TY - JOUR
T1 - New Beamforming Designs for Joint Spatial Division and Multiplexing in Large-Scale MISO Multi-User Systems
AU - Jeon, Younghyun
AU - Song, Changick
AU - Lee, Sang Rim
AU - Maeng, Seungjoo
AU - Jung, Jaehoon
AU - Lee, Inkyu
N1 - Funding Information:
Manuscript received November 3, 2015; revised April 12, 2016, October 4, 2016, and January 10, 2017; accepted February 8, 2017. Date of publication March 17, 2017; date of current version May 8, 2017. This work was supported by the National Research Foundation of Korea funded by the Korea Government under Grant 2014R1A2A1A10049769 and Grant 2015R1C1A1A02036927. This paper was presented at the IEEE PIMRC, Valencia, Spain, 2016. The associate editor coordinating the review of this paper and approving it for publication was M. Kountouris.
PY - 2017/5
Y1 - 2017/5
N2 - In this paper, we study a joint spatial division multiplexing (JSDM) beamforming scheme, which enables large-scale spatial multiplexing gains for massive multi-input multi-output downlink systems. In contrast to the conventional JSDM, which employs a block diagonalization method as a pre-beamformer, we aim to maximize sum-rate by applying minimum-mean-squared error (MMSE) approaches when designing a pre-beamformer and a multi-user precoder sequentially. First, to suppress inter-group interference, we design the pre-beamformer, which minimizes an upper bound of the sum mean-squared-error in the large-scale array regime. Then, to mitigate same-group interference, we present the multi-user precoder based on the weighted MMSE (WMMSE) optimization method, which requires the same channel state information overhead as the conventional JSDM. Also, in order to reduce the computational complexity, we compute deterministic equivalents of the WMMSE beamforming parameters to generate the beamformers by employing asymptotic results of large system analysis. Through simulation results, we confirm that the proposed two-step beamforming methods bring substantial performance gains in terms of sum-rate over the conventional JSDM schemes especially in a low and medium signal-to-noise ratio regime with comparable complexity.
AB - In this paper, we study a joint spatial division multiplexing (JSDM) beamforming scheme, which enables large-scale spatial multiplexing gains for massive multi-input multi-output downlink systems. In contrast to the conventional JSDM, which employs a block diagonalization method as a pre-beamformer, we aim to maximize sum-rate by applying minimum-mean-squared error (MMSE) approaches when designing a pre-beamformer and a multi-user precoder sequentially. First, to suppress inter-group interference, we design the pre-beamformer, which minimizes an upper bound of the sum mean-squared-error in the large-scale array regime. Then, to mitigate same-group interference, we present the multi-user precoder based on the weighted MMSE (WMMSE) optimization method, which requires the same channel state information overhead as the conventional JSDM. Also, in order to reduce the computational complexity, we compute deterministic equivalents of the WMMSE beamforming parameters to generate the beamformers by employing asymptotic results of large system analysis. Through simulation results, we confirm that the proposed two-step beamforming methods bring substantial performance gains in terms of sum-rate over the conventional JSDM schemes especially in a low and medium signal-to-noise ratio regime with comparable complexity.
KW - Massive MIMO systems
KW - two-stage beamforming
KW - weighted MMSE
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U2 - 10.1109/TWC.2017.2673845
DO - 10.1109/TWC.2017.2673845
M3 - Article
AN - SCOPUS:85028693480
VL - 16
SP - 3029
EP - 3041
JO - IEEE Transactions on Wireless Communications
JF - IEEE Transactions on Wireless Communications
SN - 1536-1276
IS - 5
M1 - 7880687
ER -