As a key enabling technology for 5G wireless, millimeter wave (mmWave) communication motivates the utilization of large-scale antenna arrays for achieving highly directional beamforming. However, the high cost and power consumption of RF chains stand in the way of adoption of the optimal fully digital precoding in large-array systems. To reduce the number of RF chains while still maintaining the spatial multiplexing gain of large array, a hybrid precoding architecture has been proposed for mmWave systems and received considerable interest in both industry and academia. However, the optimal hybrid precoding design has not been fully understood, especially for the multiuser MIMO case. This paper is the first work that directly addresses the nonconvex hybrid precoding problem of mmWave multi-user MIMO systems (without any approximation) by using penalty dual decomposition (PDD) method. The proposed PDD method have a guaranteed convergence to KKT solutions of the hybrid precoding problem under a mild assumption. Simulation results show that, even when both the transmitter and the receivers are equipped with the fewest RF chains that are required to support multistream transmission, hybrid precoding can still approach the performance of fully digital precoding in both the infinite resolution phase shifter case and the finite resolution phase shifter case with several bits quantization.
|Original language||English (US)|
|Number of pages||14|
|Journal||IEEE Journal on Selected Topics in Signal Processing|
|State||Published - Jun 2018|
Bibliographical noteFunding Information:
Manuscript received September 14, 2017; revised January 23, 2018 and March 23, 2018; accepted March 25, 2018. Date of publication April 6, 2018; date of current version June 30, 2018. The work of Q. Shi was supported in part by the NSFC under Grants 61671411, U1709219, and 61374020, in part by the Fundamental Research Funds for the Central Universities, and in part by the Zhejiang Provincial NSF of China under Grant LR15F010002. The work of M. Hong was supported in part by the NSF under Grants CCF-1526078 and CMMI-1727757, and in part by the AFOSR under Grant 15RT0767. The main part of this work was done when Q. Shi was a Research Fellow with M. Hong. The guest editor coordinating the review of this manuscript and approving it for publication was Prof. Wei Yu. (Corresponding author: Qingjiang Shi.) Q. Shi is with the School of Software Engineering, Tongji University, Shanghai 201804, China (e-mail:,email@example.com).
- hybrid precoding
- penalty dual decomposition method