- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
[IEEE ICASSP 2018 - 2018 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) - Calgary, AB (2018.4.15-2018.4.20)] 2018 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) - Dithered Beamforming for Channel Estimation in Mmwave-Based Massive Mimo
摘要： In this work we consider the challenging problem of channel estimation at the receiver of a massive multiple-input multiple-output system with hybrid analog/digital beamforming and low-resolution quantization. We propose a dithered beamforming architecture, where random control signals are injected to the analog part of the receiver beamformer and to the analog-to-digital converters to introduce randomness into the signal capturing process and combat the stair-case quantization effects. The statistical properties of the dithered output are captured via an Expectation-Maximization approximation of the maximum a-posteriori estimator. A low-complexity algorithm is proposed which exhibits performance close to the oracle-based least-squares estimation of the sparse channel.
关键词： low resolution analog-to-digital converter (ADC),hybrid analog/digital beamforming,millimeter wave (mmWave) massive MIMO
更新于2025-09-23 15:19:57
-
[IEEE 2018 IEEE 29th Annual International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC) - Bologna, Italy (2018.9.9-2018.9.12)] 2018 IEEE 29th Annual International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC) - Analyzing the Channel Aging Effects on Massive MIMO Downlink by Ray-Tracing
摘要： The in?uence of channel aging effects on massive Multiple-Input Multiple-Output (MIMO) downlink performance for a single-cell urban scenario is investigated by ray-tracing simulations. The scenario comprises 256 base station antennas and 64 single antenna users, which are mobile and travel with a constant speed. Ray-tracing simulations are used to calculate the instantaneous channels in every 100 microseconds for a 10 milliseconds time span. The average downlink data rate in the network is calculated at each time instance. The deterioration of the performance is demonstrated when the channel state information (CSI) available at the base station gradually deviates from the actual channel. The procedure is repeated for different user speeds and different numbers of transmitter antennas. The results are compared to a statistical channel aging model where the aging effect is captured by introducing a correlation coef?cient and a random error parameter to a previously known channel matrix.
关键词： downlink,massive MIMO,ray tracing,time-varying channels
更新于2025-09-19 17:15:36
-
[IEEE 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Chicago, IL, USA (2019.6.16-2019.6.21)] 2019 IEEE 46th Photovoltaic Specialists Conference (PVSC) - Physics-guided characterization and optimization of solar cells using surrogate machine learning model
摘要： Multiple transmitting antennas can considerably increase the downlink spectral ef?ciency 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 ef?ciency. 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 ef?ciency of uni-directional traf?c, 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 ef?ciency. 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 ef?ciency 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 ef?ciency improvement of 130% and 8% with closed and open loop training, respectively.
关键词： full-duplex systems,massive MIMO,Wireless communication,multiuser MIMO systems,limited feedback
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) - Peculiarities of propagation and long distance focusing of expanded Gaussian laser beams
摘要： This paper concerns with a wireless-energy-transfer (WET)-enabled massive multiple-input-multiple-output (MIMO) system with superimposed pilot (SP)-aided channel estimation. Unlike the conventional WET-enabled frame transmission schemes, with the aid of SP, both the uplink (UL) channel estimation and wireless information transmission (WIT) that powered by the downlink (DL) WET can be operated simultaneously, and thus provide the potential for improving the UL achievable throughput. The impact that the SP has on the performance of such a WET-enabled massive MIMO system is mathematically characterized, and the optimal solution, including the SP power-allocation and the ratio of time-allocation between the duration of UL WIT and DL WET, is derived with regard to maximize the UL achievable throughput. Numerical results demonstrate the proposed SP-aided WET technique yields a superior performance than the conventional pilot-only-based schemes.
