- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Upstream and Downstream Analysis of an Optical Fronthaul System Based on DSP-Assisted Channel Aggregation
摘要： In this paper, we focus on a well-known optical fronthauling architecture based on frequency division multiplexed digital signal processing (DSP)-assisted channel aggregation, and we present new results related to the optimization of the optical setup, proposing an efficient technique for the optimization of the transmission. In particular, we report an original pre-emphasis technique to equalize the performance of the radio channels, especially focusing on the upstream (US) link that has more critical characteristics but has not typically been treated in detail in previous works on this topic. The effects of both radio and optical impairments on the error vector magnitude (EVM) are taken into account. An analytical description of our approach is provided, and then it is applied on an experimental setup (able to aggregate up to 96 20-MHz radio signals), showing the possibility of minimizing the maximum EVM at the output of the fronthauling link, for both downstream and US transmission. Additionally, a low complexity technique to practically estimate the EVM per channel by taking advantage of only the DSP-aggregation/deaggregation functionalities is proposed and, again, experimentally demonstrated.
关键词： Radio-over-fiber,Mobile fronthaul,DSP-assisted channel aggregation,OFDM,Frequency division multiplexing
更新于2025-09-23 15:21:01
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[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) - Photomedicine and Its Place in Medicine of the 21th Century
摘要： Digital television signal is a promising signal of opportunity for wireless positioning. This paper studies the time of arrival (TOA) estimation on the European standard DVB-T signals in the context of positioning. Theoretical analysis on the autocorrelation of the pilot signal and multipath error envelop suggests that DVB-T has the appropriate characteristics for positioning. A software defined radio-based DVB-T receiver is developed for field testing, in which the radio frequency DVB-T signals are first sampled by universal software radio peripheral, and then algorithms of the coarse symbol synchronization, the pilot detection, the first path acquisition, and the delay tracking are sequentially performed to obtain the TOA estimation. To quantify the TOA tracking results on real DVB-T signals, field testing campaigns are carried out in five cities in Southern France. Test results showed that, in the high signal-noise ratio condition, the 2-σ error interval is within 1 m. By taking into account all the field tests, the interval of 95% accuracy is within 4 m and the corresponding C/N0 varies from 48 to 62 dB-Hz. In addition, with the developed TOA estimation method, the synchronization of the emitters with global positioning system time is evaluated and the distance difference of the multiple emitters within single frequency networks are also measured during the tests.
关键词： delay locked loop,software defined radio (SDR),wireless positioning,Digital TV,orthogonal frequency division multiplexing (OFDM),time of arrival
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE 5th International Conference for Convergence in Technology (I2CT) - Bombay, India (2019.3.29-2019.3.31)] 2019 IEEE 5th International Conference for Convergence in Technology (I2CT) - Performance Analysis of CuI as Hole Transport Layer in Perovskite (CH <sub/>3</sub> NH <sub/>3</sub> PbX <sub/>3</sub> , X: I, Br, Cl) Solar Cell
摘要： Clipping is one of the simplest peak-to-average power ratio reduction schemes for orthogonal frequency division multiplexing (OFDM). Deliberately clipping the transmission signal degrades system performance, and clipping mitigation is required at the receiver for information restoration. In this paper, we acknowledge the sparse nature of the clipping signal and propose a low-complexity Bayesian clipping estimation scheme. The proposed scheme utilizes a priori information about the sparsity rate and noise variance for enhanced recovery. At the same time, the proposed scheme is robust against inaccurate estimates of the clipping signal statistics. The undistorted phase property of the clipped signal, as well as the clipping likelihood, is utilized for enhanced reconstruction. Furthermore, motivated by the nature of modern OFDM-based communication systems, we extend our clipping reconstruction approach to multiple antenna receivers and multi-user OFDM. We also address the problem of channel estimation from pilots contaminated by the clipping distortion. Numerical findings are presented that depict favorable results for the proposed scheme compared to the established sparse reconstruction schemes.
