Performance Analysis Methods for Coherent Chaos-Shift-Keying Systems

In this chapter we begin our formal study of chaos-based digital communication systems. The areas of investigation to be described here include the operation, analysis and performance evaluation of communication systems that employ chaotic signals for carrying digital information. As surveyed in the previous chapter, the most widely studied chaos-based digital communication systems are the so-called chaos-shift-keying (CSK) system [Dedieu et al. (1993)] and the differential chaos-shift-keying (DCSK) system [Kolumbán et al. (1996)]. In this chapter we focus our attention on the CSK system, in which digital symbols are encoded with different chaotic signals. In the binary case, the CSK transmitter essentially transmits two chaotic signals which are derived from two chaos generating sources, one at a time, according to the binary signal being sent. Clearly, the receiver is able to demodulate the transmitted signal if it can distinguish between the chaotic signal segments generated from the two chaos generators. Alternatively, the transmitted signal may be generated from one chaos generator in which a parameter is modulated according to the binary signal being sent. In this case, the receiver’s job is to work out the parametric change by observing the transmitted signal.