Application-Based Coexistence of Different Waveforms on Non-Orthogonal Multiple Access

Mehmet Mert Sahin,Huseyin Arslan

doi:10.1109/ojcoms.2020.3044680

Abstract

In the study, the coexistence of different waveform structures on the same resource element is studied under the theory of non-orthogonal multiple access (NOMA). This study introduces a paradigm-shift on NOMA towards the application-centric waveform coexistence. Throughout this article, the coexistence of different waveforms is explained with two specific use cases, which are power-balanced NOMA and joint radar-sensing and communication with NOMA. For the first use case, block error rate (BLER) performance in the power-balanced regime for two user is improved compared to conventional NOMA transmission with the same waveform. For the joint radar-sensing and communication aspect, the superiority of proposed NOMA scheme over orthogonal frequency division multiplexing (OFDM) joint radar-communication (JRC) scheme is demonstrated regarding radar ambiguity, channel estimation mean-square error (MSE) and bit-error rate (BER) performances. In addition, some of the previous works in the literature are reviewed regarding waveform coexistence in a non-orthogonal manner. However, the concept is not limited to these use cases. With the rapid development of wireless technology, next-generation wireless systems are proposed to be flexible and hybrid, having different kinds of capabilities such as sensing, security, intelligence, control, and computing. Therefore, the concept of different waveforms’ coexistence to meet these concerns are becoming impressive for researchers.

Highlights

T HE IDEA of serving multiple users in the same wireless resources, including frequency, time, code, and space, has become an appealing research area over almost thirty years
In LTE, the downlink non-orthogonal multiple access (NOMA) scheme, called multi-user superposition transmission (MUST), was studied for the 3rd Generation Partnership Project (3GPP) Release 14 [2], whose motivation is weak in 5G, because higher performance gains can be provided with downlink massive multiple-input multiple-output (MIMO) [3]
This article aims to introduce the concept called applicationbased waveform-domain coexistence on NOMA to meet wide variety of applications proposed in 5G, 6G and beyond wireless networks

Summary

INTRODUCTION

T HE IDEA of serving multiple users in the same wireless resources, including frequency, time, code, and space, has become an appealing research area over almost thirty years. With rapid developments in hardware such as large antenna arrays for millimeter wave (mmWave) and THz frequencies, efficient amplifiers, and ultra-capable digital signal processing (DSP) chips; and software regarding algorithms for detection and estimation capabilities, radar and communication systems tend to intersect in order to provide efficient usage of radio resources Combining these two different worlds to work in harmony will pave the way for new techniques in wireless technologies that may enable lots of promising applications in wireless technologies to emerge [8]. The other use case is the implementation of the proposed NOMA concept including frequency modulated continuous-wave (FMCW) and OFDM waveforms in joint radar-sensing and communication, which is presented in [18]. Two different use cases, which are power-balanced NOMA and joint radar-sensing and communication is studied in the view of waveform coexistence on the same resources.

PREVIOUS WORKS

CONVENTIONAL POWER-DOMAIN NOMA WITH

CONCLUSION