1Introducing Dual Regularization Parameters into
Regularized Channel Inversion (RCI)-BasedVector Perturbation for Modulo Loss Reduction
Yafei Hou, Satoshi Tsukamoto, Kazuto Yano, Masahiro Uno,
Kiyoshi Kobayashi
ATR Wave Engineering Laboratories, Kyoto, Japan{yfhou, tsukamoto, kzyano, uno, kobayashi}@atr.jp

Abstract—This paper proposes a method to reduce the symbol error caused by modulo operator for regularized channel inversion(RCI)-based vector perturbation (RCI-VP). The proposed method introduces dual regularization parameters of RCI precoding matrix.
First regularization parameter ®1 is set so as to maximize the signal to interference plus noise ratio (SINR) value of each stream tofind the optimal perturbation vector. The second regularization parameter ®2 is set so as to minimize the total MSE between thetransmitted perturbation vector and received perturbation vector to reduce the symbol error caused by modulo operator. The
simulated results confirm that the proposed method can improve the performance of RCI-VP over i.i.d. MIMO channel andfrequency-selective fading MIMO channel.
Keyword—Vector perturbation, SINR maximization, Modulo loss, Regularization parameter, Minimum mean square error
Yafei Hou received his B.S. degree in Electronic Engineering from Anhui University of Technology and Science, China, in 1999 andM.S. degree in Computer Science from Wuhan University, China, in 2002, respectively. He received the Ph.D. degrees from Fudan
University, China and Kochi University of Technology (KUT), Japan, as an international student of cooperation between KUT and Fudan University in 2007. From August 2007 to September 2010, He was a post-doctoral reseach fellow at the Research Center for Inf
ormation and Communication Systems, Ryukoku University, Japan. Since Oct. 2010, He has been a research scientist at ATR Wave E
ngineering Laboratories, Japan. His main areas of interest are communication systems, wireless networks, ad-hoc networks and signal processing. He is a member of IEICE and IEEE.
Satoshi Tsukamoto received his B. E. degree in electronics engineering from Tokyo Denki University (TDU) in 1991 and BLA degree from the Open University of Japan (OUJ) in 2005. From 1997 to 2005, he worked in Cybernetics Technology Co., Ltd., Tokyo, Japan, and involved in many projects for developments of experimental systems and system prototypes for wireless communications. Since November 2005, He has been a senior researcher at Wave Engineering Laboratories of ATR, Japan. He is a committee member of commission C, Japan National Committee of URSI, and is also a member of IEICE and IEEE.
Kazuto Yano received a B.E. degree in electrical and electronic engineering, M.S. and Ph.D. degrees in communications and computerengineering from Kyoto University in 2000, 2002, and 2005, respectively. He was a research fellow of the Japan Society for the PromotionScience (JSPS) from 2004 to 2006. In 2006, he joined the Advanced Telecommunications Research Institute International (ATR). Currently, he isa senior research scientist of the Wave Engineering Laboratories, ATR. His research interests include space-time signal processing for interference
suppression, MIMO transmission, and PHY/MAC cross-layer design of cognitive radio for ISM bands. He received the IEEE VTS Japan 2001
Researcher's Encouragement Award, the IEICE Young Researcher's Award in 2007, the Ericsson Young Scientist Award 2007 and the IEICE
2007 Active Research Award in Radio Communication Systems. He also received 2010 Young Investigator Award in Software Radio from IEICE
Technical Committee on Software Radio. He is a member of IEICE and IEEE.
Masahiro Uno received the B.E. and M.E. degrees in electronics engineering from Sophia University, Tokyo, Japan, in 1988 and 199
0. He joined Sony Corporation, Tokyo, Japan, in 1990, where he was involved in the research and development of wireless communication systems. From Oct. 2010 to Mar. 2013, he has been with Advanced Telecommunication Research Institute, International (ATR) in Kyoto, Japan as the head of Wireless Communication Systems Department, Wave Engineering Laboratories. From Apr. 2013, he is in Device Solution Business Group, Sony Corporation. His research interests are digital and analog signal processing technologies for w
ireless communication systems. He is a member of IEICE and IEEE.

Kiyoshi Kobayashi received the B.E., M.E. and Ph.D. degrees from Tokyo University of Science, Japan, in 1987, 1989 and 2004, respectively. He joined NTT Radio Communication Systems Laboratories in 1989. Currently, he is the director of ATR Wave Engineeri
ng Laboratories at Advanced Telecommunications Research Institute International, where he is engaged in research on advanced techno
logies for wireless communications. He is a member of IEEE, AIAA and IEICE.