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oe1(光电查) - 科学论文

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  • [IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Modulation of Conductivity in Manganese Vanadium Oxide

    摘要: Cloud radio access network (C-RAN) and massive multiple-input multiple-output (MIMO) are recognized as two key technologies for the fifth-generation mobile networks. In this paper, we consider the energy efficiency-based user association problem in massive MIMO empowered C-RAN, where multiple antennae are clustered at each remote radio head (RRH). We first obtain the deterministic equivalent expression of the energy efficiency, and then propose three user association algorithms, named nearest-based user association (NBUA), single-candidate RRH user association (SCRUA), and multi-candidate RRHs user association (MCRUA), respectively. In NBUA and SCRUA, each user is associated with only one RRH, and in MCRUA, multiple RRHs can serve the same user. In our algorithms, the impact of the power consumption of fronthaul links and antennas is considered by allowing inefficient RRHs to be turned into sleep mode. We provide the numerical comparisons of the proposed algorithms and a state-of-the-art baseline, which associates each user with the nearest RRH. The results show that our proposed algorithms achieve higher energy efficiency than the baseline algorithm. The proposed MCRUA algorithm achieves a good balance between spectral and energy efficiency, and the performance gain is more significant when the number of users is large.

    关键词: Cloud radio access networks,energy efficiency,massive MIMO,user association

    更新于2025-09-19 17:13:59

  • [IEEE 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Sozopol, Bulgaria (2019.9.6-2019.9.8)] 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Super-Collimation by Circular Grating near Mirror

    摘要: In practical mobile communication engineering applications, surfaces of antenna array deployment regions are usually uneven. Therefore, massive multi-input–multi-output (MIMO) communication systems usually transmit wireless signals by irregular antenna arrays. To evaluate the performance of irregular antenna arrays, the matrix correlation coef?cient and the ergodic received gain are de?ned for massive MIMO communication systems with mutual coupling effects. Furthermore, the lower bound of the ergodic achievable rate, symbol error rate, and average outage probability is ?rst derived for multi-user massive MIMO communication systems using irregular antenna arrays. Asymptotic results are also derived when the number of antennae approaches in?nity. Numerical results indicate that there exists a maximum achievable rate when the number of antennae keeps increasing in massive MIMO communication systems using irregular antenna arrays. Moreover, the irregular antenna array outperforms the regular antenna array in the achievable rate of massive MIMO communication systems when the number of antennae is larger than or equal to a given threshold.

    关键词: achievable rate,Massive MIMO,mutual coupling,irregular antenna array

    更新于2025-09-19 17:13:59

  • [IEEE 2019 21st International Middle East Power Systems Conference (MEPCON) - Cairo, Egypt (2019.12.17-2019.12.19)] 2019 21st International Middle East Power Systems Conference (MEPCON) - Optimal Allocation for Photovoltaic/ Wind Turbine Applying A Hybrid Butterfly Genetic Algorithm

    摘要: To achieve insights about the impact of amplified loop interference, we consider a dual-hop full-duplex (FD) massive multiple-input multiple-output (MIMO) amplify-and-forward (AF) relaying system in terms of achievable ergodic rates for each user pair as well as spectrum and energy efficiencies. It is assumed that the base station (or relay) is equipped with MRx receive antennas and MTx transmit antennas, while all sources and destinations have a single antenna. For such FD massive MIMO AF relaying systems, the closed-form expressions of the lower bounds of achievable ergodic rates are derived first with a finite number of receive and transmit antennas at base station. Then, the asymptotic performance analysis is performed by considering three different power-scaling schemes: 1) PS = ES /MRx and PR = ER; 2) PS = ES and PR = ER/MTx; and 3) PS = ES /MRx and PR = ER/MTx, where ES and ER are fixed, and PS and PR denote the transmit powers of each source and relay, respectively. Our results show that only when the power-scaling 2) is utilized, do the FD massive MIMO AF relay systems have the ability to restrict the loop interference, so that the system performance is free of loop interference when the number of antennas at the relay is large enough. On the contrary, with the power-scaling cases 1) and 3), the systems have no ability to cancel the loop interference even if MRx or MTx (or both) goes to infinity. The insight is different from the results in the FD massive MIMO decode-and-forward relaying systems where the loop interference can be entirely eliminated for the three power-scaling cases.

