The Performance of SLNR Beamformers in Multi-user MIMO Systems

  • Khalid W. Hameed
  • Ahmed M. Abdulkhaleq
  • Yasir Al-Yasir
  • Naser Ojaroudi Parchin
  • Ashwain Rayit
  • Majid Al Khambashi
  • Raed A. Abd-AlhameedEmail author
  • James M. Noras
Conference paper
Part of the Lecture Notes of the Institute for Computer Sciences, Social Informatics and Telecommunications Engineering book series (LNICST, volume 263)


Beamforming in multi-user MIMO (MU-MIMO) systems is a vital part of modern wireless communication systems. Researchers looking for best operational performance normally optimize the problem and then solve for best weight solutions. The weight optimization problem contains variables in numerator and dominator: this leads to so-called variable coupling, making the problem hard to solve. Formulating the optimization in terms of the signal to leakage and noise ratio (SLNR) helps in decoupling the problem variables. In this paper we study the performance of the SLNR with variable numbers of users and handset antennas. The results show that there is an optimum and the capacity curve is a concave over these two parameters. The performances of two further variations of this method are also considered.


Beamforming Generalized eigenvalue decomposition MU-MIMO Optimal point SLNR 


  1. 1.
    Alexiou, A., Haardt, M.: Smart antenna technologies for future wireless systems: trends and challenges. IEEE Commun. Mag. 42, 90–97 (2004)CrossRefGoogle Scholar
  2. 2.
    Spencer, Q.H., Peel, C.B., Swindlehurst, A.L., Haardt, M.: An introduction to the multi-user MIMO downlink. IEEE Commun. Mag. 42, 60–67 (2004)CrossRefGoogle Scholar
  3. 3.
    Gesbert, D., Hanly, S., Huang, H., Shitz, S.S., Simeone, O., Yu, W.: Multi-cell MIMO cooperative networks: a new look at interference. IEEE J. Sel. Areas Commun. 28, 1380–1408 (2010)CrossRefGoogle Scholar
  4. 4.
    Spencer, Q.H., Swindlehurst, A.L., Haardt, M.: Zero-forcing methods for downlink spatial multiplexing in multiuser MIMO channels. IEEE Trans. Signal Process. 52, 461–471 (2004)MathSciNetCrossRefGoogle Scholar
  5. 5.
    Peel, C.B., Hochwald, B.M., Swindlehurst, A.L.: A vector-perturbation technique for near-capacity multiantenna multiuser communication-part I: channel inversion and regularization. IEEE Trans. Commun. 53, 195–202 (2005)CrossRefGoogle Scholar
  6. 6.
    Zhang, F., Huang, Y., Jin, S., Jiang, L., Wang, G.: Reduced-backhaul coordinated beamforming for massive MIMO heterogeneous networks. In: 2015 IEEE Wireless Communications and Networking Conference (WCNC), pp. 129–134 (2015)Google Scholar
  7. 7.
    Rashid-Farrokhi, F., Liu, K.R., Tassiulas, L.: Transmit beamforming and power control for cellular wireless systems. IEEE J. Sel. Areas Commun. 16, 1437–1450 (1998)CrossRefGoogle Scholar
  8. 8.
    Yu, W., Lan, T.: Transmitter optimization for the multi-antenna downlink with per-antenna power constraints. IEEE Trans. Signal Process. 55, 2646–2660 (2007)MathSciNetCrossRefGoogle Scholar
  9. 9.
    Shi, S., Schubert, M., Boche, H.: Rate optimization for multiuser MIMO systems with linear processing. IEEE Trans. Signal Process. 56, 4020–4030 (2008)MathSciNetCrossRefGoogle Scholar
  10. 10.
    Tarighat, A., Sadek, M., Sayed, A.H.: A multi user beamforming scheme for downlink MIMO channels based on maximizing signal-to-leakage ratios. In: IEEE International Conference on Acoustics, Speech, and Signal Processing, Proceedings (ICASSP 2005), vol. 3, pp. iii/1129–iii/1132 (2005)Google Scholar
  11. 11.
    Sadek, M., Tarighat, A., Sayed, A.H.: Active antenna selection in multiuser MIMO communications. IEEE Trans. Signal Process. 55, 1498–1510 (2007)MathSciNetCrossRefGoogle Scholar
  12. 12.
    Sadek, M., Tarighat, A., Sayed, A.H.: A leakage-based precoding scheme for downlink multi-user MIMO channels. IEEE Trans. Wirel. Commun. 6, 1711–1721 (2007)CrossRefGoogle Scholar
  13. 13.
    Jung, M., Kim, Y., Lee, J., Choi, S.: Optimal number of users in zero-forcing based multiuser MIMO systems with large number of antennas. J. Commun. Netw. 15, 362–369 (2013)CrossRefGoogle Scholar
  14. 14.
    Hameed, K.W., Abd-Alhameed, R.A., Radwan, A.: Optimal array size for multiuser MIMO. In: IWCMC-SICM, Cyprus (2018)Google Scholar
  15. 15.
    Van Chien, T., Björnson, E.: Massive MIMO communications. In: Xiang, W., Zheng, K., Shen, X. (eds.) 5G Mobile Communications, pp. 77–116. Springer, Cham (2017). Scholar
  16. 16.
    Hameed, K.W., Al-Yasir, Y., Parchin, N.O., Abd-Alhameed, R.A., Excell, P.S.: On the equivalence between Eigen and channel inversion based precoders. In: Miraz, M., Excell, P., Ware, A., Soomro, S., Ali, M. (eds.) iCETiC 2018. LNICST, vol. 200, pp. 161–172. Springer, Cham (2018). Scholar

Copyright information

© ICST Institute for Computer Sciences, Social Informatics and Telecommunications Engineering 2019

Authors and Affiliations

  • Khalid W. Hameed
    • 1
    • 2
  • Ahmed M. Abdulkhaleq
    • 1
    • 2
  • Yasir Al-Yasir
    • 1
  • Naser Ojaroudi Parchin
    • 1
  • Ashwain Rayit
    • 3
  • Majid Al Khambashi
    • 4
  • Raed A. Abd-Alhameed
    • 1
    Email author
  • James M. Noras
    • 1
  1. 1.Bradford UniversityBradfordUK
  2. 2.Al-Nahrain UniversityBaghdadIraq
  3. 3.SARAS Technology LimitedLeedsUK
  4. 4.Al-Zahra College for WomenMuscatOman

Personalised recommendations