scholarly journals A Novel Analysis Method of Pre-adjusting System for Self-interference Cancellation in Analog Domain

2018 ◽  
Vol 17 ◽  
pp. 01002
Author(s):  
Hui-Hui Li ◽  
Nan Chen ◽  
Xiandeng He
Keyword(s):  
Theoretical Analysis ◽  
Amplitude Modulation ◽  
Interference Cancellation ◽  
Analysis Method ◽  
Attenuation Coefficients ◽  
Real Environment ◽  
Modulation Signal ◽  
Simulation Results ◽  
Analog Domain ◽  
Better Than

Pre-adjusting system, which computes the attenuation coefficients of self-interference cancellation, is one of the most important parts in a practical self-interference cancellation system. In this paper, a new way is given to analyze the pre-adjusting system in analog domain, and a clear theoretical analysis is carried out. Meanwhile, a method for solving the optimal attenuation vector is introduced. The simulation results show that the Interference Cancellation Ratio(ICR) can reach up to 62.8 dB in an ideal environment and 50.4 dB in a real environment, which are much better than the ordinary demand of 40 dB in analog domain. Finally, an amplitude modulation signal is verified in our method, with shows good performance, too.

Precession Characteristics Analysis of Ballistic Target Based on Non-Ideal Scattering Centers

2012 ◽  
Vol 580 ◽  
pp. 329-333
Author(s):  
Qi Lie Ma ◽  
Wei Hong Lu ◽  
Cun Qian Feng ◽  
Jie Zhang ◽  
Zhe Wang
Keyword(s):  
Theoretical Analysis ◽  
Frequency Modulation ◽  
Target Recognition ◽  
Problem Model ◽  
Scattering Centers ◽  
Characteristics Analysis ◽  
Radar Echo ◽  
Modulation Signal ◽  
Micro Motion ◽  
Simulation Results

Precession characteristics are very important for ballistic target recognition. It is theoretically approved that the radar echo is sinusoidal frequency modulation signal when the micro-motion of scattering centers is the same as warhead itself. But this assumption disagrees with the fact. To solve this problem, model of precession target is set and the expression of the micro-Doppler of the non-ideal scattering centers is obtained in the paper. Then, precession characteristics of warhead are presented in the end of the paper. Finally, the correctness of theoretical analysis is validated through the simulation results.

scholarly journals Pilot Reuse Mode Based on Continuous Pilot Reuse Factors

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Dongsheng Han ◽  
Kai Fu ◽  
Zhixiong Chen
Keyword(s):  
Theoretical Analysis ◽  
Spectral Efficiency ◽  
Multiple Input Multiple Output ◽  
Multiple Input ◽  
Key Technologies ◽  
High Spectral Efficiency ◽  
Input Multiple Output ◽  
Traditional Mode ◽  
Simulation Results ◽  
Better Than

Massive multiple-input multiple-output techniques have attracted wide attention as one of the key technologies of 5G. Pilot reuse based on the same pilot sequence is necessary among different users due to limited pilot resources. In this study, a pilot reuse mode based on continuous pilot reuse factors is proposed to pursue a flexible pilot reuse mode with high spectral efficiency (SE). In this mode, users in every cell are grouped, and different groups use different pilot reuse factors. Therefore, any overall pilot reuse factor is achieved to increase the flexibility of pilot reuse considerably. A theoretical analysis proves that the proposed pilot reuse based on continuous pilot reuse factors is superior to the traditional pilot reuse based on single pilot reuse factor to some extent in terms of SE. A new method to search the optimal pilot reuse based on continuous pilot reuse factors is also introduced. Simulation results demonstrate that, in most cases, the optimal pilot reuse mode based on continuous pilot reuse factors is better than the traditional mode. Such superiority still exists under a limited number of antennas.

