Pub Date : 2024-08-26DOI: 10.1109/LCOMM.2024.3449950
Nemanja Stefan Perović;Le-Nam Tran
In the context of emerging stacked intelligent metasurface (SIM)-based holographic MIMO (HMIMO) systems, a fundamental problem is to study the mutual information (MI) between transmitted and received signals to establish their capacity. However, direct optimization or analytical evaluation of the MI, particularly for discrete signaling, is often intractable. To address this challenge, we adopt the channel cutoff rate (CR) as an alternative optimization metric for the MI maximization. In this regard, we propose an alternating projected gradient method (APGM), which optimizes the CR of a SIM-based HMIMO system by adjusting signal precoding and the phase shifts across the transmit and receive SIMs on a layer-by-layer basis. Simulation results indicate that the proposed algorithm significantly enhances the CR, achieving substantial gains, compared to the case with random SIM phase shifts, that are proportional to those observed for the corresponding MI. This justifies the effectiveness of using the channel CR for the MI optimization. Moreover, we demonstrate that the integration of digital precoding, even on a modest scale, has a significant impact on the ultimate performance of SIM-aided systems.
在新出现的基于堆叠智能元面（SIM）的全息多输入多输出（HMIMO）系统中，一个基本问题是研究发射和接收信号之间的互信息（MI），以确定其容量。然而，直接优化或分析评估互信息（尤其是离散信号）往往难以实现。为了应对这一挑战，我们采用信道截止率 (CR) 作为 MI 最大化的替代优化指标。为此，我们提出了一种交替投影梯度法（APGM），通过逐层调整信号预编码以及发送和接收 SIM 的相移来优化基于 SIM 的 HMIMO 系统的 CR。仿真结果表明，与采用随机 SIM 相移的情况相比，所提出的算法大大提高了信噪比，实现了与相应 MI 观察到的信噪比成正比的大幅增益。这证明了在 MI 优化中使用信道 CR 的有效性。此外，我们还证明了数字预编码的集成，即使规模不大，也会对 SIM 辅助系统的最终性能产生重大影响。
{"title":"Mutual Information Optimization for SIM-Based Holographic MIMO Systems","authors":"Nemanja Stefan Perović;Le-Nam Tran","doi":"10.1109/LCOMM.2024.3449950","DOIUrl":"10.1109/LCOMM.2024.3449950","url":null,"abstract":"In the context of emerging stacked intelligent metasurface (SIM)-based holographic MIMO (HMIMO) systems, a fundamental problem is to study the mutual information (MI) between transmitted and received signals to establish their capacity. However, direct optimization or analytical evaluation of the MI, particularly for discrete signaling, is often intractable. To address this challenge, we adopt the channel cutoff rate (CR) as an alternative optimization metric for the MI maximization. In this regard, we propose an alternating projected gradient method (APGM), which optimizes the CR of a SIM-based HMIMO system by adjusting signal precoding and the phase shifts across the transmit and receive SIMs on a layer-by-layer basis. Simulation results indicate that the proposed algorithm significantly enhances the CR, achieving substantial gains, compared to the case with random SIM phase shifts, that are proportional to those observed for the corresponding MI. This justifies the effectiveness of using the channel CR for the MI optimization. Moreover, we demonstrate that the integration of digital precoding, even on a modest scale, has a significant impact on the ultimate performance of SIM-aided systems.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"28 11","pages":"2583-2587"},"PeriodicalIF":3.7,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190035","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-26DOI: 10.1109/LCOMM.2024.3450275
Hongliang He;Nengcheng Chen;Di Gao;Xingmei Li;Min Yang
This letter investigates the physical-layer security of multi-user networks and proposes a secure and interference-free transmission scheme. The scheme constructs the transmitted signals of different users by using the characteristics of the Hadamard matrix, and injects self-interference and artificial noise that can be eliminated by legitimate users but not by eavesdroppers, thereby significantly improving security. We analyze the asymptotic security performance and obtain the secrecy outage probability when the number of users is large enough. Finally, simulation results exhibit the security performance of the proposed scheme.
