检索结果-南通市图书馆

Optimal design study of high order FIR digital filters based on neural network algorithm

在线全文

学校读者我要写书评

暂无评论

Journal of Systems engineering and Electronics 2004年第2期15卷 115-119,130页

作者： Wang Xiaohua & He Yigangcollege of Electrical and information engineering, Hunan University, Changsha 410082, P. R. China college of Electrical and information engineering, Changsha University of Science and Technology,Changsha 410077, P. R. China college of Electrical and information engineering Hunan University Changsha 410082 P. R. China college of Electrical and information engineering Changsha University of Science and Technology Changsha 410077 P. R. China

An optimal design approach of high order FIR digital filter is developed based on the algorithm of neural networks with cosine basis function . The main idea is to minimize the sum of the square errors between the amplitude response of the desired FIR filter and that of the designed by training the weights of neural networks, then obtains the impulse response of FIR digital filter . The convergence theorem of the neural networks algorithm is presented and proved, and the optimal design method is introduced by designing four kinds of FIR digital filters , i.e., low-pass, high-pass, bandpass , and band-stop FIR digital filter. The results of the amplitude responses show that attenuation in stop-bands is more than 60 dB with no ripple and pulse existing in pass-bands, and cutoff frequency of passband and stop-band is easily controlled precisely .The presented optimal design approach of high order FIR digital filter is significantly effective.

关键词： high order FIR digital filters amplitude-frequency response neural network convergence theorem optimal design.

Novel multi-objective optimization algorithm

在线全文

学校读者我要写书评

暂无评论

系统工程与电子技术：英文版 2014年第4期25卷 697-710页

作者： Jie Zeng Wei Nie college of information engineering Shenzhen University Modern Communication and information Processing Key Laboratory Shenzhen University

Many multi-objective evolutionary algorithms(MOEAs)can converge to the Pareto optimal front and work well on two or three objectives, but they deteriorate when faced with manyobjective problems. Indicator-based MOEAs, which adopt various indicators to evaluate the fitness values(instead of the Paretodominance relation to select candidate solutions), have been regarded as promising schemes that yield more satisfactory results than well-known algorithms, such as non-dominated sorting genetic algorithm(NSGA-II) and strength Pareto evolutionary algorithm(SPEA2). However, they can suffer from having a slow convergence speed. This paper proposes a new indicatorbased multi-objective optimization algorithm, namely, the multiobjective shuffled frog leaping algorithm based on the ε indicator(ε-MOSFLA). This algorithm adopts a memetic meta-heuristic,namely, the SFLA, which is characterized by the powerful capability of global search and quick convergence as an evolutionary strategy and a simple and effective ε-indicator as a fitness assignment scheme to conduct the search procedure. Experimental results, in comparison with other representative indicator-based MOEAs and traditional Pareto-based MOEAs on several standard test problems with up to 50 objectives, show that ε-MOSFLA is the best algorithm for solving many-objective optimization problems in terms of the solution quality as well as the speed of convergence.

关键词： evolutionary algorithm multi-objective optimization shuffled frog leaping algorithm(SFLA) convergence

ON THE ALMOST SURELY ASYMPTOTIC BOUNDS OF A CLASS OF ORNSTEIN-UHLENBECK PROCESSES IN INFINITE DIMENSIONS

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems Science & Complexity 2008年第3期21卷 416-426页

作者： Yuhong LI college of Hydropower and information engineering Huazhong University of Science and Technology Wuhan 430074 China

Given a real-valued separable M-type 2 Banach space X with the p-th power of the norm of C2-class, the almost sure asymptotic upper bounds of the solutions of the Ornstein-Uhlenbeck Processes described by the following equations {dz（t）=A（t,z（t））dt＋σ（t,z（t））dW（t）,z（0）=z0∈X,are investigated. This study generalizes the corresponding well-known finite dimensional results of Lapeyre （1989） and Mao （1992）.

