Secure upgraded spatial modulation for wireless transmission systems

Physical layer security (PLS) is gaining traction as a potent supplement, if not a complete replacement for encryption-based secure communication systems. The PLS strategy with secret key generation using physical signatures and a novel spatial modulation technique is presented. In this paper, a chaotic theory-based secret key generation method and an upgraded spatial modulation (USM) method with multiple amplitude and phase keying signal constellations are proposed, which ensures secure communication and improves spectral efficiency. The four security levels built into USM are (i) secret key generation, (ii) adaptive selection, (iii) mapping table shuffling, and (iv) transmit vector rotation. The proposed work is compared with other conventional techniques in terms of key strength, spectral efficiency, energy efficiency, and secrecy, and the BER performance of USM has a significant improvement over existing techniques.