{"title":"Secure and Interference-Free Transmission in Wireless Multiuser Networks","authors":"Hongliang He;Nengcheng Chen;Di Gao;Xingmei Li;Min Yang","doi":"10.1109/LCOMM.2024.3450275","DOIUrl":"10.1109/LCOMM.2024.3450275","url":null,"abstract":"This letter investigates the physical-layer security of multi-user networks and proposes a secure and interference-free transmission scheme. The scheme constructs the transmitted signals of different users by using the characteristics of the Hadamard matrix, and injects self-interference and artificial noise that can be eliminated by legitimate users but not by eavesdroppers, thereby significantly improving security. We analyze the asymptotic security performance and obtain the secrecy outage probability when the number of users is large enough. Finally, simulation results exhibit the security performance of the proposed scheme.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"28 10","pages":"2238-2242"},"PeriodicalIF":3.7,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-26DOI: 10.1109/LCOMM.2024.3449568
Mengyu Liu;Cunhua Pan;Kangda Zhi;Hong Ren;Jiangzhou Wang
In this letter, we investigate the hybrid precoding design problem for the near-field wideband terahertz (THz) systems. Due to the large physical size of the whole array, the extremely large-scale antenna array (ELAA) exhibits spatial non-stationarity across the array. Users only effectively communicate with a portion of the antenna elements of ELAA called visibility regions (VRs). To leverage this characteristic for reducing the computational complexity in hybrid precoding design, we initially develop a VR detection algorithm to identify the corresponding VRs for different users. Subsequently, we employ the acquired VR information for true-time delayer (TTD)-based hybrid precoding design to mitigate the beam split effect. Simulation results validate that the proposed algorithm significantly reduces the computational complexity compared to other benchmark schemes while maintaining negligible performance loss.
{"title":"Hybrid Precoding Design for Near-Field Wideband THz Systems With Spatial Non-Stationarity","authors":"Mengyu Liu;Cunhua Pan;Kangda Zhi;Hong Ren;Jiangzhou Wang","doi":"10.1109/LCOMM.2024.3449568","DOIUrl":"10.1109/LCOMM.2024.3449568","url":null,"abstract":"In this letter, we investigate the hybrid precoding design problem for the near-field wideband terahertz (THz) systems. Due to the large physical size of the whole array, the extremely large-scale antenna array (ELAA) exhibits spatial non-stationarity across the array. Users only effectively communicate with a portion of the antenna elements of ELAA called visibility regions (VRs). To leverage this characteristic for reducing the computational complexity in hybrid precoding design, we initially develop a VR detection algorithm to identify the corresponding VRs for different users. Subsequently, we employ the acquired VR information for true-time delayer (TTD)-based hybrid precoding design to mitigate the beam split effect. Simulation results validate that the proposed algorithm significantly reduces the computational complexity compared to other benchmark schemes while maintaining negligible performance loss.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"28 10","pages":"2372-2376"},"PeriodicalIF":3.7,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-26DOI: 10.1109/LCOMM.2024.3450082
Tuna Ozates;Uras Kargı;Aykut Koç
Semantic communication, a paradigm concentrating on correctly transmitting underlying semantic information instead of bit sequences, has proved effective. Deep learning (DL) enabled methods are mainly used with basic natural language processing (NLP) techniques for the semantic communication of texts. However, most of the previous work approaches the problem by treating text as a generic continuum of sequences of textual information without leveraging underlying intrinsic and advanced linguistic properties of natural languages. A prime example of such linguistic features is the sememes, the smallest and indivisible semantic units of textual information (analogous to the Periodic Table of Matter). This letter proposes Sememe-based Semantic Communications (SememeSC), a semantic communication paradigm that utilizes sememe knowledge in natural languages. We provided experimental results verifying that the proposed SememeSC performs superior to baselines in additive white Gaussian noise (AWGN) and Rayleigh fading channels. Codes and data are available at https://github.com/koc-lab/sememesc .
