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12 pages, 1072 KiB  
Article
Performance Evaluation of IM/DD FSO Communication System Under Dust Storm Conditions
by Maged Abdullah Esmail
Technologies 2025, 13(7), 288; https://doi.org/10.3390/technologies13070288 - 7 Jul 2025
Viewed by 266
Abstract
Free-space optical (FSO) communication is a promising high-capacity solution for future wireless networks, particularly for backhaul and fronthaul links in 5G and emerging 6G systems. However, it remains highly vulnerable to environmental impairment, especially in arid regions prone to dust storms. While prior [...] Read more.
Free-space optical (FSO) communication is a promising high-capacity solution for future wireless networks, particularly for backhaul and fronthaul links in 5G and emerging 6G systems. However, it remains highly vulnerable to environmental impairment, especially in arid regions prone to dust storms. While prior studies have addressed atmospheric effects such as fog and turbulence, the specific impact of dust on signal performance remains insufficiently explored. This work presents a probabilistic modeling framework for evaluating the performance of an intensity modulation/direct detection (IM/DD) FSO system under dust storm conditions. Using a controlled laboratory environment, we conducted measurements of the optical signal under dust-induced channel conditions using real-world dust samples collected from an actual dust storm. We identified the Beta distribution as the most accurate model for the measured signal fluctuations. Closed-form expressions were derived for average bit error rate (BER), outage probability, and channel capacity. The close agreement between the analytical, approximate, and simulated results validates the proposed model as a reliable tool for evaluating FSO system performance. The results show that the forward error correction (FEC) BER threshold of 103 is achieved at approximately 10.5 dB, and the outage probability drops below 103 at 10 dB average SNR. Full article
(This article belongs to the Section Information and Communication Technologies)
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17 pages, 2256 KiB  
Article
Scalable Statistical Channel Estimation and Its Applications in User-Centric Cell-Free Massive MIMO Systems
by Ling Xing, Dongle Wang, Xiaohui Zhang, Honghai Wu and Kaikai Deng
Sensors 2025, 25(11), 3263; https://doi.org/10.3390/s25113263 - 22 May 2025
Viewed by 464
Abstract
Cell-free massive multiple-input multiple-output (mMIMO) technology utilizes collaborative signal processing to significantly improve system performance. In cell-free mMIMO systems, accurate channel state information (CSI) is a key element in improving the overall system performance. The existing statistical CSI acquisition methods for large-scale fading [...] Read more.
Cell-free massive multiple-input multiple-output (mMIMO) technology utilizes collaborative signal processing to significantly improve system performance. In cell-free mMIMO systems, accurate channel state information (CSI) is a key element in improving the overall system performance. The existing statistical CSI acquisition methods for large-scale fading (LSF) processing schemes assume that each access points (APs) provides service to all user equipments (UEs) in the system. However, as the number of UEs or APs increases, the computational complexity of statistical CSI estimation tends to infinity, which is not scalable in large-scale networks. To address this limitation, this paper proposes a scalable statistical CSI estimation method under the user-centric cell-free mMIMO system, which blindly estimates the partial statistical CSI required for LSF schemes using uplink (UL) data signals. Additionally, the estimated partial statistical CSI can also be used for downlink (DL) LSF precoding (LSFP) or power control in fully distributed precoding. Simulation results show that under the LSFP scheme, the proposed method can achieve comparable spectral efficiency (SE) with the traditional CSI acquisition scheme while ensuring scalability. When applied to power control in fully distributed precoding, it significantly reduces the fronthaul link CSI overhead while maintaining a nearly similar SE performance compared to existing solutions. Full article
(This article belongs to the Section Communications)
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17 pages, 3268 KiB  
Article
Simulative Analysis of Stimulated Raman Scattering Effects on WDM-PON Based 5G Fronthaul Networks
by Yan Xu, Shuai Wang and Asad Saleem
Sensors 2025, 25(10), 3237; https://doi.org/10.3390/s25103237 - 21 May 2025
Viewed by 503
Abstract
In future hybrid fiber and radio access networks, wavelength division multiplexing passive optical networks (WDM-PON) based fifth-generation (5G) fronthaul systems are anticipated to coexist with current protocols, potentially leading to non-linearity impairment due to stimulated Raman scattering (SRS). To meet the loss budget [...] Read more.