ANALYSIS OF GENERALIZED OPTIMAL CURRENT LATTICE MODEL FOR TRAFFIC FLOW

2008 ◽  
Vol 19 (05) ◽  
pp. 727-739 ◽  
Author(s):  
WEN-XING ZHU ◽  
EN-XIAN CHI
Keyword(s):  
Traffic Flow ◽  
Lattice Model ◽  
Vries Equation ◽  
Linear Stability Theory ◽  
Analysis Method ◽  
Optimal Current ◽  
Simulation Results ◽  
The Stability ◽  
Propagation Velocities ◽  
Better Than

A generalized optimal current lattice model (GOCLM) for traffic flow is proposed to describe the motion of the dynamical traffic flow with a consideration of multi-interaction of the front lattice sites. In order to verify the reasonability of the new model, the stability condition is obtained by the use of linear stability theory. The modified KdV (Korteweg–de Vries) equation is derived by the use of the nonlinear analysis method and the kink-antikink soliton solution is obtained near the critical point. The propagation velocities of density waves are calculated for different numbers of the front interactions. A numerical simulation is carried out to check out the performance of GOCLM for traffic flow. The simulation results show that GOCLM is better than the previous models in suppressing the traffic jams.

scholarly journals Simulation and Nonlinearity Optimization of a High-Pressure Sensor

Sensors ◽  
2020 ◽  
Vol 20 (16) ◽  
pp. 4419
Author(s):  
Ting Li ◽  
Haiping Shang ◽  
Weibing Wang
Keyword(s):  
High Pressure ◽  
Pressure Sensor ◽  
Pressure Sensors ◽  
Original Model ◽  
Ansys Software ◽  
Nonlinear Error ◽  
Sensor Model ◽  
Optimized Model ◽  
Simulation Results ◽  
Better Than

A pressure sensor in the range of 0–120 MPa with a square diaphragm was designed and fabricated, which was isolated by the oil-filled package. The nonlinearity of the device without circuit compensation is better than 0.4%, and the accuracy is 0.43%. This sensor model was simulated by ANSYS software. Based on this model, we simulated the output voltage and nonlinearity when piezoresistors locations change. The simulation results showed that as the stress of the longitudinal resistor (RL) was increased compared to the transverse resistor (RT), the nonlinear error of the pressure sensor would first decrease to about 0 and then increase. The theoretical calculation and mathematical fitting were given to this phenomenon. Based on this discovery, a method for optimizing the nonlinearity of high-pressure sensors while ensuring the maximum sensitivity was proposed. In the simulation, the output of the optimized model had a significant improvement over the original model, and the nonlinear error significantly decreased from 0.106% to 0.0000713%.

scholarly journals Injection-rolling nozzle in an imprint system with continuous injection direct rolling for ultra-thin microstructure guide light plate

2021 ◽  
Vol 13 (4) ◽  
pp. 168781402110112
Author(s):  
Yan Lou ◽  
Kewei Chen ◽  
Xiangwei Zhou ◽  
Yanfeng Feng
Keyword(s):  
Flow Velocity ◽  
Superior Performance ◽  
Light Transmittance ◽  
Velocity Difference ◽  
Orthogonal Experiments ◽  
Width Direction ◽  
Direct Rolling ◽  
Simulation Results ◽  
Continuous Injection ◽  
Better Than

A novel Injection-rolling Nozzle (IRN) in an imprint system with continuous injection direct rolling (CIDR) for ultra-thin microstructure polymer guide light plates was developed to achieve uniform flow velocity and temperature at the width direction of the cavity exit. A novel IRN cavity was designed. There are eight of feature parameters of cavity were optimized by orthogonal experiments and numerical simulation. Results show that the flow velocity at the width direction of the IRN outlet can reach uniformity, which is far better than that of traditional cavity. The smallest flow velocity difference and temperature difference was 0.6 mm/s and 0.24 K, respectively. The superior performance of the IRN was verified through a CIDR experiment. Several 0.35-mm thick, 340-mm wide, and 10-m long microstructural Polymethyl Methacrylate (PMMA) guide light plates were manufactured. The average filling rates of the microgrooves with the aspect ratio 1:3 reached above 93%. The average light transmittance is 88%.