{"title":"Sememe-Based Semantic Communications","authors":"Tuna Ozates;Uras Kargı;Aykut Koç","doi":"10.1109/LCOMM.2024.3450082","DOIUrl":"10.1109/LCOMM.2024.3450082","url":null,"abstract":"Semantic communication, a paradigm concentrating on correctly transmitting underlying semantic information instead of bit sequences, has proved effective. Deep learning (DL) enabled methods are mainly used with basic natural language processing (NLP) techniques for the semantic communication of texts. However, most of the previous work approaches the problem by treating text as a generic continuum of sequences of textual information without leveraging underlying intrinsic and advanced linguistic properties of natural languages. A prime example of such linguistic features is the sememes, the smallest and indivisible semantic units of textual information (analogous to the Periodic Table of Matter). This letter proposes Sememe-based Semantic Communications (SememeSC), a semantic communication paradigm that utilizes sememe knowledge in natural languages. We provided experimental results verifying that the proposed SememeSC performs superior to baselines in additive white Gaussian noise (AWGN) and Rayleigh fading channels. Codes and data are available at \u0000<uri>https://github.com/koc-lab/sememesc</uri>\u0000.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"28 10","pages":"2308-2312"},"PeriodicalIF":3.7,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190034","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-26DOI: 10.1109/LCOMM.2024.3450309
Min-Kuan Chang;Chun-Tse Hsu;Guu-Chang Yang
The current mindset of semantic communications focuses on how to have the sentence received exactly. However, as long as the received sentence and the original sentence are perceived the same or similarly, it can be reviewed as a successful semantic-level transmission. Hence, we design a new architecture for the semantic communication system based on BART-like model (Lewis et al., 2019), called GenSC. The proposed GenSC further takes the token-level correlation between consecutive tokens into account during the semantic encoding and this bidirectional correlation helps correct or fill in a “semantically similar token” at the semantic decoder when a token is missing or corrupted during transmission. The simulation shows that compared to conventional approaches such as Xie et al. (2021) and Liu et al. (2022), GenSC can improve the bilingual evaluation understudy (BLEU) and semantic similarity (SS) scores at low SNR regions a lot and enjoy higher BLEU and SS scores at high SNR regions. When SNR is 0dB, GenSC outperforms (Xie et al., 2021) and (Liu et al., 2022) by around 30% (resp. 84%) and 18% (resp. 55%) in terms of BLEU (resp. SS), respectively.
{"title":"GenSC: Generative Semantic Communication Systems Using BART-Like Model","authors":"Min-Kuan Chang;Chun-Tse Hsu;Guu-Chang Yang","doi":"10.1109/LCOMM.2024.3450309","DOIUrl":"10.1109/LCOMM.2024.3450309","url":null,"abstract":"The current mindset of semantic communications focuses on how to have the sentence received exactly. However, as long as the received sentence and the original sentence are perceived the same or similarly, it can be reviewed as a successful semantic-level transmission. Hence, we design a new architecture for the semantic communication system based on BART-like model (Lewis et al., 2019), called GenSC. The proposed GenSC further takes the token-level correlation between consecutive tokens into account during the semantic encoding and this bidirectional correlation helps correct or fill in a “semantically similar token” at the semantic decoder when a token is missing or corrupted during transmission. The simulation shows that compared to conventional approaches such as Xie et al. (2021) and Liu et al. (2022), GenSC can improve the bilingual evaluation understudy (BLEU) and semantic similarity (SS) scores at low SNR regions a lot and enjoy higher BLEU and SS scores at high SNR regions. When SNR is 0dB, GenSC outperforms (Xie et al., 2021) and (Liu et al., 2022) by around 30% (resp. 84%) and 18% (resp. 55%) in terms of BLEU (resp. SS), respectively.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"28 10","pages":"2298-2302"},"PeriodicalIF":3.7,"publicationDate":"2024-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-23DOI: 10.1109/LCOMM.2024.3448491
Minha Mubarak;B. S. Vineeth
Frameless ALOHA (FA) is a slotted-time random access protocol for collision channels that uses successive interference cancellation (SIC) techniques to improve decoding performance. In this letter, we characterize the average and distribution of age of information (AoI) for FA with M users. Transmissions in FA are organized into rounds of random length. We compare different round termination methods and observe that the average AoI is minimum for a method where the round terminates when a single user transmits in a slot. We then obtain a novel numerical characterization of the packet decoding probability for FA under the above method to terminate a round. The characterization of the packet decoding probability is then used to obtain novel characterizations of the average AoI as well as the distribution of AoI for any M. These characterizations match with simulations and can be utilized in optimizing FA protocol parameters for average AoI or any general function of AoI.
