paper_authors: Alessandro Nordio, Carla Fabiana Chiasserini, Emanuele Viterbo for: 本研究旨在准确地Localizing N个无人航空器（UAV）在3D空间中，UAVs组成一个群体，通过相互通信，并通过时域频率空间（OTFS）模ulates信号来进行通信。methods: 本研究使用了一种迭代算法，名为Turbo Iterative Positioning（TIP），通过信念传播方法，有效地利用了时差到达（TDoA）测量结果中的LoS和非LoS paths之间的时差。results: 本研究的numerical results和实际轨迹数据显示，通过利用多重射频信号的多path链接，可以实现very accurate的UAV localization和速度测量，即使具有有限的延迟-Doppler分辨率。本研究的方案Robustness也得到了证明，性能接近Cramer-Rao bound。Abstract
We consider the problem of accurately localizing N unmanned aerial vehicles (UAV) in 3D space where the UAVs are part of a swarm and communicate with each other through orthogonal time-frequency space (OTFS) modulated signals. Each receiving UAV estimates the multipath wireless channel on each link formed by the line-of-sight (LoS) transmission and by the single reflections from the remaining N-2 UAVs. The estimated power delay profiles are communicated to an edge server, which is in charge of computing the exact location and speed of the UAVs. To obtain the UAVs locations and velocities, we propose an iterative algorithm, named Turbo Iterative Positioning (TIP), which, using a belief-propagation approach, effectively exploits the time difference of arrival (TDoA) measurements between the LoS and the non-LoS paths. Enabling a full cold start (no prior knowledge), our solution first maps each TDoA's profile element to a specific ID of the reflecting UAV's. The Doppler shifts measured by the OTFS receivers associated with each path are also used to estimate the UAV's velocities. The localization of the N UAVs is then derived via gradient descent optimization, with the aid of turbo-like iterations that can progressively correct some of the residual errors in the initial ID mapping operation. Our numerical results, obtained also using real-world traces, show how the multipath links are beneficial to achieving very accurate localization and speed of all UAVs, even with a limited delay-Doppler resolution. Robustness of our scheme is proven by its performance approaching the Cramer-Rao bound.
摘要
我们考虑一个精确地对N个无人机（UAV）进行三维空间 Localization的问题，这些UAV彼此通过时间频率空间（OTFS）快速干扰信号互动。每个接收UAV估计彼此之间的多普勒无线通信道，包括直线视线（LoS）传输和剩下N-2 UAV的单反射。估计的电力延迟资料传递到Edge服务器，这个服务器负责计算UAV的精确位置和速度。为了获取UAV的位置和速度，我们提出了一个迭代算法，名为Turbo迭代位置定位（TIP），这个算法使用信念传递方法，对TDoA测量值进行有效地利用，以获取UAV的位置和速度。我们的解决方案不需要实际的对称知识，可以实现冷启动（完全实际）。我们首先将每个TDoA的资料夹映射到特定的反射UAV的ID中。OTFS接收器相关的每条路径也使用Doppler偏移量估计UAV的速度。然后，我们使用梯度下降优化，透过迭代调整过程，逐渐纠正初始ID映射过程中的余额错误。我们的数据分析结果显示，多普勒连接可以实现UAV的精确位置和速度测量，即使延迟-Doppler分辨率有限。我们的方案的稳定性被证明为接近Cramer-Rao bound。
Odor-Based Molecular Communications: State-of-the-Art, Vision, Challenges, and Frontier Directions
paper_authors: Dilara Aktas, Beyza Ezgi Ortlek, Meltem Civas, Elham Baradari, Ayse Sila Okcu, Melanie Whitfield, Oktay Cetinkaya, Ozgur Baris Akan for:* This paper aims to explore the concept of odor-based molecular communication (OMC) and its potential applications in the Internet of Everything (IoE).methods:* The paper examines olfactory systems in nature, including aspects of odor information, channels, reception, spatial perception, and cognitive functions.* The paper compares various communication systems to highlight the unique characteristics, advantages, and potential applications of OMC.results:* The paper lays the groundwork for exploring the modeling of an end-to-end OMC channel, considering the design of OMC transmitters and receivers, and developing innovative OMC techniques.Abstract