    关键词: relay,Full-duplex,massive MIMO,energy efficiency,amplify-and-forward,ergodic rates

    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) - Temperature and Irradiance Dependence of Current and Voltage at Maximum Power of Crystalline Silicon Photovoltaic Modules

    摘要: With the coming of the Internet of Things (IoT) and the fifth generation (5G) wireless communication era, more and more lightweight user equipments (UEs) appear in our life. The private information they gather and transmit on the uplink will likely face security risks, since the lightweight UEs are probably with limited number of antennas, e.g., only one antenna, limited power and low signal processing and data computing capabilities, which may inherently weaken the corresponding secrecy performance. As a consequence, traditional cryptographic techniques and complex physical layer security techniques with favorable secrecy performance may not be suitable for lightweight UEs due to high implementation complexity. Moreover, it is highly plausible that the unauthorized nodes can utilize much more powerful large antenna array, i.e., massive multiple-input multiple-output (MIMO) technology, to intercept the uplink information sent by the lightweight UEs due to the maturity of massive MIMO technology by then. Considering the possibility of facing massive MIMO eavesdropper, we propose to adopt the uplink original symbol phase rotated (UOSPR) scheme to secure the uplink transmission for lightweight single-antenna UEs in this paper. By employing the UOSPR secure transmission scheme, the lightweight UEs will randomly rotate the original information bearing symbols before they are transmitted to the BS on the uplink. This can be viewed as a symbol encryption process. The BS is then assured to be able to infer the accurate phase rotation and recover the original symbols while the massive MIMO eavesdropper can learn little useful information about the randomly rotated phase. The corresponding secrecy analysis of the UOSPR scheme on the uplink transmission is presented in detail. Furthermore, we show that the UOSPR scheme is with low complexity from the perspective of the lightweight UEs, which potentially makes it a candidate uplink secure transmission scheme in IoT and 5G scenarios. Simulation results are provided to further corroborate the effectiveness of the UOSPR secure transmission scheme.

    关键词: uplink transmission,random phase rotation,physical layer security,secrecy analysis,Massive MIMO

    更新于2025-09-19 17:13:59

  • [IEEE 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Sozopol, Bulgaria (2019.9.6-2019.9.8)] 2019 IEEE 8th International Conference on Advanced Optoelectronics and Lasers (CAOL) - Generation of radially polarized beams by intracavity waveguide technique

    摘要: The development of base stations (BSs) with large aperture antenna arrays, enabled partially by the utilization of cmWave and mmWave frequency bands, will require radiated testing in fading conditions. In this paper, the objective is to investigate the suitable measurement distances and physical dimensions of the over-the-air setups for the performance evaluation of massive multiple-input multiple-output (MIMO) BSs in anechoic chambers with multiple probes. Setup dimension is the major cost factor in the test systems and is thus the key issue to be investigated. The purpose is to determine whether the conventional far field criteria must be followed when determining the range of the setup or if they can be relieved. The impact of limited test setup dimension on various metrics, e.g., far field criteria, field performance within the test area, system link budget analysis, direction of arrival estimation algorithm as well as multi-user MIMO sum-rate capacity are investigated to determine the range of the test setup. It was found that the link budget does not support for the measurement distances claimed by the Fraunhofer distance. Most of the utilized metrics, especially the sum rate capacity, indicate that smaller setup sizes can still yield reasonable measurement accuracy. Simulations were performed at 2.6, 3.5, and 28 GHz frequencies.

    关键词: over the air testing,performance evaluation,Massive MIMO base station,multi-probe anechoic chamber setup.

    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) - Effect of irradiance data on the optimal sizing of photovoltaic water pumping systems

    摘要: Cloud radio access network (C-RAN) and massive multiple-input multiple-output (MIMO) are recognized as two key technologies for the fifth-generation mobile networks. In this paper, we consider the energy efficiency-based user association problem in massive MIMO empowered C-RAN, where multiple antennae are clustered at each remote radio head (RRH). We first obtain the deterministic equivalent expression of the energy efficiency, and then propose three user association algorithms, named nearest-based user association (NBUA), single-candidate RRH user association (SCRUA), and multi-candidate RRHs user association (MCRUA), respectively. In NBUA and SCRUA, each user is associated with only one RRH, and in MCRUA, multiple RRHs can serve the same user. In our algorithms, the impact of the power consumption of fronthaul links and antennas is considered by allowing inefficient RRHs to be turned into sleep mode. We provide the numerical comparisons of the proposed algorithms and a state-of-the-art baseline, which associates each user with the nearest RRH. The results show that our proposed algorithms achieve higher energy efficiency than the baseline algorithm. The proposed MCRUA algorithm achieves a good balance between spectral and energy efficiency, and the performance gain is more significant when the number of users is large.

