# On the Secure Energy Efficiency of TAS/MRC with Relaying and Jamming Strategies (Extended Version)

## TL;DR

This paper analyzes the secure energy efficiency of TAS/MRC strategies with relaying and jamming in multi-antenna cooperative networks, comparing schemes and optimizing antenna use under secrecy constraints.

## Contribution

It introduces a SEE maximization framework with CSI-based power and secrecy rate allocation, comparing AN and CSI-DF schemes in multi-antenna cooperative scenarios.

## Key findings

- CSI-DF generally outperforms AN in SEE.
- Optimal number of antennas balances secure throughput and power.
- Eavesdropper proximity affects scheme performance.

## Abstract

In this paper we investigate the secure energy efficiency (SEE) in a cooperative scenario where all nodes are equipped with multiple antennas. Moreover, we employ secrecy rate and power allocation at Alice and at the relay in order to maximize the SEE, subjected to a constraint in terms of a minimal required secrecy outage probability. Only the channel state information (CSI) with respect to the legitimate nodes is available. Then, we compare the Artificial-Noise (AN) scheme with CSI-Aided Decode-and-Forward (CSI-DF), which exploits the CSI to choose the best communication path (direct or cooperative). Our results show that CSI-DF outperforms AN in terms of SEE in most scenarios, except when Eve is closer to the relay or with the increase of antennas at Eve. Additionally, we also show that the maximization of SEE implies in an optimal number of antennas to be used at each node, which is due to the trade-off between secure throughput and power consumption.