A Multi-cell Open-Loop Communication Approach to Ultra-Reliable Mobile Networks
Chun‐Hung Liu, Yu Dong Luo, Lina Pu · 2021
Traditional means of achieving highly reliable wireless communications are to rely on a closed-loop communication methodology, which needs to implement complicated feedback communication mechanisms. Such closed-loop communication means inevitably incur feedback communication latency and thus lead to a fundamental tradeoff problem of simultaneously achieving high reliability and low latency. To avoid encountering this tradeoff problem, in this paper we adopt an open-loop communication methodology in a mobile network and propose a multi-cell association scheme to enhance the reliability of open-loop communication. The multi-cell association scheme helps users connect to multiple base stations (BSs), which form a virtual cell of the user. We first characterize the distribution of the number of the users associating with a BS for the multi-cell association scheme and then use it to establish the accurate models of signal-to-interference ratios (SIRs) in the downlink and uplink. The downlink and uplink communication reliabilities, which are defined based on the SIRs in the downlink and uplink, are accurately analyzed and their explicit upper bounds are found. Our analytical and simulated results show that jointly adopting open-loop communication and multi-cell association is able to significantly improve the communication reliability of users, thereby creating an ultra-reliable mobile network.