Communication Signal Design Lab.

한국어

송홍엽 교수의 잡글

SHANNON : CRACKING THE CHANNEL

2004.04.13 06:18

송홍엽 조회 수:20436 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 9404
공지 젊은 학부생 여러분에게... 송홍엽 2008.11.20 6367
공지 우리학과 대학원생 모두에게 (특히, 박사과정들에게) 하고싶은 말입니다. 송홍엽 2014.01.20 8420
27 대학원생 생활 가이드 [퍼온글] 송홍엽 2007.10.11 8464
26 [펀글] 조선일보 1월2일 사설: 교육개혁 송홍엽 2008.01.03 3037
25 [펀글] 교육의 의미 송홍엽 2008.02.19 3021
24 [펀글] 한반도 운하 건설을 반대하며 송홍엽 2008.02.20 3347
23 [펀글] 추장의 선언 [1] 송홍엽 2008.02.22 7983
22 암호이야기 송홍엽 2008.05.21 3096
21 우리학부 전공 2-3학년생에 대한 조언 송홍엽 2008.05.22 3949
20 글 잘 쓰는 이공계가 성공한다 송홍엽 2008.05.22 27700
19 [펀글] 전화기를 최초로 발명한 사람은 누구인가 송홍엽 2008.05.23 6992
18 수학사 바로잡기 (1) - 오일러의 36명 장교문제와 조선시대 최석정 (수정본 - 일부 오류 수정) [1] file 송홍엽 2008.06.03 7281
17 수학사 바로잡기 (2) 송홍엽 2008.06.03 7895
16 수학사 바로잡기 (3) - 월간 과학동아 2008년 7월호 강석기 기자의 글 송홍엽 2008.06.20 4326
15 김정한 교수의 '창의적 수학교육' [1] file 송홍엽 2008.06.20 6147
14 [펀글]수학의 open problems 모음. 송홍엽 2008.07.30 15215
13 움직이는 글자 태그 송홍엽 2008.09.04 3921
12 [퍼온글] FM방식 개발한 암스트롱 송홍엽 2008.09.24 4146
11 [퍼온글] 해석학적 극한의 의미 송홍엽 2008.12.18 4113
10 [퍼온글] 수학의 힘 -- 동아일보 컬럼 2008.12.18 송홍엽 2008.12.18 3805