In the literature, machine learning (ML) has been implemented at the base station (BS) and user equipment (UE) to improve the precision of downlink channel state information (CSI). However, ML implementation at the UE can be infeasible for various reasons, such as UE power consumption. Motivated by this issue, we propose a CSI learning mechanism at BS, called CSILaBS, to avoid ML at UE. To this end, by exploiting channel predictor (CP) at BS, a light-weight predictor function (PF) is considered for feedback evaluation at the UE. CSILaBS reduces over-the-air feedback overhead, improves CSI quality, and lowers the computation cost of UE. Besides, in a multiuser environment, we propose various mechanisms to select the feedback by exploiting PF while aiming to improve CSI accuracy. We also address various ML-based CPs, such as NeuralProphet (NP), an ML-inspired statistical algorithm. Furthermore, inspired to use a statistical model and ML together, we propose a novel hybrid framework composed of a recurrent neural network and NP, which yields better prediction accuracy than individual models. The performance of CSILaBS is evaluated through an empirical dataset recorded at Nokia Bell-Labs. The outcomes show that ML elimination at UE can retain performance gains, for example, precoding quality.
在文献中，机器学习（ML）已在基站（BS）和用户设备（UE）上实施，以提高下行链路信道状态信息（CSI）的精度。然而，由于各种原因（如 UE 功耗），在 UE 上实施 ML 可能是不可行的。受这一问题的启发，我们提出了一种在 BS 上的 CSI 学习机制，称为 CSILaBS，以避免在 UE 上进行 ML。CSILaBS 减少了空中反馈开销，提高了 CSI 质量，降低了 UE 的计算成本。此外，在多用户环境中，我们提出了利用 PF 选择反馈的各种机制，目的是提高 CSI 精度。我们还讨论了各种基于 ML 的 CP，如神经先知（NP），一种受 ML 启发的统计算法。此外，受统计模型和 ML 结合使用的启发，我们提出了一种由递归神经网络和 NP 组成的新型混合框架，它比单个模型产生了更好的预测精度。我们通过诺基亚贝尔实验室记录的经验数据集对 CSILaBS 的性能进行了评估。结果表明，在 UE 消除 ML 可以保持性能增益，例如预编码质量。
{"title":"Massive MIMO CSI Feedback using Channel Prediction: How to Avoid Machine Learning at UE?","authors":"Muhammad Karam Shehzad, Luca Rose, Mohamad Assaad","doi":"arxiv-2403.13363","DOIUrl":"https://doi.org/arxiv-2403.13363","url":null,"abstract":"In the literature, machine learning (ML) has been implemented at the base\u0000station (BS) and user equipment (UE) to improve the precision of downlink\u0000channel state information (CSI). However, ML implementation at the UE can be\u0000infeasible for various reasons, such as UE power consumption. Motivated by this\u0000issue, we propose a CSI learning mechanism at BS, called CSILaBS, to avoid ML\u0000at UE. To this end, by exploiting channel predictor (CP) at BS, a light-weight\u0000predictor function (PF) is considered for feedback evaluation at the UE.\u0000CSILaBS reduces over-the-air feedback overhead, improves CSI quality, and\u0000lowers the computation cost of UE. Besides, in a multiuser environment, we\u0000propose various mechanisms to select the feedback by exploiting PF while aiming\u0000to improve CSI accuracy. We also address various ML-based CPs, such as\u0000NeuralProphet (NP), an ML-inspired statistical algorithm. Furthermore, inspired\u0000to use a statistical model and ML together, we propose a novel hybrid framework\u0000composed of a recurrent neural network and NP, which yields better prediction\u0000accuracy than individual models. The performance of CSILaBS is evaluated\u0000through an empirical dataset recorded at Nokia Bell-Labs. The outcomes show\u0000that ML elimination at UE can retain performance gains, for example, precoding\u0000quality.","PeriodicalId":501433,"journal":{"name":"arXiv - CS - Information Theory","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140198926","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The recent paper (IEEE Trans. IT 69, 1680) introduced an analytical method for calculating the channel capacity without the need for iteration. This method has certain limitations that restrict its applicability. Furthermore, the paper does not provide an explanation as to why the channel capacity can be solved analytically in this particular case. In order to broaden the scope of this method and address its limitations, we turn our attention to the reverse em-problem, proposed by Toyota (Information Geometry, 3, 1355 (2020)). This reverse em-problem involves iteratively applying the inverse map of the em iteration to calculate the channel capacity, which represents the maximum mutual information. However, several open problems remained unresolved in Toyota's work. To overcome these challenges, we formulate the reverse em-problem based on Bregman divergence and provide solutions to these open problems. Building upon these results, we transform the reverse em-problem into em-problems and derive a non-iterative formula for the reverse em-problem. This formula can be viewed as a generalization of the aforementioned analytical calculation method. Importantly, this derivation sheds light on the information geometrical structure underlying this special case. By effectively addressing the limitations of the previous analytical method and providing a deeper understanding of the underlying information geometrical structure, our work significantly expands the applicability of the proposed method for calculating the channel capacity without iteration.
