Pre-Weighting Based Contention Resolution Diversity Slotted ALOHA Scheme for Geostationary Earth Orbit Satellite Networks

Bo ZHAO  Guangliang REN  Huining ZHANG  

IEICE TRANSACTIONS on Communications   Vol.E102-B   No.3   pp.648-658
Publication Date: 2019/03/01
Online ISSN: 1745-1345
DOI: 10.1587/transcom.2018EBP3152
Type of Manuscript: PAPER
Category: Satellite Communications
CRDSA,  pre-weighting scheme,  deadlock problems,  virtual MIMO,  JMMD algorithm,  

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Pre-weighting based Contention Resolution Diversity Slotted ALOHA-like (PW-CRDSA-like) schemes with joint multi-user multi-slot detection (JMMD) algorithm are proposed to improve the throughput of random access (RA) in geostationary earth orbit (GEO) satellite networks. The packet and its replicas are weighted by different pre-weighting factors at each user terminal, and are sent in randomly selected slots within a frame. The correlation of channels between user terminals and satellite node in different slots are removed by using pre-weighting factors. At the gateway station, after the decoding processing of CRDSA, the combinations of remained signals in slots that can construct virtual multiple-input multiple-output (MIMO) signal models are found and decoded by the JMMD algorithm. Deadlock problems that can be equivalent to virtual MIMO signal models in the conventional CRDSA-like schemes can be effectively resolved, which improves the throughput of these CRDSA-like schemes. Simulation results show that the PW-CRDSA-like schemes with the JMMD significantly outperform the conventional CRDSA-like schemes in terms of the throughput under equal packet loss ratio (PLR) conditions (e.g. PLR =10-2), and as the number of the transmitted replicas increases, the throughput of the PW-CRDSA-like schemes also increases, and the normalized maximum throughput of the PW-CRDSA-5 (i.e., PW-CRDSA with 5 replicas) scheme can reach 0.95.