无帧 ALOHA（FA）是一种用于碰撞信道的时隙-时间随机接入协议，它使用连续干扰消除（SIC）技术来提高解码性能。在这封信中，我们描述了有 M 个用户的 FA 的信息年龄（AoI）平均值和分布。FA 中的传输被组织成随机长度的轮次。我们对不同的轮次终止方法进行了比较，发现当单个用户在一个时隙内进行传输时，轮次终止方法的平均 AoI 最小。然后，我们获得了在上述终止一轮方法下 FA 的数据包解码概率的新数字特征。这些特征与模拟结果相吻合，可用于优化平均 AoI 或 AoI 的任何一般函数的 FA 协议参数。
{"title":"On the Average and Distribution of Age of Information for Frameless ALOHA","authors":"Minha Mubarak;B. S. Vineeth","doi":"10.1109/LCOMM.2024.3448491","DOIUrl":"10.1109/LCOMM.2024.3448491","url":null,"abstract":"Frameless ALOHA (FA) is a slotted-time random access protocol for collision channels that uses successive interference cancellation (SIC) techniques to improve decoding performance. In this letter, we characterize the average and distribution of age of information (AoI) for FA with M users. Transmissions in FA are organized into rounds of random length. We compare different round termination methods and observe that the average AoI is minimum for a method where the round terminates when a single user transmits in a slot. We then obtain a novel numerical characterization of the packet decoding probability for FA under the above method to terminate a round. The characterization of the packet decoding probability is then used to obtain novel characterizations of the average AoI as well as the distribution of AoI for any M. These characterizations match with simulations and can be utilized in optimizing FA protocol parameters for average AoI or any general function of AoI.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"28 10","pages":"2268-2272"},"PeriodicalIF":3.7,"publicationDate":"2024-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190036","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-22DOI: 10.1109/LCOMM.2024.3448372
Derek K. P. Asiedu;Sumaila A. Mahama;Ji-Hoon Yun;Mustapha Benjillali;Samir Saoudi
In this letter, we develop a two-stage framework, based on both analytical modeling and machine learning (ML), for the analysis and optimization of a communication setup where the primary receivers (PRs) of a massive multiple-input multiple-output (mMIMO) multi-user non-orthogonal multiple access (NOMA) enabled primary network (PN) coexist symbiotically with a secondary network (SN) of backscatter-enabled tag transmitters (STs). The PN provides radio frequency signals to excite the semi-passive STs in their backscatter communication channel while gaining spatial diversity from the backscattering of the STs’ desired signals. We aim to jointly optimize the primary transmitter (PT) beamforming, the PRs clustering, and the STs reflection coefficient to achieve maximal energy efficiency (EE). We propose an ML-based modified mean shift clustering for the PR clustering and an alternating optimization (AO) algorithm after the PR clustering to maximize the EE of Symbiotic radio network. We illustrate the proposed approach’s superiority over conventional benchmarks with the help of simulation results.
在这封信中，我们开发了一个基于分析建模和机器学习（ML）的两阶段框架，用于分析和优化一种通信设置，在这种设置中，支持大规模多输入多输出（mMIMO）多用户非正交多址（NOMA）的主网络（PN）的主接收器（PR）与支持反向散射的标签发射器（ST）的辅助网络（SN）共存。主网络提供无线电频率信号，以激励其反向散射通信信道中的半被动 ST，同时从 ST 所需信号的反向散射中获得空间分集。我们的目标是联合优化主发射机（PT）波束成形、PRs 聚类和 STs 反射系数，以实现最高能效（EE）。我们针对 PR 聚类提出了一种基于 ML 的修正均值移动聚类，并在 PR 聚类后提出了一种交替优化 (AO) 算法，以实现共生无线网络的能效最大化。我们借助仿真结果说明了所提出的方法优于传统基准。
{"title":"Energy-Efficiency With Massive MIMO MU-NOMA in Symbiotic BackCom IoT Networks","authors":"Derek K. P. Asiedu;Sumaila A. Mahama;Ji-Hoon Yun;Mustapha Benjillali;Samir Saoudi","doi":"10.1109/LCOMM.2024.3448372","DOIUrl":"10.1109/LCOMM.2024.3448372","url":null,"abstract":"In this letter, we develop a two-stage framework, based on both analytical modeling and machine learning (ML), for the analysis and optimization of a communication setup where the primary receivers (PRs) of a massive multiple-input multiple-output (mMIMO) multi-user non-orthogonal multiple access (NOMA) enabled primary network (PN) coexist symbiotically with a secondary network (SN) of backscatter-enabled tag transmitters (STs). The PN provides radio frequency signals to excite the semi-passive STs in their backscatter communication channel while gaining spatial diversity from the backscattering of the STs’ desired signals. We aim to jointly optimize the primary transmitter (PT) beamforming, the PRs clustering, and the STs reflection coefficient to achieve maximal energy efficiency (EE). We propose an ML-based modified mean shift clustering for the PR clustering and an alternating optimization (AO) algorithm after the PR clustering to maximize the EE of Symbiotic radio network. We illustrate the proposed approach’s superiority over conventional benchmarks with the help of simulation results.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"28 10","pages":"2318-2322"},"PeriodicalIF":3.7,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190038","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-22DOI: 10.1109/LCOMM.2024.3448202
