- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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[IEEE 2018 41st International Conference on Telecommunications and Signal Processing (TSP) - Athens, Greece (2018.7.4-2018.7.6)] 2018 41st International Conference on Telecommunications and Signal Processing (TSP) - Studying an Optimal Approach to Design Combined Fiber-Wireless Telecom Systems
摘要： We proposed a new approach to design interface hardware for next-generation telecom systems of combined fiber-wireless architecture based on nonlinear behavioral modeling in widespread off-the-shelf CAD tool NI AWRDE. To validate the approach, we research in detail a prospective base station operating in EU-assigned band (3.4-3.8 GHz) of 5G networks, which has easy-to-configure layout using the same cost- and power-efficient LW-VCSEL in downlink and uplink channels and direct modulation of LW-VCSEL in period-doubling state.
关键词： fronthaul fiber-wireless architecture,vertical cavity surface-emitting laser,base station,fifth-generation telecom network,computer-aided design
更新于2025-09-23 15:22:29
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The Non-coherent Ultra-Dense C-RAN is Capable of Outperforming its Coherent Counterpart at a Limited Fronthaul Capacity
摘要： The weighted sum rate maximization problem of ultra-dense cloud radio access networks (C-RANs) is considered, where realistic fronthaul capacity constraints are incorporated. To reduce the training overhead, pilot reuse is adopted and the transmit-beamforming is designed to be robust to the channel estimation errors. In contrast to the conventional C-RAN where the remote radio heads (RRHs) coherently transmit their data symbols to the user, we consider their non-coherent transmission, where no strict phase-synchronization is required. By exploiting the classic successive interference cancellation (SIC) technique, we first derive the closed-form expressions of the individual data rates from each serving RRH to the user and the overall data rate for each user that is not related to their decoding order. Then, we adopt the reweighted l1-norm technique to approximate the l0-norm in the fronthaul capacity constraints as the weighted power constraints. A low-complexity algorithm based on a novel sequential convex approximation (SCA) algorithm is developed to solve the resultant optimization problem with convergence guarantee. A beneficial initialization method is proposed to find the initial points of the SCA algorithm. Our simulation results show that in the high fronthaul capacity regime, the coherent transmission is superior to the non-coherent one in terms of its weighted sum rate. However, significant performance gains can be achieved by the non-coherent transmission over the coherent one in the low fronthaul capacity regime, which is the case in ultra-dense C-RANs, where mmWave fronthaul links with stringent capacity requirements are employed.
关键词： Ultra-dense networks (UDN),pilot reuse,non-coherent transmission,C-RAN,limited fronthaul capacity
更新于2025-09-23 15:21:21
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[IEEE 2019 IEEE CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON) - Valparaiso, Chile (2019.11.13-2019.11.27)] 2019 IEEE CHILEAN Conference on Electrical, Electronics Engineering, Information and Communication Technologies (CHILECON) - Explosive detection system based on Leddar sensor and Self-Organizing Maps in controled environments
摘要： Mobile fronthaul is an important network segment that bridges wireless baseband units and remote radio units to support cloud radio access network. We review recent progresses on the use of frequency-division multiplexing to achieve highly bandwidth-efficient mobile fronthaul with low latency. We present digital signal processing (DSP) techniques for channel aggregation and deaggregation, frequency-domain windowing, adjacent channel leak age ratio reduction, and synchronous transmission of both the I/Q waveforms of wireless signals and the control words (CWs) used for control and management purposes. In a proof-of-concept experiment, we demonstrate the transmission of 48 20-MHz LTE signals with a common public radio interface (CPRI) equivalent data rate of 59 Gb/s, achieving a low round-trip DSP latency of <2 μs and a low mean error-vector magnitude (EVM) of ～2.5% after fiber transmission. In a follow-up experiment, we further demonstrate the transmission of 32 20-MHz LTE signals together with CPRI-compliant CWs, corresponding to a CPRI-equivalent data rate of 39.32 Gb/s, in single optical wavelength channel that requires an RF bandwidth of only ～1.6 GHz. After transmission over 5-km standard single-mode fiber, the CWs are recovered without error, while the LTE signals are recovered with an EVM of lower than 3%. Applying this technique to future 5G wireless networks with massive multiple-input multiple-output is also discussed. This efficient mobile fronthaul technique may find promising applications in future integrated fiber/wireless access networks to provide ultrabroadband access services.
