PLS-IoT Enhancement against Eavesdropping via Spatially Distributed Constellation Obfuscation

Wireless communication has become a ubiquitous facet of modern-day life. With the advent of Internet of Things (IoT) and massive machine-type connectivity, the number of devices is expected to increase even more. However, increased dependence on wireless connectivity is marred with risks related to user privacy and data confidentiality, especially for low-power IoT devices. Therefore, it is imperative to provide an extremely reliable secure algorithm with minimal complexity and computational expense in IoT paradigm. With that in mind, this letter presents asymmetric multi-level physical layer security (PLS) scheme, in which each transmitted symbol undergoes two types of distortion: channel-based phase distortion and multi-reception amplitude randomization. The proposed scheme offers a substantial security advantage for legitimate links, while also streamlining receiver design. Numerical results indicate that the scheme effectively confounds eavesdroppers without compromising the bit error rate of the intended receiver. Additionally, the proposed scheme provides another level of security by concealing the modulation information, requiring the receiver to detect the modulation scheme before detecting transmitted symbols.