For the coverage enhancement problem in the scenario of direct-to-satellite service,this paper gives solutions from limited link aspect and wide coverage aspect,studying a series of key technologies including signal repetition transmission,multi-slot joint channel estimation,reference signal power increasing,high gain antenna,beam splitting,beam hopping,power allocation and service-based dynamic resource allocation.For each key technology,this paper analyzes from following three aspects:theoretical analysis,performance evaluation,impact on specification and optimization ideas.Studies show that repeated transmission can directly and effectively improve the link budget performance,but for time-domain resource-constrained scenarios,multi-slot joint channel estimation technology and reference signal power enhancement can provide limited link budget gain.System-level coverage enhancement relies on the beam management to flexibly schedule on-board resources from multiple dimensions to achieve wide-area coverage enhancement.
维普
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