User-Centric Beam Selection and Precoding Design for Coordinated Multiple-Satellite Systems

TL;DR

This paper proposes a joint optimization framework for user-centric beam selection and precoding in coordinated satellite systems, utilizing DFT beamforming and duality analysis to improve power efficiency and user SINR targets.

Contribution

It introduces a novel joint cluster association and precoding design method with duality-based iterative algorithms for coordinated satellite communications.

Findings

Enhanced power efficiency in satellite beamforming

Effective user SINR target achievement

Fast duality-based beam selection method

Abstract

This paper introduces a joint optimization framework for user-centric beam selection and linear precoding (LP) design in a coordinated multiple-satellite (CoMSat) system, employing a Digital-Fourier-Transform-based (DFT) beamforming (BF) technique. Regarding serving users at their target SINRs and minimizing the total transmit power, the scheme aims to efficiently determine satellites for users to associate with and activate the best cluster of beams together with optimizing LP for every satellite-to-user transmission. These technical objectives are first framed as a complex mixed-integer programming (MIP) challenge. To tackle this, we reformulate it into a joint cluster association and LP design problem. Then, by theoretically analyzing the duality relationship between downlink and uplink transmissions, we develop an efficient iterative method to identify the optimal solution. Additionally, a simpler duality approach for rapid beam selection and LP design is presented for comparison purposes. Simulation results underscore the effectiveness of our proposed schemes across various settings.