The Effect of a Pulsed Interference Signal on an Adaptive Array

1982 ◽  
Vol AES-18 (3) ◽  
pp. 297-309 ◽  
Author(s):  
R.T. Compton
Keyword(s):  
Adaptive Array ◽  
Interference Signal

scholarly journals Theoretical Analysis of Interference Cancellation System Utilizing an Orthogonal Matched Filter and Adaptive Array Antenna for MANET

2019 ◽  
Vol 8 (3) ◽  
pp. 48 ◽  
Author(s):  
Harada ◽  
Takabayashi ◽  
Kobayashi ◽  
Sakakibara ◽  
Kohno
Keyword(s):  
Theoretical Analysis ◽  
Interference Cancellation ◽  
Multiple Access ◽  
Mean Squared Error ◽  
Matched Filter ◽  
Array Antenna ◽  
Adaptive Array ◽  
Interference Signal ◽  
Minimum Mean Squared Error ◽  
Code Division Multiple

This study provides a mathematical model and theoretical analysis of an interference cancellation system combining an orthogonal matched filter (OMF) and adaptive array antenna that is called the extended OMF (EOMF). In recent years, an increase in the number of applications of mobile ad hoc networks (MANETs) is expected. To realize a highly reliable MANET, it is essential to introduce a method for cancelling the interference from other nodes. This research focuses on a scheme based on Code Division Multiple Access (CDMA) that enables simultaneous multiple access and low latency communication. However, there are problems with deteriorating performance due to the near–far problem and the increase in the amount of interference as the number of users increases. Additionally, another problem is that the spreading sequence of each user is unknown in a MANET. The OMF is expected to be a solution to these problems. The OMF performs interference cancellation by generating and subtracting a replica of the interference signal that is contained in the received signal. However, the OMF may generate an incorrect replica in the near–far problem. The EOMF compensates for the OMF’s weakness by combining the OMF with an adaptive array antenna. In this research, optimal parameters are derived from mathematical modelling and theoretical analysis of the EOMF. Specifically, the optimal weight vector and the minimum mean squared error that allow the adaptive algorithm to converge are derived and obtained from the numerical results.

scholarly journals A Study on Radar Target Detection using Space Time Adaptive Processing Algorithm and LCMV Algorithm

2021 ◽  
Vol 12 (5) ◽  
pp. 243-248
Author(s):  
Kwan-Hyeong Lee
Keyword(s):  
Correlation Matrix ◽  
Weight Vector ◽  
Direction Of Arrival Estimation ◽  
Adaptive Array ◽  
Radar Target ◽  
Interference Signal ◽  
Music Algorithm ◽  
Processing Power ◽  
Space Time Adaptive Processing ◽  
Optimal Weight Vector

In this paper, we study the directionof arrival estimation of the desired target in adaptive array MV algorithm to update the weight, and the optimized weight removes the interference signal. The target signal is estimated using the optimized weight vector and the high resolution the direction of arrival estimation MUSIC algorithm. We calculate the inverse of the correlation matrix using the QR method to reduce the processing power consumption of the optimized weight. The optimal weight vector is applied to the proposed algorithm to estimate the desired target direction from the output power spectrum. The performance of the proposed method is compared with the existing method by simulation. The experimental method estimates three targets from the antenna received signal. The existing method did not estimate the three desired targets at [-30o,-20, -10o]. The proposed method accurately estimates the desired three targets at [-30o,-20, -10o]. In the [-10o, 0, 10o] target estimation, the existing method reduces the estimated resolution of the target, but the proposed method accurately estimates the target. We proved that the proposed method in the simulation was superior to the existing method.

Detection method of combustion oscillation characteristics under strong noise background

2020 ◽  
Vol 21 (6) ◽  
pp. 612
Author(s):  
Yunkun Wei ◽  
Tianhong Zhang ◽  
Zhonglin Lin ◽  
Qi Xie ◽  
Yan Zhang
Keyword(s):  
Radiation Thermometry ◽  
Hydroxyl Group ◽  
Interference Signal ◽  
Engine Vibration ◽  
Combustion Technology ◽  
Lean Fuel ◽  
Combustion Oscillation ◽  
Aero Engines ◽  
Temperature Measurement System ◽  
Multispectral Radiation Thermometry

