Filtered-OFDM - Enabler for Flexible Waveform in The 5th Generation Cellular Networks

TL;DR

This paper introduces filtered-OFDM (f-OFDM), a flexible waveform technique for 5G networks that improves spectrum efficiency by allowing different services to use tailored waveforms in separate subbands.

Contribution

The paper presents the design and advantages of f-OFDM, enabling diverse service requirements and demonstrating significant throughput gains over traditional OFDM in 5G.

Findings

f-OFDM achieves up to 46% throughput improvement.

Allows different waveforms for different services.

Enhances spectrum utilization in 5G networks.

Abstract

The underlying waveform has always been a shaping factor for each generation of the cellular networks, such as orthogonal frequency division multiplexing (OFDM) for the 4th generation cellular networks (4G). To meet the diversified and pronounced expectations upon the upcoming 5G cellular networks, here we present an enabler for flexible waveform configuration, named as filtered-OFDM (f-OFDM). With the conventional OFDM, a unified numerology is applied across the bandwidth provided, balancing among the channel characteristics and the service requirements, and the spectrum efficiency is limited by the compromise we made. In contrast, with f-OFDM, the assigned bandwidth is split up into several subbands, and different types of services are accommodated in different subbands with the most suitable waveform and numerology, leading to an improved spectrum utilization. After outlining the general framework of f-OFDM, several important design aspects are also discussed, including filter design and guard tone arrangement. In addition, an extensive comparison among the existing 5G waveform candidates is also included to illustrate the advantages of f-OFDM. Our simulations indicate that, in a specific scenario with four distinct types of services, f-OFDM provides up to 46% of throughput gains over the conventional OFDM scheme.