# Hybrid Spatio-Temporal Artificial Noise Design for Secure MIMOME-OFDM Systems

## TL;DR

This paper proposes a hybrid spatio-temporal artificial noise scheme for secure MISO-OFDM systems, deriving closed-form secrecy rate expressions and optimizing power allocation to enhance security against passive eavesdroppers.

## Contribution

It introduces a novel hybrid artificial noise design in both spatial and temporal domains for secure wireless communication, with analytical secrecy rate formulas and power allocation strategies.

## Key findings

- Closed-form secrecy rate expressions derived for large antenna systems
- Optimized power allocation improves secrecy performance
- Simulation results validate the effectiveness of the proposed scheme

## Abstract

This paper investigates artificial noise injection into the temporal and spatial dimensions of a legitimate wireless communication system to secure its transmissions from potential eavesdropping. We consider a multiple-input single-output (MISO) orthogonal frequency division multiplexing (OFDM) system in the presence of a single-antenna passive eavesdropper and derive both the secrecy rate and average secrecy rate of the legitimate system. It is assumed that the legitimate transmitter knows the full channel information of the legitimate transceivers but does not know the instantaneous channel state information of the passive eavesdropper. Closed-form expressions for the secrecy rate and average secrecy rate are derived for the asymptotic case with a large number of transmit antennas. We also investigate 1) the power allocation between the data and the AN; 2) the power allocation between the spatial and the temporal AN. Computer simulations are carried out to evaluate the performance of our proposed artificial noise scheme.