A Novel CSI Feedback Method for Dynamic SU/MU MIMO Adaptation

• Published in: Wireless personal communications Vol. 71; no. 3; pp. 2111 - 2123
• Main Authors: Peng, Yuefeng, Yang, Wei, Zhu, Yuan, Kim, Young-Il
• Format: Journal Article
• Language: English
• Published: Boston Springer US 01.08.2013; Springer
• Subjects: Applied sciences; Channels; Communications Engineering; Computer Communication Networks; Dynamical systems; Dynamics; Engineering; Equipments and installations; Exact sciences and technology; Feedback; Gain; Mobile radiocommunication systems; Networks; Radiocommunications; Reporting; Signal,Image and Speech Processing; Stations; Switches; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Teletraffic; Wireless communication; MU-MIMO; Feedback; SU-MIMO; CSI reporting; MIMO system; Multiple access; Channel estimation; Base station; Feedback regulation; Wireless network
• DOI: 10.1007/s11277-012-0926-6
• ISSN: 0929-6212

Channel state information (CSI) reporting at one mobile station (MS) often targets maximizing the throughput of one single link, hence is optimized for single-user multi-input multi-output (SU-MIMO) transmission at base station (BS). However, the system wide throughput may not be maximized when BS is performing multi-user multi-input multi-output (MU-MIMO) transmission utilizing the SU-MIMO optimized CSI reports, and vice versa. This CSI mismatch can cause system throughput degradation. In this paper, a novel CSI feedback method is proposed which can switch between SU-MIMO optimized CSI reporting mode and MU-MIMO optimized CSI reporting mode when instructed by BS’s signaling. System level simulation results show when BS is performing MU-MIMO transmission, significant throughput gain can be obtained if MS feeds back MU-MIMO optimized CSI reports instead of SU-MIMO optimized CSI reports. With the instruction of the BS signaling to dynamic indicate MS to switch between SU-MIMO and MU-MIMO optimized CSI reporting modes, the SU-MIMO performance is not compromised either.