Joint Optimization of Time-Slot Scheduling and Beamforming for Cooperative Satellites with Per-Antenna Power Constraints

In this paper, we investigate the time-slot user scheduling and beamforming design for cooperative satellites. We take into account the more practical constraint of per-antenna power constraint (PAPC). Unlike traditional approaches where these two issues are usually studied separately, we adopt a joint optimization strategy to maximize the max-min fairness (MMF) spectral efficiency of the cooperative satellite system. Thus, we formulate the MMF problem to optimize time-slot user scheduling and beamforming design. We first obtain the decoupling problem of the initial problem through equivalent transformation in order to reduce its complexity. Then, we proposed an efficient convex relaxation method based on the successive convex approximation (SCA) and semi-definite relaxation (SDR) technique to solve the decoupled problem. Numerical experiments show the superiority of our proposed joint optimization algorithm.