Research on Beamforming Algorithm for Group Scenario in Broadband Trunking System Downlink

In recent years, broadband trunking system has attracted much attention as its high rate, which can replace narrow band trunking system in private network. Beamforming technology, developed from smart antenna technology, sending the signal precoding processing, can effectively improve the system’s energy efficiency. In this paper, the multicast beamforming algorithm based on the group user CSI is proposed to improve the energy efficiency of the system. Multi-user beamforming technology can improve the energy efficiency of BSs in group scenarios of broadband Trunking system, and guarantee the QoS of group users. The two optimization problems are both NP-hard. The paper adopts SDR, dropping some constraints in the original optimization problem, transform the original optimization problem into SDP to achieve the approximation solution. The improved algorithm guarantees the QoS of the group users by changing the priority of the user. Multi-user beamforming technology can improve the energy efficiency of base stations in group scenarios of broadband Trunking system, and guarantee the QoS of group users.