In future hybrid fiber and radio access networks, wavelength division multiplexing passive optical networks (WDM-PON) based fifth-generation (5G) fronthaul systems are anticipated to coexist with current protocols, potentially leading to non-linearity impairment due to stimulated Raman scattering (SRS). To meet the loss budget requirements of 5G fronthaul networks, this paper investigates the power changes induced by SRS in WDM-PON based 5G fronthaul systems. The study examines wavelength allocation schemes utilizing both the C-band and O-band, with modulation formats including non-return-to-zero (NRZ), optical double-binary (ODB), and four-level pulse amplitude modulation (PAM4). Simulation results indicate that SRS non-linearity impairment causes a power depletion of 1.3 dB in the 20 km C-band link scenario, regardless of whether the modulation formats are 25 Gb/s or 50 Gb/s NRZ, ODB, and PAM4, indicating that the SRS-induced power changes are largely independent of both modulation formats and modulation rates. This effect occurs when only the upstream and downstream wavelengths of the 5G fronthaul are broadcast. However, when the 5G fronthaul wavelengths coexist with previous protocols, the maximum power depletion increases significantly to 10.1 dB. In the O-band scenario, the SRS-induced maximum power depletion reaches 1.5 dB with NRZ, ODB, and PAM4 modulation formats at both 25 Gb/s and 50 Gb/s. Based on these analyses, the SRS non-linearity impairment shall be fully considered when planning the wavelengths for 5G fronthaul transmission. Full article
(This article belongs to the Special Issue Novel Technology in Optical Communications)
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14 pages, 1074 KiB  
Article
WDM-PON Free Space Optical (FSO) System Utilizing LDPC Decoding for Enhanced Cellular C-RAN Fronthaul Networks
by Dokhyl AlQahtani and Fady El-Nahal
Photonics 2025, 12(4), 391; https://doi.org/10.3390/photonics12040391 - 17 Apr 2025
Cited by 1 | Viewed by 796
Abstract
Modern cellular systems rely on high-capacity and low-latency optical networks to meet ever-increasing data demands. Centralized Radio Access Network (C-RAN) architectures offer a cost-effective approach for deploying mobile infrastructures. In this work, we propose a flexible and cost-efficient fronthaul topology that combines Wavelength [...] Read more.
Modern cellular systems rely on high-capacity and low-latency optical networks to meet ever-increasing data demands. Centralized Radio Access Network (C-RAN) architectures offer a cost-effective approach for deploying mobile infrastructures. In this work, we propose a flexible and cost-efficient fronthaul topology that combines Wavelength Division Multiplexing (WDM) passive optical networks (PONs) with free-space optical (FSO) links. To enhance overall system performance, we introduce Low-Density Parity Check (LDPC) decoding, which provides robust error-correction capabilities against atmospheric turbulence and noise. Our system transmits 20 Gbps, 16-QAM intensity-modulated orthogonal frequency-division multiplexing (OFDM) signals, achieving a substantial reduction in bit error rate (BER). Numerical results show that the proposed WDM-PON-FSO architecture, augmented with LDPC decoding, maintains reliable transmission over 2 km under strong turbulence conditions. Full article
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14 pages, 1376 KiB  
Article
Ultra-Wideband Analog Radio-over-Fiber Communication System Employing Pulse-Position Modulation
by Sandis Migla, Kristaps Rubuls, Nikolajs Tihomorskis, Toms Salgals, Oskars Ozolins, Vjaceslavs Bobrovs, Sandis Spolitis and Arturs Aboltins
Appl. Sci. 2025, 15(8), 4222; https://doi.org/10.3390/app15084222 - 11 Apr 2025
Viewed by 685
Abstract
This research presents a novel approach to 28 GHz impulse radio ultra-wideband (IR-UWB) transmission using pulse position modulation (PPM) over an analog radio-over-fiber (ARoF) link, investigating the impact of fiber-based fronthaul on the overall performance of the communication system. In this setup, an [...] Read more.
