- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Non-Uniform Quantization Codebook Based Hybrid Precoding to Reduce Feedback Overhead in Millimeter Wave MIMO Systems
摘要： In this paper, we propose two non-uniform quantization (NUQ) codebook based hybrid precoding schemes for two main hybrid precoding implementations, i.e., the full-connected structure and the sub-connected structure, to reduce the feedback overhead in millimeter wave single user multiple-input multiple-output (SU-MIMO) systems. Specifically, we firstly group the angles of the arrive/departure (AOAs/AODs) of the scattering paths into several spatial lobes by exploiting the sparseness property of the millimeter wave in the angular domain, which divides the total angular domain into effective spatial lobes' coverage angles and ineffective coverage angles. Then, we map the quantization bits non-uniformly to different coverage angles and construct NUQ codebooks, where high numbers of quantization bits are employed for the effective coverage angles to quantize AoAs/AoDs and zero quantization bit is employed for ineffective coverage angles. Finally, two low-complexity hybrid analog/digital precoding schemes are proposed that utilize the NUQ codebooks. Simulation results demonstrate that, the proposed two NUQ codebook based hybrid precoding schemes achieve near-optimal spectral efficiencies and show the superiority in reducing the feedback overhead compared with the uniform quantization codebook based works.
关键词： feedback overhead,non-uniform quantization,spatial lobe,Millimeter wave communication,hybrid precoding
更新于2025-09-23 15:23:52
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Precoding and Detection for Broadband Single Carrier Terahertz Massive MIMO Systems Using LSQR Algorithm
摘要： The terahertz (THz) communication utilizes the frequency spectrum above 300 GHz and is widely considered as a promising solution to the future high-speed short-range wireless communication beyond millimeter wave (mmWave) communication. While providing tens of gigahertz bandwidth, it is subjected to high propagation path loss, inter-symbol and inter-user interferences. The massive multiple-input-multiple-output (MIMO) can be applied to address these problems by cooperation between many access point (AP) antennas. However, the THz channel characteristics, including high propagation path loss, frequency selectivity and big number of samples per channel impulse response (CIR), require carefully tailored algorithm for massive MIMO signal processing. In this paper, we propose a single carrier minimum mean square error (MMSE) precoding and detection algorithm for frequency selective THz channels. The MIMO signal transmission is described with the block matrices. A gain control heuristic is introduced to reduce the complexity. The sparsity property of the channel is utilized to construct sparse channel matrices and the least square QR (LSQR) algorithm is applied to efficiently solve the problems. Besides the uniform antenna array, the hybrid array consisting of several subarrays is considered as well. Simulation results show that the massive MIMO array can provide a satisfactory performance in terms of bit error rate (BER).
关键词： detection,massive MIMO,frequency selective channel,precoding,LSQR algorithm,block matrix,minimum mean square error,THz communication
更新于2025-09-23 15:23:52
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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) - Studies on Co-sputtered Al-Zn-Sn-O Films: A New TCO for Thin film Solar Cells
摘要： Hybrid analog/digital multiple-input multiple-output architectures were recently proposed as an alternative for fully digital-precoding in millimeter wave wireless communication systems. This is motivated by the possible reduction in the number of RF chains and analog-to-digital converters. In these architectures, the analog processing network is usually based on variable phase shifters. In this paper, we propose hybrid architectures based on switching networks to reduce the complexity and the power consumption of the structures based on phase shifters. We define a power consumption model and use it to evaluate the energy efficiency of both structures. To estimate the complete MIMO channel, we propose an open-loop compressive channel estimation technique that is independent of the hardware used in the analog processing stage. We analyze the performance of the new estimation algorithm for hybrid architectures based on phase shifters and switches. Using the estimate, we develop two algorithms for the design of the hybrid combiner based on switches and analyze the achieved spectral efficiency. Finally, we study the tradeoffs between power consumption, hardware complexity, and spectral efficiency for hybrid architectures based on phase shifting networks and switching networks. Numerical results show that architectures based on switches obtain equal or better channel estimation performance to that obtained using phase shifters, while reducing hardware complexity and power consumption. For equal power consumption, all the hybrid architectures provide similar spectral efficiencies.
