# On the Performance of Ultra-Reliable Decode and Forward Relaying Under the Finite Blocklength

## TL;DR

This paper analyzes the outage probability of decode-and-forward relaying protocols with finite blocklength over Rayleigh fading channels, providing closed-form expressions and comparing their ultra-reliable performance to direct transmission.

## Contribution

It derives closed-form outage probability expressions for three DF relaying protocols with finite blocklength in Rayleigh fading channels, highlighting their ultra-reliable performance advantages.

## Key findings

- Cooperative relaying can outperform direct transmission in outage probability.
- Closed-form expressions enable precise performance analysis.
- Relaying protocols show improved ultra-reliable communication performance.

## Abstract

In this paper, we examine the performance of the decode-and-forward (DF) relaying protocols with finite blocklength (FB). We provide the overall outage probability of three distinct DF relaying protocols, where the channels are assumed to be quasi static Rayleigh fading. More importantly, we derive the closed form expressions of the outage probability in the three relaying scenarios. We illustrate protocols where the cooperative communications outperform the direct transmission (DT). In addition, we compare the operating efficiency of the cooperative schemes in the ultra-reliable (UR) region.