Pseudorandom Sequences in Spread-Spectrum Communications Generated by Cellular Automata

Abstract

Dynamical systems methods have been recently used in spread-spectrum digital communication systems. Theexpansion of the spectrum using a pseudorandom sequence with a higher frequency than the information signal is thekey feature for its robustness against the signal traveling interference through the channel. In this work, we propose togenerate pseudorandom sequences by employing cellular automata and we check these sequences have thenecessary properties which are required in modern communication systems. The computed sequences obtained bythe cellular automata are tested in a quadrature phase shift keying (QPSK) spread-spectrum communication system.The efficiency of the system is analyzed by computing the bit error rate under different signal to noise ratio conditions.These results are compared with systems that employ Golden code and other typical pseudorandom sequences.