- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Approximate quantum state reconstruction without a quantum channel
摘要： We investigate the optimal quantum state reconstruction from the cloud to many spatially separated users by a measure-broadcast-prepare scheme without the availability of the quantum channel. The quantum state equally distributed from the cloud to an arbitrary number of users is generated at each port by an ensemble of known quantum states with assistance from classical information of measurement outcomes by broadcasting. The obtained quantum state for each user is optimal in the sense that the ?delity universally achieves the upper bound. We present the universal quantum state distribution by providing physical realizable measurement bases in the cloud as well as the reconstruction method for each user. The quantum state reconstruction scheme works for arbitrary many identical pure input states in the general dimensional system.
关键词： measure-broadcast-prepare scheme,quantum channel,quantum state reconstruction,optimal ?delity
更新于2025-09-04 15:30:14
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[IEEE 2018 IEEE International Conference on Communications (ICC 2018) - Kansas City, MO (2018.5.20-2018.5.24)] 2018 IEEE International Conference on Communications (ICC) - Beamspace Channel Estimation for Wideband Millimeter-Wave MIMO with Lens Antenna Array
摘要： Beamspace channel estimation is essential for wideband millimeter-wave (mmWave) MIMO with lens antenna array to achieve the substantial increase in data rates, but with a considerably reduced number of radio-frequency chains. However, most of existing beamspace channel estimation schemes are designed for narrowband mmWave systems, while a very few wideband schemes assume that the beamspace channel enjoys the ideal common support in frequency domain. In this paper, inspired by the classical successive interference cancellation for multi-user detection, we propose an efficient successive support detection (SSD) based beamspace channel estimation scheme without the assumption of common support. Specifically, we first demonstrate that each path component of the wideband beamspace channel exhibits a unique frequency-varying sparse structure. Based on this, we then estimate all sparse path components one by one. For each path component, its supports at different frequencies are jointly estimated to improve the estimation accuracy, and then its influence is removed to estimate the remained path components. Once all path components have been estimated, the wideband beamspace channel can be recovered at a low complexity. Simulation results verify that the proposed SSD based beamspace channel estimation scheme is able to achieve higher accuracy than existing wideband schemes.
关键词： beamspace channel estimation,wideband millimeter-wave MIMO,frequency-varying sparse structure,successive support detection,lens antenna array
更新于2025-09-04 15:30:14
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NOVEL DATA ACQUISITION METHOD FOR INTERFERENCE SUPPRESSION IN DUAL-CHANNEL SAR
摘要： Various interference sources either intentional or unintentional can mask the synthetic aperture radar (SAR) signals and cause image degradation. With a novel data acquisition mode, a new method based on dual-channel SAR is applied to suppress the interference. Using the received dual-channel data, the two-dimensional location of the interference source can be estimated and then the interference can be removed via a Two-Channel-Cancelation method. By establishing a linear model of the interference-removed signal, the SAR image is reconstructed based on compressed sensing (CS) theory. Our method requires only a minor change to the traditional SAR system hardware while obtains a higher resolution. Simulation results are shown to demonstrate the validity of the proposed method.
关键词： interference suppression,SAR,dual-channel,data acquisition,compressed sensing
更新于2025-09-04 15:30:14
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Three-channel filter-based non-imaging passive ranging system based on oxygen absorption
摘要： A three-channel ?lter-based non-imaging passive ranging system based on oxygen absorption is proposed and demonstrated. This system utilizes three band pass ?lters to quickly estimate the oxygen band-average transmission near 762 nm, and uses three simultaneous spectral measurement channels which are de?ned by the di?erent band pass ?lters to capture the three band pass signals of the target. A short range experiment from 100 m to 300 m and a long range experiment at 1945 m are conducted with a 1000 W halogen lamp, and the measured band-average oxygen transmission of the both experiments are compared to the predicted curve derived from the line-by-line transmission model to estimate the range. Averaged range error of 2.14% is achieved in the short range experiment and range error of 6.72% is obtained in the long range experiment.
