Pub Date : 2024-12-09DOI: 10.1109/LCOMM.2024.3512665
Santiago Fernández;J. Alfonso Bailón-Martínez;Juan E. Galeote-Cazorla;F. Javier López-Martínez
We introduce and characterize the operational diversity order (ODO) in fading channels, as a proxy to the classical notion of diversity order at any arbitrary operational signal-to-noise ratio (SNR). Thanks to this definition, relevant insights are brought up in a number of cases: 1) We quantify that in dominant line-of-sight scenarios an increased diversity order is attainable compared to that achieved asymptotically, even in the single-antenna case; 2) this effect is attenuated, but still visible, in the presence of an additional dominant specular component; 3) the decay slope in Rayleigh product channels increases very slowly, never fully achieving unitary slope for a finite SNR.
{"title":"Analytical Characterization of the Operational Diversity Order in Fading Channels","authors":"Santiago Fernández;J. Alfonso Bailón-Martínez;Juan E. Galeote-Cazorla;F. Javier López-Martínez","doi":"10.1109/LCOMM.2024.3512665","DOIUrl":"https://doi.org/10.1109/LCOMM.2024.3512665","url":null,"abstract":"We introduce and characterize the operational diversity order (ODO) in fading channels, as a proxy to the classical notion of diversity order at any arbitrary operational signal-to-noise ratio (SNR). Thanks to this definition, relevant insights are brought up in a number of cases: 1) We quantify that in dominant line-of-sight scenarios an increased diversity order is attainable compared to that achieved asymptotically, even in the single-antenna case; 2) this effect is attenuated, but still visible, in the presence of an additional dominant specular component; 3) the decay slope in Rayleigh product channels increases very slowly, never fully achieving unitary slope for a finite SNR.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"29 2","pages":"274-278"},"PeriodicalIF":3.7,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10781412","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403999","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"计算机科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-12-09DOI: 10.1109/LCOMM.2024.3513556
Gabriel O. Ferreira;Chiara Ravazzi;Fabrizio Dabbene;Giuseppe C. Calafiore
In this letter we consider the problem of minimizing the base stations transmission powers in OFDMA heterogeneous networks, while respecting users’ individual throughput demands. The decision variables are the users’ working bandwidths, their association, and the base stations transmission powers. To deal with wireless channel uncertainty, the channel gains are treated as random variables respecting a log-normal distribution, leading to a non-convex chance constrained mixed-integer optimization problem, which is then formulated as a mixed-integer Robust Geometric Program. The efficacy of the proposed method is shown in a real-world scenario of a large European city.
{"title":"Power Minimization and Resource Allocation in HetNets With Uncertain Channel Gains","authors":"Gabriel O. Ferreira;Chiara Ravazzi;Fabrizio Dabbene;Giuseppe C. Calafiore","doi":"10.1109/LCOMM.2024.3513556","DOIUrl":"https://doi.org/10.1109/LCOMM.2024.3513556","url":null,"abstract":"In this letter we consider the problem of minimizing the base stations transmission powers in OFDMA heterogeneous networks, while respecting users’ individual throughput demands. The decision variables are the users’ working bandwidths, their association, and the base stations transmission powers. To deal with wireless channel uncertainty, the channel gains are treated as random variables respecting a log-normal distribution, leading to a non-convex chance constrained mixed-integer optimization problem, which is then formulated as a mixed-integer Robust Geometric Program. The efficacy of the proposed method is shown in a real-world scenario of a large European city.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"29 1","pages":"235-239"},"PeriodicalIF":3.7,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938364","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 : 2024-12-09DOI: 10.1109/LCOMM.2024.3514493
Hassan Noghrei;Mohammad-Reza Sadeghi;Wai Ho Mow
The quality and quantity of training data significantly affect deep learning model performance. In error correction, generating high-quality samples with minimal noise is crucial. This letter presents a method that combines a modified Importance Sampling (IS) distribution with active learning to generate high-quality samples. The suggested IS distribution generates samples iteratively from shells with error probabilities within a specific range. This approach enhances the performance of BCH(63,36) and BCH(63,45) codes with cycle-reduced parity-check matrices. The proposed IS-based-active Weight Belief Propagation (WBP) decoder improves the error-floor region by up to 1.9dB on the BER curve compared to the conventional WBP decoder.
