说明：  信息论大牛Gallager写的Principles of Digital Communications(数字通信原理），在亚马逊上的评价比另一牛人Proakis写的Communication Systems Engineering还高！ 2008年出的新书哦！ OCW上有Gallager的数字通信开放课程，可下载录像。
(Information Theory Big cattle Gallager wrote Principles of Digital Communications (digital communications theory), in the Amazon than the other cattle on the evaluation of human Proakis written Communication Systems Engineering even higher! In 2008 a new book, Oh! OCW on Gallager' s digital communication open courses, downloadable video.)