最近的一篇论文（IEEE Trans. IT 69, 1680）介绍了一种无需迭代即可计算信道容量的分析方法。这种方法有一定的局限性，限制了其适用性。此外，论文也没有解释为什么在这种特殊情况下可以用分析方法解决信道容量问题。为了扩大该方法的应用范围并解决其局限性，我们将注意力转向丰田提出的反向 em 问题（《信息几何》，3, 1355 (2020)）。这个逆向 em 问题涉及迭代应用迭代的逆映射来计算信道容量，它代表了最大的互信息。然而，在丰田的工作中仍有几个未解决的问题。为了克服这些挑战，我们基于布雷格曼发散法提出了反向em问题，并提供了这些开放问题的解决方案。在这些结果的基础上，我们将反向 em 问题转化为 em 问题，并推导出反向 em 问题的非迭代公式。这个公式可以看作是上述分析计算方法的一般化。重要的是，这一推导揭示了这一特例背后的信息几何结构。通过有效解决前述分析方法的局限性，并提供对底层信息几何结构的更深入理解，我们的工作大大扩展了无迭代信道容量计算方法的适用性。
{"title":"Reverse em-problem based on Bregman divergence and its application to classical and quantum information theory","authors":"Masahito Hayashi","doi":"arxiv-2403.09252","DOIUrl":"https://doi.org/arxiv-2403.09252","url":null,"abstract":"The recent paper (IEEE Trans. IT 69, 1680) introduced an analytical method\u0000for calculating the channel capacity without the need for iteration. This\u0000method has certain limitations that restrict its applicability. Furthermore,\u0000the paper does not provide an explanation as to why the channel capacity can be\u0000solved analytically in this particular case. In order to broaden the scope of\u0000this method and address its limitations, we turn our attention to the reverse\u0000em-problem, proposed by Toyota (Information Geometry, 3, 1355 (2020)). This\u0000reverse em-problem involves iteratively applying the inverse map of the em\u0000iteration to calculate the channel capacity, which represents the maximum\u0000mutual information. However, several open problems remained unresolved in\u0000Toyota's work. To overcome these challenges, we formulate the reverse\u0000em-problem based on Bregman divergence and provide solutions to these open\u0000problems. Building upon these results, we transform the reverse em-problem into\u0000em-problems and derive a non-iterative formula for the reverse em-problem. This\u0000formula can be viewed as a generalization of the aforementioned analytical\u0000calculation method. Importantly, this derivation sheds light on the information\u0000geometrical structure underlying this special case. By effectively addressing\u0000the limitations of the previous analytical method and providing a deeper\u0000understanding of the underlying information geometrical structure, our work\u0000significantly expands the applicability of the proposed method for calculating\u0000the channel capacity without iteration.","PeriodicalId":501433,"journal":{"name":"arXiv - CS - Information Theory","volume":"98 3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140148633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Conversation demands attention. Speakers must call words to mind, listeners must make sense of them, and both together must negotiate this flow of information, all in fractions of a second. We used large language models to study how this works in a large-scale dataset of English-language conversation, the CANDOR corpus. We provide a new estimate of the information density of unstructured conversation, of approximately 13 bits/second, and find significant effects associated with the cognitive load of both retrieving, and presenting, that information. We also reveal a role for backchannels -- the brief yeahs, uh-huhs, and mhmms that listeners provide -- in regulating the production of novelty: the lead-up to a backchannel is associated with declining information rate, while speech downstream rebounds to previous rates. Our results provide new insights into long-standing theories of how we respond to fluctuating demands on cognitive resources, and how we negotiate those demands in partnership with others.
