Unified SER Performance Analysis and Improvement for Multiuser MIMO Downlink with Correlation Rotation Linear Precoding

• Published in: IEEE transactions on wireless communications Vol. 12; no. 4; pp. 1678 - 1685
• Main Authors: Liu, Zu-Jun, Wang, Jie-Ling, Sun, De-Chun, Yi, Ke-Chu
• Format: Journal Article
• Language: English
• Published: New York, NY IEEE 01.04.2013; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Applied sciences; Asymptotic properties; Channels; Codes; Coding, codes; Complexity; Correlation; correlation rotation (CR); Downlink; Exact sciences and technology; Exact solutions; Information, signal and communications theory; Interference; Iterative methods; linear precoding; Mathematical analysis; Mathematical models; MIMO; multiuser interference (MUI); Multiuser multiple-input multiple-output (MIMO); Phase shift keying; power allocation; Resource management; Signal and communications theory; Signal to noise ratio; Studies; Systems, networks and services of telecommunications; Telecommunications; Telecommunications and information theory; Transmission and modulation (techniques and equipments); Performance evaluation; MIMO system; Multiple access; Asymptotic behavior; Downlink; Iterative method; Closed form equation; Power allocation; Computational complexity; Information transmission; Degradation; linear precoding; correlation rotation (CR); Coding; Telecommunication system; Numerical simulation; multiuser interference (MUI); Pretreatment; Signal to interference plus noise ratio; Damaging; Multiuser multiple-input multiple-output (MIMO)
• ISSN: 1536-1276; 1558-2248
• DOI: 10.1109/TWC.2013.022113.120502

In multiuser multiple-input multiple-output (MIMO) downlink communications, system performance suffers from multiuser interference (MUI). Contrary to common practice where MUI is suppressed, correlation rotation (CR) linear precoding makes MUI constructive via rotating the angle of correlation between transmitted symbols. With the derived closed-form instantaneous SINR expression, we analyze the unified SER performance for CR precoding, and identify the channel condition under which the MUI exploitation via CR precoding will fail and consequently lead to the unified SER performance degradation. To solve the problem, two power allocation schemes that are subject to power constraint are proposed: one is iterative scheme that directly minimizes the unified SER, and the other has a closed-form solution that maximizes the minimum user SINR. The asymptotic behavior and computational complexity of the proposed schemes are analyzed. Numerical and simulation results show that both schemes can avoid the degradation of unified SER performance and furthermore offer performance gains. Moreover, the closed-form solution with much lower complexity can provide a comparable performance to that of the iterative scheme.