# How to Scale Up the Spectral Efficiency of Multi-way Massive MIMO Relaying?

## TL;DR

This paper introduces a new multi-way massive MIMO relay protocol that significantly improves spectral efficiency by using successive cancelation decoding and zero-forcing, nearly doubling the performance of conventional methods.

## Contribution

A novel transmission protocol for multi-way massive MIMO that reduces time-slots and doubles spectral efficiency using successive cancelation decoding and zero-forcing.

## Key findings

- Nearly double the spectral efficiency compared to conventional schemes.
- Uses only half the time-slots of traditional methods.
- Provides a tight analytical approximation of spectral efficiency.

## Abstract

This paper considers a decode-and-forward (DF) multi-way massive multiple-input multiple-output (MIMO) relay system where many users exchange their data with the aid of a relay station equipped with a massive antenna array. We propose a new transmission protocol which leverages successive cancelation decoding and zero-forcing (ZF) at the users. By using properties of massive MIMO, a tight analytical approximation of the spectral efficiency is derived. We show that our proposed scheme uses only half of the time-slots required in the conventional scheme (in which the number of time-slots is equal to the number of users [1]), to exchange data across different users. As a result, the sum spectral efficiency of our proposed scheme is nearly double the one of the conventional scheme, thereby boosting the performance of multi-way massive MIMO to unprecedented levels.