{"title":"From \"um\" to \"yeah\": Producing, predicting, and regulating information flow in human conversation","authors":"Claire Augusta Bergey, Simon DeDeo","doi":"arxiv-2403.08890","DOIUrl":"https://doi.org/arxiv-2403.08890","url":null,"abstract":"Conversation demands attention. Speakers must call words to mind, listeners\u0000must make sense of them, and both together must negotiate this flow of\u0000information, all in fractions of a second. We used large language models to\u0000study how this works in a large-scale dataset of English-language conversation,\u0000the CANDOR corpus. We provide a new estimate of the information density of\u0000unstructured conversation, of approximately 13 bits/second, and find\u0000significant effects associated with the cognitive load of both retrieving, and\u0000presenting, that information. We also reveal a role for backchannels -- the\u0000brief yeahs, uh-huhs, and mhmms that listeners provide -- in regulating the\u0000production of novelty: the lead-up to a backchannel is associated with\u0000declining information rate, while speech downstream rebounds to previous rates.\u0000Our results provide new insights into long-standing theories of how we respond\u0000to fluctuating demands on cognitive resources, and how we negotiate those\u0000demands in partnership with others.","PeriodicalId":501433,"journal":{"name":"arXiv - CS - Information Theory","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140148538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Electrochemical communication is a mechanism that enables intercellular interaction among bacteria within communities. Bacteria achieves synchronization and coordinates collective actions at the population level through the utilization of electrochemical signals. In this work, we investigate the response of bacterial biofilms to artificial potassium concentration stimulation. We introduce signal inputs at a specific location within the biofilm and observe their transmission to other regions, facilitated by intermediary cells that amplify and relay the signal. We analyze the output signals when biofilm regions are subjected to different input signal types and explore their impact on biofilm growth. Furthermore, we investigate how the temporal gap between input pulses influences output signal characteristics, demonstrating that an appropriate gap yields distinct and well-defined output signals. Our research sheds light on the potential of bacterial biofilms as communication nodes in electrochemical communication networks.
{"title":"Electrochemical Communication in Bacterial Biofilms: A Study on Potassium Stimulation and Signal Transmission","authors":"Nithin V. Sabu, Bige Deniz Unluturk","doi":"arxiv-2403.08926","DOIUrl":"https://doi.org/arxiv-2403.08926","url":null,"abstract":"Electrochemical communication is a mechanism that enables intercellular\u0000interaction among bacteria within communities. Bacteria achieves\u0000synchronization and coordinates collective actions at the population level\u0000through the utilization of electrochemical signals. In this work, we\u0000investigate the response of bacterial biofilms to artificial potassium\u0000concentration stimulation. We introduce signal inputs at a specific location\u0000within the biofilm and observe their transmission to other regions, facilitated\u0000by intermediary cells that amplify and relay the signal. We analyze the output\u0000signals when biofilm regions are subjected to different input signal types and\u0000explore their impact on biofilm growth. Furthermore, we investigate how the\u0000temporal gap between input pulses influences output signal characteristics,\u0000demonstrating that an appropriate gap yields distinct and well-defined output\u0000signals. Our research sheds light on the potential of bacterial biofilms as\u0000communication nodes in electrochemical communication networks.","PeriodicalId":501433,"journal":{"name":"arXiv - CS - Information Theory","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140148634","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In the coming sixth generation (6G) communication era, to provide seamless and ubiquitous connections, the space-air-ground-sea integrated network (SAGSIN) is envisioned to address the challenges of communication coverage in areas with difficult conditions, such as the forest, desert, and sea. Considering the fundamental limitations of the SAGSIN including large-scale scenarios, highly dynamic channels, and limited device capabilities, traditional communications based on Shannon information theory cannot satisfy the communication demands. Moreover, bit-level reconstruction is usually redundant for many human-to-machine or machine-to-machine applications in the SAGSIN. Therefore, it is imperative to consider high-level communications towards semantics exchange, called semantic communications. In this survey, according to the interpretations of the term "semantics", including "significance", "meaning", and "effectiveness-related information", we review state-of-the-art works on semantic communications from three perspectives, which are 1) significance representation and protection, 2) meaning similarity measurement and meaning enhancement, and 3) ultimate effectiveness and effectiveness yielding. Sequentially, three types of semantic communication systems can be correspondingly introduced, namely the significance-oriented, meaning-oriented, and effectiveness/task-oriented semantic communication systems. Implementation of the above three types of systems in the SAGSIN necessitates a new perception-communication-computing-actuation-integrated paradigm (PCCAIP), where all the available perception, computing, and actuation techniques jointly facilitates significance-oriented sampling & transmission, semantic extraction & reconstruction, and task decision. Finally, we point out some future challenges on semantic communications in the SAGSIN. ...
