The Experts below are selected from a list of 7299 Experts worldwide ranked by ideXlab platform
K.j. Ray Liu - One of the best experts on this subject based on the ideXlab platform.
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Time-Reversal Massive Multipath Effect: A Single-Antenna 'Massive MIMO' Solution
IEEE Transactions on Communications, 2016Co-Authors: Yi Han, Beibei Wang, Yan Chen, K.j. Ray LiuAbstract:The explosion of mobile data traffic calls for new efficient 5G technologies. Massive multiple-input multiple- output (MIMO), which has shown the great potential in improv- ing the achievable rate with a very large number of antennas, has become a popular candidate. However, the requirement of deploying a large number of antennas at the base station may not be feasible in indoor scenarios due to the high implementation complexity. Does there exist a good alternative that can achieve similar system performance to massive MIMO for indoor envi- ronment? In this paper, we show that by using time-reversal (TR) signal processing, with a sufficiently large bandwidth, one can harvest the massive Multipaths naturally existing in a rich- scattering environment to form a large number of virtual antennas and achieve the desired massive Multipath Effect with a single antenna. We answer the above question by analyzing the TR massive Multipath Effect and the achievable rate with some waveforms. We also derive the corresponding asymptotic achievable rate under a massive Multipath setting. Experiment results based on real indoor channel measurements show that the massive Multipaths can be revealed with a sufficiently large bandwidth in a practical indoor environment. Moreover, based on our experiments with real indoor measurements, the achievable rate of the TR wideband system is evaluated.
Sugjoon Yoon - One of the best experts on this subject based on the ideXlab platform.
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AsiaSim - Forward-backward time varying forgetting factor kalman filter based landing angle estimation algorithm for UAV (unmanned aerial vehicle) autolanding modelling
Lecture Notes in Computer Science, 2005Co-Authors: Seokrim Choi, Jun-seok Lim, Sugjoon YoonAbstract:This paper discusses a landing angle estimation algorithm in UAV (Unmanned Aerial Vehicle) autolanding simulation. In UAV autolanding with radar system, the ground Multipath Effect and the time varying landing angle make it difficult to estimate landing angle information of UAV. This paper proposed a new algorithm based on forward-backward Kalman filter with time varying forgetting factor. This algorithm Effectively handles the Multipath Effect and time varying landing angle environments to estimate highly accurate landing angle.
Deming Liu - One of the best experts on this subject based on the ideXlab platform.
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optimized self interference cancellation based on optical dual parallel mzm for co frequency and co time full duplex wireless communication under nonlinear distortion and emulated Multipath Effect
Optics Express, 2019Co-Authors: Yucheng Zhang, Linbojie Huang, Lei Deng, Mengfan Cheng, Ming Tang, Deming LiuAbstract:Co-frequency and co-time full duplex (CCFD) technique has the potential to further improve the capacity of the fifth-generation (5G) system. However, in a CCFD-based transceiver, the self-interference-cancellation (SIC) module is essential because the transmitted signal is also captured by the receiving antenna. In this paper, an optimized SIC technique is proposed based on a dual-parallel Mach-Zehnder modulator (DP-MZM). In addition to the Multipath Effect between the transmitting and receiving antennas, the nonlinear distortion induced by the used optical and electrical components is considered and analyzed for the first time. In this scheme, one of the children MZMs is biased at 90°. The bias points of the other child MZM and the parent MZM are swept for SIC optimization. Compared to the traditional SIC scheme using DP-MZM, the power of the received signal is increased by 6 dB and the robustness to the bias point drift is improved. In our experiment, over 35 dB cancellation ratio is achieved for 200 MHz filtered orthogonal frequency division multiplexing (F-OFDM) interference signal with carrier frequency from 2.5 GHz to 6 GHz. To mitigate the influence of Multipath Effect and nonlinear distortion, the recursive least squared (RLS) linear equalizer and the RLS Volterra equalizer are designed and compared. Finally, 42 dB cancellation ratio is achieved for 200 MHz F-OFDM signal with carrier frequency of 4.5 GHz in the presence of nonlinear distortion and emulated Multipath Effect.
Yi Han - One of the best experts on this subject based on the ideXlab platform.
