Outage Probability of Dual-Hop Multiple Antenna AF Relaying Systems with Interference

TL;DR

This paper analytically evaluates the outage probability of dual-hop multiple antenna AF relaying systems with interference, comparing fixed-gain and variable-gain schemes and highlighting the impact on diversity order.

Contribution

It derives exact and approximate outage probability expressions for both relaying schemes and characterizes their diversity orders under interference conditions.

Findings

Variable-gain relaying outperforms fixed-gain in outage probability.

Fixed-gain relaying achieves a diversity order of one.

The diversity order of variable-gain relaying depends on antenna placement.

Abstract

This paper presents an analytical investigation on the outage performance of dual-hop multiple antenna amplify-and-forward relaying systems in the presence of interference. For both the fixed-gain and variable-gain relaying schemes, exact analytical expressions for the outage probability of the systems are derived. Moreover, simple outage probability approximations at the high signal to noise ratio regime are provided, and the diversity order achieved by the systems are characterized. Our results suggest that variable-gain relaying systems always outperform the corresponding fixed-gain relaying systems. In addition, the fixed-gain relaying schemes only achieve diversity order of one, while the achievable diversity order of the variable-gain relaying scheme depends on the location of the multiple antennas.