An Efficient Quadratic Conversion Architecture for Real-Time Wideband DDC

2014 ◽  
Vol 527 ◽  
pp. 180-184
Author(s):  
Liu Zhang
Keyword(s):  
Real Time ◽  
Polyphase Filter ◽  
Simulation Results ◽  
Process Cost ◽  
Sample Rate ◽  
Polyphase Filters ◽  
Frequency Mixing

This paper presents an efficient quadratic conversion architecture for real-time wideband DDC, it can move IF signal to baseband in two steps. Firstly, IF signal is moved to baseband nearby with the help of an structure based on polyphase filter, which places mixers after polyphase filters. Then, the signal is moved to baseband through conventional orthogonal frequency mixing. This presented architecture can reduce filter resources and effectively reduce the sample rate and process cost. Finally, simulation results are presented to illustrate the validity of the new structure.

A Unitary-UCA-Root-MUSIC Algorithm Based on MSWF

2014 ◽  
Vol 610 ◽  
pp. 339-344
Author(s):  
Qiang Guo ◽  
Yun Fei An
Keyword(s):  
Computer Simulation ◽  
Computational Complexity ◽  
Real Time ◽  
Unitary Transformation ◽  
Wiener Filter ◽  
Doa Estimation ◽  
Signal Subspace ◽  
Music Algorithm ◽  
Multi Stage ◽  
Simulation Results

A UCA-Root-MUSIC algorithm for direction-of-arrival (DOA) estimation is proposed in this paper which is based on UCA-RB-MUSIC [1]. The method utilizes not only a unitary transformation matrix different from UCA-RB-MUSIC but also the multi-stage Wiener filter (MSWF) to estimate the signal subspace and the number of sources, so that the new method has lower computational complexity and is more conducive to the real-time implementation. The computer simulation results demonstrate the improvement with the proposed method.

Real-Time Signal Denoising Algorithm in Wheel Force Transducer

2014 ◽  
Vol 615 ◽  
pp. 244-247
Author(s):  
Dong Wang ◽  
Guo Yu Lin ◽  
Wei Gong Zhang
Keyword(s):  
Kalman Filter ◽  
Real Time ◽  
Extended Kalman Filter ◽  
Unscented Kalman Filter ◽  
Force Transducer ◽  
Time Signal ◽  
Signal Denoising ◽  
Observation Function ◽  
Simulation Results ◽  
Wheel Force Transducer

The wheel force transducer (WFT) is used to measure dynamic wheel loads. Unlike other force sensors, WFT is rotating with the wheel. For this reason, the outputs and the inputs of the transducer are nonlinearly related, and traditional Kalman Filter is not suitable. In this paper, a new real-time filter algorithm utilizing Quadrature Kalman Filter (QKF) is proposed to solve this problem. In Quadrature Kalman Filter, Singer model is introduced to track the wheel force, and the observation function is established for WFT. The simulation results illustrate that the new filter outperforms the traditional Unscented Kalman Filter (UKF) and Extended Kalman Filter (EKF).

FPGA Implementation of Real-Time Adaptive Bidirectional Equalization for Histogram

2012 ◽  
Vol 461 ◽  
pp. 215-219
Author(s):  
Yu Qian Zhao ◽  
Zhi Gang Li
Keyword(s):  
Image Processing ◽  
Real Time ◽  
Processing Speed ◽  
Local Maximum ◽  
Histogram Equalization ◽  
Infrared Images ◽  
Single Frame ◽  
Processing Effects ◽  
Simulation Results ◽  
Enhancement Algorithm

According to the characteristics of infrared images, a contrast enhancement algorithm was presented. The principium of FPGA-based adaptive bidirectional plateau histogram equalization was given in this paper. The plateau value was obtained by finding local maximum and whole maximum in statistical histogram based on dimensional histogram statistic. Statistical histogram was modified by the plateau value and balanced in gray scale and gray spacing. Test data generated by single frame image, which was simulated by FPGA-based real-time adaptive bidirectional plateau histogram equalization. The simulation results indicates that the precept meet the requests well in both the image processing effects and processing speed

The Design of a Wavelet-Based Neural Network Adaptive Filter

2013 ◽  
Vol 860-863 ◽  
pp. 2791-2795
Author(s):  
Qian Xiao ◽  
Yu Shan Jiang ◽  
Ru Zheng Cui
Keyword(s):  
Neural Network ◽  
Wavelet Transform ◽  
Real Time ◽  
Adaptive Filter ◽  
Adaptive Algorithm ◽  
Distributed Storage ◽  
Hopfield Neural Network ◽  
Lms Algorithm ◽  
The Neural Network ◽  
Simulation Results

Aiming at the large calculation workload of adaptive algorithm in adaptive filter based on wavelet transform, affecting the filtering speed, a wavelet-based neural network adaptive filter is constructed in this paper. Since the neural network has the ability of distributed storage and fast self-evolution, use Hopfield neural network to implement adaptive filter LMS algorithm in this filter so as to improve the speed of operation. The simulation results prove that, the new filter can achieve rapid real-time denoising.

