Performance Comparison of Hybrid Chaotic Maps Based on Speech Scrambling for OFDM Techniques

Abstract

This paper presents a speech encryption model that uses two different chaotic maps (Hennon and Logistic maps) based on the OFDM technique. The purpose of using the encrypted chaotic key in OFDM techniques is to improve the Bit Error Rate (BER) performance in receiver side which has robustness against AWGN effects, thus increasing the security of data transmitted. In the last few years, a significant research effort has been devoted, concerning secret chaotic key as compared with the conventional OFDM modulation schemes. Chaotic maps have a wideband, non-periodic, unpredictable nature, very sensitive to initial conditions; so chaotic map is used for security. This paper uses two chaotic maps Logistic & Hennon each individually to create encrypted undercover keys and compares a model performance between them. The comparison showed that the performance is similar to the two chaotic maps with a minimal difference between them (After SNR=16 dB the BER=10-3). As for residual Intelligibility Measurements, they are very close and there is little difference in the limits (0.01-0.1) for R, SSNR and CD test. The suggested model has been carried out by employing MATLAB by utilizing SIMULINK (R2018b). Execution of this program is studied, the outcomes are good.