Hybrid automatic repeat request (HARQ) is a potential technique for communication systems in non-terrestrial networks (NTN) to ensure reliability. However, the long round-trip time (RTT) within NTN diminishes the information timeliness when applying HARQ. Moreover, the absence of perfect channel state information (CSI) poses challenges to the precise design of HARQ strategies. In this paper, we introduce a novel coded HARQ scheme for NTN, in which the age of coded information (C-AoI) is proposed as a metric of information timeliness to guide the search for the optimal coded HARQ strategy. The rate-compatible inherited bits codeword construction (RCIC) is introduced for HARQ process to enhance the transmission efficiency. By applying Markov decision process (MDP) and Q-learning algorithm in the optimization, the obtained coded HARQ scheme significantly outperforms the existing schemes in terms of information timeliness and number of transmissions. The throughput of satellite-terrestrial links is also improved.


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    Title :

    AoI-Based Coded Hybrid Automatic Repeat Request Strategy for Non- Terrestrial Networks


    Contributors:
    Du, Ruopu (author) / Feng, Bowen (author) / Yang, Yi (author) / Zhang, Qinyu (author)


    Publication date :

    2024-06-24


    Size :

    599547 byte





    Type of media :

    Conference paper


    Type of material :

    Electronic Resource


    Language :

    English