Resource Allocation Approach for Differential Doppler Reduction in NB-IoT over LEO Satellite

Internet of things (IoT) over satellite is an attractive system architecture which has been proposed as a key-enabling technology, to extend the coverage in remote areas (e.g. desert, ocean, forest, etc), particularly where a terrestrial network is impossible or impractical to reach. One of the most promising technologies that fit the IoT vision of low-power, wide area networks (LPWAN) is the narrowband IoT (NB-IoT). While low earth orbit (LEO) satellites are favourable because of their lower round trip time (RTT) and lower propagation loss in the communication link, they come up with a significantly increased Doppler shift. In our NB-IoT over LEO satellite architecture, we identify the problem of high differential Doppler among channels of different users on Earth, which leads to the performance degradation of our system. In this paper, we propose a resource allocation approach in order to reduce the high values of differential Doppler under the maximum value supported by the standard itself