A Simple Lower Bound of Trellis Complexity of Linear Block Codes

Yue Dianwu
(Department of Communication Engineering, Nanjing Institute of Posts and Telecommunications, 210003, Nanjing, PRC)

Abstract In this paper, we study trellis complexity of linear codes and derive asimple lower bound of trellis complexity of linear codes from knowledge of dimension/length profiles and generalized Hamming weighs. D.J.Muder has given another simple lower bound of trellis complexity of linear codes, the two bounds complement each other.

Keywords Linear block code, Trellis complexity, Dimension/length profiles, Generalized Hamming weight

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On the Problems of the Synchronization of Chaotic Systems

Jiang Guoping, Yang Xiuxia
(Department of Electronic Engineering, Nanjing Institute of Posts and Telecommunications, 210003, Nanjing, PRC)

Abstract In this paper, the definition and methods of the Synchronization of Chaotic Systems are introduced, and the disadvantages of the current chaotic synchronization methods are analyzed and pointed out. The relations between synchronization and nonlinear observers are revealed.

Keywords Nonlinear systems, State observers, Chaotic synchronization

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A Speech Recognition-oriented New Neural Network

Wang Xiaoming¹, Zheng Baoyu²
1 (Department of Information Engineering, Nanjing Institute of Posts and Telecommunications, 210003, Nanjing, PRC)
2 (Graduate School, Nanjing Institute of Posts and Telecommunications, 210003, Nanjing, PRC)

Abstract A new neural network is proposed in this paper. The training and recognition algorithms are described. In order to improve the ability of modeling the temporal signal, a preprocessing approach named nonlinear segmentation and representing-frame feature extraction are employed. Based on the new neural network, a Chinese speech recognition system is established and has achieved high performance in experiments.

Keywords Neural network, Speech recognition, Nonlinear segmentation

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Lee Error Correcting Codes with Its Application to QAM Systems

Fu Haiyang, Peng Jianglong
(Department of Communication Engineering, Nanjing institute of posts and Telecommunications, 210003, Nanjing, PRC)

Abstract This paper introduces the characteristics and construction of a multi-level linear error correcting code——Lee code, which is transparent to phase ambiguity. Then the application of Lee codes is extended from PSK to 64QAM systems.Finally, a performance comparison between transmission systems with and without Lee codes is made, and the results are analyzed.

Keywords Phase ambiguity, Phase transparence, Lee error correcting code

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Robust Image Coding Based on Correlation of Data

Song Jianxin, Bi Houjie
(Department of Information Engineering, Nanjing Institute of Posts and Telecommunications, 210003, Nanjing, PRC)

Abstract Information separate principle for robust image coding under ATM environment is presented. Based on the principle, the method of segment and concealment using the correlation of image is presented. Correlation data for concealment are supplied with the segment. The best concealment result is got with the correlation concealment.

Keywords Image coding, Image segment, Image communication, Cell-loss concealment

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A Scheme of GSM Half-rate Speech Coding at Speed of 6.25 kbit/s

Feng Yuwen, Zhou Yuechen
(Department of Communication Engineering, Nanjing Institute of Posts and Telecommunications, 210003, Nanjing, PRC)

Abstract Three main parts of CELP on which GSM half-rate speech coding is based are improved respectively in this paper. A fast algorithm combined quantization with roots-solving is also proposed in LSP parameters prediction. A method of decreasing the search range step by step is used in LTP with friction delay. A Gaussian over-lapped and clipped codebook is used in codebook search. The improvements result in a significant reduction in calculation complexity, so that the whole CELP codec can be real-time implemented with a single DSP chip without degradation of the reconstructed speech.

Keywords Half-rate speech coding, Code excited linear prediction, Linear spectrum pairs parameters, Friction delay, Digital signal processing

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An Improved Binary Multiplication-free Arithmetic Codes

Mu Mingsheng
(Department of Information Engineering, Nanjing Institute of Posts and Telecommunications, 210003, Nanjing, PRC)

Abstract Arithmetic coding is a powerful lossless data compression technique. Based on the scheme proposed by Rissanen and Mohiaddin, this paper gives a black-white alphabet multiplication-free arithmetic coding scheme which only uses shift-and-add and looks-up table. Both theoretical analysis and computer simulation show that the multiplication-free scheme is better for all cases.