关键词： Passive ranging,Oxygen spectroscopy,Atmospheric absorption,Three-channel,Filter-based
更新于2025-09-04 15:30:14
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[IEEE 2018 - 3DTV-Conference: The True Vision - Capture, Transmission and Display of 3D Video (3DTV-CON) - Helsinki (2018.6.3-2018.6.5)] 2018 - 3DTV-Conference: The True Vision - Capture, Transmission and Display of 3D Video (3DTV-CON) - CHANNEL-MISMATCH DETECTION ALGORITHM FOR STEREOSCOPIC VIDEO USING CONVOLUTIONAL NEURAL NETWORK
摘要： Channel mismatch (the result of swapping left and right views) is a 3D-video artifact that can cause major viewer discomfort. This work presents a novel high-accuracy method of channel-mismatch detection. In addition to the features described in our previous work, we introduce a new feature based on a convolutional neural network; it predicts channel-mismatch probability on the basis of the stereoscopic views and corresponding disparity maps. A logistic-regression model trained on the described features makes the ?nal prediction. We tested this model on a set of 900 stereoscopic-video scenes, and it outperformed existing channel-mismatch detection methods that previously served in analyses of full-length stereoscopic movies.
关键词： machine learning,channel mismatch,quality assessment,convolutional neural networks,Stereoscopic video
更新于2025-09-04 15:30:14
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Dual‐mode and triple‐band 10‐antenna handset array and its multiple‐input multiple‐output performance evaluation in 5G
摘要： A 10-element multiple-input multiple-output (MIMO) handset antenna array with triple-band operation in the long-term evolution band 42 (3400-3600 MHz), band 43 (3600-3800 MHz), and band 46 (5150-5925 MHz) is studied in this article. Acceptable antenna performances are obtained by using polarization and pattern diversity techniques. To assess the multiplexing performances of the handset array in 5G, an 8-element base station array covering 3.4-7.1 GHz is presented and studied. An 8 × 10 MIMO system incorporating 8 transmit antennas, propagation scenario and 10 receive antennas is successfully reported, and its multiplexing performances are evaluated. The computed channel capacities in the low and high bands can be as high as 43.3 bps/Hz and 41.6 bps/Hz, which are promising for multi-gigabit-per-second (multi-Gbps) data transmission in 5G. The effects of user's hand and low MIMO order on the channel capacities are also investigated. Results show the robust performances of the proposed antenna system.
关键词： MIMO antenna,5G,channel capacity,mobile handset
更新于2025-09-04 15:30:14
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Recording Raman Spectra Using a Dynamic Fourier Transform Spectrometer
摘要： We have developed a dynamic Fourier transform spectrometer for recording Raman spectra in the near-IR range (800–1100 nm). Stability and reliability of operation of the spectrometer is achieved by using corner re? ectors in the design as mirrors in the main channel. In order to record a weak Raman signal, we set up a white light channel in the spectrometer which enables locking into the zero optical path difference when summing the interferograms over several scans. A reference channel with sampling frequency λ/4 lets us improve the sampling accuracy and the signal-to-noise ratio of the emission spectra. Using our spectrometer, we recorded the Raman spectra of test substances with known positions of the emission lines: 1,4-bis(5-phenyl-2-oxazolyl)benzene (POPOP, C24H16N2O2), stilbene (C14H12), acetylsalicylic acid (C9H8O4). Comparison of the POPOP Raman spectra obtained on the dynamic Fourier transform spectrometer and a diffraction spectrometer for the same experimental conditions showed that they qualitatively matched, and the time required to record the spectrum on the dynamic Fourier transform spectrometer was 4 times shorter.
关键词： Raman spectroscopy,dynamic Fourier transform spectrometer,white-light channel,Fourier transform spectrometer in the visible and near-IR ranges,corner re? ector
更新于2025-09-04 15:30:14