This research presents a novel approach to 28 GHz impulse radio ultra-wideband (IR-UWB) transmission using pulse position modulation (PPM) over an analog radio-over-fiber (ARoF) link, investigating the impact of fiber-based fronthaul on the overall performance of the communication system. In this setup, an arbitrary waveform generator (AWG) is employed for PPM signal generation, while demodulation is performed with a commercial time-to-digital converter (TDC) based on an event timer. To enhance the reliability of transmitted reference PPM (TR-PPM) signals, the transmission system integrates Gray coding and Consultative Committee for Space Data Systems (CCSDS)-standard-compliant Reed-Solomon (RS) error correcting code (ECC). System performance was evaluated by transmitting pseudorandom binary sequences (PRBSs) and measuring the bit error ratio (BER) across a 5-m wireless link between two 20 dBi gain horn (Ka-band) antennas, with and without a 20 km single-mode optical fiber (SMF) link in transmitter side and ECC at the receiver side. The system achieved a BER of less than 8.17 × 10−7, using a time bin duration of 200 ps and a pulse duration of 100 ps, demonstrating robust performance and significant potential for space-to-ground telecommunication applications. Full article
(This article belongs to the Special Issue Recent Advances in Microwave Devices and Intelligent Systems)
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20 pages, 5129 KiB  
Article
Multi-Band Analog Radio-over-Fiber Mobile Fronthaul System for Indoor Positioning, Beamforming, and Wireless Access
by Hang Yang, Wei Tian, Jianhua Li and Yang Chen
Sensors 2025, 25(7), 2338; https://doi.org/10.3390/s25072338 - 7 Apr 2025
Viewed by 635
Abstract
In response to the urgent demands of the Internet of Things for precise indoor target positioning and information interaction, this paper proposes a multi-band analog radio-over-fiber mobile fronthaul system. The objective is to obtain the target’s location in indoor environments while integrating remote [...] Read more.
In response to the urgent demands of the Internet of Things for precise indoor target positioning and information interaction, this paper proposes a multi-band analog radio-over-fiber mobile fronthaul system. The objective is to obtain the target’s location in indoor environments while integrating remote beamforming capabilities to achieve wireless access to the targets. Vector signals centered at 3, 4, 5, and 6 GHz for indoor positioning and centered at 30 GHz for wireless access are generated centrally in the distributed unit (DU) and fiber-distributed to the active antenna unit (AAU) in the multi-band analog radio-over-fiber mobile fronthaul system. Target positioning is achieved by radiating electromagnetic waves indoors through four omnidirectional antennas in conjunction with a pre-trained neural network, while high-speed wireless communication is realized through a phased array antenna (PAA) comprising four antenna elements. Remote beamforming for the PAA is implemented through the integration of an optical true time delay pool in the multi-band analog radio-over-fiber mobile fronthaul system. This integration decouples the weight control of beamforming from the AAU, enabling centralized control of beam direction at the DU and thereby reducing the complexity and cost of the AAU. Simulation results show that the average accuracy of localization classification can reach 86.92%, and six discrete beam directions are achieved via the optical true time delay pool. In the optical transmission layer, when the received optical power is 10 dBm, the error vector magnitudes (EVMs) of vector signals in all frequency bands remain below 3%. In the wireless transmission layer, two beam directions were selected for verification. Once the beam is aligned with the target device at maximum gain and the received signal is properly processed, the EVM of millimeter-wave vector signals remains below 11%. Full article
(This article belongs to the Section Communications)
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17 pages, 5419 KiB  
Article
Fiber/Free-Space Optics with Open Radio Access Networks Supplements the Coverage of Millimeter-Wave Beamforming for Future 5G and 6G Communication
by Cheng-Kai Yao, Hsin-Piao Lin, Chiun-Lang Cheng, Ming-An Chung, Yu-Shian Lin, Wen-Bo Wu, Chun-Wei Chiang and Peng-Chun Peng
Fibers 2025, 13(4), 39; https://doi.org/10.3390/fib13040039 - 2 Apr 2025
Cited by 2 | Viewed by 907
Abstract
Conceptually, this paper aims to help reduce the communication blind spots originating from the design of millimeter-wave (mmW) beamforming by deploying radio units of an open radio access network (O-RAN) with free-space optics (FSOs) as the backhaul and the fiber-optic link as the [...] Read more.
