Communication Signal Design Lab.

한국어

송홍엽 교수의 잡글

SHANNON : CRACKING THE CHANNEL

2004.04.13 06:18

송홍엽 조회 수:13961 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 8898
공지 젊은 학부생 여러분에게... 송홍엽 2008.11.20 5946
공지 우리학과 대학원생 모두에게 (특히, 박사과정들에게) 하고싶은 말입니다. 송홍엽 2014.01.20 6747
89 [퍼온글] 우리전공의 학부생이 공부하면 좋을 수학과목 ?? 송홍엽 2003.03.23 6167
88 지금 내 전공분야는 공부한던 시절엔 나에게 가장 힘든 분야였답니다... 송홍엽 2003.06.03 4867
87 벡터공간이란 무엇일까.. 송홍엽 2003.10.06 13975
86 유클리디안 n차원 벡터공간 (and Online-HW1) 송홍엽 2003.10.06 7356
85 basis란.. (and Online-HW2) 송홍엽 2003.10.06 63193
84 디지털 이야기... 송홍엽 2003.10.06 3310
83 하다마드 행렬에 대해서 (part 1) [1] 송홍엽 2003.10.06 10266
82 [일반인을 위한 교양강좌] CDMA 통신기술 (2001.7) 송홍엽 2003.10.13 3534
81 채널코딩에 관한 첫번째 이야기 송홍엽 2003.10.13 4742
80 쉬었다가는 페이지 file 송홍엽 2003.10.20 3694
79 채널코딩 둘째이야기... 송홍엽 2003.11.12 5974
78 채널코딩 세째 이야기 송홍엽 2003.11.13 4988
77 Dr. Shannon 송홍엽 2003.12.07 14993
76 [공지] 게시판을 열면서 송홍엽 2004.03.30 3754
75 funny story 송홍엽 2004.04.01 11921
74 [퍼온글] 달력의 유래 송홍엽 2004.04.01 5189
73 유명한 퍼즐1 송홍엽 2004.04.01 3455
72 Golomb-Puzzle 2003.12 file 송홍엽 2004.04.02 3603
71 DMS와 정보량 송홍엽 2004.04.04 3487
70 수집합이란... 송홍엽 2004.04.13 3583