{"title":"Efficient Active Deep Decoding of Linear Codes Using Importance Sampling","authors":"Hassan Noghrei;Mohammad-Reza Sadeghi;Wai Ho Mow","doi":"10.1109/LCOMM.2024.3514493","DOIUrl":"https://doi.org/10.1109/LCOMM.2024.3514493","url":null,"abstract":"The quality and quantity of training data significantly affect deep learning model performance. In error correction, generating high-quality samples with minimal noise is crucial. This letter presents a method that combines a modified Importance Sampling (IS) distribution with active learning to generate high-quality samples. The suggested IS distribution generates samples iteratively from shells with error probabilities within a specific range. This approach enhances the performance of BCH(63,36) and BCH(63,45) codes with cycle-reduced parity-check matrices. The proposed IS-based-active Weight Belief Propagation (WBP) decoder improves the error-floor region by up to 1.9dB on the BER curve compared to the conventional WBP decoder.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"29 2","pages":"299-302"},"PeriodicalIF":3.7,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403856","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 : 2024-12-09DOI: 10.1109/LCOMM.2024.3513939
Zhen Chen;Zizhuo Fang;Zhangling Duan;Mang Ou;Xiang Bi
As a paradigm shift in the scheme of wireless access, non-orthogonal multiple access (NOMA) can achieve massive connectivity and improve spectral efficiency, but introduces high complexity at the successive-interference-cancelation (SIC) receiver. In order to ensure low implementation complexity, SIC decoding has been designed by using a single criterion. The instantaneous-signal-power (ISP) criterion has been widely applied in NOMA, and the user with stronger ISP is first decoded. However, the ISP criterion ignores the impact caused by the data rate requirements in NOMA systems. Recently, we have proposed a new SIC criterion, namely the Relative ISP (RISP) criterion, to improve the ISP criterion to consider the impact of the target-data-rate (TDR) of each user. RISP is defined as a form of the ratio of ISP to TDR. In this letter, for the general multiple-user case at high signal-to-noise ratio, we mathematically prove that the RISP criterion has the better outage performance than the ISP criterion. Our conclusion provides a basic guidance for the design and implementation of NOMA systems in the next generation of wireless communication networks.
{"title":"A Note on the RISP Criterion for NOMA Systems","authors":"Zhen Chen;Zizhuo Fang;Zhangling Duan;Mang Ou;Xiang Bi","doi":"10.1109/LCOMM.2024.3513939","DOIUrl":"https://doi.org/10.1109/LCOMM.2024.3513939","url":null,"abstract":"As a paradigm shift in the scheme of wireless access, non-orthogonal multiple access (NOMA) can achieve massive connectivity and improve spectral efficiency, but introduces high complexity at the successive-interference-cancelation (SIC) receiver. In order to ensure low implementation complexity, SIC decoding has been designed by using a single criterion. The instantaneous-signal-power (ISP) criterion has been widely applied in NOMA, and the user with stronger ISP is first decoded. However, the ISP criterion ignores the impact caused by the data rate requirements in NOMA systems. Recently, we have proposed a new SIC criterion, namely the Relative ISP (RISP) criterion, to improve the ISP criterion to consider the impact of the target-data-rate (TDR) of each user. RISP is defined as a form of the ratio of ISP to TDR. In this letter, for the general multiple-user case at high signal-to-noise ratio, we mathematically prove that the RISP criterion has the better outage performance than the ISP criterion. Our conclusion provides a basic guidance for the design and implementation of NOMA systems in the next generation of wireless communication networks.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"29 2","pages":"294-298"},"PeriodicalIF":3.7,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403977","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}
In this letter, we investigate the training latency minimization problem for a multi-task federated learning (FL) framework with model decomposition over wireless communication networks. To handle the non-independent and non-identically distributed (non-IID) data, we first transform the multi-class classification task into multiple binary classification tasks. We then introduce sampling equalization to ensure the convergence of FL system. The optimization problem aims to minimize the training latency under energy and FL convergence constraints by optimizing task selection, number of learning iterations, and communication resource allocation. We decompose it into three sub-problems and propose alternating algorithm to address each sub-problem iteratively. Numerical results validate that the proposed algorithm significantly reduces time consumption compared to the conventional algorithms.