Conceptually, this paper aims to help reduce the communication blind spots originating from the design of millimeter-wave (mmW) beamforming by deploying radio units of an open radio access network (O-RAN) with free-space optics (FSOs) as the backhaul and the fiber-optic link as the fronthaul. At frequencies exceeding 24 GHz, the transmission reach of 5G/6G beamforming is limited to a few hundred meters, and the periphery area of the sector operational range of beamforming introduces a communication blind spot. Using FSOs as the backhaul and a fiber-optic link as the fronthaul, O-RAN empowers the radio unit to extend over greater distances to supplement the communication range that mmW beamforming cannot adequately cover. Notably, O-RAN is a prime example of next-generation wireless networks renowned for their adaptability and open architecture to enhance the cost-effectiveness of this integration. A 200 meter-long FSO link for backhaul and a fiber-optic link of up to 10 km for fronthaul were erected, thereby enabling the reach of communication services from urban centers to suburban and remote rural areas. Furthermore, in the context of beamforming, reinforcement learning (RL) was employed to optimize the error vector magnitude (EVM) by dynamically adjusting the beamforming phase based on the communication user’s location. In summary, the integration of RL-based mmW beamforming with the proposed O-RAN communication setup is operational. It lends scalability and cost-effectiveness to current and future communication infrastructures in urban, peri-urban, and rural areas. Full article
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36 pages, 16208 KiB  
Article
End-to-End Power Models for 5G Radio Access Network Architectures with a Perspective on 6G
by Bhuvaneshwar Doorgakant, Tulsi Pawan Fowdur and Mobayode O. Akinsolu
Mathematics 2025, 13(3), 466; https://doi.org/10.3390/math13030466 - 30 Jan 2025
Cited by 4 | Viewed by 1886
Abstract
5G, the fifth-generation mobile network, is predicted to significantly increase the traditional trajectory of energy consumption. It now uses four times as much energy as 4G, the fourth-generation mobile network. As a result, compared to previous generations, 5G’s increased cell density makes energy [...] Read more.
5G, the fifth-generation mobile network, is predicted to significantly increase the traditional trajectory of energy consumption. It now uses four times as much energy as 4G, the fourth-generation mobile network. As a result, compared to previous generations, 5G’s increased cell density makes energy efficiency a top priority. The objective of this paper is to formulate end-to-end power consumption models for three different 5G radio access network (RAN) deployment architectures, namely the 5G distributed RAN, the 5G centralized RAN with dedicated hardware and the 5G Cloud Centralized-RAN. The end-to-end modelling of the power consumption of a complete 5G system is obtained by combining the power models of individual components such as the base station, the core network, front-haul, mid-haul and backhaul links, as applicable for the different architectures. The authors considered the deployment of software-defined networking (SDN) at the 5G Core network and gigabit passive optical network as access technology for the backhaul network. This study examines the end-to-end power consumption of 5G networks across various architectures, focusing on key dependent parameters. The findings indicate that the 5G distributed RAN scenario has the highest power consumption among the three models evaluated. In comparison, the centralized 5G and 5G Cloud C-RAN scenarios consume 12% and 20% less power, respectively, than the Centralized RAN solution. Additionally, calculations reveal that base stations account for 74% to 78% of the total power consumption in 5G networks. These insights helped pioneer the calculation of the end-to-end power requirements of different 5G network architectures, forming a solid foundation for their sustainable implementation. Furthermore, this study lays the groundwork for extending power modeling to future 6G networks. Full article
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13 pages, 6831 KiB  
Article
Demonstration of a Hybrid B5G System Integrating VLC and RF-Based Technologies with Access Networks
by Tomás Powell Villena Andrade, Celso Henrique de Souza Lopes, Letícia Carneiro de Souza and Arismar Cerqueira Sodré Junior
Appl. Sci. 2025, 15(2), 955; https://doi.org/10.3390/app15020955 - 19 Jan 2025
Viewed by 1037
Abstract
Visible-light communication (VLC) has emerged as a promising technology to provide the very high-throughput wireless communications demanded by beyond-fifth-generation (B5G) applications. However, few works are found in the literature regarding the integration of VLC systems with other wireless communications technologies and with access [...] Read more.