关键词： Clipping,Bayesian sparse signal estimation,OFDM,PAPR reduction,multi-user communication,channel estimation
更新于2025-09-23 15:19:57
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[IEEE 2019 Second Balkan Junior Conference on Lighting (Balkan Light Junior) - Plovdiv, Bulgaria (2019.9.19-2019.9.21)] 2019 Second Balkan Junior Conference on Lighting (Balkan Light Junior) - Modelling the Thermal Conditions of a LED Lamp
摘要： Clipping is one of the simplest peak-to-average power ratio reduction schemes for orthogonal frequency division multiplexing (OFDM). Deliberately clipping the transmission signal degrades system performance, and clipping mitigation is required at the receiver for information restoration. In this paper, we acknowledge the sparse nature of the clipping signal and propose a low-complexity Bayesian clipping estimation scheme. The proposed scheme utilizes a priori information about the sparsity rate and noise variance for enhanced recovery. At the same time, the proposed scheme is robust against inaccurate estimates of the clipping signal statistics. The undistorted phase property of the clipped signal, as well as the clipping likelihood, is utilized for enhanced reconstruction. Furthermore, motivated by the nature of modern OFDM-based communication systems, we extend our clipping reconstruction approach to multiple antenna receivers and multi-user OFDM. We also address the problem of channel estimation from pilots contaminated by the clipping distortion. Numerical findings are presented that depict favorable results for the proposed scheme compared to the established sparse reconstruction schemes.
关键词： Clipping,Bayesian sparse signal estimation,OFDM,PAPR reduction,multi-user communication,channel estimation
更新于2025-09-23 15:19:57
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Performance studies of MIMO based DCO-OFDM in underwater wireless optical communication systems
摘要： The research in underwater communication system is focused towards wireless networks in view of recent developments in wireless technology and increasing need for deep sea data mining. The underwater wireless optical communication (UWOC) have more advantages for short-range wireless links due to very high bandwidth and data rate than acoustic communication. Although UWOC offers high capacity links at low latencies, they suffer from limited communication range due to various distinctive characteristics of underwater channel. A major degrading effect associated with the underwater channel is turbulence-induced fading. To mitigate this fading and to extend the viable communication range, spatial multipath diversity techniques can be adopted over UWOC links. The proposed work evaluates the performance of a multicarrier modulation scheme, i.e., MIMO based DC biased Optical Orthogonal Frequency Division Multiplexing (DCO-OFDM) for underwater wireless optical channel. The simulation of MIMO-DC biased optical OFDM technique employing spatial diversity in underwater optical communication is a novel approach towards the determination of an optimal modulation technique for underwater optical wireless channels. The performance is evaluated based on the various parameters such as Signal to Interference plus Noise Ratio (SINR), Throughput and Bit Error Rate (BER). A simple experiment is conducted to demonstrate the BER performance assessment for different link distance of 0.45 m and 1.5 m with different transmitter and receiver configurations (SIMO and MIMO) for both clear water and coastal water using MIMO DCO OFDM technique.
关键词： SNR,BER,MIMO,DCO-OFDM,QAM,Underwater wireless optical communication
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) - Shaping Electromagnetic Waves by Using Bianisotropic Huygensa?? Metasurface
摘要： The characterization of the performance of wireless devices is key to developing new RF products conforming to the latest communications protocols. Traditionally, communication performance tests have focused on the RF performance of the tested devices, e.g., smart phones, pads, laptops, and so on. In particular, the focus has shifted from conducted (i.e., cabled) measurements to more realistic over-the-air (OTA) characterization of the RF performance of these devices in transmit or receive mode. For example, the receiver performance of 2G and 3G wireless devices can be measured in terms of the total isotropic sensitivity (TIS) that depends on the antenna and the receiver parts of a wireless device. These measurements can be performed in a reverberation chamber setup. However, standard TIS measurements can be time-consuming and do not reflect the actual performance gains of multiple-input multiple-output antenna systems operating over orthogonal frequency division multiplexing channels, such as those encountered in 4G long-term evolution (LTE) systems. Therefore, in order to meet both time and cost efficiency requirements, we propose here a new method to determine the TIS, as well as the diversity performance, of an LTE device based on throughput measurements. The proposed method shows that the TIS of an LTE device is characterized much faster directly from OTA throughput measurements than from standard TIS measurements and with excellent accuracy.