Vincent Corlay;Viet-Hoa Nguyen;Nicolas Gresset
We consider the positioning problem in non line-of-sight (NLoS) situations, where several base stations (BS) try to locate a user equipment (UE) based on uplink angle of arrival (AoA) measurements and a digital twin of the environment. Ray launching in a Monte Carlo manner according to the AoA statistics enables to produce a map of points for each BS. These points represent the intersections of the rays with a xy plane at a given user equipment (UE) elevation. We propose to fit a parametric probability density function (pdf), such as a Gaussian mixture model (GMM), to each map of points. Multiplying the obtained pdfs for each BS enables to compute the position probability of the UE. This approach yields an algorithm robust to a reduced number of launched rays. Moreover, these parametric pdfs may be fitted and stored in an offline phase such that ray tracing can be avoided in the online phase. This significantly reduces the computational complexity of the positioning method.
我们考虑的是非视距（NLoS）情况下的定位问题，在这种情况下，多个基站（BS）试图根据上行链路到达角（AoA）测量结果和环境的数字孪生图定位用户设备（UE）。根据 AoA 统计数据以蒙特卡洛方式发射光线，可为每个基站生成一张点地图。这些点代表在给定用户设备（UE）海拔高度上光线与 xy 平面的交点。我们建议对每个点图拟合一个参数概率密度函数（pdf），如高斯混合模型（GMM）。将获得的每个 BS 的 pdf 相乘，就能计算出 UE 的位置概率。这种方法产生的算法对发射射线数量的减少具有鲁棒性。此外，这些参数 pdf 可以在离线阶段进行拟合和存储，从而避免在在线阶段进行射线追踪。这大大降低了定位方法的计算复杂度。
{"title":"Probabilistic Positioning via Ray Tracing With Noisy Angle of Arrival Measurements","authors":"Vincent Corlay;Viet-Hoa Nguyen;Nicolas Gresset","doi":"10.1109/LCOMM.2024.3448202","DOIUrl":"10.1109/LCOMM.2024.3448202","url":null,"abstract":"We consider the positioning problem in non line-of-sight (NLoS) situations, where several base stations (BS) try to locate a user equipment (UE) based on uplink angle of arrival (AoA) measurements and a digital twin of the environment. Ray launching in a Monte Carlo manner according to the AoA statistics enables to produce a map of points for each BS. These points represent the intersections of the rays with a xy plane at a given user equipment (UE) elevation. We propose to fit a parametric probability density function (pdf), such as a Gaussian mixture model (GMM), to each map of points. Multiplying the obtained pdfs for each BS enables to compute the position probability of the UE. This approach yields an algorithm robust to a reduced number of launched rays. Moreover, these parametric pdfs may be fitted and stored in an offline phase such that ray tracing can be avoided in the online phase. This significantly reduces the computational complexity of the positioning method.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"28 10","pages":"2278-2282"},"PeriodicalIF":3.7,"publicationDate":"2024-08-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190037","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-21DOI: 10.1109/LCOMM.2024.3447352
Mohammad Nasiraee;Javad Kazemitabar;Jalil Kazemitabar
The bijection property in the law of total probability has potential applications. For instance, it relates to the uniqueness of a capacity-achieving distribution, resulting in maximum information transmission from a transmitter. This letter focuses on this property and demonstrates, through a counterexample, that it does not always exist. Additionally, the letter establishes a link between the law and the moment problem context by applying Taylor expansion to the integrand. As a main result, this research provides a sufficient condition for a unique measure to be satisfied in the law of total probability, named generalized Carleman’s condition. Lastly, it applies this condition when the integrand is the generalized Poisson distribution, which is a standard model typically used for counting events in science.
