像。这种方法首先建立了快照测量和MR图像之间的映射，然后使用自我监督 Bayesian 重建网络来恢复MR图像。最后，研究人员开发了一种三维分布的分数基于扩散模型，以捕捉3D-MC-CMR图像的自然分布。results:实验结果表明，该方法比传统的压缩感知和现有的自我监督深度学习MRI重建方法更高效。它还可以在高速度压缩率14的情况下获得高质量的T1和T1rho参数地图，与参照地图相似。Abstract
Long scan time significantly hinders the widespread applications of three-dimensional multi-contrast cardiac magnetic resonance (3D-MC-CMR) imaging. This study aims to accelerate 3D-MC-CMR acquisition by a novel method based on score-based diffusion models with self-supervised learning. Specifically, we first establish a mapping between the undersampled k-space measurements and the MR images, utilizing a self-supervised Bayesian reconstruction network. Secondly, we develop a joint score-based diffusion model on 3D-MC-CMR images to capture their inherent distribution. The 3D-MC-CMR images are finally reconstructed using the conditioned Langenvin Markov chain Monte Carlo sampling. This approach enables accurate reconstruction without fully sampled training data. Its performance was tested on the dataset acquired by a 3D joint myocardial T1 and T1rho mapping sequence. The T1 and T1rho maps were estimated via a dictionary matching method from the reconstructed images. Experimental results show that the proposed method outperforms traditional compressed sensing and existing self-supervised deep learning MRI reconstruction methods. It also achieves high quality T1 and T1rho parametric maps close to the reference maps obtained by traditional mapping sequences, even at a high acceleration rate of 14.
摘要
长时间扫描减少了三维多contrast室内Magnetic Resonance成像（3D-MC-CMR）的广泛应用。本研究目的是加速3D-MC-CMR获取的速度。我们采用了一种基于得分分布模型的自我超vised学习方法。首先，我们使用一种自我超vised Bayesian重建网络将不完全样本空间测量映射到MR图像中。其次，我们开发了一种三维分布Score-based扩散模型，以捕捉3D-MC-CMR图像的内在分布。最后，我们使用 conditioned Langenvin Markov chain Monte Carlo采样来重建图像。这种方法可以准确重建图像，不需要完全的样本数据。我们对一个3D联合肌肉T1和T1rho映射序列上获取的数据进行了实验测试。结果表明，我们的方法比传统的压缩感知和现有的自我超vised深度学习MRI重建方法更好。它还可以在高速度减少14%的情况下获得高质量的T1和T1rho参数图像，与传统映射序列中的参考图像几乎相同。
Space Observation by the Australia Telescope Compact Array: Performance Characterization using GPS Satellite Observation
paper_authors: Hamed Nosrati, Stephanie Smith, Douglas B. Hayman
for: 用于升级澳大利亚天体望远镜数据启用空间卫星定位应用
methods: 基于干扰数据的系统模型，实现距离和方向估算
results: 与最新的二线元素（TLE）进行比较，显示距离和方向信息都得到了明显改善Abstract
In order to operationalize the Australia Telescope Compact Array (ATCA) for space situational awareness (SSA) applications, we develop a system model for range and direction of arrival (DOA) estimation based on the interferometric data. We employ the observational data collected from global positioning system (GPS) satellites to evaluate the developed model and demonstrate that, compared to a priori location propagated from the most recent two-line element (TLE), both range and direction information are improved significantly.
摘要
为了使澳大利亚望远镜数组（ATCA）用于空间定位意识（SSA）应用，我们开发了基于互相干涉数据的系统模型，以便估算距离和方向信息。我们使用全球定位系统（GPS）卫星的观测数据来评估我们开发的模型，并证明在比之前两行元素（TLE）的位置进行质量提高后，距离和方向信息都得到了显著改善。