关键词： Almost surely asymptotic bounds infinite dimension M-type 2 Banach space Ornstein-Uhlenbeck Processes

Complex transient dynamics of hidden attractors in a simple 4D system

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2015年第5期24卷 270-274页

作者：党小宇李春彪包伯成武花干 college of Electronic and information engineering Nanjing University of Aeronautics and Astronautics School of Electronic & information engineering Nanjing University of Information Science & Technology School of information Science and engineering Changzhou University School of Electronic and Optical engineering Nanjing University of Science and Technology

A simple four-dimensional system with only one control parameter is proposed in this paper. The novel system has a line or no equilibrium for the global control parameter and exhibits complex transient transition behaviors of hyperchaotic attractors, periodic orbits, and unstable sinks. Especially, for the nonzero-valued control parameter, there exists no equilibrium in the proposed system, leading to the formation of various hidden attractors with complex transient dynamics. The research results indicate that the dynamics of the system shows weak chaotic robustness and depends greatly on the initial states.

关键词： transient dynamics hidden attractor equilibrium

Improving TCP Performance over Wireless Links Using Link-Layer Retransmission and Explicit Loss Notification

在线全文

学校读者我要写书评

暂无评论

Journal of Systems engineering and Electronics 2002年第4期13卷 17-23页

作者： Zhou Zhizhao & Han Zhengzhi college of Electronic and information engineering, Shanghai Jiaotong University, Shanghai 200030, P. R. China college of Electronic and information engineering Shanghai Jiaotong University Shanghai 200030 P. R. China

In order to support the mobility of computers during communication, the transport control protocol (TCP) connections between fixed host and mobile host often traverse wired and wireless networks, and the recovery of the losses due to wireless transmission error is much different from congestion control. This paper analyzes the interaction between TCP and link layer retransmission scheme when the correlated packet are losses handled, indicates that a higher value of the maximum number of successive link layer timeout retransmissions has an adverse effect on TCP ability to perform congestion control rapidly. To achieve a better TCP performance, the paper proposes a strategy combining link-layer selective-reject automatic repeat request (ARQ) with explicit loss notification mechanism, which can respond to congestion quickly while keeping wireless link more reliable, and make TCP react to the different packet losses more suitably.

关键词： Congestion control (communication) Mechanisms Performance Transmissions

A circular zone partition method for identifying Duffing oscillator state transition and its application to BPSK signal demodulation

在线全文

学校读者我要写书评

暂无评论

Science China(information Sciences) 2011年第6期54卷 1274-1282页

作者： FU YongQing 1 , WU DongMei 1 , ZHANG Lin 2 & LI XingYuan 1 1 college of information and Communication engineering, Harbin engineering University, Harbin 150001, China 2 college of Underwater Acoustic engineering, Harbin engineering University, Harbin 150001, China 1. college of information and Communication engineering Harbin Engineering University Harbin 150001 China2. College of Underwater Acoustic Engineering Harbin Engineering University Harbin 150001 China

When a Duffing oscillator is applied to signal detection, identifying its state transition is indispensable. Due to lack of an effective method for automatically distinguishing the state transition, phase analysis is extensively used. However, it needs ocular estimation to identify phase pattern corresponding to transition of Duffing oscillator. Hence it is not fit for communication signal demodulation. To solve the problem, this paper proposes a method, called circular zone partition (CZP), for partitioning trajectory on the phase plane of Duffing oscillator. First, a computing model for Duffing oscillator is described. Then, the fundamental principle and algorithm for the CZP method are discussed. Meanwhile the equation of a circular zone divider and its realization are presented. Thus, by way of the divider, the two-dimensional phase trajectory pattern of Duffing oscillator driven by an external signal can be transformed into the one-dimensional time signal, whose envelop after being filtered is able to indicate the state transition, i.e. the presence or the absence of external signal. Finally, to verify the effect of the CZP method on binary phase shifted keying (BPSK) signal demodulation, two examples are presented and simulation results show that this CZP method is accurate and valid for BPSK signal demodulation.

