On the Transmission Method for Short-Range MIMO Communication

This paper investigates a transmission scheme that is suitable for short-range multiple-input-multiple-output (MIMO) transmission. Since the distance between two array antennas that face each other is comparable with the size of the array antenna aperture in short-range MIMO, the propagation characteristics are greatly different from those in conventional MIMO. Unlike conventional MIMO, the optimal element spacing, which maximizes channel capacity, exists in short-range MIMO. Moreover, the channel capacity with optimal antenna spacing exceeds the ergodic capacity of independent identically distributed (i.i.d.) channels since optimal eigenvalue distribution, which can maximize channel capacity, is obtained in the short-range MIMO. In this paper, we focus on the actual transmission methods, because complex transmission schemes such as eigenmode transmission or maximum-likelihood detection are required to obtain ideal channel capacity. We clarify that the channel capacity obtained by zero forcing (ZF) at the receiver without beamforming at the transmitter is almost the same as that using eigenmode transmission when considering the optimal element spacing. The effectiveness of short-range MIMO communication is also clarified using a 4 × 4 MIMO testbed with actual signals based on the IEEE 802.11n standard. Simulated and measured results show that optimal element spacing is a key parameter in the short-range MIMO communication. We found that designing antenna arrays with optimal element spacing is a very effective approach to achieving a simple hardware configuration.

[1]  Rohit U. Nabar,et al.  Introduction to Space-Time Wireless Communications , 2003 .

[2]  Frode Bøhagen,et al.  Construction and capacity analysis of high-rank line-of-sight MIMO channels , 2005, IEEE Wireless Communications and Networking Conference, 2005.

[3]  Steve Rockwell,et al.  Gigabit wireless personal area networks: Motivation, challenges and implementation , 2009, 2009 IEEE Radio and Wireless Symposium.

[4]  Naoki Honma,et al.  16×16 MIMO Testbed for MU-MIMO Downlink Transmission , 2010, IEICE Trans. Commun..

[5]  Mary Ann Ingram,et al.  Distributed source model for short-range MIMO , 2003 .

[6]  Emre Telatar,et al.  Capacity of Multi-antenna Gaussian Channels , 1999, Eur. Trans. Telecommun..

[7]  Thomas Haustein,et al.  Smart geometrical antenna design exploiting the LOS component to enhance a MIMO System based on Rayleigh-fading in indoor scenarios , 2003, 14th IEEE Proceedings on Personal, Indoor and Mobile Radio Communications, 2003. PIMRC 2003..

[8]  Andrew R. Nix,et al.  Design and Performance Assessment of High-Capacity MIMO Architectures in the Presence of a Line-of-Sight Component , 2007, IEEE Transactions on Vehicular Technology.

[9]  M. J. Gans,et al.  On Limits of Wireless Communications in a Fading Environment when Using Multiple Antennas , 1998, Wirel. Pers. Commun..

[10]  Iickho Song,et al.  Decoding With Hypothesis Testing: A Near ML Decoding Scheme for MIMO Systems , 2011, IEEE Transactions on Vehicular Technology.

[11]  Yuhei Nagao,et al.  A Gigabit MIMO WLAN system with international standardization strategy , 2009, 2009 International Symposium on Intelligent Signal Processing and Communication Systems (ISPACS).

[12]  Naoki Honma,et al.  Short range MIMO communication , 2009, 2009 3rd European Conference on Antennas and Propagation.

[13]  Andreas Hutter,et al.  Analysis of MIMO capacity gains for indoor propagation channels with LOS component , 2002, The 13th IEEE International Symposium on Personal, Indoor and Mobile Radio Communications.