Cellular Systems with Full-Duplex Compress-and-Forward Relaying and Cooperative Base Stations

TL;DR

This paper investigates a multicell relay system with full-duplex relays using a compress-and-forward scheme, demonstrating it can eliminate inter-relay interference and outperform amplify-and-forward methods in cellular networks.

Contribution

It introduces a novel distributed compress-and-forward scheme for full-duplex relay-assisted cellular systems and derives the achievable sum-rate as a fixed point solution.

Findings

CF scheme eliminates inter-relay interference

Achieves rates close to the cut-set upper bound for strong relay power

Outperforms amplify-and-forward schemes in numerical evaluations

Abstract

In this paper the advantages provided by multicell processing of signals transmitted by mobile terminals (MTs) which are received via dedicated relay terminals (RTs) are studied. It is assumed that each RT is capable of full-duplex operation and receives the transmission of adjacent relay terminals. Focusing on intra-cell TDMA and non-fading channels, a simplified relay-aided uplink cellular model based on a model introduced by Wyner is considered. Assuming a nomadic application in which the RTs are oblivious to the MTs' codebooks, a form of distributed compress-and-forward (CF) scheme with decoder side information is employed. The per-cell sum-rate of the CF scheme is derived and is given as a solution of a simple fixed point equation. This achievable rate reveals that the CF scheme is able to completely eliminate the inter-relay interference, and it approaches a ``cut-set-like'' upper bound for strong RTs transmission power. The CF rate is also shown to surpass the rate of an amplify-and-forward scheme via numerical calculations for a wide range of the system parameters.