Keywords Arithmetic coding, Multiplication-free, Shift-and-add and looks-up table

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A Study on Radio Propagation under Indoor Environments by using SBR

Zhang Baohua, Yue Zhongzhu, Wu Zhizhong
(Department of Electronic Engineering, Nanjing Institute of Posts and Telecommunications, 210003, Nanjing, PRC)

Abstract In this paper, how to calculate electric field in indoor environment by using SBR (Shooting and Bouncing Rays) is presented. In addition, vector effective height of antennas is introduced. Electric field in furnished rooms is calculated and its results are analyzed.

Keywords Mobile communications, Indoor microcell, Shooting and bouncing rays, Vector effective antenna height

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Self-phase Modulation in High Data Rate Optical Fiber Communication Systems

Pang Ran¹, Wang Wenqing², Sun Jinlun¹
1 (Department of Communication Engineering, Nanjing Institute of Posts and Telecommunications, 210003, Nanjing, PRC)
2 (Institute of Optical Fiber Communication, Nanjing Institute of Posts and Telecommunications, 210003, Nanjing, PRC)

Abstract The self-phase modulation (SPM) and its effect on performance degradation of the long distance optical fiber communication system with high data rate are discussed in this paper. The interaction between group velocity dispersion (GVD) and SPM is studied. Finally, the relevant computer simulation results are also given.

Keywords Nonlinearity, Self-phase modulation, Dispersion compensation

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A TMN-based Billing Management System for Mobile Communication Networks

Mao Haiyan, Zhang Xiaoying, Ju Ti
(Department of Computer Science and Technology, Nanjing Institute of Posts and Telecommunications, 210003, Nanjing, PRC)

Abstract With the swift development of mobile communication in China, it has been a urgent task to adopt a real-time on-line billing system. The technology and standard recommendation about TMN are introduced in this paper. Also the implementation of a TMN-based billing management system for mobile communication is proposed, which has been put into practice in Billing Management system for mobile communication in Gan Su province.

Keywords Mobile communications, Telecommunication management networks, Real-timeand On-line gathering, Consolidated billing

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A Model and a Platform for Interconnecting the Existing Telecommunication Management Subsystems

Li Lingjuan, Zheng Yan, Wang Shaodi
(Department of Computer Science and Technology, Nanjing Institute of Posts and Telecommunications, 210003, Nanjing, PRC)

Abstract In this paper, the necessity of interconnecting the existing telecommunication management subsystems is analyzed, the interconnection model and platform based on TMN standards are proposed, and the issue related to implementation are discussed.

Keywords Telecommunication management networks, Telecommunication management subsystem, Interconnection, Integrated network management systems

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The Concept of Distributed Object Applied to Communication Connection Management

Wang Wennai¹, Chen Jianning², Tang Baomin¹
1 (Department of Communication Engineering, Nanjing Institute of Posts and Telecommunications, 210003, Nanjing, PRC)
2 (Nanjing Electric Power Automation Research Institute, Nanjing, 210003, PRC)

Abstract In this paper, the distributive characteristic for the management of communication connection is discussed. A new object concept whose attributes and behaviors can be distributed on computational nodes, named distributed object, is proposed and applied to commumication connection modelling in order to reduce the commplexity of the fault and performance management subsystem.

Keywords Communication connection management, Distributed processing, Telecommunication management networks

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The Realization of the Middleware Interface for TCP/IP Network

Fang Jun, Wu Xiaobing, Shen Jinlong
(Department of Computer Science and Technology, Nanjing Institute of Posts and Telecommunications, 210003, Nanjing, PRC)

Abstract Middleware is a set of distributed service software in the networking environment, which provides Application Programming Interface (API) which is simpler and more effective than operating system and networking system service. This paper discusses the conception of Middleware and how to realize the Middleware interface for TCP/IP networks with VC via MFC, VB via ActiveX and Delphi via VCL, etc.

Keywords Middleware, Transmission Control Protocol/Internet Protocol, Network interface

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The Technique for Implementing Q.931

Zhang Jieyu, Huang Huiqin
(Department of Communication Engineering, Nanjing Institute of Posts and Telecommunications, 210003, Nanjing, PRC)

Abstract User Network Interface (UNI) is one of the important techniques to implement the ISDN. This paper not only introduces LAY 3 protocol——Q.931 in UNI but also presents some key techniques to realize it.