{"title":"Semantics-Empowered Space-Air-Ground-Sea Integrated Network: New Paradigm, Frameworks, and Challenges","authors":"Siqi Meng, Shaohua Wu, Jiaming Zhang, Junlan Cheng, Haibo Zhou, Rongxing Lu, Qinyu Zhang","doi":"arxiv-2402.14297","DOIUrl":"https://doi.org/arxiv-2402.14297","url":null,"abstract":"In the coming sixth generation (6G) communication era, to provide seamless\u0000and ubiquitous connections, the space-air-ground-sea integrated network\u0000(SAGSIN) is envisioned to address the challenges of communication coverage in\u0000areas with difficult conditions, such as the forest, desert, and sea.\u0000Considering the fundamental limitations of the SAGSIN including large-scale\u0000scenarios, highly dynamic channels, and limited device capabilities,\u0000traditional communications based on Shannon information theory cannot satisfy\u0000the communication demands. Moreover, bit-level reconstruction is usually\u0000redundant for many human-to-machine or machine-to-machine applications in the\u0000SAGSIN. Therefore, it is imperative to consider high-level communications\u0000towards semantics exchange, called semantic communications. In this survey,\u0000according to the interpretations of the term \"semantics\", including\u0000\"significance\", \"meaning\", and \"effectiveness-related information\", we review\u0000state-of-the-art works on semantic communications from three perspectives,\u0000which are 1) significance representation and protection, 2) meaning similarity\u0000measurement and meaning enhancement, and 3) ultimate effectiveness and\u0000effectiveness yielding. Sequentially, three types of semantic communication\u0000systems can be correspondingly introduced, namely the significance-oriented,\u0000meaning-oriented, and effectiveness/task-oriented semantic communication\u0000systems. Implementation of the above three types of systems in the SAGSIN\u0000necessitates a new perception-communication-computing-actuation-integrated\u0000paradigm (PCCAIP), where all the available perception, computing, and actuation\u0000techniques jointly facilitates significance-oriented sampling & transmission,\u0000semantic extraction & reconstruction, and task decision. Finally, we point out\u0000some future challenges on semantic communications in the SAGSIN. ...","PeriodicalId":501433,"journal":{"name":"arXiv - CS - Information Theory","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139951199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We leverage the Multiplicative Weight Update (MWU) method to develop a decentralized algorithm that significantly improves the performance of dynamic time division duplexing (D-TDD) in small cell networks. The proposed algorithm adaptively adjusts the time portion allocated to uplink (UL) and downlink (DL) transmissions at every node during each scheduled time slot, aligning the packet transmissions toward the most appropriate link directions according to the feedback of signal-to-interference ratio information. Our simulation results reveal that compared to the (conventional) fixed configuration of UL/DL transmission probabilities in D-TDD, incorporating MWU into D-TDD brings about a two-fold improvement of mean packet throughput in the DL and a three-fold improvement of the same performance metric in the UL, resulting in the D-TDD even outperforming Static-TDD in the UL. It also shows that the proposed scheme maintains a consistent performance gain in the presence of an ascending traffic load, validating its effectiveness in boosting the network performance. This work also demonstrates an approach that accounts for algorithmic considerations at the forefront when solving stochastic problems.