{"title":"Task Selection and Resource Optimization in Multi-Task Federated Learning With Model Decomposition","authors":"Haowen Sun;Ming Chen;Zhaohui Yang;Yijin Pan;Yihan Cang;Zhaoyang Zhang","doi":"10.1109/LCOMM.2024.3511663","DOIUrl":"https://doi.org/10.1109/LCOMM.2024.3511663","url":null,"abstract":"In this letter, we investigate the training latency minimization problem for a multi-task federated learning (FL) framework with model decomposition over wireless communication networks. To handle the non-independent and non-identically distributed (non-IID) data, we first transform the multi-class classification task into multiple binary classification tasks. We then introduce sampling equalization to ensure the convergence of FL system. The optimization problem aims to minimize the training latency under energy and FL convergence constraints by optimizing task selection, number of learning iterations, and communication resource allocation. We decompose it into three sub-problems and propose alternating algorithm to address each sub-problem iteratively. Numerical results validate that the proposed algorithm significantly reduces time consumption compared to the conventional algorithms.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"29 1","pages":"225-229"},"PeriodicalIF":3.7,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938362","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 : 2024-12-05DOI: 10.1109/LCOMM.2024.3511692
Chi Qiu;Qingqing Wu;Wen Chen;Ying Gao;Wanming Hao
Intelligent reflecting surface (IRS)-assisted terahertz (THz) communication is becoming a key technology for next-generation wireless networks. Although IRS has great promise, it is severely hindered by the beam squint problem resulting from the frequency-independent nature of the passive reflecting elements, especially in ultra-wide THz bands. To address this problem, we introduce time delay modules to the IRS and focus on the weighted sum rate maximization problem through the joint optimization of transmit beamforming, IRS phase shifts, and time delays. To solve the formulated optimization problem, an alternating optimization algorithm that decomposes the original problem into three subproblems is proposed. Specifically, we apply semidefinite relaxation and successive convex approximation techniques to solve each subproblem. Simulation results demonstrate the superiority of the proposed scheme over recent literature works. Particularly, it achieves near-optimal performance with slightly increased hardware cost.
{"title":"Wideband Beamforming Design for IRS-Assisted Multi-User THz Communications","authors":"Chi Qiu;Qingqing Wu;Wen Chen;Ying Gao;Wanming Hao","doi":"10.1109/LCOMM.2024.3511692","DOIUrl":"https://doi.org/10.1109/LCOMM.2024.3511692","url":null,"abstract":"Intelligent reflecting surface (IRS)-assisted terahertz (THz) communication is becoming a key technology for next-generation wireless networks. Although IRS has great promise, it is severely hindered by the beam squint problem resulting from the frequency-independent nature of the passive reflecting elements, especially in ultra-wide THz bands. To address this problem, we introduce time delay modules to the IRS and focus on the weighted sum rate maximization problem through the joint optimization of transmit beamforming, IRS phase shifts, and time delays. To solve the formulated optimization problem, an alternating optimization algorithm that decomposes the original problem into three subproblems is proposed. Specifically, we apply semidefinite relaxation and successive convex approximation techniques to solve each subproblem. Simulation results demonstrate the superiority of the proposed scheme over recent literature works. Particularly, it achieves near-optimal performance with slightly increased hardware cost.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"29 2","pages":"269-273"},"PeriodicalIF":3.7,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403855","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 : 2024-12-04DOI: 10.1109/LCOMM.2024.3511038
Xiaodi Zhang;Dong Li;Jinnan Piao
In this letter, we propose a latency prediction method based on random forests (RFs) and gradient boosting machine (GBM) to estimate the maximum latency of audio-video bridging (AVB) traffic in time-sensitive networks. We use a dataset collected from actual networks as the input features for the RFs. Then, we use the prediction results of the RFs as input features for the GBM to complete the model training. The experimental results show that the proposed method, compared to network calculus, performs better in terms of deviations as well as error metrics when the link utilization is 25%.
