Software Defined Waveform for Interference Mitigation in Integrated Satellite-Terrestrial Networks

Despite remarkable strides in communication performance achieved by terrestrial networks, their high-cost deployments pose significant barriers to extending coverage in remote regions. The sixth generation mobile communication system aspires to realize ubiquitous connectivity; yet, the acute scarcity of spectrum resources renders integrated satellite-terrestrial networks (ISTNs) vulnerable to interference challenges during spectrum sharing. This article categorizes various interference phenomena encountered within ISTNs and delineates the corresponding mitigation methods from the dual perspectives of processing location and domain. Existing interference mitigation techniques remain constrained by scenario dependency, exhibiting limited scalability and adaptability when confronted with inherently open environments, difficulties in updates, and stringent payload limitations of ISTNs. To address these obstacles, we propose software defined waveform (SDW). Following an exposition of boundaries of software and hardware components, triggering mechanisms, and a strategic framework underpinned by knowledge graph, we design and simulate two reconfigurable waveforms as cases, namely generalized orthogonal frequency division multiplexing and generalised 2-D modulation, thereby substantiating the effectiveness of SDW. The article concludes with analyses and discussions of the prospective advantages and issues of our proposal.