{"title":"Boosting Dynamic TDD in Small Cell Networks by the Multiplicative Weight Update Method","authors":"Jiaqi Zhu, Nikolaos Pappas, Howard H. Yang","doi":"arxiv-2402.05641","DOIUrl":"https://doi.org/arxiv-2402.05641","url":null,"abstract":"We leverage the Multiplicative Weight Update (MWU) method to develop a\u0000decentralized algorithm that significantly improves the performance of dynamic\u0000time division duplexing (D-TDD) in small cell networks. The proposed algorithm\u0000adaptively adjusts the time portion allocated to uplink (UL) and downlink (DL)\u0000transmissions at every node during each scheduled time slot, aligning the\u0000packet transmissions toward the most appropriate link directions according to\u0000the feedback of signal-to-interference ratio information. Our simulation\u0000results reveal that compared to the (conventional) fixed configuration of UL/DL\u0000transmission probabilities in D-TDD, incorporating MWU into D-TDD brings about\u0000a two-fold improvement of mean packet throughput in the DL and a three-fold\u0000improvement of the same performance metric in the UL, resulting in the D-TDD\u0000even outperforming Static-TDD in the UL. It also shows that the proposed scheme\u0000maintains a consistent performance gain in the presence of an ascending traffic\u0000load, validating its effectiveness in boosting the network performance. This\u0000work also demonstrates an approach that accounts for algorithmic considerations\u0000at the forefront when solving stochastic problems.","PeriodicalId":501433,"journal":{"name":"arXiv - CS - Information Theory","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139761396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Recent progress in studying emph{treelike committee machines} (TCM) neural networks (NN) in cite{Stojnictcmspnncaprdt23,Stojnictcmspnncapliftedrdt23,Stojnictcmspnncapdiffactrdt23} showed that the Random Duality Theory (RDT) and its a emph{partially lifted}(pl RDT) variant are powerful tools that can be used for very precise networks capacity analysis. Here, we consider emph{wide} hidden layer networks and uncover that certain aspects of numerical difficulties faced in cite{Stojnictcmspnncapdiffactrdt23} miraculously disappear. In particular, we employ recently developed emph{fully lifted} (fl) RDT to characterize the emph{wide} ($drightarrow infty$) TCM nets capacity. We obtain explicit, closed form, capacity characterizations for a very generic class of the hidden layer activations. While the utilized approach significantly lowers the amount of the needed numerical evaluations, the ultimate fl RDT usefulness and success still require a solid portion of the residual numerical work. To get the concrete capacity values, we take four very famous activations examples: emph{textbf{ReLU}}, textbf{emph{quadratic}}, textbf{emph{erf}}, and textbf{emph{tanh}}. After successfully conducting all the residual numerical work for all of them, we uncover that the whole lifting mechanism exhibits a remarkably rapid convergence with the relative improvements no better than $sim 0.1%$ happening already on the 3-rd level of lifting. As a convenient bonus, we also uncover that the capacity characterizations obtained on the first and second level of lifting precisely match those obtained through the statistical physics replica theory methods in cite{ZavPeh21} for the generic and in cite{BalMalZech19} for the ReLU activations.
{"title":"Exact capacity of the emph{wide} hidden layer treelike neural networks with generic activations","authors":"Mihailo Stojnic","doi":"arxiv-2402.05719","DOIUrl":"https://doi.org/arxiv-2402.05719","url":null,"abstract":"Recent progress in studying emph{treelike committee machines} (TCM) neural\u0000networks (NN) in\u0000cite{Stojnictcmspnncaprdt23,Stojnictcmspnncapliftedrdt23,Stojnictcmspnncapdiffactrdt23}\u0000showed that the Random Duality Theory (RDT) and its a emph{partially\u0000lifted}(pl RDT) variant are powerful tools that can be used for very precise\u0000networks capacity analysis. Here, we consider emph{wide} hidden layer networks\u0000and uncover that certain aspects of numerical difficulties faced in\u0000cite{Stojnictcmspnncapdiffactrdt23} miraculously disappear. In particular, we\u0000employ recently developed emph{fully lifted} (fl) RDT to characterize the\u0000emph{wide} ($drightarrow infty$) TCM nets capacity. We obtain explicit,\u0000closed form, capacity characterizations for a very generic class of the hidden\u0000layer activations. While the utilized approach significantly lowers the amount\u0000of the needed numerical