{"title":"Maximum Latency Prediction Based on Random Forests and Gradient Boosting Machine for AVB Traffic in TSN","authors":"Xiaodi Zhang;Dong Li;Jinnan Piao","doi":"10.1109/LCOMM.2024.3511038","DOIUrl":"https://doi.org/10.1109/LCOMM.2024.3511038","url":null,"abstract":"In this letter, we propose a latency prediction method based on random forests (RFs) and gradient boosting machine (GBM) to estimate the maximum latency of audio-video bridging (AVB) traffic in time-sensitive networks. We use a dataset collected from actual networks as the input features for the RFs. Then, we use the prediction results of the RFs as input features for the GBM to complete the model training. The experimental results show that the proposed method, compared to network calculus, performs better in terms of deviations as well as error metrics when the link utilization is 25%.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"29 2","pages":"264-268"},"PeriodicalIF":3.7,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143403982","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 : 2024-12-04DOI: 10.1109/LCOMM.2024.3511549
Xian Zhang;Wanguo Jiao;Wenhui Liu;Chenhao Qi
In this letter, we consider the energy efficiency (EE) of the secure full-duplex integrated sensing and communication system. The base station simultaneously performs full-duplex wireless communications and targets sensing, where one of the targets is an eavesdropper. To achieve EE maximization under the secure rate and sensing constraints, we jointly optimize the transmit and receive beamforming as well as designing artificial noise. Since this problem is non-convex, we propose an algorithm based on semi-definite relaxation, successive convex approximation and fractional programming. The results indicate that the EE is optimized while the tradeoff among sensing performance, transmit power and EE is also achieved.
{"title":"Energy Efficiency Optimization in Secure Full-Duplex ISAC Systems","authors":"Xian Zhang;Wanguo Jiao;Wenhui Liu;Chenhao Qi","doi":"10.1109/LCOMM.2024.3511549","DOIUrl":"https://doi.org/10.1109/LCOMM.2024.3511549","url":null,"abstract":"In this letter, we consider the energy efficiency (EE) of the secure full-duplex integrated sensing and communication system. The base station simultaneously performs full-duplex wireless communications and targets sensing, where one of the targets is an eavesdropper. To achieve EE maximization under the secure rate and sensing constraints, we jointly optimize the transmit and receive beamforming as well as designing artificial noise. Since this problem is non-convex, we propose an algorithm based on semi-definite relaxation, successive convex approximation and fractional programming. The results indicate that the EE is optimized while the tradeoff among sensing performance, transmit power and EE is also achieved.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"29 1","pages":"220-224"},"PeriodicalIF":3.7,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938361","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 : 2024-12-04DOI: 10.1109/LCOMM.2024.3510727
Sai Li;Xiaoyu Dang;Xiangbin Yu;Jie Li;Yunhang Lin;Beien Cheng
In this letter, we present a power-efficient downlink non-orthogonal multiple access (NOMA) enabled by continuous phase modulation (CPM), which improves the efficiency of the transmitter’s power amplifier (PA) by exploiting a low peak-to-average power ratio (PAPR), thereby achieving power-efficient downlink transmission. First, the system model is established. Then, we investigate the PAPR, spectral efficiency, bit-error-rate (BER) performance with/without nonlinear distortions and computational complexity, and the conventional scheme is also provided as a benchmark. The numerical results show that CPM-NOMA can achieve about $3sim 6$ (dB) PAPR performance gain compared to conventional schemes. In the absence of nonlinear distortions, CPM-NOMA can obtain comparable or even better BER performance than conventional schemes with similar computational complexity. In the presence of nonlinear distortions, CPM-NOMA can offer robust and power-efficient downlink transmission with smaller PAPR and BER performance losses, and is also suitable for efficient PAs, but not for conventional schemes. Finally, CPM-NOMA can also achieve the trade-off between spectral efficiency, power efficiency and BER.