A tuneable rat-race coupler for full duplex communications

2021 ◽  
pp. 1-7
Author(s):  
G. T. Watkins
Keyword(s):  
Interference Cancellation ◽  
Phase Shifter ◽  
Dipole Antenna ◽  
Full Duplex ◽  
Frequency Channel ◽  
Ism Band ◽  
Single Antenna ◽  
Variable Attenuator ◽  
Degree Of Isolation ◽  
Better Than

Abstract Full duplex (FD) could potentially double wireless communications capacity by allowing simultaneous transmission and reception on the same frequency channel. A single antenna architecture is proposed here based on a modified rat-race coupler to couple the transmit and receive paths to the antenna while providing a degree of isolation. To allow the self-interference cancellation (SiC) to be maximized, the rat-race coupler was made tuneable. This compensated for both the limited isolation of the rat race and self-interference caused by antenna mismatch. Tuneable operation was achieved by removing the fourth port of the rat race and inserting a variable attenuator and variable phase shifter into the loop. In simulation with a 50 Ω load on the antenna port, better than −65 dB narrowband SiC was achieved over the whole 2.45 GHz industrial, scientific and medical (ISM) band. Inserting the S-parameters of a commercially available sleeve dipole antenna into the simulation, better than −57 dB narrowband SiC could be tuned over the whole band. Practically, better than −58 dB narrowband tuneable SiC was achieved with a practical antenna. When excited with a 20 MHz Wi-Fi signal, −42 dB average SiC could be achieved with the antenna.

scholarly journals Robust Adaptive Filtering Algorithm for Self-Interference Cancellation with Impulsive Noise

Electronics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 196
Author(s):  
Jun Lu ◽  
Qunfei Zhang ◽  
Wentao Shi ◽  
Lingling Zhang ◽  
Juan Shi
Keyword(s):  
Adaptive Filtering ◽  
Interference Cancellation ◽  
Impulsive Noise ◽  
Weight Vector ◽  
Filtering Algorithm ◽  
Convergence Performance ◽  
Simulation Results ◽  
Robust Adaptive ◽  
Arctangent Cost Function ◽  
Simultaneous Transmission

Self-interference (SI) is usually generated by the simultaneous transmission and reception in the same system, and the variable SI channel and impulsive noise make it difficult to eliminate. Therefore, this paper proposes an adaptive digital SI cancellation algorithm, which is an improved normalized sub-band adaptive filtering (NSAF) algorithm based on the sparsity of the SI channel and the arctangent cost function. The weight vector is hardly updated when the impulsive noise occurs, and the iteration error resulting from impulsive noise is significantly reduced. Another major factor affecting the performance of SI cancellation is the variable SI channel. To solve this problem, the sparsity of the SI channel is estimated with the estimation of the weight vector at each iteration, and it is used to adjust the weight vector. Then, the convergence performance and calculation complexity are analyzed theoretically. Simulation results indicate that the proposed algorithm has better performance than the referenced algorithms.

Simulation on Effect of Five Kinds of Belt Structures on Tire Performance

2012 ◽  
Vol 501 ◽  
pp. 151-155
Author(s):  
Yong Liu ◽  
Ge Zhang ◽  
Hua Yan ◽  
Yu Mei Ding ◽  
Wei Min Yang
Keyword(s):  
The Other ◽  
Molding Process ◽  
Simulation Results ◽  
Better Than

In this article, three kinds of belt named B, C and D type are invented, then their main performance are compared with the other two kinds of belt structures introduced in previous papers. Simulation results showed that B and D-type belts are better than the other three. Comparatively the latter needs less material, its molding process is easier, and the tire body is lighter than B type tire, so in general it can be considered that D-type belt is the best among the five kinds of belt structures.

scholarly journals Current-Mode Third-Order Quadrature Oscillator Using CDTAs

2009 ◽  
Vol 2009 ◽  
pp. 1-5 ◽  
Author(s):  
Jiun-Wei Horng
Keyword(s):  
Theoretical Analysis ◽  
Phase Difference ◽  
Oscillation Frequency ◽  
Current Mode ◽  
Third Order ◽  
Quadrature Oscillator ◽  
Oscillation Condition ◽  
Transconductance Amplifiers ◽  
Simulation Results ◽  
A Current

This paper describes a current-mode third-order quadrature oscillator based on current differencing transconductance amplifiers (CDTAs). Outputs of two current-mode sinusoids with90°phase difference are available in the quadrature oscillator circuit. The oscillation condition and oscillation frequency are orthogonal controllable. The proposed circuit employs only grounded capacitors and is ideal for integration. Simulation results are included to confirm the theoretical analysis.

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