Spread Spectrum Communication System with Particle in a Box Electronic Circuit

Abstract

A spread spectrum communication system based on the electronic model of the particle in a box system is proposed. This circuit allows a robust and simple electronic emulation of the mechanical behavior of the collisions of a particle inside a box, exhibiting rich chaotic behavior. The required nonlinearity to emulate the box walls is implemented in a simple way when compared with other analog electronic chaotic circuits. In this system, binary data stream information 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 send 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 synchronized by a phase lock 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 information was sent through a transmission channel with the following lengths: 1000 meters and 5000 meters. The experimental results demonstrated that the particle in a box electronic circuit can be used in a spread spectrum communication system.