How Codes Work: The Receiver End In order for the output of the receiver to be identical to the original data, the following relationship must be true: d(t) · c(t) · c(t)=d(t) In other words, c(t) · c(t) must be equal to unity. Note that c(t) is a binary sequence made up of +1s and -1s. Therefore: If c(t) is +1, c(t) · c(t) is equal to +1 If c(t) is -1, c(t) · c(t) is also equal to +1 Since c(t) · c(t) is equal to +1, the condition d(t) · c(t) · c(t) = d(t) is met. Therefore the output of our simple receiver is the recovered original data d(t). CODE: AN INTRODUCTION By Dr. Ernest Simo © 1999 DR. ERNEST SIMO - SPACE2000