Real-Time Trajectory Generation and Reachability Determination in Autorotative Flare

2020 ◽  
Vol 65 (3) ◽  
pp. 1-17
Author(s):  
Brian F. Eberle ◽  
Jonathan D. Rogers
Keyword(s):  
Real Time ◽  
Trajectory Generation ◽  
Contact Theory ◽  
Simulation Environment ◽  
Order Model ◽  
Landing Point ◽  
Overall Performance ◽  
Simulation Results ◽  
Six Degree Of Freedom ◽  
Trajectory Generator

Autorotation maneuvers inherently offer little margin for error in execution and induce high pilot workload, particularly as the aircraft nears the ground in an autorotative flare. Control augmentation systems may potentially reduce pilot workload while simultaneously improving the likelihood of a successful landing by offering the pilot appropriate cues. This paper presents an initial investigation of a real-time trajectory generation scheme for autorotative flare based on time-to-contact theory. The algorithm exhibits deterministic runtime performance and provides a speed trajectory that can be tracked by a pilot or inner-loop controller to bring the vehicle to a desired landing point at the time of touchdown. A low-order model of the helicopter dynamics in autorotation is used to evaluate dynamic feasibility of the generated trajectories. By generating and evaluating trajectories to an array of candidate landing points, the set of reachable landing points in front of the aircraft is determined. Simulation results are presented in which the trajectory generator is coupled with a previously derived autorotation controller. Example cases and trade studies are conducted in a six degree-of-freedom simulation environment to demonstrate overall performance as well as robustness of the algorithm to variations in target landing point, helicopter gross weight, and winds. The robustness of the reachability determination portion of the algorithm is likewise evaluated through trade studies examining off-nominal flare entry conditions and the effects of winds.

RC Polyphase Filter as Complex Analog Hilbert Filter

2019 ◽  
Vol 888 ◽  
pp. 29-36 ◽  
Author(s):  
Yoshiro Tamura ◽  
Ryo Sekiyama ◽  
Shu Sasaki ◽  
Koji Asami ◽  
Haruo Kobayashi
Keyword(s):  
Numerical Simulations ◽  
Polyphase Filter ◽  
Order Case ◽  
Complex Analog ◽  
Polyphase Filters

This paper presents that the RC polyphase filer has characteristics as a complex analog Hilbert filter. Phase characteristics of the RC polyphase filter have the same as the Hilbert filter. Also its gain characteristics can be approximated as the Hilbert filter; as its order becomes higher, its gain characteristics become closer to the Hilbert filter. We have proved these for 1st to 4th RC polyphase filters, as well as in general n-th order case, and also confirmed with numerical simulations.

A study of azimuthal electromagnetic wave LWD based on self-adaptive hp finite element method

2018 ◽  
Vol 32 (34n36) ◽  
pp. 1840073
Author(s):  
Hui Li ◽  
Yi-Bo Jiang ◽  
Jian-Wen Cai
Keyword(s):  
Numerical Simulation ◽  
Finite Element Method ◽  
Finite Element ◽  
Electromagnetic Wave ◽  
Real Time ◽  
Simulation Results ◽  
Peak Value ◽  
Element Method ◽  
Self Adaptive ◽  
Hp Finite Element

Azimuthal electromagnetic wave logging-while-drilling (LWD) technology can detect weak electromagnetic wave signal and realize real-time resistivity imaging. It has great values to reduce drilling cost and increase drilling rate. In this paper, self-adaptive hp finite element method (FEM) has been used to study the azimuthal resistivity LWD responses in different conditions. Numerical simulation results show that amplitude attenuation and phase shift of directional electromagnetic wave signals are closely related to induced magnetic field and azimuthal angle. The peak value and polarity of geological guidance signals can be used to distinguish reservoir interface and achieve real-time geosteering drilling. Numerical simulation results also show the accuracy of the self-adaptive hp FEM and provide physical interpretation of peak value and polarity of the geological guidance signals.

A Method for Real-Time Radar Signal Main Sorting

2013 ◽  
Vol 760-762 ◽  
pp. 567-571
Author(s):  
Hong Chao Wu ◽  
Wei Hua Xiao ◽  
Jian Feng Pu
Keyword(s):  
Real Time ◽  
Pulse Sequence ◽  
High Accuracy ◽  
Radar Signal ◽  
Sorting Algorithm ◽  
The Real ◽  
Sorting Algorithms ◽  
Key Technologies ◽  
Simulation Results ◽  
Sequence Simulation

The real-time radar signal sorting is one of the key technologies for electronic reconnaissance, first analyzes the defects of traditional main sorting algorithms, and then proposes a comprehensive main sorting algorithm. The method first uses the SDIF algorithm to sort PRI fixed and PRI stagger radar signal, then uses dynamic expansion association method to search PRI jitter radar signal. When using the SDIF algorithm, in order to improve the efficiency of extraction of PRI, first taking amplitude pretreatment, then only accumulate the signals whose amplitude meet certain requirements. After extracting PRI, extract to the original full pulse sequence. Simulation results show that the method of sorting has high accuracy and good real-time.

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