Visible-light communication (VLC) has emerged as a promising technology to provide the very high-throughput wireless communications demanded by beyond-fifth-generation (B5G) applications. However, few works are found in the literature regarding the integration of VLC systems with other wireless communications technologies and with access networks. In this context, and as a proof of concept, we implement and experimentally evaluate a hybrid network architecture based on VLC, radio-over-fiber (RoF), free space optics (FSO), fiber-wireless (FiWi), and millimeter-waves (mm-waves) for B5G applications. Such optical networks make use of fiber-optic links based on RoF technology as backhauls, whereas their fronthauls might be either by FSO or RoF. Finally, a triple-wireless-access network is ensured by VLC, FiWi, and mm-wave links. The latter use a real 5G new radio (5G NR) signal. The system performance is evaluated in terms of a root mean square error vector magnitude (EVMRMS) parameter in accordance with the 3rd-Generation Partnership Project (3GPP) requirements. The experimental results demonstrate a total maximal theoretical throughput of approximately 1.66 Gbps, aligning with the digital performance requirements set by 3GPP. Full article
(This article belongs to the Special Issue Visible Light Communications (VLC) Networks)
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19 pages, 1177 KiB  
Article
Joint Divergence Angle of Free Space Optics (FSO) Link and UAV Trajectory Design in FSO-Based UAV-Enabled Wireless Power Transfer Relay Systems
by Jinho Kang
Photonics 2024, 11(12), 1136; https://doi.org/10.3390/photonics11121136 - 2 Dec 2024
Viewed by 1443
Abstract
Free Space Optics (FSO)-based UAV-enabled wireless power transfer (WPT) relay systems have emerged as a key technology for 6G networks, efficiently providing continuous power to Internet of Things (IoT) devices even in remote areas such as disaster recovery zones, maritime regions, and military [...] Read more.
Free Space Optics (FSO)-based UAV-enabled wireless power transfer (WPT) relay systems have emerged as a key technology for 6G networks, efficiently providing continuous power to Internet of Things (IoT) devices even in remote areas such as disaster recovery zones, maritime regions, and military networks, while addressing the limited battery capacity of UAVs through the FSO fronthaul link. However, the harvested power at the ground devices depends on the displacement and diameter of the FSO beam spot reaching the UAV, as well as the UAV trajectory, which affects both the FSO link and the radio-frequency (RF) link simultaneously. In this paper, we propose a joint design of the divergence angle in the FSO link and the UAV trajectory, in order to maximize the power transfer efficiency. Driven by the analysis of the optimal condition for the divergence angle, we develop a hybrid BS-PSO-based method to jointly optimize them while improving optimization performance. Numerical results demonstrate that the proposed method substantially increases power transfer efficiency and improves the optimization capability. Full article
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10 pages, 1622 KiB  
Proceeding Paper
Analysis of Conventional Direct Detection and Coherent Optical Receivers in Optical Access Networks
by Johanna Berenice Arguero Tello, Milton N. Tipán, Germán V. Arévalo and Christian Tipantuña
Eng. Proc. 2024, 77(1), 30; https://doi.org/10.3390/engproc2024077030 - 18 Nov 2024
Viewed by 1486
Abstract
This study evaluated the use of GFDM transmission in passive optical networks (PONs) by comparing the performance of coherent and non-coherent optical receivers using OptSim 2023.12sp2 and Matlab 2018b ®. The study concentrated on transmitting 10 Gb/s radio frequency signals over optical [...] Read more.
