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oe1(光电查) - 科学论文

13 条数据
?? 中文(中国)
  • Passive Optical Network Based Mobile Backhaul Enabling Ultra-Low Latency for Communications Among Base Stations

    摘要: Low latency is of key importance for mobile networks to support emerging time-critical applications, such as road traffic safety and efficiency. Meanwhile, a passive optical network (PON) is widely recognized as a promising solution for mobile backhaul networks thanks to its high capacity and low energy consumption. In the conventional PON-based mobile backhaul network, where base stations (BSs) are co-located with optical network units, the traffic between the neighboring BSs that are mainly caused by user mobility has to be first sent to the optical line terminal and even further, e.g., edge nodes of mobile core networks, resulting in high latency, although the adjacent BSs are geographically located close to each other. In this paper, a novel PON-based architecture is proposed for mobile backhaul to enhance the connectivity between neighboring BSs. Meanwhile, a tailored medium access control protocol and dynamic bandwidth allocation algorithm are introduced to support fast inter-BS communications. The results reveal that a low latency (less than 1 ms packet delay) for communications among any adjacent BSs can be achieved in the proposed PON-based mobile backhaul network, demonstrating great potential to support future time-critical applications.

    关键词: Low latency,Mobile backhaul,Passive optical network,User mobility,Inter-base station communications

    更新于2025-09-23 15:22:29

  • Design and measurement of a 5G mmW mobile backhaul transceiver at 28 GHz

    摘要: High throughput and ultra low latency are the main requirements for fifth generation (5G) mobile broadband communications. Densely populated urban environments require utilization of previously underutilized millimeter wave frequency spectrum for higher data rates. The Ka-band, previously used in satellite applications, is of particular interest to terrestrial 5G mobile networks. New radio solutions are required for these frequencies, such as multiple wireless base stations organized in small cells and highly directional antennas to compensate for higher path loss. Wireless backhaul is predicted to be the most cost-effective and versatile solution to connect 5G base stations to the core network. Wireless backhaul enables flexible and easy installation of 5G base stations in ad hoc networks, supporting large crowd gatherings such as concerts and sports events. In this article, we present an architecture of a wireless backhaul transceiver, which operates on the 26.5–29.5-GHz band. The architecture described in this paper was implemented, and the performance of the receiver (Rx) array has been measured. We also present over-the-air antenna array measurement results using the Rx. The measurement results show that unequal Rx channel gains and antenna gains do not have a significant effect on the shape of the main lobe of the radiation pattern. We have measured a coherence gain of 2.7 dB from two Rx channels that is close to the theoretical value of 3.0 dB. We have achieved a conducted Rx EVM of better than 2% using a 100-MHz 16-QAM modulated signal at 26.5 GHz.

    关键词: Antenna pattern,Beamforming,Millimeter wave,Radio frequency,Transceiver,5G,Antenna array,Backhaul

    更新于2025-09-23 15:21:01

  • 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

  • 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

  • [IEEE 2019 IEEE International Conference on Telecommunications and Photonics (ICTP) - Dhaka, Bangladesh (2019.12.28-2019.12.30)] 2019 IEEE International Conference on Telecommunications and Photonics (ICTP) - Hollow-core Photonic Crystal Fiber Sensor for Refractive Index Sensing

    摘要: 5G is the next cellular generation and is expected to quench the growing thirst for taxing data rates and to enable the Internet of Things. Focused research and standardization work have been addressing the corresponding challenges from the radio perspective while employing advanced features, such as network densification, massive multiple-input-multiple-output antennae, coordinated multi-point processing, inter-cell interference mitigation techniques, carrier aggregation, and new spectrum exploration. Nevertheless, a new bottleneck has emerged: the backhaul. The ultra-dense and heavy traffic cells should be connected to the core network through the backhaul, often with extreme requirements in terms of capacity, latency, availability, energy, and cost efficiency. This pioneering survey explains the 5G backhaul paradigm, presents a critical analysis of legacy, cutting-edge solutions, and new trends in backhauling, and proposes a novel consolidated 5G backhaul framework. A new joint radio access and backhaul perspective is proposed for the evaluation of backhaul technologies which reinforces the belief that no single solution can solve the holistic 5G backhaul problem. This paper also reveals hidden advantages and shortcomings of backhaul solutions, which are not evident when backhaul technologies are inspected as an independent part of the 5G network. This survey is key in identifying essential catalysts that are believed to jointly pave the way to solving the beyond-2020 backhauling challenge. Lessons learned, unsolved challenges, and a new consolidated 5G backhaul vision are thus presented.

    关键词: backhaul as a service,heterogeneous network,SDN,small cells,SON,backhaul,C-RAN,fronthaul,5G

    更新于2025-09-19 17:13:59

  • [IEEE 2019 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC) - Macao, Macao (2019.12.1-2019.12.4)] 2019 IEEE PES Asia-Pacific Power and Energy Engineering Conference (APPEEC) - Optimum Connection Structure for Photovoltaic Array Considering Shadow Influence

    摘要: Wireless backhaul networks provide vital infrastructure support for large public and private networks, and their efficient design is essential for smoothly handling the rapid growth of the Internet traffic. For its efficient capacity utilization, a well-planned topology would be crucial for such networks. Existing studies on planning for wireless backhaul network topologies have mostly focused on a single parameter or on a few performance aspects, e.g., to minimize the network cost or to maximize the network reliability. It would, however, be more realistic to consider multiple performance aspects jointly, subject to a variety of system constraints for a microwave-based wireless backhaul network, as proposed in this paper. For the optimization, we formulate a general cost that incorporates the various performance aspects considered, based on different weight factors. We develop an integer linear programming (ILP) optimization model and also propose an efficient heuristic algorithm to plan cost-minimized tree topologies for both single stage and multi-stage design scenarios. This paper shows that the proposed heuristic algorithm is efficient to optimize multiple system objectives jointly and performs close to the ILP model. The performances of the topologies planned with the periodic constraint and the single stage scenario are also close to each other further confirming the efficiency of the proposed heuristic algorithm.