Humankind mimics the processes and strategies that nature has perfected and uses them as a model to address its problems. That has recently found a new direction, i.e., a novel communication technology called molecular communication (MC), using molecules to encode, transmit, and receive information. Despite extensive research, an innate MC method with plenty of natural instances, i.e., olfactory or odor communication, has not yet been studied with the tools of information and communication technologies (ICT). Existing studies focus on digitizing this sense and developing actuators without inspecting the principles of odor-based information coding and MC, which significantly limits its application potential. Hence, there is a need to focus cross-disciplinary research efforts to reveal the fundamentals of this unconventional communication modality from an ICT perspective. The ways of natural odor MC in nature need to be anatomized and engineered for end-to-end communication among humans and human-made things to enable several multi-sense augmented reality technologies reinforced with olfactory senses for novel applications and solutions in the Internet of Everything (IoE). This paper introduces the concept of odor-based molecular communication (OMC) and provides a comprehensive examination of olfactory systems. It explores odor communication in nature, including aspects of odor information, channels, reception, spatial perception, and cognitive functions. Additionally, a comprehensive comparison of various communication systems sets the foundation for further investigation. By highlighting the unique characteristics, advantages, and potential applications of OMC through this comparative analysis, the paper lays the groundwork for exploring the modeling of an end-to-end OMC channel, considering the design of OMC transmitters and receivers, and developing innovative OMC techniques.
摘要
人类会模仿自然界的过程和策略，用作解决问题的模型。最近发现了一个新的方向，即基于分子的通信技术（MC），使用分子编码、传输和接收信息。尽管已进行了广泛的研究，但是没有尝试使用信息和通信技术（ICT）的工具来研究自然界中的嗅觉通信。现有的研究主要关注数字化这种感官和开发无 actuators，而未能够研究嗅觉信息编码和MC的基本原理，这限制了其应用前景。因此，需要进行跨学科研究，以探索嗅觉通信模式的基本原理从ICT的角度。自然界中的嗅觉通信需要被解剖和工程化，以实现人类和人工物之间的端到端通信，以推动多感官增强现实技术，并提供新的应用和解决方案在互联网东西（IoE）中。本文引入了基于嗅觉分子通信（OMC）的概念，并进行了全面的嗅觉系统的检查。它探讨了自然界中嗅觉信息的方面，包括嗅觉通信的途径、感知、空间识别和认知功能。此外，还进行了多种通信系统的比较分析，为进一步的调查提供了基础。通过强调OMC的独特特点、优势和应用前景，本文奠定了发展OMC技术的基础，包括设计OMC传输器和接收器，以及开发创新OMC技术。
Multi-dimensional Energy Limitation in Sphere Shaping for Nonlinear Interference Noise Mitigation
results: 比 conventinal ESS提高0.19比特/4D符号的可能信息率，且对多 span 系统的实现效果不好Abstract
We propose Four-Dimensional (4D) energy limit enumerative sphere shaping (ESS) of $M$-QAM signaling to minimize rate loss and improve the transmission performance over non-linear WDM optical-fiber systems. Simulation results show that the proposed scheme outperforms the conventional ESS by $0.19$~bit/4D-symbol in achievable information rate over a $205$-km single-span link and a WDM transmission of five polarization-division-multiplexed channels with $400$-Gbit/s net rate per channel. We also study the achieved performance over several shaping block lengths and show that the achieved gains do not scale well over multi-span systems.
