Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing

Guilin, China

Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing

Guilin, China
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Cao W.,Guilin University of Electronic Technology | Liu P.,Guilin University of Electronic Technology | Li S.,Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing | Li J.,Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing
ISAPE 2016 - Proceedings of the 11th International Symposium on Antennas, Propagation and EM Theory | Year: 2016

This paper presents a ultra-broadband loaded monopole antenna. To broaden the operation bandwidth of the monopole antenna and efficiently resolve the problem of the nulls of the antenna pattern, a novel antenna design method is proposed by loading with lumped elements. The loads are parallel resistor/inductor (RL) circuits. The loaded antenna having a larger bandwidth, with the maximum gain is almost at the horizontal radiation direction. Finally the gain of the system is greater than 5 dBi over the entire frequency band of operation. © 2016 IEEE.


Wang J.,Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing | Wang J.,Guilin University of Electronic Technology | Jiang Y.,Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing | Jiang Y.,Nanjing Southeast University
Optics Express | Year: 2017

As a direct band gap two-dimensional (2D) semiconductor material, black phosphorus (BP) bridges the characteristics of graphene, with a zero or near-zero band gap, and transition metal dichalcogenides, with a wide band gap. In the infrared (IR) regime, 2D BP materials can harvest electromagnetic energy due to losses derived from its surface conductivity. In this paper, we propose an IR absorber design comprising 2D BP metamaterials sandwiched between dielectric layers. The multilayered sandwich-like absorber structure is mounted on a full reflective gold mirror, which forms a Fabry-Perot resonator to strengthen light-matter interactions. Harvested surface plasmons are excited around the 2D BP metamaterial edges, and the incident IR light can be efficiently dissipated by increasing the number of layers of the sandwich-like structure (NLSS). The physical absorption mechanism can be attributed to the destructive interference from the metamaterials, which can be enhanced with increasing NLSS. Here, a phase difference of about 180° is obtained between the directly reflected wave from the first interface and the emergent wave derived from the superposition of the multiple reflections among the resonator, and the amplitude of the emergent wave is steadily reduced to a value close to that of the directly reflected wave with increasing NLSS for incident transverse-magnetic polarized IR illumination. © 2017 Optical Society of America.


Gu L.,Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing | Gu L.,Nanjing University of Posts and Telecommunications
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2013

The locality sensitive k-means clustering has been proposed recently. However, it performance depends greatly on the choice of the initial centers and only proper initial centers enable this clustering approach to produce a better accuracies. In this paper, an evolutionary locality sensitive k-means clustering method is presented. This new approach uses the genetic algorithms for finding its initial centers by minimizing the Davies Bouldin clustering validity index regarded as the fitness function. To investigate the effective of our approach, some experiments are done on several datasets. Experimental results show that the proposed method can get the clustering performance significantly compared to other clustering algorithms. © 2013 Springer-Verlag Berlin Heidelberg.


Gu L.,Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing | Gu L.,Nanjing University of Posts and Telecommunications
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2013

Semi-supervised clustering can take advantage of some labeled data called seeds to bring a great benefit to the clustering of unlabeled data. This paper uses the seeding-based semi-supervised idea for a fuzzy clustering method inspired by diffusion processes, which has been presented recently. To investigate the effectiveness of our approach, experiments are done on three UCI real data sets. Experimental results show that the proposed algorithm can improve the clustering performance significantly compared to other semi-supervised clustering approaches. © 2013 Springer-Verlag Berlin Heidelberg.


Zhang H.,South China Normal University | Zhang H.,Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing | Gao S.,South China Normal University | Gao S.,Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing | And 3 more authors.
IEEE Transactions on Vehicular Technology | Year: 2016

This paper concerns the uplink of multicell multiuser multiple-input multiple-output (MIMO) systems. To tackle the effect of pilot contamination that is generally viewed as a bottleneck in previous work, this paper presents a superimposed pilot (SP)-aided uplink channel estimation scheme and mathematically characterizes the impact that an SP has on the performance of such a very large MIMO system. It is shown that there are two types of interference components that do not vanish, even when the number of antennas M grows to infinity. The first type, which is referred to as cross-contamination, is due to the correlation between the SP and data among different cells. The second type, which is referred to as self-contamination, is due to the dependence between channel estimation and estimation error. Cross-contamination is, in principle, similar to pilot contamination in a conventional pilot-based multicell MIMO system, whereas self-contamination is unique for the SP-aided scheme. Both theoretical and simulation results demonstrate that the SP-aided scheme can effectively reduce the estimation contamination by increasing the data frame size and, in turn, achieve a significant improvement over the spectral efficiency, in comparison with conventional pilot-based methods. © 2015 IEEE.


