Chaotic Spreading Sequence for Spread Spectrum Modulation in Stochastic Wireless Channels

Abstract

In wireless communication system, spread spectrum techniques have been widely used because of the advantages like robustness against interference and noise, low probability of intercept, realization of Code Division Multiple Access (CDMA) and so on. One of the key aspects in such methods is the generation of the spreading sequence which continues to be challenging issue. This paper proposes a scheme for generating binary sequences from chaotic logistic map for use in Direct Sequence Spread Spectrum (DS SS) system in fading environment. The main advantages of such usage are increased security of the data transmission and ease of generation of a extended numbers of chaotic sequences. Generally to spread the bandwidth of the transmitting signals, pseudo-noise (PN) sequences, Gold sequences have been used extensively. We have generated a binary spreading sequences using logistic map. A comparison between Gold sequences and proposed sequences in faded environment have been derived. It is clearly seen that our sequences are comparable and even superior to Gold sequences in several key aspects such as bit error rate (BER), computational time and mutual information for three different spreading code lengths. Therefore, the proposed sequences can be effectively used as spreading sequences in high data rate modulation schemes.

Keywords: Logistic map code, Gold code, BER, DS SS.

Cite as: Katyayani Kashyap, Manash Pratim Sarma, Kandarpa Kumar Sarma, “Chaotic Spreading Sequence for Spread Spectrum Modulation in Stochastic Wireless Channels†ADBU J.Engg.Tech., 1(2014) 0011402(5pp)