IEICE Transactions on Communications

IEICE Transactions on Communications 2008 E91-B(2):459-465; doi:10.1093/ietcom/e91-b.2.459

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Copyright © 2008 The Institute of Electronics, Information and Communication Engineers

Regular Section -- Papers -- Wireless Communication Technologies

MIMO System with Relative Phase Difference Time-Shift Modulation for Rician Fading Environment

Kenichi KOBAYASHI¹, Takao SOMEYA¹, Tomoaki OHTSUKI², Sigit P.W. JAROT³ and Tsuyoshi KASHIMA³

¹ The authors are with the Graduate School of Electrical Engineering, Tokyo University of Science, Noda-shi, 278-8510 Japan., ² The author is with the Department of Information and Computer Science, Keio University, Yokohama-shi, 223-8522 Japan. E-mail: ohtsuki{at}ics.keio.ac.jp, ³ The authors are with NOKIA JAPAN, Nokia Research Center, Tokyo, 153-0064 Japan.

Multiple-Input Multiple-Output (MIMO) systems that realize high-speed data transmission with multiple antennas at both transmitter and receiver are drawing much attention. In line-of sight (LOS) environments, the performance of MIMO systems depends largely on the difference of the phase difference of direct paths from transmit antennas to each receive antenna. When the phase difference of direct paths are close to each other, the spatial division multiplexing (SDM) channels are not orthogonal to each other so signal detection becomes difficult. In this paper, we propose a MIMO system with relative phase difference time-shift modulation (RPDTM) in Rician fading environments. The proposed scheme transmits independent signals from each antenna at each time slot where the relative phase difference between signal constellations used by transmit antennas varies in a pre-determined pattern. This transmission virtually changes the phase difference of direct paths from transmit antennas to each receive antenna without lowering data rate and without knowledge of the channels. In addition, forward error correction coding (ECC) is applied to exploit the time slots where the receiver can detect the signals easily to improve the detection performance. If there are time slots where the receiver can separate the received signal, the receiver can decode the data by using the time slots and the correlation between data. From the results of computer simulation, we show that MIMO system with RPDTM can achieve the better bit error rate (BER) than the conventional MIMO system. We also show that the MIMO system with RPDTM is effective by about Rician factor K = 10 dB.

Key Words: MIMO, Rician fading, direct path, phase difference, Turbo code

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Manuscript received November 15, 2006. Manuscript revised June 8, 2007.

Reference

[1] P.F. Driessen and G.J. Foschini, "On the capacity formula for multiple input multiple output wireless channels," IEEE Trans. Commun., vol.47, no.2, pp.173–176, Feb. 1999.

[2] D. Gesbert, H. Bolcskei, D.A. Gore, and A.J. Paulraj, "Outdoor MIMO wireless channel: Models and performance prediction," IEEE Trans. Commun., vol.50, no.12, pp.1926–1934, Dec. 2002.

[3] D. Gesbert, H. Bolcskei, D.A. Gore, and A.J. Paulraj, "MIMO wireless channel: Capacity and performance prediction," Proc. IEEE PIMRC 2004, vol.2, pp.1126–1130, Sept. 2004.

[4] Y. Murakami, K. Kobayashi, M. Orihashi, and T. Matsuoka, "Analysis of BER performances using channel matrix eigenvalue in MIMO systems under Rayleigh and Rician fading channels," Proc. IEEE PIMRC 2004, vol.2, pp.1126–1130, Sept. 2004.

[5] Y. Li, P.H.W. Fung, Y. Wu, and S. Sun, "Bit-interleaved coded modulation in linear dispersion coded MIMO system over spatially correlated Rician fading channel," Global Telecommunications Conference, 2004. GLOBECOM'04. IEEE, vol.1, pp.5–9, Dec. 2004.

[6] Y. Murakami, K. Kobayashi, T. Matsuoka, and K. Takahashi, "Performance analysis based on channel matrix eigenvalue for MIMO systems in LOS environments," IEICE Trans. Fundamantals, vol.E88-A, no.10, pp.2926–2936, Oct. 2005.

[7] Y. Murakami, K. Kobayashi, T. Matsuoka, and K. Takahashi, "Design of transmission technique utilizing linear combination diversity in consideration of LOS environments," IEICE Trans. Fundamantals, vol.E88-A, no.11, pp.3127–3133, Nov. 2005.

[8] K. Kobayashi, Y. Murakami, M. Orihashi, and T. Matsuoka, "Varying interleave patterns with iterative decoding for improved performance in MIMO systems," Personal Indoor and Mobile Radio Communications (PIMRC2004), vol.2, pp.1429–1433, Sept. 2004.

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This Article Abstract Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Add to My Personal Archive Download to citation manager Request Permissions Google Scholar Articles by KOBAYASHI, K. Articles by KASHIMA, T. Search for Related Content Social Bookmarking          What's this?