    关键词: periodic network planning,Network planning,wireless backhaul network,network optimization

    更新于2025-09-19 17:13:59

  • [IEEE 2019 International Conference on Optical MEMS and Nanophotonics (OMN) - Daejeon, Korea (South) (2019.7.28-2019.8.1)] 2019 International Conference on Optical MEMS and Nanophotonics (OMN) - Subwavelength sampled photonics waveguides in silicon nitride for efficient fiber mode-matching

    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: 5G,Fronthaul,LTE,Backhaul,small cells,optical wireless communications,LED

    更新于2025-09-19 17:13:59

  • [IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Performance Optimization of P <sup>+</sup> N Silicon Solar Cell with Screen-printed Boron Emitter

    摘要: 5G de?nition and standardization projects are well underway, and governing characteristics and major challenges have been identi?ed. A critical network element impacting the potential performance of 5G networks is the backhaul, which is expected to expand in length and breadth to cater to the exponential growth of small cells while offering high throughput in the order of gigabit per second and less than 1 ms latency with high resilience and energy ef?ciency. Such performance may only be possible with direct optical ?ber connections that are often not available country-wide and are cumbersome and expensive to deploy. On the other hand, a prime 5G characteristic is diversity, which describes the radio access network, the backhaul, and also the types of user applications and devices. Thus, we propose a novel, distributed, self-optimized, end-to-end user-cell-backhaul association scheme that intelligently associates users with candidate cells based on corresponding dynamic radio and backhaul conditions while abiding by users’ requirements. Radio cells broadcast multiple bias factors, each re?ecting a dynamic performance indicator (DPI) of the end-to-end network performance such as capacity, latency, resilience, energy consumption, and so on. A given user would employ these factors to derive a user-centric cell ranking that motivates it to select the cell with radio and backhaul performance that conforms to the user requirements. Reinforcement learning is used at the radio cells to optimise the bias factors for each DPI in a way that maximise the system throughput while minimising the gap between the users’ achievable and required end-to-end quality of experience (QoE). Preliminary results show considerable improvement in users’ QoE and cumulative system throughput when compared with the state-of-the-art user-cell association schemes.

    关键词: multiple attribute decision making,SON,user-centric,Backhaul,reinforcement learning,user-cell association,fronthaul

    更新于2025-09-19 17:13:59

  • Design and Experimental Evaluation of Equalization Algorithms for Line-of-Sight Spatial Multiplexing at 60 GHz

    摘要: With large bandwidths, millimeter wave (mmWave) line-of-sight (LoS) MIMO technology employing parallel stream transmission is well suited for future wireless backhaul systems. However, hardware imperfections of mmWave transceivers cause additional signal processing challenges. Considering the channel and hardware properties, this work proposes a novel frame structure with high temporal efficiency. The required MIMO processing can be decomposed into two steps. The first one removes the interantenna interference including the carrier frequency offsets. In the second step, the intersymbol interference brought by the frequency-selective components is cancelled with a parallel structure. As a comparison, a more general decision-directed least mean square approach (DD-LMS) for joint processing of all effects is introduced. With a 60 GHz 2×2 LoS MIMO demonstrator, only the widely linear version of DD-LMS achieves performance of about 0.2dB~0.6dB better than the proposed method, but requires approximately 4 times more complexity. The proposed method with parallel processing chains is well suited especially for larger LoS MIMO systems, e.g., for a system with 16 streams, its required complexity is less than 7% of the widely linear DD-LMS.

    关键词: Channel Equalization,MIMO,Line of Sight,Synchronization,Backhaul,Millimeter Wave

    更新于2025-09-10 09:29:36

  • [IEEE 2018 IEEE 5G World Forum (5GWF) - Silicon Valley, CA (2018.7.9-2018.7.11)] 2018 IEEE 5G World Forum (5GWF) - Capacity Estimation for Self-Backhaul in mmWave Networks

    摘要: We consider the performance implications of using self-backhaul in a millimeter wave (mmWave) wireless network. In a self-backhauled network some nonanchored basestations route their traf?c through another anchored basestation rather than utilize an expensive wired backhaul. Self-backhaul is particularly attractive in the mmWave context since we can form narrow beams that reduce the interference due to the backhaul links. In this work we study how interference and load affect the overall performance of self-backhauled networks and we examine which network parameters determine whether self-backhaul is bene?cial. We demonstrate that highly directional beams and a steep path loss function improve the tradeoffs associated with self-backhaul. We also develop a scaling law that allows us to easily estimate the self-backhaul capacity.

    关键词: wireless network,mmWave,interference,load,capacity estimation,self-backhaul

    更新于2025-09-09 09:28:46