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This paper concerns the uplink (UL) and downlink decoupled access in heterogeneous networks (HetNets) with multi-antenna base stations (BSs). Departure from the traditional minimum pathloss policy, a maximum UL signal-to-noise ratio (SNR) user association policy that takes account of multiple antennas at BSs is proposed. Based on the proposed association policy, the UL association probabilities and...
Traditional OFDM techniques in VLC suffer from high PAPR and serious clipping distortion. In this paper, we propose a Precoded-DC-Biased Optical OFDM technique for VLC system. Numerical simulations are presented, proving substantial benefits in terms of PAPR and BER.
A coupling reduction method is proposed by using stacked electromagnetic band gap (EBG) structure for a two-element antenna array. The stacked EBG is a periodic multilevel layered electromagnetic band gap structures (PML-EBG). The PML-EBG is set in the middle of two identical patch antennas with distance of 0.13λ. The proposed antenna operates at 2.55GHz. A good isolation is achieved by the use of...
The Feature Selective Validation (FSV) Method has been developed as a standard technique to mimic an expert's opinion of concurrence between computational electromagnetics (CEM) and measurement datasets. In this paper, FSV is used to compare the design simulation and measurement of the microstrip antenna to verify the difference between the simulation data and the measured data. First, a typical patch...
In this paper, the modeling and simulation of the electromagnetic environment of shipboard equipment is studied. The electromagnetic environment simulation of the ship is carried out on the basis of establishing the sea surface and the ship model and under the different electromagnetic physical quantity. Sea and ship models will be drawn by CAD software, obtaining the electromagnetic simulation results...
A high efficiency, low cost pollution air monitoring system based on space-borne terahertz radiometer is proposed. The radiometers are fixed on the MEO satellites on GPS or BDS. Four operating frequency point of the radiometer are chosen to monitor SO2 and NH3 and the design scheme is shown. The diameter of radiometer Cassegrain reflector antenna is 1,000mm. After reflection, the radiation is splitted...
As one widely applied swarm intelligent algorithm, particle swarm optimization (PSO) algorithm has obtained the attention of various scholars with its advantages of easy implementation, high precision and fast convergence. Firstly, aiming to solve the problems that PSO has low searching speed and PSO is easy to fall into local optimal solution especially when dealing with high-dimension model, this...
Aiming at earthquake prediction field, this paper puts forward a multi-expert multi-attribute uncertainty management algorithm based on DS evidence theory. Seismic signal has so much uncertainty that traditional mathematical statistics method cannot solve. Considering DS theory is an excellent uncertainty reasoning method, we extract three instantaneous attributes of plural seismic signal as prediction...
In this paper, a novel electromagnetic band gap (EBG) structure is proposed to reduce the mutual coupling between two element MIMO antenna. The proposed array antennas consist of two rectangular patch antennas and three EBG structure units inserted between them on the substrate. The proposed MIMO antenna is designed on FR4-epoxy substrate with a thickness of 1.1mm, permittivity is 4.4 and loss tangent...
In this paper, we propose a modified Boolean Particle Swarm Optimization velocity mutual (GEBPSO-vm) algorithm to design thinned planar array, and then optimize the side lobe level of thinned planar array. This new algorithm introduces the concept of feedback factor and G inertia weight factor. The feedback factor will generate an additional speed factor, which makes the evolution direction of the...
System-level EMC evaluation is an important issue of telecommunication system modeling and simulation. It is proposed the introduction of space object conjunction method to EMC modeling and simulation. Some basic concepts are defined and the prediction equations are discussed briefly, which construct a new effective evaluation method of conjunction probability to improve the performance of radio systems.
The pollution flashover performance of current transformer external insulation declines with the contamination accumulation in the long-term operation, so it is necessary to consider the operation environment and surface dirt in the design process. Based on the NOVA38i CT (Current Transformer), the finite element model of polluted external insulation is proposed. The electric field distribution around...
Insulator flashover is a great threat of power system's safe and stable operation and surface discharge detection of contaminated insulators is an effective approach of flashover warning. Surface discharge detection method of contaminated insulators based on ultraviolet images' parameters is proposed in this paper. Experiment system of contaminated insulators surface discharge is designed to acquire...
This paper presents a method of extracting and evaluating one-dimensional dynamic sea surface features based on the feature selective validation (FSV). The Monte Carlo method is used to model the one-dimensional dynamic sea surface. The influence of different wind speeds on sea surface height fluctuation is simulated and analyzed. At the same time, the distribution of gravity spectrum and tensor spectrum...
Surface impedance boundary condition (SIBC) is a potential way to improve the efficiency of finite difference time domain (FDTD) method. In this paper, we propose an efficient SIBC, the PEC backed SIBC (PEC-SIBC). We first derived the updating equations of PEC-SIBC for 1D. The updating equations for 2D and 3D can be derived following the same procedure. Later, we verified the accuracy of PEC-SIBC...
In this paper, it is discussed the problem of electromagnetic compatibility after the installation of rescue system which broaden the usage of modern helicopter and it is proposed some technical measures to improve the electromagnetic compatibility. It is presented a deep research on the performance of the search and rescue helicopters' electromagnetic compatibility evaluation workflow including the...
This paper presents a millimeter wave channel measurement in Urban Microcell (UMi) scenario at 28 GHz with a bandwidth of 400 MHz. During measuring, a steerable horn antenna is used at receiver (RX) side while an omnidirectional antenna is used at transmitter (TX) side. The horn antenna not only rotates in azimuth with a step of 5° but also points into three different vertical angles. Based on the...
Recently, we reported a novel absorbing boundary condition (ABC), surface impedance absorbing boundary (SIABC). SIABC has a comparable absorbing performance compared to CPML, but requires a sufficient long distance between the boundary and the scatter. In this paper, we focus on this issue and introduce the non-uniform SIABC. Non-uniform SIABC archives a similar absorbing performance as the uniform...
An ultra-wideband (UWB) bandpass filter with dual notch bands using a short-circuited T-shaped resonator and an inner T-shaped resonator is proposed. It is based on the filter of microstrip lines and rectangular patch multiple mode resonator with inner rectangular slot. The proposed filter using a short-circuited T-shaped resonator coupled to the main transmission line of the basic BSF to achieve...
In this paper, we firstly use the method of extending the sea surface area to get the effective electromagnetic calculation results by software of Ship EDF. Then, we estimate the optimal sample size for the two-dimensional ocean wave simulation model based on the theory of statistics. Finally, we obtain the radio wave propagation characteristics on the sea surface in different sea states, different...
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