Communication Signal Design Lab.

한국어

송홍엽 교수의 잡글

SHANNON : CRACKING THE CHANNEL

2004.04.13 06:18

송홍엽 조회 수:17100 추천:180



In 1948. Claude Shannon, then a young engineer working at Bell Telephone Laboratories in Murray Hill, M.J., published a landmark paper titled “A Mathematical Theory of Communication.” In that paper, Shannon defined what the once fuzzy concept of “information” meant for communications engineers and proposed a precise way to quantify it : in his theory, the fundamental unit of information is the bit.
Shannon showed that every communications channel has a maximum rate for reliable data transmission, which he called the channel capacity, measured in bits per second. He demonstrated that by using certain coding schemes, you could transmit data up to the channel’s full capacity, virtually free of errors-an astonishing result that surprised engineers at the time.
   “I can’t think of anybody who could ever have guessed that such a theory existed,” says Robert Fano, an emeritus professor of computer science at the Massachusetts Institute of Technology, in Cambridge, and a pioneer in the information theory field. “It’s just an intellectual jump; it’s very profound.”
   The channel capacity became an essential benchmark for communications engineers, a measure of what a system can and cannot do, expressed in many cases by the famous formula, C=Wlog2(1+P/N). In the formula, C is the capacity in bits per second, W is the bandwidth in hertz, P is the transmitter power in watts, and N is the noise power, also in watts.
   From space probes to cellphones and CD players, Shannon’s ideas are invisibly embedded in the digital technologies that make our lives more interesting and comfortable.
   A thinker, juggling enthusiast, and exceptional chess player, Shannon was also famous for riding the halls of Bell Labs on a unicycle. He died on 24 February 2001, at age 84, after a long battle with Alzheimer’s disease. –E.G.



165.132.59.119 송홍엽: IEEE Spectrum 2004년 3월호에서 발췌한 글입니다...  -[04/12-22:48]-

221.149.77.165 박재석: Bell Lab은 New Jersey에 있다고합니다. Murray Hill, M.J -> N.J  -[10/13-22:07]-
번호 제목 글쓴이 날짜 조회 수
공지 논문에 영어작문 주의사항 몇 가지 송홍엽 2008.05.22 9008
공지 젊은 학부생 여러분에게... 송홍엽 2008.11.20 5978
공지 우리학과 대학원생 모두에게 (특히, 박사과정들에게) 하고싶은 말입니다. 송홍엽 2014.01.20 6889
68 글 잘 쓰는 이공계가 성공한다 송홍엽 2008.05.22 21094
67 우리학부 전공 2-3학년생에 대한 조언 송홍엽 2008.05.22 3827
66 암호이야기 송홍엽 2008.05.21 2979
65 [펀글] 추장의 선언 [1] 송홍엽 2008.02.22 7770
64 [펀글] 한반도 운하 건설을 반대하며 송홍엽 2008.02.20 3265
63 [펀글] 교육의 의미 송홍엽 2008.02.19 2944
62 [펀글] 조선일보 1월2일 사설: 교육개혁 송홍엽 2008.01.03 2959
61 대학원생 생활 가이드 [퍼온글] 송홍엽 2007.10.11 8328
60 [퍼온글] 명왕성 이야기 송홍엽 2007.05.23 3916
59 연구실 멤버들에게 송홍엽 2006.11.30 3689
58 Re..학위논문작성시 주의점 송홍엽 2006.09.26 3729
57 학위논문작성시 주의점 송홍엽 2006.09.24 4166
56 [펀글-조선일보] 대중적인 책 내면 ‘이단아’ 취급 송홍엽 2006.09.18 3378
55 대수학과 선형대수학 송홍엽 2006.05.16 3809
54 수학자와 공학자 송홍엽 2006.05.09 4768
53 [퍼온글] 명왕성 이야기 송홍엽 2006.04.26 5380
52 Outlook Express Backup [1] 송홍엽 2006.03.04 21483
51 [퍼온글] 애플컴퓨터 로고의 유래(?) 송홍엽 2006.02.09 5898
50 [퍼온글]과학자들은 왜 속이는가 송홍엽 2006.02.07 4627