关键词： fifth-generation (5G),frequency-division multiplexing (FDM),common public radio interface (CPRI),Cloud radio access network (C-RAN),optical fiber transmission,mobile fronthaul
更新于2025-09-23 15:21:01
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Upstream and Downstream Analysis of an Optical Fronthaul System Based on DSP-Assisted Channel Aggregation
摘要： In this paper, we focus on a well-known optical fronthauling architecture based on frequency division multiplexed digital signal processing (DSP)-assisted channel aggregation, and we present new results related to the optimization of the optical setup, proposing an efficient technique for the optimization of the transmission. In particular, we report an original pre-emphasis technique to equalize the performance of the radio channels, especially focusing on the upstream (US) link that has more critical characteristics but has not typically been treated in detail in previous works on this topic. The effects of both radio and optical impairments on the error vector magnitude (EVM) are taken into account. An analytical description of our approach is provided, and then it is applied on an experimental setup (able to aggregate up to 96 20-MHz radio signals), showing the possibility of minimizing the maximum EVM at the output of the fronthauling link, for both downstream and US transmission. Additionally, a low complexity technique to practically estimate the EVM per channel by taking advantage of only the DSP-aggregation/deaggregation functionalities is proposed and, again, experimentally demonstrated.
关键词： Radio-over-fiber,Mobile fronthaul,DSP-assisted channel aggregation,OFDM,Frequency division multiplexing
更新于2025-09-23 15:21:01
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5G/NGPON Evolution and Convergence: Developing on Spatial Multiplexing of Optical Fiber Links for 5G Infrastructures
摘要： The offering of demanding telecommunication services as promised by the 5G specifications raise the necessity for high capacity, flexible, adaptive, and power conserving fronthaul. Toward this goal, the role of the passive optical network which is responsible for interconnecting the central office (CO) with the cell-sites is crucial. Among the latest related technologies that need to be integrated in the context of the next generation passive optical networks (NGPONs), the most promising for increasing the provided bandwidth, is the optical spatial multiplexing. In this paper, we present the key 5G technologies, focusing on spatial division multiplexing, which constitutes the main innovation of the blueSPACE 5G Infrastructure Public Private Partnership (5G PPP) project. Exploiting the recent developments on multicore fibers (MCFs), optical beamforming networks (OBFNs), analog radio over fiber (ARoF), and spatial-spectral resources granularity in the context of Spectrally Spatially Flexible Optical Networks (SS-FONs), we describe a complete approach for the 5G fronthaul, emphasizing on the efficient allocation of optical resources while aiming at minimizing energy consumption. The modeled optimization problem is thoroughly presented, and the introduced scheme is evaluated through a real-world based simulation scenario, exhibiting quite promising results.
关键词： power saving optimization,5G fronthaul,ODN granularity,optical SDM,spatial and spectral dimensions,NGPON
更新于2025-09-23 15:19:57
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Automatic Compensation for Defects of Laser Reflective Patterns in Optics-Based Auto-Focusing Microscopes
摘要： This paper summarizes recent work on the use of optical wireless links as a robust outdoor backhaul solution for small radio cells, such as WiFi, LTE and 5G, over distances between 20 and 200 m. Results of a 5-month outdoor field trial in Berlin, Germany, indicate that the visibility range was never below 180 m, with more than 1 km in 99% of all times during this period. Rate-adaptive transmission proved to improve the availability remarkably in the occasional presence of fog or sunlight. A mathematical model of the backhaul link including these impairments is presented and implemented to obtain an optimized link design. A prototype was realized, accordingly, using low-cost optoelectronic components and a 1 Gb/s baseband chipset. Gross data rates of 800, 500, and 225 Mb/s have been achieved in real-time operation over 20, 100, and 215 m outdoor link distance, respectively, with 2 ms latency at 95% load. Finally, we discuss further evolution towards 5G mobile networks.
关键词： Fronthaul,LTE,small cells,5G,Backhaul,LED,optical wireless communications
更新于2025-09-23 15:19:57
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[IEEE 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - Xiamen, China (2019.12.17-2019.12.20)] 2019 Photonics & Electromagnetics Research Symposium - Fall (PIERS - Fall) - 2 ??m Thulium-doped Fiber Laser Based on Synchronously Pumped Mode-locking
摘要： Mobile fronthaul is an important network segment that bridges wireless baseband units and remote radio units to support cloud radio access network. We review recent progresses on the use of frequency-division multiplexing to achieve highly bandwidth-efficient mobile fronthaul with low latency. We present digital signal processing (DSP) techniques for channel aggregation and deaggregation, frequency-domain windowing, adjacent channel leakage ratio reduction, and synchronous transmission of both the I/Q waveforms of wireless signals and the control words (CWs) used for control and management purposes. In a proof-of-concept experiment, we demonstrate the transmission of 48 20-MHz LTE signals with a common public radio interface (CPRI) equivalent data rate of 59 Gb/s, achieving a low round-trip DSP latency of <2 μs and a low mean error-vector magnitude (EVM) of ～2.5% after fiber transmission. In a follow-up experiment, we further demonstrate the transmission of 32 20-MHz LTE signals together with CPRI-compliant CWs, corresponding to a CPRI-equivalent data rate of 39.32 Gb/s, in single optical wavelength channel that requires an RF bandwidth of only ～1.6 GHz. After transmission over 5-km standard single-mode fiber, the CWs are recovered without error, while the LTE signals are recovered with an EVM of lower than 3%. Applying this technique to future 5G wireless networks with massive multiple-input multiple-output is also discussed. This efficient mobile fronthaul technique may find promising applications in future integrated fiber/wireless access networks to provide ultrabroadband access services.
