Notice of Violation of IEEE Publication Principles: An Efficient Nonlinear Quantized Constant Envelope Precoding for Massive MU-MIMO Systems

Notice of Violation of IEEE Publication Principles

"An Efficient Nonlinear Quantized Constant Envelope Precoding for Massive MU-MIMO Systems,"
by R. Liang, H. Li, W. Zhang, C. Liu and Y. Guo,
in IEEE Systems Journal, Early Access

After a careful and considered review of the content and authorship of this paper by a duly constituted expert committee, this paper has been found to be in violation of IEEE’s Publication Principles.

This paper contains content from the papers cited below. Credit notices were used, but due to the absence of quotation marks or offset text, the copied content is not clearly referenced or specifically identified.

"VLSI Design of a 3-bit Constant-Modulus Precoder for Massive MU-MIMO,"
by O. Castañeda, S. Jacobsson, G. Durisi, T. Goldstein and C. Studer,
in the Proceedings of the IEEE International Symposium on Circuits and Systems (ISCAS), May 2018

"Quantized Precoding for Massive MU-MIMO,"
by S. Jacobsson, G. Durisi, M. Coldrey, T. Goldstein and C. Studer,
in IEEE Transactions on Communications, vol. 65, no. 11, pp. 4670-4684, November 2017


Massive multiuser multiple-input–multiple-output (MU-MIMO) systems are foreseen as the key technology in next-generation wireless communication systems. However, many radio-frequency (RF) chains will require high power consumption and lots of hardware cost. One of the practical solutions is using low-resolution discrete phase shifters (PSs) for each antenna and RF chain. This article designs a nonlinear quantized constant envelope precoding algorithm for MU-MIMO systems with low-resolution discrete PS at the base station. In this algorithm, the quantized constant envelope precoding problem is presented as a nonconvex optimization problem. The multiuser interference is minimized by solving the optimal precoded vector and the associated precoding factors. First, we consider relaxing the nonconvex constraint on the 1-bit quantized constant envelope precoding to a continuous set of convex constraints on the unit circle. Afterwards, the semidefinite relaxation method is used to tackle the equivalent 1-bit quantized precoding problem. We further extend the algorithm to provide multi-bit quantized constant envelop precoding. Finally, the simulations are carried out under various conditions and compared with the most advanced precoding methods. The results demonstrate that this algorithm achieves a comparable performance to the existing precoding methods. At the same time, the corresponding performance-complexity tradeoff is more conducive to the expansion of the proposed algorithm to the multibit case.