关键词： chaos nonlinear oscillators signal detection digital communication receivers

MMSE relay precoding schemes based on quantization error compensation for multi-relay system

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(information Sciences) 2010年第12期53卷 2548-2556页

作者： LI Ting 1,2 & YANG LuXi 2 1 college of Communication and information engineering,Nanjing University of Posts and Telecommunications,Nanjing 210003,China 2 School of information Science and engineering,Southeast University,Nanjing 210096,China 1. college of Communication and information engineering Nanjing University of Posts and Telecommunications Nanjing 210003 China2. School of Information Science and Engineering Southeast University Nanjing 210096 China

In order to deal with the performance degradation resulting from the quantization error,this paper introduces the statistics of Grassmannian codebook's quantization error into relay precoding design for multirelay *** on the two-step MMSE optimization algorithm for relay precoding and receiver equalizing with full feedback under QoS requirements,we first propose a limited feedback two-step MMSE optimization scheme for relay precoding and receiver equalizing with quantization error compensation,and then we propose a limited feedback joint MMSE optimization scheme for relay precoding and receiver equalizing with quantization error compensation subject to a global power constraint at the output of *** results show that the proposed joint MMSE optimization scheme with quantization error compensation has a much lower bit-error rate than the two-step MMSE optimization scheme with quantization error compensation and the joint MMSE optimization scheme without quantization error compensation.

关键词： multi-relay precoding limited feedback minimum mean square error

QoS-guaranteed multi-relay selection and power allocation optimization in cooperative systems

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2010年第6期17卷 25-31页

作者： CHEN Dan,JI Hong,LI Xi,LI Yi college of information and Communication engineering,Beijing University of Posts and Telecommunications,Beijing 100876,China [a] college of information Communication engineering Beijing University of Posts Telecommunications Beijing 100876 China

This paper investigates the relay selection and power allocation problem in multi-user based cooperative networks,where intermediate relay nodes help source forward information to destination using decode-and-forward （DF） relaying protocol. Specifically,we propose a novel multi-relay nodes selection strategy taking both instantaneous channel state information （I-CSI） and residual energy into consideration,by which ＇emergence＇ diversity gain can be achieved and the imbalance of resource utilization can be overcome. Besides,using Largangian dual-primal decomposition and subgradient projection approach,an optimal power allocation algorithm at source and cooperative relay nodes is presented with the constraints of each user＇s individual quality of service （QoS） requirements and system total transmit power. Theoretical analysis and simulation results demonstrate that the proposed scheme can significantly improve energy efficiency,while guaranteeing a good balance between achievable data rate and average network lifetime with relatively low implementation complexity.

关键词： cooperative diversity relay selection resource allocation Lagrangian dual-primal decomposition subgradient projection

Performance of iteratively decoded bit-interleaved coded modulation with chaos based interleaving strategies

在线全文

学校读者我要写书评

暂无评论

Science China(information Sciences) 2010年第4期53卷 833-841页

作者： ZOU XueLan1*, LIU WeiYan2 & FENG GuangZeng3 1Department of Electronic and information engineering, Zhejiang Institute of Media and Communications, Hangzhou 310018, China 2Department of information engineering, Jiangsu City Vocation college, Nanjing 210036, China 3college of Communication and information engineering, Nanjing University of Posts and Telecommunications, Nanjing 210003, China 1. Department of Electronic and information engineering Zhejiang Institute of Media and Communications Hangzhou 310018 China2. Department of Information Engineering Jiangsu City Vocation College Nanjing 210036 China3. College of Communication and Information Engineering Nanjing University of Posts and Telecommunications Nanjing 210003 China

Bit-interleaved coded modulation with iterative decoding (BICM-ID) is a bandwidth efficient trans- mission scheme which is well suitable for next-generation mobile communications. The interleaver design is critical to the high performance of BICM-ID. In this paper we investigate the application of the chaos theory to the interleaver design to further improve the performance of BICM-ID. A new interleaving scheme based on the chaos theory is proposed. Compared with the random interleaver, the proposed approach has the ad- vantages including lower system delay and higher transmission efficiency. Simulation results in both additive white Gaussian noise (AWGN) channel and Rayleigh fading channel are provided, which demonstrates that the new interleaver is better than the random interleaver and exhibits excellent performance when applied to the BICM-ID system.

关键词： chaos interleaving bit-interleaved coded modulation (BICM) iterative decoding