2020/10/25 by Jinho Choi, Choi, Jinho
Computer Science · Engineering · #Distributed Sensor Networks and Detection Algorithms #FOS: Computer and information sciences #Indoor and Outdoor Localization Technologies #Information Theory (cs.IT) #Wireless Communication Security Techniques
paper · pdf · doi:10.48550/arxiv.2010.13250
openalex publication_date 2020/10/25 · openalex created_date 2022/07/25 · openalex updated_date 2026/07/28
In this paper, we study grant-free random access with massive multiple input\nmultiple output (MIMO) systems. We first show that the performance of massive\nMIMO based grant-free random access is mainly decided by the probability of\npreamble collision. The implication of this is that although the number of\nantennas can be arbitrarily large, the (average) number of successful packet\ntransmissions can be limited by the number of preambles. Then, we propose an\napproach to preamble collision reduction without increasing the number of\npreambles using the notion of superpositioned preambles (S-preambles). Since\nthe channel estimation for conjugate beamforming can be carried out when unused\nS-preambles are known, a simple approach is derived to detect unused\nS-preambles and its performance is analyzed for a special case (superpositions\nwith 2 preambles). Based on analysis and simulation results, it is confirmed\nthat the proposed approach with S-preambles can increase the success\nprobability with the same spectral efficiency as the conventional approach.\n