This paper introduces the realization method of Beidou anti-jamming antenna hardware and software, theory analysis and MATLAB simulation of antenna array and adaptive algorithm. The space time joint anti-jamming algor...
详细信息
ISBN:
(纸本)9781509050369;9781509050352
This paper introduces the realization method of Beidou anti-jamming antenna hardware and software, theory analysis and MATLAB simulation of antenna array and adaptive algorithm. The space time joint anti-jamming algorithm based on the linear constraint minimum variance criterion is adopted as the core of the anti-jamming processor. It is designed and implemented successfully. the anti-jamming ability of the antenna is tested and verified. The antenna has the capability of resisting single jam 75 dB and resisting three jam 60 dB. Finally, the difference between theoretical simulation and practical implementation is analyzed, and future work is prospected.
The challenges for today's wireless communication technology are increased data rates, channel capacity and spectrum efficiency with reduced interference. The adaptive antenna array is capable of adapting to the v...
详细信息
ISBN:
(纸本)9781467385497
The challenges for today's wireless communication technology are increased data rates, channel capacity and spectrum efficiency with reduced interference. The adaptive antenna array is capable of adapting to the varying signal environments automatically and forms beams in the directions of the desired signals by steering nulls in the directions of interfering signals. Therefore smart antenna is the best solution to overcome the above mentioned challenges. Smart antennas uses advanced digital signal processing algorithms to enhance the detection of desired users in an interfering environment through spatial filtering. In this paper we will discuss the influence of Least Mean Squares (LMS), Recursive Least Squares (RLS) and Normalized Least Mean Square (NLMS) algorithms in adaptive beamforming. The simulations used for the study are carried out using MATLAB R2013a.
This paper introduces the realization method of Beidou anti-jamming antenna hardware and software, theory analysis and MATLAB simulation of antenna array and adaptive algorithm. The space time joint anti-jamming algor...
详细信息
ISBN:
(纸本)9781509050352
This paper introduces the realization method of Beidou anti-jamming antenna hardware and software, theory analysis and MATLAB simulation of antenna array and adaptive algorithm. The space time joint anti-jamming algorithm based on the linear constraint minimum variance criterion is adopted as the core of the anti-jamming processor. It is designed and implemented successfully. the anti-jamming ability of the antenna is tested and verified. The antenna has the capability of resisting single jam 75 dB and resisting three jam 60 dB. Finally, the difference between theoretical simulation and practical implementation is analyzed, and future work is prospected.
In this paper, the track control problem of hypersonic a vehicle with modeling uncertainties, external disturbance, and multifault is studied and analyzed. First, a fault model of a second-order system including distu...
详细信息
In this paper, the track control problem of hypersonic a vehicle with modeling uncertainties, external disturbance, and multifault is studied and analyzed. First, a fault model of a second-order system including disturbance is established by introducing auxiliary error variables on the basis of feedback linearization for a longitudinal model of the hypersonic vehicle. Second, for a fault-free actuator and system model with unknown upper bound disturbance, a fast adaptive terminal sliding mode controller is designed, which ensures the sliding mode manifold is finite-time stable. To solve the multifault problem of actuator, based on the passive fault-tolerant control method, a fast adaptive terminal sliding mode fault-tolerant controller is designed, which guarantees that the system state is finite-time stabile in the event of actuator failure. The controller adopts two adaptive algorithms to estimate the unknown fault information and system disturbance information. Finally, a rigorous proof using Lyapunov theory is given for the stability of the designed controllers. Numerical simulation is run for the longitudinal nonlinear dynamic model of a hypersonic vehicle and simulation results prove the effectiveness of the two designed controllers.
Oil spills generate a large cost in environmental and economic terms. Their identification plays an important role in oil-spill response. We propose an oil spill detection method with improved adaptive enhancement on ...
详细信息
Oil spills generate a large cost in environmental and economic terms. Their identification plays an important role in oil-spill response. We propose an oil spill detection method with improved adaptive enhancement on X-band marine radar systems. The radar images used in this paper were acquired on 21 July 2010, from the teaching-training ship YUKUN of the Dalian Maritime University. According to the shape characteristic of co-channel interference, two convolutional filters are used to detect the location of the interference, followed by a mean filter to erase the interference. Small objects, such as bright speckles, are taken as a mask in the radar image and improved by the Fields-of-Experts model. The region marked by strong reflected signals from the sea's surface is selected to identify oil spills. The selected region is subject to improved adaptive enhancement designed based on features of radar images. With the proposed adaptive enhancement technique, calculated oil spill detection is comparable to visual interpretation in accuracy.
