TAILIEUCHUNG - A Mathematical Theory of Communication

THE recent development of various methods of modulation such as PCM and PPM which exchange bandwidth for signal-to-noise ratio has intensified the interest in a general theory of communication. A basis for such a theory is contained in the important papers of Nyquist1 and Hartley2 on this subject. In the present paper we will extend the theory to include a number of new factors, in particular the effect of noise in the channel, and the savings possible due to the statistical structure of the original message and due to the nature of the final destination of the information | Reprinted with corrections from The Bell System Technical Journal Vol. 27 pp. 379-423 623-656 July October 1948. A Mathematical Theory of Communication By C. E. SHANNON Introduction The recent development of various methods of modulation such as PCM and PPM which exchange bandwidth for signal-to-noise ratio has intensified the interest in a general theory of communication. A basis for such a theory is contained in the important papers of Nyquist1 and Hartley2 on this subject. In the present paper we will extend the theory to include a number of new factors in particular the effect of noise in the channel and the savings possible due to the statistical structure of the original message and due to the nature of the final destination of the information. The fundamental problem of communication is that of reproducing at one point either exactly or approximately a message selected at another point. Frequently the messages have meaning that is they refer to or are correlated according to some system with certain physical or conceptual entities. These semantic aspects of communication are irrelevant to the engineering problem. The significant aspect is that the actual message is one selected from a set of possible messages. The system must be designed to operate for each possible selection not just the one which will actually be chosen since this is unknown at the time of design. If the number of messages in the set is finite then this number or any monotonic function of this number can be regarded as a measure of the information produced when one message is chosen from the set all choices being equally likely. As was pointed out by Hartley the most natural choice is the logarithmic function. Although this definition must be generalized considerably when we consider the influence of the statistics of the message and when we have a continuous range of messages we will in all cases use an essentially logarithmic measure. The logarithmic measure is more convenient for .

• Kĩ thuật Viễn thông
• DISCRETE NOISELESS SYSTEMS
• communication
• fundamental problem
• possible messages
• logarithmic
• information source
• Shannon McMillan theorem
• The consistent distribution
• Arbitrary information source
• Relative entropy density
• Non memory information source
• Open Source Security Tool
• Operating System
• Information Security
• Open Source Software
• Port Scanners
• Combining Source and Target Language Information
• Name Tagging
• Machine Translation Output
• báo cáo khoa học
• báo cáo ngôn ngữ
• xử lý ngôn ngữ tự nhiên
• Profile Characteristics
• Information source utilization
• Dry land farmers
• Package of practices
• Frequency of information
• Information Science
• Driven multi criteria source selection
• Multi criteria decision analysis
• Multi objective optimization
• Information retrieval
• Information utilization behavior
• Socio economic profile and suggestions
• Ginger growers
• Source consultancy
• Ginger growing farmers
• Business professionals
• Business information systems
• Information systems
• Source of business value
• Internet security
• The innovative technologies
• Technology essentials
• Using data
• Enterprise systems
• Creating business value
• Managing IS projects
• E commerce
• Social media
• IT hardware
• Details of networking
• Query relational databases
• Agricultural information system
• An Giang
• Open source WebGIS
• Interactive map
• Building an information system
• Cashless system
• Mass media exposure
• Internet exposure
• Information regarding cashless system
• Information sciences
• Bilingual autoencoder based efficient harmonization
• Multi source private data
• Accurate predictive modeling
• Distributed EHR
• Water erosion prediction project
• Surface runoff
• Soil erosion
• Agricultural non point source
• Geographic information system
• Measuring
• Demonstrating and focusing
• Literacy and Basic
• business plan completion
• Organization Information
• Legal Information
• báo cáo hóa học
• công trình nghiên cứu về hóa học
• tài liệu về hóa học
• cách trình bày báo cáo
• Project Management
• Strategic Planning
• Global Projects
• Knowledge Management
• Source Software
• EVA Issues
• How Open is the Future
• Internet development
• the future of information technology
• open source
• through technology