{"title":"Energy-Efficient Downlink NOMA Transmission Enabled by Continuous Phase Modulation","authors":"Sai Li;Xiaoyu Dang;Xiangbin Yu;Jie Li;Yunhang Lin;Beien Cheng","doi":"10.1109/LCOMM.2024.3510727","DOIUrl":"https://doi.org/10.1109/LCOMM.2024.3510727","url":null,"abstract":"In this letter, we present a power-efficient downlink non-orthogonal multiple access (NOMA) enabled by continuous phase modulation (CPM), which improves the efficiency of the transmitter’s power amplifier (PA) by exploiting a low peak-to-average power ratio (PAPR), thereby achieving power-efficient downlink transmission. First, the system model is established. Then, we investigate the PAPR, spectral efficiency, bit-error-rate (BER) performance with/without nonlinear distortions and computational complexity, and the conventional scheme is also provided as a benchmark. The numerical results show that CPM-NOMA can achieve about \u0000<inline-formula> <tex-math>$3sim 6$ </tex-math></inline-formula>\u0000 (dB) PAPR performance gain compared to conventional schemes. In the absence of nonlinear distortions, CPM-NOMA can obtain comparable or even better BER performance than conventional schemes with similar computational complexity. In the presence of nonlinear distortions, CPM-NOMA can offer robust and power-efficient downlink transmission with smaller PAPR and BER performance losses, and is also suitable for efficient PAs, but not for conventional schemes. Finally, CPM-NOMA can also achieve the trade-off between spectral efficiency, power efficiency and BER.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"29 1","pages":"210-214"},"PeriodicalIF":3.7,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938357","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}
A simple geometric shaping method is proposed for optical wireless communication systems based on intensity modulation and direct detection (IM/DD) from an information-theoretic perspective. Constellations consisting of equiprobable levels with exponential-like distribution are obtained, which possesses asymptotic optimality in the sense that the high-SNR capacity of average-intensity constrained optical intensity channel can be approached by such constellations with increasing size. All $2^{b}$ levels ( $bin mathbb {N}$ ) of the obtained constellation can be represented by a basic level and $b+2$ bits, thereby reducing the required resolution of the digital-to-analog converter (DAC) without affecting the asymptotic optimality. Achievable information rate evaluations verify the asymptotic optimality. As an example, error performance results of a simple 16-level LDPC coded modulation scheme show that a shaping gain of 0.65 dB can be obtained by applying the proposed constellation design. This method can also be applied to more specific IM/DD channel models, since it only requires a near-optimal continuous input distribution.
{"title":"Geometric Constellation Shaping for Wireless Optical Intensity Channels: An Information-Theoretic Approach","authors":"Suhua Zhou;Tianqi Li;Zhaoxi Fang;Jing Zhou;Wenyi Zhang","doi":"10.1109/LCOMM.2024.3511129","DOIUrl":"https://doi.org/10.1109/LCOMM.2024.3511129","url":null,"abstract":"A simple geometric shaping method is proposed for optical wireless communication systems based on intensity modulation and direct detection (IM/DD) from an information-theoretic perspective. Constellations consisting of equiprobable levels with exponential-like distribution are obtained, which possesses asymptotic optimality in the sense that the high-SNR capacity of average-intensity constrained optical intensity channel can be approached by such constellations with increasing size. All \u0000<inline-formula> <tex-math>$2^{b}$ </tex-math></inline-formula>\u0000 levels (\u0000<inline-formula> <tex-math>$bin mathbb {N}$ </tex-math></inline-formula>\u0000) of the obtained constellation can be represented by a basic level and \u0000<inline-formula> <tex-math>$b+2$ </tex-math></inline-formula>\u0000 bits, thereby reducing the required resolution of the digital-to-analog converter (DAC) without affecting the asymptotic optimality. Achievable information rate evaluations verify the asymptotic optimality. As an example, error performance results of a simple 16-level LDPC coded modulation scheme show that a shaping gain of 0.65 dB can be obtained by applying the proposed constellation design. This method can also be applied to more specific IM/DD channel models, since it only requires a near-optimal continuous input distribution.","PeriodicalId":13197,"journal":{"name":"IEEE Communications Letters","volume":"29 1","pages":"215-219"},"PeriodicalIF":3.7,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142938358","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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