关键词： TIS,OTA,MIMO,LTE,reverberation chamber,OFDM,throughput
更新于2025-09-23 15:19:57
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[IEEE 2019 IEEE Conference on Power Electronics and Renewable Energy (CPERE) - Aswan City, Egypt (2019.10.23-2019.10.25)] 2019 IEEE Conference on Power Electronics and Renewable Energy (CPERE) - Experimental Demonstration of superior SiC MOSFET and GaN HEMT Performance within Single Phase Microinverter for Low-Power Photovoltaic Applications
摘要： In this paper, we propose joint angle-delay subspace based-channel estimation in single cell for broadband massive multiple-input and multiple-output systems employing orthogonal frequency division multiplexing modulation. Based on a parametric channel model, we present a new concept of the joint angle-delay subspace, which can be tracked by the low-complexity low-rank adaptive ?ltering algorithm. Then, we investigate an interference-free transmission condition that the joint angle-delay subspaces of the users reusing the same pilots are non-overlapping. Since the channel statistics are usually unknown, we develop a robust minimum mean square error (MMSE) estimator under the worst precondition of pilot decontamination, considering that the joint angle-delay subspaces of the interfering users fully overlap. Furthermore, motivated by the interference-free transmission criteria, we present a novel low-complexity greedy pilot scheduling algorithm to avoid the problem of initial value sensitivity. Simulation results show that the joint angle-delay subspace can be estimated effectively, and the proposed pilot reuse scheme combined with robust MMSE channel estimation offers signi?cant performance gains.
关键词： pilot scheduling,robust channel estimation.,Joint angle-delay subspace,pilot decontamination,massive MIMO-OFDM
更新于2025-09-23 15:19:57
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Self-Aligning and Flexible Dielectric Waveguide Plug for MMICs at G-Band
摘要： In this paper, we propose joint angle-delay subspace based-channel estimation in single cell for broadband massive multiple-input and multiple-output systems employing orthogonal frequency division multiplexing modulation. Based on a parametric channel model, we present a new concept of the joint angle-delay subspace, which can be tracked by the low-complexity low-rank adaptive ?ltering algorithm. Then, we investigate an interference-free transmission condition that the joint angle-delay subspaces of the users reusing the same pilots are non-overlapping. Since the channel statistics are usually unknown, we develop a robust minimum mean square error (MMSE) estimator under the worst precondition of pilot decontamination, considering that the joint angle-delay subspaces of the interfering users fully overlap. Furthermore, motivated by the interference-free transmission criteria, we present a novel low-complexity greedy pilot scheduling algorithm to avoid the problem of initial value sensitivity. Simulation results show that the joint angle-delay subspace can be estimated effectively, and the proposed pilot reuse scheme combined with robust MMSE channel estimation offers signi?cant performance gains.
关键词： pilot scheduling,robust channel estimation.,Joint angle-delay subspace,pilot decontamination,massive MIMO-OFDM
更新于2025-09-23 15:19:57
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[IEEE 2019 Sixteenth International Conference on Wireless and Optical Communication Networks (WOCN) - Bhopal, India (2019.12.19-2019.12.21)] 2019 Sixteenth International Conference on Wireless and Optical Communication Networks (WOCN) - Anomaly Based Performance On Sensing Errors By ANN
摘要： Clipping is one of the simplest peak-to-average power ratio reduction schemes for orthogonal frequency division multiplexing (OFDM). Deliberately clipping the transmission signal degrades system performance, and clipping mitigation is required at the receiver for information restoration. In this paper, we acknowledge the sparse nature of the clipping signal and propose a low-complexity Bayesian clipping estimation scheme. The proposed scheme utilizes a priori information about the sparsity rate and noise variance for enhanced recovery. At the same time, the proposed scheme is robust against inaccurate estimates of the clipping signal statistics. The undistorted phase property of the clipped signal, as well as the clipping likelihood, is utilized for enhanced reconstruction. Furthermore, motivated by the nature of modern OFDM-based communication systems, we extend our clipping reconstruction approach to multiple antenna receivers and multi-user OFDM. We also address the problem of channel estimation from pilots contaminated by the clipping distortion. Numerical findings are presented that depict favorable results for the proposed scheme compared to the established sparse reconstruction schemes.
关键词： PAPR reduction,channel estimation,Clipping,OFDM,Bayesian sparse signal estimation,multi-user communication
更新于2025-09-23 15:19:57
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Single-Sideband OFDM Transmission via a Silicon Microring IQ Modulator
摘要： We experimentally demonstrate the generation of a single-sideband orthogonal frequency division multiplexed (OFDM) signal using an on-chip silicon photonics microring-based IQ modulator. Over 18 dB sideband suppression ratio is achieved for the wideband OFDM: 15.7 GHz data band and 2.7 GHz guard band. The 31.4 Gb/s signal was transmitted over 20 km of standard single-mode fiber with a bit error rate below the forward error correction threshold. While single-sideband continuous-wave signals have been produced with such hardware, this is the first demonstration of stable data transmission on the single sideband carrier.
关键词： Silicon Photonics,Single Side-band,OFDM,Microring Modulator
更新于2025-09-23 15:19:57