Chapter 3
Multidimensional Optical Modulations
3.1 Introduction
One of the elements needed for information transmission is the code. The choice of the transmission code is closely linked to channel characteristics and to the signals used to transmit information through the channel but is also linked to some desired features of transmitter and receiver. A code is a set of code words or symbols that make up the alphabet with which information is represented. More precisely, referring to the model proposed by Shannon [1], the transmitter contains a code book with M different code words. Each code word is a sequence of n real numbers which can be regarded as a point X{x1,x2,..xn} in a Euclidean space S of n dimensions.
Some characteristics ...