摘要
我们提议四维（4D）能量限数列式圆形几何（ESS）来减少率损和提高传输性能 над 非线性滤波器系统。模拟结果显示，我们的方案比传统ESS提高了0.19比特/4D符号的可能信息率，在205公里单 span 链路上传输五条极化分多频道的400 Gbit/s网络率。我们还研究了不同的数列块长度所得到的性能，结果显示，所得到的优化不对多 span 系统 scales well。Here's a breakdown of the translation:* "We propose" is translated as "我们提议" (wǒmen tīshì)* "Four-Dimensional" is translated as "四维" (sìwèi)* "energy limit enumerative sphere shaping" is translated as "能量限数列式圆形几何" (néngyù jiào xiàng yǐngyòu yuánxìng)* "of $M$-QAM signaling" is translated as "几何信号的$M$-QAM" (jīhè xìnshì de $M$-QAM)* "to minimize rate loss and improve the transmission performance" is translated as "来减少率损和提高传输性能" (lái jiǎnshǎo jìshè yǔ fāngkuò yùnxìng)* "over non-linear WDM optical-fiber systems" is translated as " над 非线性滤波器系统" (fēi xiàn xìng yìbò qì zhì)* "Simulation results show" is translated as "模拟结果显示" (móxì jiéguǒ yǐnshì)* "that the proposed scheme outperforms the conventional ESS by $0.19$~bit/4D-symbol" is translated as "所提出的方案比传统ESS提高了0.19比特/4D符号" (suǒ tīshì de fāngyìn bǐ chuánxīn ESS jìshè yǐnshì)* "in achievable information rate" is translated as "的可能信息率" (de kěnéng xìnwén yìndù)* "over a $205$-km single-span link" is translated as "在205公里单 span 链路上" (zhī yī qiān liàng zhī yī qiān)* "and a WDM transmission of five polarization-division-multiplexed channels with $400$-Gbit/s net rate per channel" is translated as "以及五条极化分多频道的400 Gbit/s网络率" (yǐn yǐ jī hóng fāng qiū duō yī qiān)* "We also study the achieved performance over several shaping block lengths" is translated as "我们还研究了不同的数列块长度所得到的性能" (wǒmen hái yánjiū le bùdìng de duō zhì qiū yǐn yì)* "and show that the achieved gains do not scale well over multi-span systems" is translated as "并显示所得到的优化不对多 span 系统 scales well" (yǔshì suǒ de yǐn yì bù dài zhì yǐn yì)
Fault-Tolerant Four-Dimensional Constellation for Coherent Optical Transmission Systems
results: 比PDM-8QAM-星和4D-2A-8PSK增加10.6%和4%的最大传输距离（400km和160km），具有较好的抗干扰性能和稳定性。Abstract
We propose a 4-dimensional 2-ary amplitude ring-switched modulation format with 64 symbols, which is denoted as 4D-2A-RS64 encoded over two polarization tributaries to improve the transmission performance over long-haul optical fibers in the presence of the non-linear Kerr effect. At a spectral efficiency of 6 bits per 4D, simulation results show that this format outperforms the polarization division multiplexed (PDM) 8QAM-star modulation as well as the 4D-2A-8PSK over links without inline dispersion management. We evaluate the performance for a WDM transmission of $11\times90~\mathrm{Gbaud}$ channels over a multi-span SSMF link. For an achievable information rate of $4.8\mathrm{bit/s/Hz}$, the maximum transmission distance is improved by $10.6\%$ (400 km) and $4\%$ (160 km) compared to PDM-8QAM-star and 4D-2A-8PSK respectively. The achieved gains are composed of a linear part and a non-linear part, respectively from the improved Euclidean-distance distribution and the constant power property of the 4D modulation. The geometric shaping of the proposed scheme is easy to implement and is robust to Mach-Zehnder modulator (MZM) imbalances and quantization errors stemming from the finite digital-to-analog converter (DAC) resolution. This robustness is compared to the one of other geometric-shaped non-linearity tolerant 4D schemes such as the 4D-2A-8PSK and the 4D-64PRS that can be both outperformed by our scheme in severe conditions.
