信息论与编码英文课件 第4章 信道容量.ppt

Chapter 4：Channel and Channel Capacity The goal to achieve The understanding of the goal and content how Info. Theory studies the channel Understand the basic classification of the channel and grasp the basic description method of the channel Grasp the concept of channel capacity/Channel capacity price function, as well as relations between this concept and mutual info., channel input probability distribution, channel transfer function Can calculate the channel capacity/The channel capacity price function (symmetrical discrete channel, additive Gauss noise channel without memory ) of simple channel Understand the function of the channel capacity/Capacity price function in communications system research Definition question Entropy? Entropy rate? function in lossless source coding theorem Mutual info.? Channel Capacity? function in source coding theorem Review – nature of mutual info. function : Nature.1 Relationship between mutual info. and channel input probability distribution Nature 1: I (X; Y) is a convex function of the channel input probability distribution p (x). Review – nature of mutual info. function : Nature.2 Relationship between Info. content and channel transition probability distribution Nature 2: I (X; Y) is a concave function of channel transition probability distributes p (y/X). Review – nature of mutual info. function : Nature.3 Relationship between Info. content and channel input mark relevancy Nature 3: The channel input is discrete and without memory Review – nature of mutual info. function : Nature.4 Review – nature of mutual info. function : Nature.5 Deduction of nature 3 and nature 4 : The channel input and the channel themselves are all discrete and without memory. Channel and Channel Capacity Outline classification and description of the channel The discrete channel without memory and its the capacity Continual channel and its capacity Capacity price function C(F) §4.1: Outline The content of Info. Theory r