Secure Index with OFDM-IM-based Chaotic System

Abstract

Orthogonal Frequency Division Multiplexing-Index Modulation (OFDM-IM) based on chaos is a com- munication technique that uses chaotic systems to enhance the security of OFDM-IM systems. In this technique, chaotic signals are used to modulate the index values of the subcarriers and the data using DCSK, resulting in a more robust and efficient transmission. OFDM-IM uses the activated index as an information-carrying unit, which increases data rate and spectral efficiency. In this paper, we propose a secure index strategy for our system using a logistic map and Henon map to generate the chaotic signals, considering additive white Gaussian noise (AWGN) and the Raleigh fading channel. A lookup table based on the chaotic system was created using the indices of a randomized index modulation scheme with DCSK modulation. Even if the active subcarriers and their symbols are correctly calculated until the opening frame, the randomized index modulation prevents eavesdroppers from accurately determining message bits.