摘要
我们提出了一种四维度两个参数环 switched 模调 format，用于提高长距离光纤传输性能，这种 format 被称为 4D-2A-RS64，并在两个极化传输 tributaries 上进行编码。在每个 symbol 上，我们使用了 sixteen 种可能的值，这使得我们可以在每个 symbol 上实现 six 比特的 spectral efficiency。我们通过 simulate 结果表明，这种 format 在无 inline dispersion management 的情况下可以超越 PDM 8QAM-star 和 4D-2A-8PSK 模式。我们对 $11\times90~\mathrm{Gbaud}$ ChanNels 的 WDM 传输进行评估，并对 multi-span SSMF 链进行评估。为了实现 $4.8\mathrm{bit/s/Hz}$ 的可接受信息率，我们发现了以下结果：* 在 400 km 的传输距离上，我们可以提高最大传输距离 by 10.6%，相比 PDM-8QAM-star 和 4D-2A-8PSK 模式。* 在 160 km 的传输距离上，我们可以提高最大传输距离 by 4%，相比 PDM-8QAM-star 和 4D-2A-8PSK 模式。这种提高的成果是由于 improved Euclidean-distance distribution 和 constant power property of the 4D modulation 的共同作用。我们的方案的 geometric shaping 易于实现，并且具有较高的 robustness，可以抗衡 MZM 不均衡和 DAC 的量化误差。与其他 geometric-shaped non-linearity tolerant 4D 方案相比，我们的方案可以在严格的条件下表现更好。
Optimization in Mobile Augmented Reality Systems for the Metaverse over Wireless Communications
results: 这个论文提出了一种名为LEAO算法的解决方案，并对LEAO算法和其他相关算法在不同的 simulate enario中进行了性能评估。结果显示LEAO算法在响应时间、准确率和能量消耗等方面表现出色。Abstract
As the essential technical support for Metaverse, Mobile Augmented Reality (MAR) has attracted the attention of many researchers. MAR applications rely on real-time processing of visual and audio data, and thus those heavy workloads can quickly drain the battery of a mobile device. To address such problem, edge-based solutions have appeared for handling some tasks that require more computing power. However, such strategies introduce a new trade-off: reducing the network latency and overall energy consumption requires limiting the size of the data sent to the edge server, which, in turn, results in lower accuracy. In this paper, we design an edge-based MAR system and propose a mathematical model to describe it and analyze the trade-off between latency, accuracy, server resources allocation and energy consumption. Furthermore, an algorithm named LEAO is proposed to solve this problem. We evaluate the performance of the LEAO and other related algorithms across various simulation scenarios. The results demonstrate the superiority of the LEAO algorithm. Finally, our work provides insight into optimization problem in edge-based MAR system for Metaverse.
摘要
为Metaverse的重要技术支持，移动增强现实（MAR）已经吸引了许多研究者的关注。MAR应用程序需要实时处理视觉和听音数据，因此这些重要的工作负载可以快速抽取移动设备的电池。为解决这个问题，边缘解决方案出现了，用于处理一些需要更高计算能力的任务。然而，这些策略引入了一个新的贸易OFF：以减少网络延迟和总能耗而降低数据的大小，却会导致减少准确性。在这篇论文中，我们设计了边缘基 MAR 系统，并提出了一个数学模型来描述它和分析贸易OFF。此外，我们还提出了一个名为LEAO的算法来解决这个问题。我们在多个 simulate 场景中评估了 LEAO 和其他相关的算法的性能。结果表明 LEAO 算法的超越性。最后，我们的工作为边缘基 MAR 系统的优化问题提供了深入的理解。
Combating Multi-path Interference to Improve Chirp-based Underwater Acoustic Communication
results: 比LoRa原型设计高3倍的比特错误率和显著提高的包错误率，与现状最佳系统相比提高传输率达50倍Abstract
Linear chirp-based underwater acoustic communication has been widely used due to its reliability and long-range transmission capability. However, unlike the counterpart chirp technology in wireless -- LoRa, its throughput is severely limited by the number of modulated chirps in a symbol. The fundamental challenge lies in the underwater multi-path channel, where the delayed copied of one symbol may cause inter-symbol and intra-symbol interfere. In this paper, we present UWLoRa+, a system that realizes the same chirp modulation as LoRa with higher data rate, and enhances LoRa's design to address the multi-path challenge via the following designs: a) we replace the linear chirp used by LoRa with the non-linear chirp to reduce the signal interference range and the collision probability; b) we design an algorithm that first demodulates each path and then combines the demodulation results of detected paths; and c) we replace the Hamming codes used by LoRa with the non-binary LDPC codes to mitigate the impact of the inevitable collision.Experiment results show that the new designs improve the bit error rate (BER) by 3x, and the packet error rate (PER) significantly, compared with the LoRa's naive design. Compared with an state-of-the-art system for decoding underwater LoRa chirp signal, UWLoRa+ improves the throughput by up to 50 times.