{"title":"The Bijection Property in the Law of Total Probability and Its Application in Communication Theory","authors":"Mohammad Nasiraee;Javad Kazemitabar;Jalil Kazemitabar","doi":"10.1109/LCOMM.2024.3447352","DOIUrl":"10.1109/LCOMM.2024.3447352","url":null,"abstract":"The bijection property in the law of total probability has potential applications. For instance, it relates to the uniqueness of a capacity-achieving distribution, resulting in maximum information transmission from a transmitter. This letter focuses on this property and demonstrates, through a counterexample, that it does not always exist. Additionally, the letter establishes a link between the law and the moment problem context by applying Taylor expansion to the integrand. As a main result, this research provides a sufficient condition for a unique measure to be satisfied in the law of total probability, named generalized Carleman’s condition. Lastly, it applies this condition when the integrand is the generalized Poisson distribution, which is a standard model typically used for counting events in science.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"28 11","pages":"2518-2522"},"PeriodicalIF":3.7,"publicationDate":"2024-08-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-08-19DOI: 10.1109/LCOMM.2024.3446320
Hakan Ozen;Onur Yilmaz;Gokhan M. Guvensen
This letter presents a novel beam-squint-aware (BSA) channel estimation method for uniform planar array (UPA)-type reconfigurable intelligent surface (RIS)-aided frequency- and spatial-wideband (dual-wideband) massive multiple-input multiple-output (MIMO) systems. The proposed scheme considers the angles of arrival (AoAs), angles of departure (AoDs), and propagation delays as slowly-varying, while treating the channel gains as fast-varying parameters. To estimate these parameters, we divide the estimation procedure into slow-time parameter estimation (ST-PE) and fast-time parameter estimation (FT-PE) modes. During the ST-PE mode, we propose a BSA periodogram for estimating the AoAs at the base station (BS), followed by a BSA orthogonal matching pursuit (OMP) algorithm for estimating the cascaded angles and delays. In the FT-PE mode, we propose a subspace-aware least squares (SA-LS) method to estimate the channel gains. Simulation results demonstrate the superiority of the proposed estimation methods in terms of root mean square error (RMSE) and achievable rate metrics when compared to state-of-the-art approaches.
{"title":"Beam-Squint-Aware Channel Estimation for Dual-Wideband UPA-Type RIS-Aided Massive MIMO","authors":"Hakan Ozen;Onur Yilmaz;Gokhan M. Guvensen","doi":"10.1109/LCOMM.2024.3446320","DOIUrl":"10.1109/LCOMM.2024.3446320","url":null,"abstract":"This letter presents a novel beam-squint-aware (BSA) channel estimation method for uniform planar array (UPA)-type reconfigurable intelligent surface (RIS)-aided frequency- and spatial-wideband (dual-wideband) massive multiple-input multiple-output (MIMO) systems. The proposed scheme considers the angles of arrival (AoAs), angles of departure (AoDs), and propagation delays as slowly-varying, while treating the channel gains as fast-varying parameters. To estimate these parameters, we divide the estimation procedure into slow-time parameter estimation (ST-PE) and fast-time parameter estimation (FT-PE) modes. During the ST-PE mode, we propose a BSA periodogram for estimating the AoAs at the base station (BS), followed by a BSA orthogonal matching pursuit (OMP) algorithm for estimating the cascaded angles and delays. In the FT-PE mode, we propose a subspace-aware least squares (SA-LS) method to estimate the channel gains. Simulation results demonstrate the superiority of the proposed estimation methods in terms of root mean square error (RMSE) and achievable rate metrics when compared to state-of-the-art approaches.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"28 10","pages":"2367-2371"},"PeriodicalIF":3.7,"publicationDate":"2024-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142190039","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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