chapter  12
18 Pages

Coding Theory

WithWalter D. Wallis, John C. George

Suppose you want to send an e-mail message to a friend. Your message may be an ordinary string of English words, but your computer can only send electronic messages. So a program is used to convert your words into a string of instances of two states, “power on” and “power off.” For our convenience let’s write 1 for “power on” and 0 for “power off”; your message no longer looks like “Let’s meet for lunch,” but something like 100110110011000011011100010110011011100010110011011001001011000 .