Keywords User network interface, Integrated service digital networks, Communication protocol, Communication software, Finite state machine

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Research and Implementation of Online Help System for Windows 95 Based on Visual C++ 4.0

Guo Xinghua, Wang Ruchuan
(Department of Computer Science and Technology, Nanjing Institute of Posts and Telecommunications, 210003, Nanjing, PRC)

Abstract Based on the analysis of structure, operating principle and key points of technolgy of the online help system for Windows 95, this paper elaborates the process and method of producing the system with Word 6.0 and Visual C++ 4.0.

Keywords Online help, Topic file, Context string

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Analysis and Realization of Objects' Assembly Structure

Hu Wei
(Department of Information Engineering, Nanjing Institute of Posts and Telecommunications, 210003, Nanjing, PRC)

Abstract Based on object-oriented method, this paper introduces the concept of objects' assembly structure, and proposes the methods to analyse and describe the structure, store it in relational database system and to input component object to the user interface. The paper also gives part of programs as an example and discusses the advantages of the proposed methods.

Keywords Object oriented technology, Assembly structure, Data base

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A Study on Digital Simulation of Root Locus in Z-domain for the Computer Control System

Chen Zhongmin, Wang Xue
(Department of Computer Science and Technology, Nanjing Institute of Posts and Telecommunications, 210003, Nanjing, PRC)

Abstract The design of computer control system in discrete domains and digital simulation of root locus in Z-domain are discussed, the theoretic analyses of root match and convergent test are given in detail, and their algorithms as well as software implementation in C language are also presented.

Keywords Digital simulation, Z-domain, Root locus

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Design and Implementation of Intranet Firewalls Based on Proxy Servers

Pan Li, Shen Jinlong, Zhang Yun
(Department of Computer Science and Technology, Nanjing Institute of Posts and Telecommunications, 210003, Nanjing, PRC)

Abstract Proxy servers supervise network services through controling the accesses to the protected networks on the application layer, so that they can replace or enhance the network firewalls. In this paper, the working principle of proxy servers is analyzed. Two typical kinds of Intranet firewalls based on proxy servers are proposed, and the implementation method is discussed through a case study.

Keywords Proxy server, Firewall, Intranet

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The Automatic Segmentation of Leukocyte Image

Yang Xiuxia, Jiang Guoping, Wang Houda
(Department of Electronic Engineering, Nanjing Institute of Posts and Telecommunications, 210003, Nanjing, PRC)

Ding Xiaoling
(Department of Physics, Normal Institue of Yangzhou University, 225002, Yangzhou, PRC)

Abstract According to the different sensitivity of nucleus to R,G,B signal, weacquire the area of leukocyte in image by using histogram. After a linear transform from R,G,B space to I₁,I₂,I₃ space, we use iterative self-organizing data analysis technique algorithms dividing the area of leukocyte into three parts: cytoplasm, nucleus and background, and get a whole leukocyte.

Keywords Image recognition, Image segmentation, Histogram, Freeman chain code

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The Implementation for DPLL and Frequency Translation with FPGA Devices

Gong Jianrong, Li Xiaofei
(Department of Information Engineering, Nanjing Institute of Posts and Telecommunications, 210003, Nanjing, PRC)

Abstract An implementation of the functions, digital phase-locked loop (DPLL) and frequency translation, with FPGA (Field Programmable Gate Array) is presented in this paper. The working principle and developing process of DPLL are analyzed and the problems in some aspects concerned in their design and implementation are also discussed.

Keywords Field programmable gate array, Digital phase-locked loop, Frequency translation

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A Scheme of TV-cable Ethernet Multimedia Transmission

Sun Youwei, Sun shuna
(Xi'an Institute of Posts and Telecommnications, 710061, Xi'an, PRC)

Zuo Yang
(China Engineering Physics Institute, 610000, Chengdu, PRC)

Abstract Today's Cable Television System(CATV) can provide broadband multimedia information services and computer network has the ability to control the flowing directions of various kinds of data. The combination of the two leads to a casy way to the realization of broad local band integrated area network. This paper presents and implementation sheme.

Keywords Cable television, Multimedia, Ethernet

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Uniform Boundedness of the Unequilibrium Solutions of the Steady State Semiconductor Device Equations

Xu Liwei
(Department of Basic Courses, Nanjing Institute of Posts and Telecommunications, 210003, Nanjing, PRC)

Abstract In N-dimensional case, the steady state semiconductor device equations are considered when R¹0 in this paper. The conclusions about uniform boundedness of the solutions obtained by J.Henry are extended to the case of unequilibrium semiconductor device with mixed boundary conditions.

Keywords Semiconductor physics, L^¥ norm-estimation, Local estimation, Uniform boundedness, Function space

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