Gu L.,Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing | Gu L.,Nanjing University of Posts and Telecommunications
Proceedings - 2012 International Conference on Control Engineering and Communication Technology, ICCECT 2012 | Year: 2012

The traditional one-class support vector machines problem can be transformed into solving the minimum enclose-ing ball problem by the use of the corset. In this paper, the notion of the corset is applied to a semi-supervised clustering using one-class support vector machines. Experimental results show that this proposed algorithm not only can maintain the clustering performance, but also can decrease the running time of the clustering method. © 2012 IEEE.


Zhang S.,Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing | Ni J.,Guilin University of Electronic Technology | Peng Q.,Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing
Eurasip Journal on Wireless Communications and Networking | Year: 2017

In this paper, we present a game-theoretic approach for the purpose of deriving the problem of joint beamforming and power control in cognitive radio (CR) multiple-input multiple-output (MIMO) broadcast channels (CR MIMO-BCs), where the primary users (PUs) coexist with the secondary users (SUs) and they share the same spectrum. The cognitive base station (CBS), which is equipped with multiple antennas, is capable of transmitting data to the SU’s multiple-antenna receiver by employing the technology of beamforming. The proposed approach is an application of separable games, which are formally stated by the subgames of beamforming and power control. Furthermore, based on the model of noncooperative separate games, separable cost functions for the parameters of beamforming and power control are also proposed, showing that these cost functions are convex. Therefore, the convex theory of a noncooperative game can be employed to investigate the best response strategies as well as existence of Nash equilibrium solutions. Finally, we propose an iterative algorithm to achieve the optimal Nash equilibrium of the proposed joint beamforming subgame and power control subgame. Numerical results verify both the convergence and the tracking properties of the proposed algorithm for variant scenarios. © 2017, The Author(s).


Ni J.,Guilin University of Electronic Technology | Xiao H.,Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing | Xiao H.,China Mobile
Eurasip Journal on Wireless Communications and Networking | Year: 2016

In this paper, we present a game-theoretic approach to the problem of joint transmit beamforming and power control in cognitive radio (CR) multiple-input multiple-output broadcast channels (MIMO-BCs), where the primary users (PUs) coexist with the secondary users (SUs) and share the same spectrum. The cognitive base station (CBS) is equipped with multiantenna and transmits independent data streams to several decentralized single-antenna terminals. Our design goal is to jointly adjust the beamformers and transmission powers according to individual SINR (signal-to-interference-plus-noise ratio) requirements in order to meet SINR balancing for CR MIMO-BCs. In this context, two problems need to be solved: (1) the design beamforming must enable a balancing of the SINR among all SUs for a fixed total power of CBS and (2) the total transmission power must be minimized while satisfying a set of SINR constraints for fixed beamformers. The proposed approach is an application of separable games, where beamforming vectors are modeled as beamforming subgame and power control is modeled as power control subgame. We then use the convex theory of noncooperative game to solve the optimalization problem. Finally, we propose an iterative algorithm to reach Nash equilibrium (NE) of the joint beamforming subgame and power control subgame. Numerical results are provided to validate the optimality and the convergence of the proposed algorithm. © 2016, Ni and Xiao.


Li J.,South China Normal University | Chen P.,South China Normal University | Zhang H.,South China Normal University | Zhang H.,Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing | Zhang H.,Guangdong Provincial Engineering Research Center for Optoelectronic Instrument
IEEE International Symposium on Personal, Indoor and Mobile Radio Communications, PIMRC | Year: 2015

This paper considers a wireless-energy-transfer (WET)-enabled massive multiple-input-multiple-output (MIMO) system based on superimposed pilot (SP). With the aid of SP, 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 rate. The impact that SP has on the performance of such a WET-enabled massive MIMO system is mathematically characterized, and the UL achievable throughput is maximized by optimizing the variables, including the SP power-allocation factor and the time-allocation factor between the duration of WET and WIT. Numerical results validate the effectiveness of the proposed scheme. © 2015 IEEE.


Jiang Y.,Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing | Yang L.,Jiangsu University | Yu X.,Guangxi Key Laboratory of Wireless Wideband Communication and Signal Processing
Jisuan Wuli/Chinese Journal of Computational Physics | Year: 2013

A method to calculate far-zone scattering fields of a target in half-space excited by TE wave is proposed. Formulas of Green's function in a pair of vector potentials is derived, by which far-zone scattering field Hz can be calculated. Core of the method is calculation of electric and magnetic currents and their spatial phase in near-zone, which is elaborated. Far fields of an example are considered, which validates the method. Finally monostatic RCS of Type 96 armored vehicle is calculated. It is found that the maximum RCS is reached at head-in incidence case.

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