Equal-Phase Beamforming Architecture for RF-MIMO Antenna Systems

  • Fouad Gholam
  • Javier Vía
  • Alfredo Nazábal
  • Ignacio Santamaría
Conference paper
Part of the Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering book series (LNICST, volume 45)

Abstract

This paper considers a novel multiple-input multiple-output (MIMO) architecture, which combines the signals in the radio-frequency (RF) domain. Unlike previous approaches, the proposed architecture is exclusively based on the application of different gain factors to the transmitted/received signals, and therefore it avoids the need of including a controllable phase-shifter (or sign switch) for each transmit/receive antenna. From a baseband point of view, the transceiver design consists in obtaining the optimal equal phase transmit (EPT) and equal-phase combining (EPC) beamformers. Interestingly, this problem can be exactly solved in the case of rank-one channels, which can be exploited to construct an iterative algorithm for the general MIMO case. The proposed architecture is evaluated by means of Monte Carlo simulations, which show that the slight performance degradation with respect to previous approaches is justified by the significant reduction in the hardware cost and power consumption.

Keywords

RF-MIMO beamformer equal-phase MIMO beamforming semidefinite relaxation (SDR) 

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References

  1. 1.
    MIMAX: Advanced MIMO systems for maximum reliability and performance (2008), http://www.ict-mimax.eu
  2. 2.
    Boyd, S., Vandenberghe, L.: Convex Optimization. Cambridge University Press, Cambridge (2004)CrossRefMATHGoogle Scholar
  3. 3.
    Gholam, F., Vía, J., Santamaría, I., Wickert, M., Eickhoff, R.: Simplified architectures for analogue antenna combining. In: ICT-MobileSummit 2009, Santander, Spain (June 2009)Google Scholar
  4. 4.
    Huang, D., Letaief, K.B.: Symbol-based space diversity for coded OFDM systems. IEEE Transactions on Wireless Communications 3(1), 117–127 (2004)CrossRefGoogle Scholar
  5. 5.
    Li, S., Huang, D., Letaief, K.B., Zhou, Z.: Pre-DFT processing for MIMO-OFDM systems with space-time-frequency coding  6(11), 4176–4182 (2007)Google Scholar
  6. 6.
    Rahman, M.I., Witrisal, K., Das, S.S., Fitzek, F.H.P., Olsen, O., Prasad, R.: Optimum pre-DFT combining with cyclic delay diversity for OFDM based WLAN systems. In: IEEE 59th Vehicular Technology Conference (VTC 2004-Spring), vol. 4, pp. 1844–1848 (May 2004)Google Scholar
  7. 7.
    Santamaría, I., Elvira, V., Vía, J., Ramírez, D., Pérez, J., Ibáñez, J., Eickhoff, R., Ellinger, F.: Optimal MIMO transmission schemes with adaptive antenna combining in the RF path. In: 6th European Signal Processing Conference (EUSIPCO 2008), Lausanne, Switzerland (August 2008)Google Scholar
  8. 8.
    Vía, J., Elvira, V., Santamaría, I., Eickhoff, R.: Analog antenna combining for maximum capacity under OFDM transmissions. In: IEEE International Conference on Communications (ICC 2009), Dresden, Germany (June 2009)Google Scholar
  9. 9.
    Vía, J., Elvira, V., Santamaría, I., Eickhoff, R.: Minimum BER beanforming in the RF domain for OFDM transmissions and linear receivers. In: IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP 2009), Taipei, Taiwan (April 2009)Google Scholar
  10. 10.
    Vía, J., Santamaría, I., Elvira, V., Eickhoff, R.: A General Criterion for Analog Tx-Rx Beamforming under OFDM Transmissions. IEEE Transactions on Signal Processing 58(4), 2155–2167 (2010)MathSciNetCrossRefGoogle Scholar

Copyright information

© ICST Institute for Computer Science, Social Informatics and Telecommunications Engineering 2010

Authors and Affiliations

  • Fouad Gholam
    • 1
  • Javier Vía
    • 1
  • Alfredo Nazábal
    • 1
  • Ignacio Santamaría
    • 1
  1. 1.Communications Engineering Department (DICOM)University of CantabriaSantanderSpain

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