摘要
Linear chirp-based 水下射频通信已经广泛使用，因为它的可靠性和距离传输能力很强。然而，与无线LoRa技术不同，它的传输速率受到每个符号中弹性遮盾的数量所限。这个基本挑战在水下多普通道通信中，因为延迟的弹性遮盾可能会导致内 Symbol 和 External Symbol 干扰。在这篇文章中，我们提出 UWLoRa+，一个可以实现LoRa技术中的同步驱动干扰，并且通过以下设计来解决多普通道挑战：a) 将LoRa技术中使用的线性驱动更换为非线性驱动，以减少干扰距离和碰撞几率。b) 设计一个算法，首先对每条路径进行解调，然后结合检测到的所有路径的解调结果。c) 将LoRa技术中使用的汉明码更换为非二进制的LDPC码，以减少不可预测的碰撞的影响。实验结果显示，新的设计可以提高比特错误率（BER）3倍，并且对封包错误率（PER）有很大的改善，相比于LoRa技术的原生设计。相比于现有的水下LoRa射频讯号解析系统，UWLoRa+可以提高传输速率高达50倍。
A Unified Framework for Multi-Hop Wireless Relaying with Hardware Impairments
results: 文章发现在高信号噪比下，多 hop relay 系统的总均值信号噪声比会达到高水平，与硬件不 ideal 水平成正比。此外，文章还提出了一些实用优化问题，以寻找最佳硬件不 ideal 水平。Abstract
Relaying increases the coverage area and reliability of wireless communications systems by mitigating the fading effect on the received signal. Most technical contributions in the context of these systems assume ideal hardware (ID) by neglecting the non-idealities of the transceivers, which include phase noise, in-phase/quadrature mismatch and high power amplifier nonlinearities. These non-idealities create distortion on the received signal by causing variations in the phase and attenuating the amplitude. The resulting deterioration of the performance of wireless communication systems is further magnified as the frequency of transmission increases. In this paper, we investigate the aggregate impact of hardware impairments (HI) on the general multi-hop relay system using amplify-and-forward (AF) and decode-and-forward (DF) relaying techniques over a general H-fading model. H-fading model includes free space optics, radio frequency, millimeter wave, Terahertz, and underwater fading models. Closed-form expressions of outage probability, bit error probability and ergodic capacity are derived in terms of H-functions. Following an asymptotic analysis at high signal-to-noise ratio (SNR), practical optimization problems have been formulated with the objective of finding the optimal level of HI subject to the limitation on the total HI level. The analytical solution has been derived for the Nakagami-m fading channel which is a special case of H-fading for AF and DF relaying techniques. The overall instantaneous signal-to-noise-plus-distortion ratio has been demonstrated to reach a ceiling at high SNRs which has a reciprocal proportion to the HI level of all hops transceivers on the contrary to the ID.
摘要
通过重复器提高无线通信系统的覆盖区域和可靠性，重复器可以减轻接收信号的抖抖效应。大多数技术贡献在这些系统中假设硬件是理想的（ID），忽略了发射器和接收器的非理想特性，包括相位噪声、相位和阶跃偏移和高功率扩大器非线性。这些非理想特性会在接收信号上引入偏移和减弱幅度，从而降低无线通信系统的性能。随着传输频率的增加，这种降低的效果会变得更加明显。在这篇论文中，我们研究了硬件不良（HI）对总体多跳 relay 系统的影响，使用扩大并发送（AF）和解码并发送（DF） relaying 技术，在一般 H-fading 模型下。H-fading 模型包括自由空间光学、无线电波、毫米波、teraHz 和水下折射模型。我们使用 H-函数关系 derivation 得出了干扰概率、位噪声率和平均容量的关系。通过高信噪比（SNR）的 asymptotic 分析，我们形ulated 了实用优化问题，寻找最佳的 HI 水平，以满足总体 HI 水平的限制。对 Nakagami-m 折射通道的特殊情况（AF 和 DF relaying 技术），我们得出了分析解。我们发现，在高 SNR 下，总体实时信号噪声比会达到最高值，与 HI 水平成反比。