User Fairness Scheme with Proportional Fair Scheduling in Multi-user MIMO Limited Feedback System

Hongyu Wang, Weixiao Meng, Trungtan Nguyen

School of Electronics and Information Engineering, Harbin Institute of Technology, Harbin, China.

DOI: 10.4236/cn.2013.53B2022                

Abstract

In Multi-user MIMO (MU-MIMO) downlink system, suitable user selection schemes can improve spatial diversity gain. In most of previous studies, it is always assumed that the base station (BS) knows full channel state information (CSI) of each user, which does not consider the reality. However, there are only limited feedback bits in real system. Besides, user fairness is often ignored in most of current user selection schemes. To discuss the user fairness and limited feedback, in this paper, the user selection scheme with limited feedback bits is proposed. The BS utilizes codebook precoding transmitting strategy with LTE codebook. Furthermore, this paper analyzes the influence of the number of feedback bits and the number of users on user fairness and system sum capacity. Simulation results show that in order to achieve better user fairness, we can use fewer bits for feedback CSI when the number of user is small, and more feedback bits when the number of users is large.

Keywords

User Fairness Scheme with Proportional Fair Scheduling in Multi-user MIMO Limited Feedback System

Conflicts of Interest

The authors declare no conflicts of interest.

References

[1]	3GPP, “Evolved Universal Terrestrial Radio Access (E-UTRA); Physical channels and modulation,” 3GPP TS 36.211 version 10.0.0 Release 10.
[2]	G. Caire and S. Shamai, “On the Achievable Throughput of a MultiantennaGassian Broadcast Channel,” IEEE Transactions on Information Theory, Vol. 49, 2003, pp. 1691-1706. doi:10.1109/TIT.2003.813523
[3]	Q. H. Spencer, A. L. Swindlehurst and M. Haardt, “Zero-Forcing Methods for Downlink Spacial Multiplexing in Multiuser MIMO Channels,” IEEE Transactions on Signal Process, Vol. 52, No. 2, 2004, pp. 461-471. doi:10.1109/TSP.2003.821107
[4]	Masoud and B. Hassibi, “On the Capacity of MIMO Broadcast Channels with Partial Side Information”, IEEE Transanctions on Information Theory, Vol. 51, 2003, pp. 506-522.
[5]	T. Yoo, N. Jindal and A. Goldsmith, “Multi-antenna Downlink Channels with Feedback and User Selection,” IEEE J. Select. Areas Commun., Vol. 25, No. 7, 2007, pp. 1478-1491. doi:10.1109/JSAC.2007.070920
[6]	K. Huang, A. Texas Univ., R. W. Hearth and J. G. Andrews, “Space Division Multiple Access with a Sum Feedback Rate Constraint,” IEEE Transactions on Signal Process, Vol. 55, No. 7, 2007, pp. 3879-3891. doi:10.1109/TSP.2007.894245
[7]	Y. X. Wang, S. Y. Hur, Y. W. Park and J.-H. Choi, “Efficient User Selection Algorithms for Multiuser MIMO Systems with Zero-forcing Dirty Paper Coding,” IEEE Journal of Communications and Networks, Vol. 13, 2011, pp. 232-239.
[8]	T. Yoo and A. Goldsmith, “On the Optimality of Multiantenna Broadcast Scheduling Using Zero-forcing Beamforming,” Ieee journal on Selected Areas in Communications, Vol. 24, No. 3, 2006, pp. 528-541. doi:10.1109/JSAC.2005.862421
[9]	N. Sharma, “A Study of Opportunism for Multiple-anrenna System,” IEEE Transactions on Information Theory, Vol. 51, No. 5, 2006, pp. 1804-1814. doi:10.1109/TIT.2005.846410
[10]	Choi and Jeongsik, “User Thoughput Estimation for the PF Scheduling Algorithm under MIMO Channel Environments,” IEEE Wireless Communications Letters, Vol. 1, 2012, pp. 528-531. doi:10.1109/WCL.2012.072012.120455