This study evaluated the use of GFDM transmission in passive optical networks (PONs) by comparing the performance of coherent and non-coherent optical receivers using OptSim 2023.12sp2 and Matlab 2018b ®. The study concentrated on transmitting 10 Gb/s radio frequency signals over optical fiber, emphasizing the significance of high-speed fronthaul links for 5G networks. The findings demonstrated that coherent detection markedly enhances receiver sensitivity by approximately 3 dB compared to direct detection, thereby augmenting the capacity of optical fronthaul networks despite the elevated cost. Additionally, the study recommended investigating pre- and post-compensation techniques to mitigate signal dispersion in optical fibers for further performance optimization. Full article
(This article belongs to the Proceedings of The XXXII Conference on Electrical and Electronic Engineering)
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8 pages, 3081 KiB  
Proceeding Paper
The Analysis of Service Convergence in an Optical Access Network
by Erick Cifuentes, David Mosquera, Christian Tipantuña, Berenice Arguero and Germán V. Arevalo
Eng. Proc. 2024, 77(1), 27; https://doi.org/10.3390/engproc2024077027 - 18 Nov 2024
Viewed by 555
Abstract
In recent years, the increasing number of internet-connected devices has exceeded the capacity of fourth-generation (4G) cellular networks, leading to the development of fifth-generation (5G) technology, designed to offer higher speeds, greater bandwidth, and lower latency. In this context, this study evaluated Universal [...] Read more.
In recent years, the increasing number of internet-connected devices has exceeded the capacity of fourth-generation (4G) cellular networks, leading to the development of fifth-generation (5G) technology, designed to offer higher speeds, greater bandwidth, and lower latency. In this context, this study evaluated Universal Filtered Multi-Carrier (UFMC) and Generalized Frequency Division Multiplexing (GFDM) techniques, implementing them in a radio-over-fiber (RoF) system and a Next-Generation Radio Access Network (NG-RAN) fronthaul link, and compared the results using communication quality metrics such as bit error rate (BER). Additionally, through signal generation and processing in Matlab, the performance of UFMC and LTE signals was analyzed, confirming that simultaneous transmission over an RoF channel allows for efficient signal separation in the frequency domain, with the UFMC giving power to LTE. Full article
(This article belongs to the Proceedings of The XXXII Conference on Electrical and Electronic Engineering)
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17 pages, 4060 KiB  
Article
Energy Efficient Multi-Active/Multi-Passive Antenna Arrays for Portable Access Points
by Muhammad Haroon Tariq, Shuai Zhang, Christos Masouros and Constantinos B. Papadias
Micromachines 2024, 15(11), 1351; https://doi.org/10.3390/mi15111351 - 1 Nov 2024
Cited by 1 | Viewed by 1518
Abstract
This article is about better wireless network connectivity. The main goal is to provide wireless service to several use cases and scenarios that may not be adequately covered today. Some of the considered scenarios are home connectivity, street-based infrastructure, emergency situations, disaster areas, [...] Read more.
