Fast Algorithm for Joint Unicast and Multicast Beamforming in Large-Scale Systems

• Published in: SPAWC : signal processing advances in wireless communications pp. 91 - 95
• Main Authors: Mohammadi, Shadi, Dong, Min, ShahbazPanahi, Shahram
• Format: Conference Proceeding
• Language: English
• Published: IEEE 27.09.2021
• Subjects: Array signal processing; large-scale optimization; Multicast algorithms; multicast beamforming; multiple groups; optimal structure; Quality of service; Signal processing algorithms; Simulation; Unicast; Unicast beamforming; Wireless communication
• DOI: 10.1109/SPAWC51858.2021.9593125

We consider a joint unicast and multi-group multicast beamforming design for a large-scale massive multiple-input multiple-output (MIMO) system, where there may be a large number of unicast users. We propose a fast algorithm that efficiently obtains the beamforming solutions for both unicast and multicast users to minimize the transmit power subject to quality-of-service (QoS) requirements. Utilizing the optimal beamforming structure obtained recently for multi-group multicast beamforming, we separate the original problem into two subproblems for the unicast and multicast users and solve them using the alternating optimization technique. We obtain the solution to the unicast subproblem in closed-form by exploring the unicast beamforming structure, which provides a key step in reducing the computational complexity of the overall algorithm. We solve the multicast subproblem using the successive convex optimization method whose complexity is independent of the number of unicast users and antennas. Simulation results show that our proposed algorithm achieves a near-optimal performance at a very low complexity for large-scale systems.