Application of the particle in a box electronic circuit in a spread spectrum communication system

A spread spectrum communication system based on the electronic model of the particle in a box system is proposed. This electronic system allows a robust and simple electronic emulation of the mechanical behaviour of the collisions of a particle inside a box, exhibiting rich chaotic behaviour. The required non-linearity to emulate the box walls is implemented in a simple way when compared with other analogue electronic chaotic circuits. In this system, a stream of binary data is transformed in the frequency modulated signal by the binary frequency shift keying (BFSK) modulator. The chaotic signal of the particle in a box electronic circuit is used to generate a broadband signal in the voltage controlled oscillator (VCO) of the transmitter. The frequency hopping signal sent to receiver is generated by mixing the binary frequency shift keying and the broadband signal. The demodulation process is done when the VCOs of transmitter and receiver are synchronised by a phase locked loop (PLL) circuit. The performance of the demodulation process is verified through the eye pattern technique applied on the recovered bit stream. A binary data stream was sent through a transmission channel with the following lengths: 2,000 metres and 8,000 metres. The experimental results demonstrated that the particle in a box electronic circuit can be used in a spread spectrum communication system.