This article is about better wireless network connectivity. The main goal is to provide wireless service to several use cases and scenarios that may not be adequately covered today. Some of the considered scenarios are home connectivity, street-based infrastructure, emergency situations, disaster areas, special event areas, and remote areas that suffer from problematic/inadequate network and possibly power infrastructure. A target system that we consider for such scenarios is that of an energy-efficient self-backhauled base station (also called a “portable access point—PAP”) that is mounted on a drone to aid/expand the land-based network. For the wireless backhaul link of the PAP, as well as for the fronthaul of the street-mounted base station, we consider newly built multi-active/multi-passive parasitic antenna arrays (MAMPs). These antenna systems lead to increased range/signal strength with low hardware complexity and power needs. This is due to their reduced number of radio frequency chains, which decreases the cost and weight of the base station system. MAMPs can show a performance close to traditional multiple input/multiple output (MIMO) systems that use as many antenna elements as RF chains and to phased arrays. They can produce a directional beam in any desired direction with higher gain and narrow beamwidth by just tuning the load values of the parasitic elements. The MAMP is designed based on radiation conditions which were produced during the research to ensure that the radiation properties of the array were good. Full article
(This article belongs to the Special Issue Microwave Passive Components, 2nd Edition)
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10 pages, 566 KiB  
Article
Cell-Free Massive MIMO Power Consumption with Serial Front-Hauls
by Danaisy Prado-Alvarez, Saúl Inca, David Martín-Sacristán and Jose F. Monserrat
Telecom 2024, 5(4), 1021-1030; https://doi.org/10.3390/telecom5040052 - 11 Oct 2024
Viewed by 1271
Abstract
Massive MIMO deployments have been traditionally based on dedicated links in the front-haul, i.e., between the central processing units and the Access Points (APs). Recently, cell-free massive Multiple-Input Multiple-Output (MIMO) systems based on serial front-haul links have been discussed to simplify the deployments, [...] Read more.
Massive MIMO deployments have been traditionally based on dedicated links in the front-haul, i.e., between the central processing units and the Access Points (APs). Recently, cell-free massive Multiple-Input Multiple-Output (MIMO) systems based on serial front-haul links have been discussed to simplify the deployments, among other reasons. However, the power consumption models currently used for cell-free massive MIMO deployments typically assume dedicated front-haul links. This paper highlights the inaccuracy of these models when applied to serial front-hauls and proposes simple adaptations to achieve more realistic results. The results obtained for an exemplary scenario show that the front-haul power would represent 61.73% of the total consumed power with the original models. In contrast, with the proposed adaptations, it could be as low as 1.59% of the total consumed power for some serial front-haul configurations. Additionally, the impact of considering APs with lower power consumption is studied, in which case, the percentages above would become 93.15% and 11.96%, respectively. Hence the importance of having power models that fit the front-haul topology. Full article
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16 pages, 4314 KiB  
Article
A Study on the Catch Losses and Mesh Selectivity Related to the Attachment of Marine Mammal Bycatch Reduction Devices on Midwater Trawl Gear
by Jung-Mo Jung, Min-Seuk Park and Kyu-Suk Choi
Fishes 2024, 9(10), 391; https://doi.org/10.3390/fishes9100391 - 28 Sep 2024
Cited by 1 | Viewed by 1650
Abstract
The National Institute of Fisheries Science in Korea is developing marine mammal bycatch reduction devices (BRDs) for high-risk fishing gear, such as trawls. We experimented with two BRD types (guiding nets) attached in front of codend at 30° and 45° angles, and catch [...] Read more.
The National Institute of Fisheries Science in Korea is developing marine mammal bycatch reduction devices (BRDs) for high-risk fishing gear, such as trawls. We experimented with two BRD types (guiding nets) attached in front of codend at 30° and 45° angles, and catch losses and mesh size selectivity were investigated. Experimental fishing operations were conducted along the East Coast of South Korea where whales and dolphins are commonly sighted. The catch was classified according to fishing location, BRD type, codend, and covernet, with measurements recorded for body length, maximum girth, and weight. The average selectivity for each haul was analyzed using the ‘selfisher’ package. The catch loss rates with the BRD attached at tilt angles of 30° and 45° were 11% and 29% for common flying squid, 6% and 28% for sailfin sandfish, and 5% and 8% for pearlside. While the mesh selectivity rates for common flying squid and pearlside remained at 0.2–0.5 across all lengths and tilt angles, the mesh selectivity curve for sailfin sandfish was estimated. There were significant differences in catch loss between 30° and 45° angles, with the 30° angle being more effective in catch loss. We observed a masking effect in the codend. Full article
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