Constructive Interference Based Secure Precoding: A New Dimension in Physical Layer Security

TL;DR

This paper introduces a novel secure precoding method that exploits constructive interference to enhance signal quality at the intended receiver while confusing eavesdroppers, improving power efficiency and security in MISO wiretap channels.

Contribution

It proposes a new constructive interference-based artificial noise precoding scheme for secure communications with both perfect and imperfect channel knowledge.

Findings

Reduces total transmit power compared to conventional schemes

Achieves lower symbol error rate at the intended receiver

Enhances security by disrupting eavesdroppers' reception

Abstract

Conventionally, interference and noise are treated as catastrophic elements in wireless communications. However, it has been shown recently that exploiting known interference constructively can even contribute to signal detection ability at the receiving end. This paper exploits this concept to design artificial noise (AN) beamformers constructive to the intended receiver (IR) yet keeping AN disruptive to possible eavesdroppers (Eves). The scenario considered here is a multiple-input single-output (MISO) wiretap channel with multiple eavesdroppers. Both perfect and imperfect channel information have been considered. The main objective is to improve the receive signal-to-interference and noise ratio (SINR) at IR through exploitation of AN power in an attempt to minimize the total transmit power, while confusing the Eves. Numerical simulations demonstrate that the proposed constructive AN precoding approach yields superior performance over conventional AN schemes in terms of transmit power as well as symbol error rate (SER).