# Incremental selective decode-and-forward relaying for power line communication

## TL;DR

This paper introduces an incremental selective decode-and-forward relay strategy for power line communication systems that enhances spectral efficiency by only using the relay when necessary, and provides analytical expressions for key performance metrics.

## Contribution

The paper proposes a novel ISDF relay strategy for PLC that improves spectral efficiency and derives closed-form expressions for outage probability and BER.

## Key findings

- Relay usage fraction is significantly reduced.
- Spectral efficiency increases with higher transmit power.
- Average BER decreases as the required rate increases.

## Abstract

In this paper, an incremental selective decode-and-forward (ISDF) relay strategy is proposed for power line communication (PLC) systems to improve the spectral efficiency. Traditional decode-and-forward (DF) relaying employs two time slots by using half-duplex relays which significantly reduces the spectral efficiency. The ISDF strategy utilizes the relay only if the direct link quality fails to attain a certain information rate, thereby improving the spectral efficiency. The path gain is assumed to be log-normally distributed with very high distance dependent signal attenuation. Furthermore, the additive noise is modeled as a Bernoulli-Gaussian process to incorporate the effects of impulsive noise contents. Closed-form expressions for the outage probability and the fraction of times the relay is in use, and an approximate closed-form expression for the average bit error rate (BER) are derived for the binary phase-shift keying signaling scheme. We observe that the fraction of times the relay is in use can be significantly reduced compared to the traditional DF strategy. It is also observed that at high transmit power, the spectral efficiency increases while the average BER decreases with increase in the required rate.