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Time-Reversal Massive Multipath Effect: A Single-Antenna 'Massive MIMO' Solution
IEEE Transactions on Communications, 2016Co-Authors: Yi Han, Beibei Wang, Yan Chen, K.j. Ray LiuAbstract:The explosion of mobile data traffic calls for new efficient 5G technologies. Massive multiple-input multiple- output (MIMO), which has shown the great potential in improv- ing the achievable rate with a very large number of antennas, has become a popular candidate. However, the requirement of deploying a large number of antennas at the base station may not be feasible in indoor scenarios due to the high implementation complexity. Does there exist a good alternative that can achieve similar system performance to massive MIMO for indoor envi- ronment? In this paper, we show that by using time-reversal (TR) signal processing, with a sufficiently large bandwidth, one can harvest the massive Multipaths naturally existing in a rich- scattering environment to form a large number of virtual antennas and achieve the desired massive Multipath Effect with a single antenna. We answer the above question by analyzing the TR massive Multipath Effect and the achievable rate with some waveforms. We also derive the corresponding asymptotic achievable rate under a massive Multipath setting. Experiment results based on real indoor channel measurements show that the massive Multipaths can be revealed with a sufficiently large bandwidth in a practical indoor environment. Moreover, based on our experiments with real indoor measurements, the achievable rate of the TR wideband system is evaluated.
Peng Peng - One of the best experts on this subject based on the ideXlab platform.
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A Facet-Based Simulation of the Multipath Effect on the EM Scattering and Doppler Spectrum of a Low-Flying Target at Maritime Scene
IEEE Geoscience and Remote Sensing Letters, 2018Co-Authors: Peng PengAbstract:A hybrid facet-based electromagnetic scheme is developed in this letter to investigate the Multipath Effect on the electromagnetic scattering and the Doppler spectrum of a low-flying target at maritime scene. In the scheme, the target and sea surface are both facetized. The facet-based small slope approximation method is developed to calculate the scattering upon the sea facet, which involves the composite scattering mechanisms upon both the long wave and short wave structures. The geometrical optics and physical optics method are combined with the fast ray-tracing technique in consideration of the Multipath scattering. The equivalent edge current method is used to consider the scattering from the edged structures on the target. The tapered wave is used in the calculation process to eliminate the nonphysical edge diffractions. Numerical simulations present the Multipath Effect on the radar scattering characteristics of a low flying missile-like target above the sea surface. The Doppler spectra of the Multipath scattering from the target flying at the time-evolving maritime scene are eventually simulated. The Multipath Effect is also investigated in the Doppler domain.
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A high resolution radar range profile simulator for low flying target above sea surface with Multipath Effect
2017Co-Authors: Peng Peng, Lixin Guo, C. M. Tong, B. ChenAbstract:To theoretically evaluate Multipath Effect on radar characteristics of low flying target. This letter presents an applicable method in description of Multipath coupling between target and ocean surface. It illustrates a composite scale scattering description over physically modelled ocean surface. Then it introduces a facet-based imaging thought in coupling consideration. The method is well suitable in application of the Multipath evaluation in electrically large scale scenes and has the advantage to reflect both specular and diffuse scattering Effects over complex surface profile. The HRRP simulation results are also presented and discussed, which show Multipath Effect clearly.
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ICSPCC - A SAR imaging simulator of a low-flying target above ocean surface with Multipath Effect
2017 IEEE International Conference on Signal Processing Communications and Computing (ICSPCC), 2017Co-Authors: Peng Peng, Lixin Guo, C. M. TongAbstract:Most of the Synthetic Aperture Radar (SAR) image simulations are focused on the target in the free space and ignores the influence of environment scattering and the scattering from the Multipath interactions between the target and background environment. In fact, the interaction for low flying target is strong and can produce undesired Multipath signals which can severely affect radar target characteristics. This paper has developed an a facet scattering model based on the real electromagnetic scattering mechanisms in description of the Multipath coupling mechanisms of low flying target above ocean surface. Finally, the SAR image simulations are made based on this model, which show apparent influence of sea surface scattering and the Multipath scattering Effect. It can help better understanding and evaluating the Multipath Effect in the radar detection of a low flying target in the real maritime environment.
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Research on G-brewster of the composite model of target on rough surface
2015 Asia-Pacific Microwave Conference (APMC), 2015Co-Authors: Sui Dongxun, Peng Peng, Tong Chuangming, Qi LihuiAbstract:Brewster phenomenon is that the value of the specific angel of incidence for which the Fresnel reflection factor for TM light is null. It also affects the Multipath Effect of target on rough surface. The composite model of target on rough surface is built up, and PO-MEC is used to calculate the scattering field of the target, which is meshed. The Multipath Effect is studied on Four Path Model with the coefficient of rough surface. The G-Brewster is brought up on the basis. The condition of its existence is studied, and the elements of the composite model are taken in account. The characteristics of G-Brewster are shown up. The conclusion on G-Brewster is meaningful to overcome Multipath interference.