关键词： wireless information and power transfer,Energy harvesting,massive MIMO,throughput maximization,channel estimation
更新于2025-09-19 17:13:59
-
[IEEE 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Rome, Italy (2019.6.17-2019.6.20)] 2019 PhotonIcs & Electromagnetics Research Symposium - Spring (PIERS-Spring) - Compact Trible-band Microstrip BPF Utilizing Interdigital-coupled Lines Feeding Structure
摘要： In this paper, we study the joint pilot assignment and resource allocation for system energy efficiency (SEE) maximization in the multi-user and multi-cell massive multi-input multi-output network. We explicitly consider the pilot contamination effect during the channel estimation in the SEE maximization problem, which aims to optimize the power allocation, the number of activated antennas, and the pilot assignment. To tackle the SEE maximization problem, we transform it into a subtractive form, which can be solved more efficiently. In particular, we develop an iterative algorithm to solve the transformed problem where optimization of power allocation and number of antennas is performed, and then pilot assignment optimization is conducted sequentially in each iteration. To tackle the first sub-problem, we employ a successive convex approximation (SCA) technique to attain a solvable convex optimization problem. Moreover, we propose a novel iterative low-complexity algorithm based on the Hungarian method to solve the pilot assignment sub-problem. We also describe how the proposed solution approach can be useful to address the sum rate (SR) maximization problem. In addition to the algorithmic developments, we characterize the optimal structure of both SEE and SR maximization problems. The numerical studies are conducted to illustrate the convergence of the proposed algorithms, impacts of different parameters on the SR and SEE, and significant performance gains of the proposed solution compared the conventional design.
关键词： Energy efficiency,multi-cell,massive MIMO,power allocation,pilot contamination,pilot assignment
更新于2025-09-19 17:13:59
-
[IEEE 2019 16th China International Forum on Solid State Lighting & 2019 International Forum on Wide Bandgap Semiconductors China (SSLChina: IFWS) - Shenzhen, China (2019.11.25-2019.11.27)] 2019 16th China International Forum on Solid State Lighting & 2019 International Forum on Wide Bandgap Semiconductors China (SSLChina: IFWS) - Thermal Simulations of a UV LED module with nanosilver sintered die attach process on graphene-coated copper substrates
摘要： Massive multiple-input multiple-output is a promising physical layer technology for 5G wireless communications due to its capability of high spectrum and energy efficiency, high spatial resolution, and simple transceiver design. To embrace its potential gains, the acquisition of channel state information is crucial, which unfortunately faces a number of challenges, such as the uplink pilot contamination, the overhead of downlink training and feedback, and the computational complexity. In order to reduce the effective channel dimensions, researchers have been investigating the low-rank (sparse) properties of channel environments from different viewpoints. This paper then provides a general overview of the current low-rank channel estimation approaches, including their basic assumptions, key results, as well as pros and cons on addressing the aforementioned tricky challenges. Comparisons among all these methods are provided for better understanding and some future research prospects for these low-rank approaches are also forecasted.
关键词： angle reciprocity,low-rank property,Massive MIMO,channel sparsity,channel estimation
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) - Magnetic Field Imaging: Strengths and limitations in characterising solar cells
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2025-09-19 17:13:59
-
[IEEE 2019 IEEE International Conference on Mechatronics and Automation (ICMA) - Tianjin, China (2019.8.4-2019.8.7)] 2019 IEEE International Conference on Mechatronics and Automation (ICMA) - Research on Optical Fiber IMU Signal Processing Based on Wavelet Algorithm
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2025-09-19 17:13:59
-
[IEEE 2019 10th International Conference on Computing, Communication and Networking Technologies (ICCCNT) - Kanpur, India (2019.7.6-2019.7.8)] 2019 10th International Conference on Computing, Communication and Networking Technologies (ICCCNT) - Numerical Investigation of Ultra-high Negative Dispersion Compensating Octagonal Photonic Crystal Fiber With High Nonlinearity
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： energy efficiency,ergodic rates,Full-duplex,massive MIMO,relay,amplify-and-forward
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) - Grid-forming Inverter Experimental Testing of Fault Current Contributions
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 efficiency (SE) and energy efficiency (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. Specifically, 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 efficiency,energy efficiency,massive MIMO,Cellular networks,relay
更新于2025-09-19 17:13:59