A Robust Covert Communication Framework Using Tunable Q-Factor Wavelet Transform

Abstract

Covert communication aims to transmit information in such a manner that the very existence of the communication remains concealed from unauthorized observers. With the rapid growth of digital multimedia transmission and surveillance technologies, designing robust and imperceptible covert communication schemes has become increasingly critical. This paper presents a robust covert communication framework based on the Tunable Q-Factor Wavelet Transform (TQWT). The proposed framework exploits the flexible time–frequency resolution of TQWT to embed covert information adaptively into host signals while maintaining high imperceptibility and resistance against detection and signal processing attacks. The embedding strategy leverages subband energy modulation and adaptive coefficient selection governed by statistical characteristics of the host signal. Extensive experimental analysis demonstrates that the proposed framework achieves superior performance in terms of imperceptibility, robustness, and payload capacity when compared with conventional wavelet-based covert communication techniques.