Inter-Numerology Interference Reduction Based on Precoding for Multi-Numerology OFDM Systems

Multi-numerology OFDM systems are a promising technique to multiplex various services and requirements for 5G and beyond. Multiplexing of multiple numerologies in a single frequency band causes the system to lose orthogonality. Due to this, a new kind of interference is introduced into the system known as inter-numerology interference (INI). In this paper, an efficient INI mitigating technique based on precoding is proposed. Simulation results show that with the proposed method, a significant reduction in INI is achieved and overall system performance is improved for multi-numerology OFDM systems.

I. Introduction

Fifth-generation (5G) is not only a mere evolution of mobile broadband. It aims to provide seamless internet connection in high mobility conditions such as trains and continuous connections in highly /sparsely populated areas. Internet of things (IoT) requires a large number of sensors connected to the network by consuming less energy, which can be enabled by 5G. It also aims to cater to some critical services like health care systems, which require low latency and high reliability. 5G aims at 1000-fold increase in mobile data volume and number of connected devices, 100-fold increase in data peak, 10-fold decrease in energy consumption and 5-fold decrease in end-to-end latency [1]. The existing network may have to go through changes in multiple magnitudes in order to achieve these targets.