Multicarrier Spread Spectrum for Mega-Constellation Satellite Networks: Challenges, Opportunities, and Future Trends

With the emerging concept of satellite mega-constellations (SatCons), connections are about to become faster and broader, building an engine to boost innovation and productivity for every industry. In the following decades, over a hundred of SatCons with enormous application potentials are on the cusp of deployment, and their long-term success hinges on reliable information exchanges. We identify the renascent multicarrier spread spectrum (MCSS) paradigm of sufficient spectral flexibility as the most effective and reasonable candidate for such issues. This article first sheds light on possible use cases for MCSS in SatCons, such as navigation-communication-telecontrol integration, physical-layer security, and intelligent anti-jamming. It also enlightens opportunities by virtue of the many benefits that MCSS may offer, and highlights major challenges encountered during its utilization. Finally, insights into future trends are provided. This article could support system designers in finding the right optimization priorities for future SatCons.

I. Introduction

The recent vigorous development of 5G, cloud computing, artificial intelligence (AI), and machine learning promises to enable a surge in the number of networked end users, stimulating an unprecedented need for ubiquitous access worldwide [1]. The COVID-19 pandemic magnified this urgency, as more and more economic, social, and educational activities are occurring online [2]. Toward this end, 5G provides rich service support and guaranteed quality of service (QoS) to sustain usage scenarios with vastly heterogeneous demands, such as enhanced Mobile Broadband (eMBB), massive Machine-Type Communications (mMTC), and ultrareliable low-latency communications (URLLC) [3], [4].