Tackling Delayed CSI in a Distributed Multi-Satellite MIMO Communication System

TL;DR

This paper proposes a novel precoding strategy for satellite-terrestrial MIMO systems that compensates for delayed CSI, improving data transmission efficiency in integrated satellite-ground networks especially at frequencies up to 1 GHz.

Contribution

We develop a computationally efficient precoding method leveraging long-term CSI characteristics to address outdated CSI in satellite MIMO systems, enhancing integration with terrestrial networks.

Findings

Effective in lower frequency bands up to 1 GHz

Reduces impact of CSI delay on data transmission

Improves satellite-terrestrial communication integration

Abstract

In this study, we explore the integration of satellites with ground-based communication networks. Specifically, we analyze downlink data transmission from a constellation of satellites to terrestrial users and address the issue of delayed channel state information (CSI). The satellites cooperate in data transmission within a cluster to create a unified, distributed massive multiple input, multiple output (MIMO) system. The CSI used for this process is inherently outdated, particularly due to the delay from the most distant satellite in the cluster. Therefore, in this paper, we develop a precoding strategy that leverages the long-term characteristics of CSI uncertainty to compensate for the undesirable impact of these unavoidable delays. Our proposed method is computationally efficient and particularly effective in lower frequency bands. As such, it holds significant promise for facilitating the integration of satellite and terrestrial communication, especially within frequency bands of up to 1 GHz.