OFDMA-Based Unsourced Random Access in LEO Satellite Internet of Things  

作　　者：Jiaqi Fang Gangle Sun Wenjin Wang Li You Rui Ding 

机构地区：[1]National Mobile Communications Research Laboratory,Southeast University,Nanjing 210096,China [2]Purple Mountain Laboratories,Nanjing 211100,China [3]Institute of Telecommunication Satellite,CAST,Beijing 100094,China

出　　处：《China Communications》2024年第1期13-23,共11页中国通信（英文版）

基　　金：supported by the National Key R&D Program of China under Grant 2023YFB2904703;the National Natural Science Foundation of China under Grant 62341110,62371122 and 62322104;the Jiangsu Province Basic Research Project under Grant BK20192002;the Fundamental Research Funds for the Central Universities under Grant 2242022k30005 and 2242023K5003。

摘　　要：This paper investigates the low earth orbit(LEO)satellite-enabled coded compressed sensing(CCS)unsourced random access(URA)in orthogonal frequency division multiple access(OFDMA)framework,where a massive uniform planar array(UPA)is equipped on the satellite.In LEO satellite communications,unavoidable timing and frequency offsets cause phase shifts in the transmitted signals,substantially diminishing the decoding performance of current terrestrial CCS URA receiver.To cope with this issue,we expand the inner codebook with predefined timing and frequency offsets and formulate the inner decoding as a tractable compressed sensing(CS)problem.Additionally,we leverage the inherent sparsity of the UPA-equipped LEO satellite angular domain channels,thereby enabling the outer decoder to support more active devices.Furthermore,the outputs of the outer decoder are used to reduce the search space of the inner decoder,which cuts down the computational complexity and accelerates the convergence of the inner decoding.Simulation results verify the effectiveness of the proposed scheme.

关 键 词：LEO OFDMA SATELLITE unsourced random access UPA 

分 类 号：TN927.2[电子电信—通信与信息系统] TN929.5[电子电信—信息与通信工程]