After the lean fuel premixed combustion technology is applied to aero engines, severe combustion oscillations will be cased and led to hidden safety hazards such as engine vibration, further energy waste and other problems. Therefore, it is increasingly important to actively control combustion oscillations. In this paper, a multispectral radiation thermometry (MRT) is used to analyze the hydroxyl group, which is a measurable research object in the combustion chamber of an aero engine, and to fit the functional relationship between the radiation intensity ratio and the temperature in different bands. The theoretical value of the error is <2%. At the same time, in order to solve the problem of weak detection signal and excessive interference signal, an improved frequency domain filtering method based on fast Fourier transform is designed. Besides, the FPGA platform is used to ensure the real-time performance of the temperature measurement system, and simulations and experiments are performed. An oscillating signal with an oscillation frequency of 315 Hz is obtained on the established test platform, and the error is only 1.42%.

Investigation of particulate systems using optical pathlength spectroscopy

2000 ◽  
Vol 627 ◽  
Author(s):  
Gabriel Popescu ◽  
Aristide Dogariu
Keyword(s):  
Path Length ◽  
Random Media ◽  
Michelson Interferometer ◽  
Industrial Process ◽  
Optical Path Length ◽  
Industrial Applications ◽  
Optical Path ◽  
Interference Signal ◽  
Optical Length ◽  
Reference Mirror

ABSTRACTIn many industrial applications involving granular media, knowledge about the structural transformations suffered during the industrial process is desirable. Optical techniques are noninvasive, fast, and versatile tools for monitoring such transformations. We have recently introduced optical path-length spectroscopy as a new technique for random media investigation. The principle of the method is to use a partially coherent source in a Michelson interferometer, where the fields from a reference mirror and the sample are combined to obtain an interference signal. When the system under investigation is a multiple-scattering medium, by tuning the optical length of the reference arm, the optical path-length probability density of light backscattered from the sample is obtained. This distribution carries information about the structural details of the medium. In the present paper, we apply the technique of optical path-length spectroscopy to investigate inhomogeneous distributions of particulate dielectrics such as ceramics and powders. The experiments are performed on suspensions of systems with different solid loads, as well as on powders and suspensions of particles with different sizes. We show that the methodology is highly sensitive to changes in volume concentration and particle size and, therefore, it can be successfully used for real-time monitoring. In addition, the technique is fiber optic-based and has all the advantages associated with the inherent versatility.

scholarly journals Adaptive Subcarrier Grouping for MMSE-SMI Adaptive Array Interference Suppression

IEEE Access ◽  
2021 ◽  
Vol 9 ◽  
pp. 18361-18372
Author(s):  
Kosuke Shima ◽  
Shun Kojima ◽  
Koki Ito ◽  
Kazuki Maruta ◽  
Chang-Jun Ahn
Keyword(s):  
Interference Suppression ◽  
Adaptive Array ◽  
Subcarrier Grouping

Pressing speed stability control of a special ceramic roller bearing press based on fuzzy adaptive PID

2021 ◽  
pp. 1-16
Author(s):  
Lijie Yang ◽  
Guimei Wang ◽  
Huadong Zhang ◽  
Jiehui Liu ◽  
Yachun Zhang
Keyword(s):  
Pid Control ◽  
Simulation Analysis ◽  
Roller Bearing ◽  
Speed Control ◽  
Stability Control ◽  
Interference Signal ◽  
Ceramic Roller ◽  
Speed Stability ◽  
Adaptive Pid Control ◽  
Fuzzy Adaptive

A special ceramic roller bearing press (SCRBP) is developed to press two bearings efficiently and precisely at the same time. A speed control mathematical model of the bearing press is built to obtain stability bearing pressing speed. The fuzzy adaptive PID controller of the bearing pressing speed of SCRBP is designed. The simulation model is also built. Fuzzy adaptive PID control is compared with conventional PID control. By simulation analysis, the simulation results show that adjusting time of fuzzy adaptive PID control is short, and its overshoot is very small, almost coincides with the set pressing speed. Moreover, fuzzy adaptive PID is suitable for the pressing speed control of the bearing pressing speed system with step interference signal. The pressing stability speed is obtained by fuzzy adaptive PID control.

Optoelectronic implementation of a 256-channel sonar adaptive-array processor

2004 ◽  
Vol 43 (35) ◽  
pp. 6421 ◽  
Author(s):  
Paulo E. X. Silveira ◽  
Gour S. Pati ◽  
Kelvin H. Wagner
Keyword(s):  
Adaptive Array ◽  
Array Processor
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