Communicating with chaos using two-dimensional symbolic dynamics

Symbolic representations of controlled chaotic orbits produced by signal generators can be used for communicating. In this Letter, communicating with chaos is investigated by using more realistic dynamical systems described by two-dimensional invertible maps. The major difficulty is how to specify a generating partition so that a good symbolic dynamics can be defined. A solution is proposed whereby hyperbolic chaotic saddles embedded in the attractor are exploited for digital encoding. Issues addressed include the channel capacity and noise immunity when these saddles are utilized for communication.