Performance analysis of spatial multiplexing MIMO-OFDM systems under frequency-selective I/Q imbalances

ABSTRACT

This paper studies the impact of one important radio transceiver impairment, namely the I/Q imbalance, on the link performance of spatial multiplexing MIMO-OFDM systems. A closed-form solution for the effective signal-to-interference-plus-noise-ratio (SINR) at the input of the receiver detection stage due to frequency-selective transmitter and receiver I/Q imbalances is derived, taking also the effects of fading multipath radio channel and additive noise into account. As will be shown, the derived SINR can be directly mapped to the achievable detection error rate at high SNR regime, yielding a valuable analytical tool for radio transceiver designers to analyze the imbalance effects at link-level without any actual data simulations. The analytical outcomes are also verified using extensive computer simulations backing up the theoretical studies. In general, the obtained results indicate that I/Q imbalance can easily become a limiting factor to the achievable link performance in future spatial multiplexing MIMO-OFDM systems, and thus should be carefully mitigated using proper digital and/or analog signal processing.

REFERENCES

• 1: G. J. Foschini , M. J. Gans, On Limits of Wireless Communications in a Fading Environment when UsingMultiple Antennas, Wireless Personal Communications: An International Journal, v.6 n.3, p.311-335, March 1998 [doi>10.1023/A:1008889222784]
• 2: A. van Zelst, "Space division multiplexing algorithms," in Proc. 10th Mediterranean Electrotech. Conf., vol. 3, pp. 1218--1221, 2000.
• 3: R. van Nee, A. van Zelst, and G. Awater, "Maximum likelihood decoding in a space division multiplexing system", in Proc. IEEE Veh. Technol. Conf., Tokyo, Japan, May 2000, vol. 1, pp. 6--10.
• 4: Arogyaswami Paulraj , Rohit Nabar , Dhananjay Gore, Introduction to Space-Time Wireless Communications, Cambridge University Press, New York, NY, 2008
• 5: David Tse , Pramod Viswanath, Fundamentals of wireless communication, Cambridge University Press, New York, NY, 2005
• 6: Behzad Razavi, RF microelectronics, Prentice-Hall, Inc., Upper Saddle River, NJ, 1998
• 7: S. Mirabbasi and K. Martin, "Classical and modern receiver architectures," IEEE Commun. Mag., vol. 38, pp. 132--139, Nov. 2000.
• 8: M. Valkama, J. Pirskanen, and M. Renfors, "Signal processing challenges for applying software radio principles in future wireless terminals: An overview," Int. J. Commun. Syst., vol. 15, pp. 741--769, Oct. 2002.
• 9: T. C. W. Schenk, "RF impairment in multiple antenna OFDM: Influence and mitigation," Ph.D. dissertation, Eindhoven University of Technology, Eindhoven, Netherlands, Nov. 2006.
• 10: Yaning Zou , Mikko Valkama , Markku Renfors, Analysis and compensation of transmitter and receiver I/Q imbalances in space-time coded multiantenna OFDM systems, EURASIP Journal on Wireless Communications and Networking, 2008, p.1-10, January 2008 [doi>10.1155/2008/391025]
• 11: T. C. W. Schenk, E. R. Fledderus, and P. F. M. Smulders, "Performance analysis of zero-IF MIMO OFDM transceivers with IQ imbalance," Journal of Communications, vol. 2, no. 7, pp. 9--19, Dec. 2007.
• 12: M. Valkama, Advanced I/Q signal processing for wideband receivers: Models and algorithms. Ph.D. dissertation, Tampere University of Technology, Tampere, Finland, Nov. 2001.
• 13: T. B. Sorensen, P. E. Mogensen, and F. Frederiksen, "Extension of the ITU channel models for wideband (OFDM) systems," in Proc. IEEE Veh. Technol. Conf., Dallas, TX, Sept. 2005, pp. 392--396.
• 14: 3GPP Technical Specification, TS 36.211 v8.3.0. "Physical channels and modulation (release 8)", May 2008.

INDEX TERMS

Primary Classification:
  B. Hardware
  B.4 INPUT/OUTPUT AND DATA COMMUNICATIONS
      B.4.1 Data Communications Devices

General Terms:
Algorithms

Keywords:
complex (I/Q) signals, direct-conversion radios, frequency-selective I/Q imbalances, multi-antenna, multi-carrier, signal-to-interference-plus-noise ratio, spatial multiplexing