    关键词: user association,Cloud radio access networks,energy efficiency,massive MIMO

    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) - Quantum-Dot Intermediate-band Solar Cell used as Bottom Cell

    摘要: Multiple transmitting antennas can considerably increase the downlink spectral efficiency by beamforming to multiple users at the same time. However, multiuser beamforming requires channel state information (CSI) at the transmitter, which leads to training overhead and reduces overall achievable spectral efficiency. In this paper, we propose and analyze a sequential beamforming strategy that utilizes full-duplex base station to implement downlink data transmission concurrently with CSI acquisition via in-band closed or open loop training. Our results demonstrate that full-duplex capability can improve the spectral efficiency of uni-directional traffic, by leveraging it to reduce the control overhead of CSI estimation. In moderate SNR regimes, we analytically derive tight approximations for the optimal training duration and characterize the associated respective spectral efficiency. We further characterize the enhanced multiplexing gain performance in the high SNR regime. In both regimes, the performance of the proposed full-duplex strategy is compared with the half-duplex counterpart to quantify spectral efficiency improvement. With experimental data and 3-D channel model from 3GPP, in a 1.4 MHz 8 × 8 system LTE system with the block length of 500 symbols, the proposed strategy attains a spectral efficiency improvement of 130% and 8% with closed and open loop training, respectively.

    关键词: limited feedback,massive MIMO systems,multiuser MIMO systems,Wireless communication,full-duplex systems

    更新于2025-09-16 10:30:52

  • [IEEE 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Huangshan, China (2019.8.5-2019.8.8)] 2019 18th International Conference on Optical Communications and Networks (ICOCN) - Deep Learning-Based Massive MIMO CSI Feedback

    摘要: Massive multi-input and multi-output technology is a key technology for future 5G wireless communication. The channel feedback problem of massive mimo becomes more and more challenging as the size of the mimo channel matrix becomes larger. A supervised deep learning-based encoder-decoder scheme was proposed to improve recinstruction quality recovery with channel the sensing algorithm, traditional compression-based Residual Attention-Net can still maintain good performance when compression is low.

    关键词: compressed sensing,massive MIMO,deep learning,residual network,attention model

    更新于2025-09-16 10:30:52

  • [IEEE 2019 International Workshop on Fiber Optics in Access Networks (FOAN) - Sarajevo, Bosnia and Herzegovina (2019.9.2-2019.9.4)] 2019 International Workshop on Fiber Optics in Access Networks (FOAN) - Overview of Wireline FTTH-Based Access Technologies in the Kosovan Telecommunication Market

    摘要: This paper investigates a multi-pair two-way massive MIMO amplify-and-forward full-duplex relay (FDR) system over Ricean fading channels, where multiple pairs of full-duplex users exchange information within pair through a full-duplex relay with a very large number of antennas (M for transmission and M for reception). First, the zero-forcing reception/zero-forcing transmission and maximum-ratio combining/maximum-ratio transmission processing matrices with imperfect channel state information at the relay are presented. Then, the corresponding asymptotic expressions (in M ) of the end-to-end signal-to-interference-plus-noise ratio are derived. Finally, the asymptotic spectral ef?ciency (SE) and energy ef?ciency (EE) at the general power scaling schemes when the number of the relay antennas tends to in?nity is analyzed. Theoretical analyses and simulation results show that, when M → ∞, the effects of channel estimation error, the self-loop of each user as well as the relay, inter-user interferences, the noise at users and the relay can be eliminated, respectively, if the power scaling scheme is properly selected. Besides, the considered multi-pair two-way FDR outperforms the multi-pair two-way half-duplex relaying on SE and EE performances when M is large. Moreover, a low complexity power control scheme is proposed to optimize the SE and we analyze the impact of the number of user pairs on the SE.

    关键词: power control,imperfect CSI,Ricean fading channels,full-duplex,Massive MIMO

    更新于2025-09-16 10:30:52

  • [IEEE 2019 International Vacuum Electronics Conference (IVEC) - Busan, Korea (South) (2019.4.28-2019.5.1)] 2019 International Vacuum Electronics Conference (IVEC) - Design of an Ka-Band Multiple-beam Corrugated Waveguide TWT

    摘要: This paper concerns with a relay-aided massive multiple input multiple output (MIMO) cellular network. The exact closed-form expressions of both spectral ef?ciency (SE) and energy ef?ciency (EE) are obtained for downlink single-cell multi-user multi-relay massive MIMO transmission in the pilot-contaminated regime, where the number of users is larger than the pilot sequence length. Based on the theoretical results of SE and EE, we investigate the effects of some system parameters [such as number of antennas at the base station (BS), transmit power at the BS, and transmit power of each relay station (RS)] on system performance, and achieve the tradeoff between SE and EE by power control. Speci?cally, the tradeoff problem is solved by joint optimization over transmit power P of the BS and transmit power pr of each RS, so as to maximize EE while satisfying the SE requirement. With the proposition that EE function is strictly quasi-concave with either P or pr , we propose two optimization methods: 1-D searching and alternate optimization. Comparatively, the former achieves a better performance, while the latter has a lower complexity. Simulation results validate the effectiveness of the two methods.

    关键词: spectral ef?ciency,Cellular networks,massive MIMO,relay,energy ef?ciency

    更新于2025-09-16 10:30:52