关键词： channel estimation,precoding,Millimeter wave,hybrid architecture,switches
更新于2025-09-23 15:21:01
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Parameters extraction of photovoltaic models using triple-phase teaching-learning-based optimization
摘要： Hybrid analog/digital multiple-input multiple-output architectures were recently proposed as an alternative for fully digital-precoding in millimeter wave wireless communication systems. This is motivated by the possible reduction in the number of RF chains and analog-to-digital converters. In these architectures, the analog processing network is usually based on variable phase shifters. In this paper, we propose hybrid architectures based on switching networks to reduce the complexity and the power consumption of the structures based on phase shifters. We define a power consumption model and use it to evaluate the energy efficiency of both structures. To estimate the complete MIMO channel, we propose an open-loop compressive channel estimation technique that is independent of the hardware used in the analog processing stage. We analyze the performance of the new estimation algorithm for hybrid architectures based on phase shifters and switches. Using the estimate, we develop two algorithms for the design of the hybrid combiner based on switches and analyze the achieved spectral efficiency. Finally, we study the tradeoffs between power consumption, hardware complexity, and spectral efficiency for hybrid architectures based on phase shifting networks and switching networks. Numerical results show that architectures based on switches obtain equal or better channel estimation performance to that obtained using phase shifters, while reducing hardware complexity and power consumption. For equal power consumption, all the hybrid architectures provide similar spectral efficiencies.
关键词： switches,precoding,Millimeter wave,hybrid architecture,channel estimation
更新于2025-09-23 15:21:01
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P-OMP-IR ALGORITHM FOR HYBRID PRECODING IN MILLIMETER WAVE MIMO SYSTEMS
摘要： This paper presents a P-OMP-IR algorithm for the hybrid precoding problem in millimeter wave (mm-Wave) multiple-input multiple-output (MIMO) systems. In the proposed approach, the digital precoding matrix is updated via the orthogonal matching pursuit (OMP) method, and the analog precoding matrix is re?ned column by column using the dominant singular value and corresponding singular vectors of a residual matrix successively. During the re?ning phase of the analog precoding matrix, an extended power method is designed to calculate the dominant singular value and the corresponding left and right singular vectors, which is able to reduce the computational complexity signi?cantly. Simulation results show that the proposed algorithm can not only reduce the residual of the hybrid precoder e?ectively, but also improve the spectral e?ciency consistently.
关键词： millimeter wave,MIMO systems,orthogonal matching pursuit,P-OMP-IR algorithm,spectral efficiency,hybrid precoding
更新于2025-09-23 15:21:01
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Hybrid Precoding for Wideband Millimeter-Wave Systems with Finite Resolution Phase Shifters
摘要： In this paper, we study the hybrid analog-digital precoding for OFDM based-wideband millimeter wave (mmwave) communication systems. Since the analog precoding matrix is performed in the time domain and used for the entire bandwidth while the digital precoding matrices are performed on a per-subcarrier basis, the resulting wideband hybrid precoding problem becomes very complicated. Moreover, in practice phase shifter (PS) usually has only finite resolution, which brings more difficulties. To solve the resulting difficult problem, we propose an efficient algorithm by leveraging the penalty decomposition method. Simulation results are finally provided to confirm the effectiveness and superiority of the proposed algorithm and show the performance improvement than the existing algorithm.
关键词： finite resolution phase shifter,wideband hybrid precoding,decomposition method,Wideband millimeter wave communication
更新于2025-09-23 15:21:01
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[IEEE 2019 International Conference on Sustainable Technologies for Industry 4.0 (STI) - Dhaka, Bangladesh (2019.12.24-2019.12.25)] 2019 International Conference on Sustainable Technologies for Industry 4.0 (STI) - A New Medium Voltage Modular Multilevel Inverter with Advanced Carrier-Based Pulse Width Modulation for Solar Photovoltaic Systems
摘要： Millimeter-wave (mmWave) communication operated in frequency bands between 30 and 300 GHz has attracted extensive attention due to the potential ability of offering orders of magnitude greater bandwidths combined with further gains via beamforming and spatial multiplexing from multi-element antenna arrays. mmwave system may exploit the hybrid analog and digital precoding to achieve simultaneously the diversity, array and multiplexing gain with a lower cost of implementation. Motivated by this, in this paper, we investigate the design of hybrid precoder and combiner with sub-connected architecture, where each radio frequency chain is connected to only a subset of base station antennas from the perspective of energy efficient transmission. The problem of interest is a non-convex and NP-hard problem that is difficult to solve directly. In order to address it, we resort to design a two-layer optimization method to solve the problem of interest by exploiting jointly the interference alignment and fractional programming. First, the analog precoder and combiner are optimized via the alternating-direction optimization method where the phase shifter can be easily adjusted with an analytical structure. Then, we optimize the digital precoder and combiner based on an effective multiple-input multiple-output channel coefficient. The convergence of the proposed algorithms is proved using the monotonic boundary theorem and fractional programming theory. Extensive simulation results are given to validate the effectiveness of the presented method and to evaluate the energy efficiency performance under various system configurations.