关键词： fifth-generation (5G),common public radio interface (CPRI),Cloud radio access network (C-RAN),optical fiber transmission,mobile fronthaul,frequency-division multiplexing (FDM)
更新于2025-09-23 15:19:57
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Proof-of-Principle Experiment of a 20-kW-Average-Power Ka-Band Gyro-Traveling Wave Tube With a Cut-Off Waveguide Section
摘要： This paper summarizes recent work on the use of optical wireless links as a robust outdoor backhaul solution for small radio cells, such as WiFi, LTE and 5G, over distances between 20 and 200 m. Results of a 5-month outdoor field trial in Berlin, Germany, indicate that the visibility range was never below 180 m, with more than 1 km in 99% of all times during this period. Rate-adaptive transmission proved to improve the availability remarkably in the occasional presence of fog or sunlight. A mathematical model of the backhaul link including these impairments is presented and implemented to obtain an optimized link design. A prototype was realized, accordingly, using low-cost optoelectronic components and a 1 Gb/s baseband chipset. Gross data rates of 800, 500, and 225 Mb/s have been achieved in real-time operation over 20, 100, and 215 m outdoor link distance, respectively, with 2 ms latency at 95% load. Finally, we discuss further evolution towards 5G mobile networks.
关键词： Backhaul,optical wireless communications,small cells,Fronthaul,LTE,LED,5G
更新于2025-09-23 15:19:57
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Joint FSO Fronthaul and Millimeter-Wave Access Link Optimization in Cloud Small Cell Networks: A Statistical-QoS Aware Approach
摘要： We investigate resource optimization for downlink cloud small cell network where the baseband unit pool communicates with the buffer-aided small remote radio heads (SRRHs) through free space optical fronthaul, and SRRHs transmit to the user equipments (UEs) by using time division multiplexing based millimeter wave access links. Our objective is to maximize the supportable aggregate data arrival rate in the network by exploiting inter-dependence of fronthaul and access links. Towards this objective, we consider maximum acceptable end-to-end queue-length bound violation probability constraints, load-balancing constraints in the access link, fronthaul link selection constraints, and transmit power budget constraints of fronthaul and access links. Since the joint fronthaul and access link optimization is a non-convex and combinatorial problem, we develop iterative solution by decomposing the original optimization problem into two sub-problems. The first sub-problem optimally obtains fronthaul and access link power allocation and fronthaul link selection by using Lagrangian dual decomposition and canonical one-to-one matching techniques. By employing Lagrangian dual decomposition and alternating optimization techniques, the second sub-problem obtains near optimal data arrival rate for each UE, UE-SRRH associations, fronthaul rate allocation among the transmitted data for the UEs, and transmission duration scheduling in millimeter wave access link. An algorithm of polynomial complexity is developed in order to determine the supportable aggregate data arrival rate by considering statistical quality-of-service requirements, and its convergence is proved. Simulation results depict that the proposed scheme significantly improves the aggregate data arrival rate over several benchmark schemes.
关键词： statistical-QoS,fronthaul,millimeter wave,optimization,Free space optical communication
更新于2025-09-19 17:15:36
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[IEEE 2018 Asia Communications and Photonics Conference (ACP) - Hangzhou, China (2018.10.26-2018.10.29)] 2018 Asia Communications and Photonics Conference (ACP) - Exploiting Core-Switching to Minimize Fronthaul Degradation using Multicore Fiber
摘要： Fronthaul connections carried by Multicore Fibers (MCFs) might experience different degradations if they are carried by different cores. This paper shows that switching fronthaul connections between the cores helps to minimizing the fronthaul service degradation.
关键词： fronthaul,5G,switching,multicore
更新于2025-09-19 17:15:36