Coexistence of OFDM and FBMC for Underlay D2D Communication in 5G Networks

TL;DR

This paper compares OFDM and FBMC/OQAM waveforms for asynchronous D2D communication in 5G networks, showing FBMC/OQAM's advantages in reducing interference in dense, edge-located clusters.

Contribution

It demonstrates the benefits of using FBMC/OQAM over OFDM for interference mitigation in asynchronous D2D underlay scenarios in 5G networks.

Findings

FBMC/OQAM significantly reduces inter-D2D interference.

Resource allocation is simplified with FBMC/OQAM.

FBMC/OQAM is optimal for small, dense D2D clusters near cell edges.

Abstract

Device-to-device (D2D) communication is being heralded as an important part of the solution to the capacity problem in future networks, and is expected to be natively supported in 5G. Given the high network complexity and required signalling overhead associated with achieving synchronization in D2D networks, it is necessary to study asynchronous D2D communications. In this paper, we consider a scenario whereby asynchronous D2D communication underlays an OFDMA macro-cell in the uplink. Motivated by the superior performance of new waveforms with increased spectral localization in the presence of frequency and time misalignments, we compare the system-level performance of a set-up for when D2D pairs use either OFDM or FBMC/OQAM. We first demonstrate that inter-D2D interference, resulting from misaligned communications, plays a significant role in clustered D2D topologies. We then demonstrate that the resource allocation procedure can be simplified when D2D pairs use FBMC/OQAM, since the high spectral localization of FBMC/OQAM results in negligible inter-D2D interference. Specifically, we identify that FBMC/OQAM is best suited to scenarios consisting of small, densely populated D2D clusters located near the encompassing cell's edge.