The aspire of this paper is in the direction of extort the Fetal Electrocardiogram (FECG) indication from the mother’s tummy signal which is an essential signal to investigate the abnormality of the fetal heart by a ...
详细信息
The aspire of this paper is in the direction of extort the Fetal Electrocardiogram (FECG) indication from the mother’s tummy signal which is an essential signal to investigate the abnormality of the fetal heart by a general practitioner. By using the least-mean-square (LMS) filter the abdomen of the mother’s are extracted. The LMS filter is an adaptive filter, in which the FIR filter coefficients are extracted from mother’s abdomen. To calculate the fetal heart beat, the FECG based signal estimation is wanted over period. The FECG of the mother is taken at the pregnancy of 20 weeks by using this system. While considering the FECG in real time manner, the maternal woman should wear a wide belt with electrodes fitted in large manner. To separate the signals, the adaptive noise canceller algorithm is used. The adaptive noise canceller algorithm is used to analyze the collected information of the electrodes which are fitted in the belt of the woman’s abdomen. This separation is here done based on predefined values by using the LabVIEW tool. The FIR filter is designed and simulated with the help of Xilinx ISE 12.1 and is implanted by using Spartan 3 of FPGA.
The active power filter has two key link for harmonic current detection and respectively compensation current tracking. This article mainly aims at harmonic current detection link. Firstly, Analysis adaptive harmonic ...
详细信息
ISBN:
(纸本)9783037852866
The active power filter has two key link for harmonic current detection and respectively compensation current tracking. This article mainly aims at harmonic current detection link. Firstly, Analysis adaptive harmonic detection methods, then based on over to LMS (Least Mean Square) adaptive algorithm as the research object, in discussing the adaptive algorithm criteria. By comparing several simulation-based LMS algorithm to achieve the results of the filter,analyse the causes of the results.
We consider the problem of proper learning of a boolean halfspace with integer weights {0, 1,..., t}, from membership queries only. The best known algorithm for this problem is an adaptive algorithm that asks n(0(t5))...
详细信息
We consider the problem of proper learning of a boolean halfspace with integer weights {0, 1,..., t}, from membership queries only. The best known algorithm for this problem is an adaptive algorithm that asks n(0(t5)) membership queries, while the best lower bound for the number of membership queries is n(Omega(t)) [1]. In this paper we close this gap and give an adaptive proper learning algorithm with two rounds, and asking n(0(t)) membership queries. We also give a non-adaptive proper learning algorithm that asks n(0(t3)) membership queries. (C) 2016 Elsevier B.V. All rights reserved.
Learning models of artificial intelligence can nowadays perform very well on a large variety of tasks. However, in practice, different task environments are best handled by different learning models, rather than a sin...
详细信息
Learning models of artificial intelligence can nowadays perform very well on a large variety of tasks. However, in practice, different task environments are best handled by different learning models, rather than a single universal approach. Most non-trivial models thus require the adjustment of several to many learning parameters, which is often done on a case-by-case basis by an external party. Meta-learning refers to the ability of an agent to autonomously and dynamically adjust its own learning parameters or meta-parameters. In this paper, we show how projective simulation, a recently developed model of artificial intelligence, can naturally be extended to account for meta-learning in reinforcement learning settings. The projective simulation approach is based on a random walk process over a network of clips. The suggested meta-learning scheme builds upon the same design and employs clip networks to monitor the agent's performance and to adjust its meta-parameters on the fly. We distinguish between reflex-type adaptation and adaptation through learning, and show the utility of both approaches. In addition, a trade-off between flexibility and learning-time is addressed. The extended model is examined on three different kinds of reinforcement learning tasks, in which the agent has different optimal values of the meta-parameters, and is shown to perform well, reaching near-optimal to optimal success rates in all of them, without ever needing to manually adjust any meta-parameter.
For a finite collection of functions within some differential field of several variables, there exists an adaptive algorithm for calculating a basis of their linear relations. We study the complexity of this algorithm...
详细信息
For a finite collection of functions within some differential field of several variables, there exists an adaptive algorithm for calculating a basis of their linear relations. We study the complexity of this algorithm, noting how it compares to some other existing techniques. Also we demonstrate some modifications for improving implementation. In the course of our analysis, we define the marginal set of a Young-like set and show how the size of the former can be bounded in terms of the size of the latter. (C) 2010 Elsevier Inc. All rights reserved.
暂无评论