Practical Demonstration of 5G NR Transport Over-Fiber System with Convolutional Neural Network

Muhammad Usman Hadi

doi:10.3390/telecom3010006

Abstract

This study describes an experimental realization using digital predistortion (DPD) for a fifth generation (5G) multiband new radio (NR) optical front haul (OFH) based Radio over Fiber (RoF) link. For the performance enhancement and complexity reduction of RoF links, a novel Convolutional Neural Network (CNN) based DPD technique is proposed, followed by comparisons with the generalised memory polynomial (GMP) based DPD method. To support enhanced mobile broad band scenario, the experimental testbed uses the 5G NR waveforms at 10 GHz with 20 MHz bandwidth and a flexible-waveform signal at 3 GHz with 20 MHz bandwidth. For 10 km of typical single mode fiber, a Mach Zehnder Modulator with two distinct radio frequency waveforms modulates a 1310 nm optical carrier utilizing distributed feedback laser. The error vector magnitude and number of estimated coefficients, and multiplications are all used to describe the experimental outcomes. The goal of the research is to see if CNN-based DPD improves performance while lowering complexity levels to meet 3GPP Release 17 criteria.

Highlights

Over-Fiber System withWith major developments in the fifth generation known as 5G and beyond 5G, the centralization of radio access network (RAN) has been established due to the ever increasing rate of base stations (BS) [1], which decreases capital expenditure by simplifying network management [2]
We have developed a foundation of all components of a Convolutional Neural Network (CNN), the digital predistortion (DPD) CNN, which was used to distort the Radio over Fiber (RoF) system, and the replicated RoF CNN, which is needed for was used to distort the RoF system, and the replicated RoF CNN, which is needed for training this DPD CNN, based on the conversation so far
Magnitude Selective Affine (MSA) DPD methods results are used to compare with our proposed CNN method

Summary

Introduction

With major developments in the fifth generation known as 5G and beyond 5G, the centralization of radio access network (RAN) has been established due to the ever increasing rate of base stations (BS) [1], which decreases capital expenditure by simplifying network management [2]. An optical fronthaul (OFH/FH) connects the base band units (BBU) to remote radio heads (RRH) to facilitate C-RAN (see Figure 1). Due to unlimited benefits and increase in wireless link reach for all kinds of applications such as short to long link applications, microwave photonics-based solutions such as Radio over Fiber (RoF). A-RoF links are, to some extent, the simplest and most cost-effective option; they suffer from nonlinearities generated from signal impairments and components such as laser modules, fiber, and photodiodes. Using D-RoF or SD-RoF is one of the alternative options

Objectives

Results

Conclusion