关键词： analog precoding and combining,interference alignment,energy efficiency,Millimeter-wave communication,multiple-input multiple-output (MIMO) system
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) - The Response Characteristics of Dielectric Logging in Anisotropic Formation
摘要： Millimeter-wave (mmWave) communication operated in frequency bands between 30 and 300 GHz has attracted extensive attention due to the potential ability of offering orders of magnitude greater bandwidths combined with further gains via beamforming and spatial multiplexing from multi-element antenna arrays. mmwave system may exploit the hybrid analog and digital precoding to achieve simultaneously the diversity, array and multiplexing gain with a lower cost of implementation. Motivated by this, in this paper, we investigate the design of hybrid precoder and combiner with sub-connected architecture, where each radio frequency chain is connected to only a subset of base station antennas from the perspective of energy efficient transmission. The problem of interest is a non-convex and NP-hard problem that is difficult to solve directly. In order to address it, we resort to design a two-layer optimization method to solve the problem of interest by exploiting jointly the interference alignment and fractional programming. First, the analog precoder and combiner are optimized via the alternating-direction optimization method where the phase shifter can be easily adjusted with an analytical structure. Then, we optimize the digital precoder and combiner based on an effective multiple-input multiple-output channel coefficient. The convergence of the proposed algorithms is proved using the monotonic boundary theorem and fractional programming theory. Extensive simulation results are given to validate the effectiveness of the presented method and to evaluate the energy efficiency performance under various system configurations.
关键词： Millimeter-wave communication,energy efficiency,interference alignment,analog precoding and combining,multiple-input multiple-output (MIMO) system
更新于2025-09-23 15:19:57
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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) - The Electrochemical Reactions in Crystalline Silicon Solar Modules
摘要： Millimeter-wave (mmWave) communication operated in frequency bands between 30 and 300 GHz has attracted extensive attention due to the potential ability of offering orders of magnitude greater bandwidths combined with further gains via beamforming and spatial multiplexing from multi-element antenna arrays. mmwave system may exploit the hybrid analog and digital precoding to achieve simultaneously the diversity, array and multiplexing gain with a lower cost of implementation. Motivated by this, in this paper, we investigate the design of hybrid precoder and combiner with sub-connected architecture, where each radio frequency chain is connected to only a subset of base station antennas from the perspective of energy efficient transmission. The problem of interest is a non-convex and NP-hard problem that is difficult to solve directly. In order to address it, we resort to design a two-layer optimization method to solve the problem of interest by exploiting jointly the interference alignment and fractional programming. First, the analog precoder and combiner are optimized via the alternating-direction optimization method where the phase shifter can be easily adjusted with an analytical structure. Then, we optimize the digital precoder and combiner based on an effective multiple-input multiple-output channel coefficient. The convergence of the proposed algorithms is proved using the monotonic boundary theorem and fractional programming theory. Extensive simulation results are given to validate the effectiveness of the presented method and to evaluate the energy efficiency performance under various system configurations.
关键词： Millimeter-wave communication,energy efficiency,interference alignment,analog precoding and combining,multiple-input multiple-output (MIMO) system
更新于2025-09-19 17:13:59
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Performance Enhancement of Probabilistically Shaped OFDM Enabled by Precoding Technique in an IM-DD System
摘要： Probabilistically shaped orthogonal frequency-division multiplexing (PS-OFDM) signal is proposed and experimentally demonstrated in a low-cost intensity-modulation and direct-detection (IM-DD) system for optical access networks. The concatenation of constant composition distribution matcher (CCDM) and low-density parity-check (LDPC) code sequentially implements probabilistic amplitude shaping (PAS) and channel coding. Thanks to the precoding scheme, all data subcarriers can be treated equally by one optimized probabilistic distribution. Experimental results demonstrate that constant amplitude zero autocorrelation sequence (CAZAC) precoding can offer optimal performance compared to orthogonal circulant transform (OCT) precoding and discrete Fourier transform spread (DFT-spread) in terms of increasing generalized mutual information (GMI) and reducing PAPR. Moreover, probabilistically-shaped 64-QAM OFDM signal can provide shaping gains of 1.04/0.94/0.64 dB at 4.0/3.6/3.0 bits/QAM symbol compared to traditional 64-QAM OFDM signal. Meanwhile, compared to traditional 16-QAM OFDM, it can offer shaping gains of 1.64/0.64 dB at 3.6/3.0 bits/QAM symbol. In addition, net data rate ranging from 32.66 to 43.55-Gb/s over 20-km single mode fiber (SMF) can be achieved by only adjusting the probabilistic distribution.
关键词： precoding technique,optical access networks,Probabilistically-shaped orthogonal frequency-division multiplexing (PS-OFDM),intensity-modulation and direct-detection (IM-DD)
更新于2025-09-16 10:30:52