evaluations, the ultimate fl RDT usefulness and success\u0000still require a solid portion of the residual numerical work. To get the\u0000concrete capacity values, we take four very famous activations examples:\u0000emph{textbf{ReLU}}, textbf{emph{quadratic}}, textbf{emph{erf}}, and\u0000textbf{emph{tanh}}. After successfully conducting all the residual numerical\u0000work for all of them, we uncover that the whole lifting mechanism exhibits a\u0000remarkably rapid convergence with the relative improvements no better than\u0000$sim 0.1%$ happening already on the 3-rd level of lifting. As a convenient\u0000bonus, we also uncover that the capacity characterizations obtained on the\u0000first and second level of lifting precisely match those obtained through the\u0000statistical physics replica theory methods in cite{ZavPeh21} for the generic\u0000and in cite{BalMalZech19} for the ReLU activations.","PeriodicalId":501433,"journal":{"name":"arXiv - CS - Information Theory","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139761411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We consider communication over the Gaussian multiple-access channel in the regime where the number of users grows linearly with the codelength. We investigate coded CDMA schemes where each user's information is encoded via a linear code before being modulated with a signature sequence. We propose an efficient approximate message passing (AMP) decoder that can be tailored to the structure of the linear code, and provide an exact asymptotic characterization of its performance. Based on this result, we consider a decoder that integrates AMP and belief propagation and characterize the tradeoff between spectral efficiency and signal-to-noise ratio, for a given target error rate. Simulation results are provided to demonstrate the benefits of the concatenated scheme at finite lengths.
{"title":"Coded Many-User Multiple Access via Approximate Message Passing","authors":"Xiaoqi Liu, Kuan Hsieh, Ramji Venkataramanan","doi":"arxiv-2402.05625","DOIUrl":"https://doi.org/arxiv-2402.05625","url":null,"abstract":"We consider communication over the Gaussian multiple-access channel in the\u0000regime where the number of users grows linearly with the codelength. We\u0000investigate coded CDMA schemes where each user's information is encoded via a\u0000linear code before being modulated with a signature sequence. We propose an\u0000efficient approximate message passing (AMP) decoder that can be tailored to the\u0000structure of the linear code, and provide an exact asymptotic characterization\u0000of its performance. Based on this result, we consider a decoder that integrates\u0000AMP and belief propagation and characterize the tradeoff between spectral\u0000efficiency and signal-to-noise ratio, for a given target error rate. Simulation\u0000results are provided to demonstrate the benefits of the concatenated scheme at\u0000finite lengths.","PeriodicalId":501433,"journal":{"name":"arXiv - CS - Information Theory","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139761414","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Farshad Rostami Ghadi, Kai-Kit Wong, F. Javier Lopez-Martinez, Wee Kiat New, Hao Xu, Chan-Byoung Chae
This paper investigates the performance of physical layer security (PLS) in fluid antenna-aided communication systems under arbitrary correlated fading channels. In particular, it is considered that a single fixed-antenna transmitter aims to send confidential information to a legitimate receiver equipped with a planar fluid antenna system (FAS), while an eavesdropper, also taking advantage of a planar FAS, attempts to decode the desired message. For this scenario, we first present analytical expressions of the equivalent channel distributions at the legitimate user and eavesdropper by using copula, so that the obtained analytical results are valid for any arbitrarily correlated fading distributions. Then, with the help of Gauss-Laguerre quadrature, we derive compact analytical expressions for the average secrecy capacity (ASC), the secrecy outage probability (SOP), and the secrecy energy efficiency (SEE) for the FAS wiretap channel. Moreover, for exemplary purposes, we also obtain the compact expression of ASC, SOP, and SEE by utilizing the Gaussian copula under correlated Rayleigh fading channels as a special case. Eventually, numerical results indicate that applying the fluid antenna with only one active port to PLS can guarantee more secure and reliable transmission, when compared to traditional antenna systems (TAS) exploiting maximal ratio combining (MRC).
{"title":"Physical Layer Security over Fluid Antenna Systems","authors":"Farshad Rostami Ghadi, Kai-Kit Wong, F. Javier Lopez-Martinez, Wee Kiat New, Hao Xu, Chan-Byoung Chae","doi":"arxiv-2402.05722","DOIUrl":"https://doi.org/arxiv-2402.05722","url":null,"abstract":"This paper investigates the performance of physical layer security (PLS) in\u0000fluid antenna-aided communication systems under arbitrary correlated fading\u0000channels. In particular, it is considered that a single fixed-antenna\u0000transmitter aims to send confidential information to a legitimate receiver\u0000equipped with a planar fluid antenna system (FAS), while an eavesdropper, also\u0000taking advantage of a planar FAS, attempts to decode the desired message. For\u0000this scenario, we first present analytical expressions of the equivalent\u0000channel distributions at the legitimate user and eavesdropper by using copula,\u0000so that the obtained analytical results are valid for any arbitrarily\u0000correlated fading distributions. Then, with the help of Gauss-Laguerre\u0000quadrature, we derive compact analytical expressions for the average secrecy\u0000capacity (ASC), the secrecy outage probability (SOP), and the secrecy energy\u0000efficiency (SEE) for the FAS wiretap channel. Moreover, for exemplary purposes,\u0000we also obtain the compact expression of ASC, SOP, and SEE by utilizing the\u0000Gaussian copula under correlated Rayleigh fading channels as a special case.\u0000Eventually, numerical results indicate that applying the fluid antenna with\u0000only one active port to PLS can guarantee more secure and reliable\u0000transmission, when compared to traditional antenna systems (TAS) exploiting\u0000maximal ratio combining (MRC).","PeriodicalId":501433,"journal":{"name":"arXiv - CS - Information Theory","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139761467","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nurdagül Anbar, Sadmir Kudin, Wilfried Meidl, Enes Pasalic, Alexandr Polujan
In Pasalic et al., IEEE Trans. Inform. Theory 69 (2023), 2702--2712, and in Anbar, Meidl, Cryptogr. Commun. 10 (2018), 235--249, two different vectorial negabent and vectorial bent-negabent concepts are introduced, which leads to seemingly contradictory results. One of the main motivations for this article is to clarify the differences and similarities between these two concepts. Moreover, the negabent concept is extended to generalized Boolean functions from (mathbb{F}_2^n) to the cyclic group (mathbb{Z}_{2^k}). It is shown how to obtain nega-(mathbb{Z}_{2^k})-bent functions from (mathbb{Z}_{2^k})-bent functions, or equivalently, corresponding non-splitting relative difference sets from the splitting relative difference sets. This generalizes the shifting results for Boolean bent and negabent functions. We finally point to constructions of (mathbb{Z}_8)-bent functions employing permutations with the ((mathcal{A}_m)) property, and more generally we show that the inverse permutation gives rise to (mathbb{Z}_{2^k})-bent functions.
{"title":"Vectorial Negabent Concepts: Similarities, Differences, and Generalizations","authors":"Nurdagül Anbar, Sadmir Kudin, Wilfried Meidl, Enes Pasalic, Alexandr Polujan","doi":"arxiv-2402.05677","DOIUrl":"https://doi.org/arxiv-2402.05677","url":null,"abstract":"In Pasalic et al., IEEE Trans. Inform. Theory 69 (2023), 2702--2712, and in\u0000Anbar, Meidl, Cryptogr. Commun. 10 (2018), 235--249, two different vectorial\u0000negabent and vectorial bent-negabent concepts are introduced, which leads to\u0000seemingly contradictory results. One of the main motivations for this article\u0000is to clarify the differences and similarities between these two concepts.\u0000Moreover, the negabent concept is extended to generalized Boolean functions\u0000from (mathbb{F}_2^n) to the cyclic group (mathbb{Z}_{2^k}). It is shown\u0000how to obtain nega-(mathbb{Z}_{2^k})-bent functions from\u0000(mathbb{Z}_{2^k})-bent functions, or equivalently, corresponding\u0000non-splitting relative difference sets from the splitting relative difference\u0000sets. This generalizes the shifting results for Boolean bent and negabent\u0000functions. We finally point to constructions of (mathbb{Z}_8)-bent functions\u0000employing permutations with the ((mathcal{A}_m)) property, and more\u0000generally we show that the inverse permutation gives rise to\u0000(mathbb{Z}_{2^k})-bent functions.","PeriodicalId":501433,"journal":{"name":"arXiv - CS - Information Theory","volume":"127 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139761615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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