Estimation of Uplink Channels for Multiple Users Using Tensor Modeling in RIS-Aided MISO Communication

Abstract

In this paper estimation of uplink channels using tensor modeling is addressed for multiple users in a reconfigurable intelligent surface (RIS)-aided multiple-input single-output (MISO) communication. The coherence interval is divided into structured frames of pilot symbols transmitted by the users and pattern of phase shifts applied by the RIS in order to estimate the base station (BS)-RIS channels and the RIS-user’s channels. Estimation methods that use tensor modeling including Khatri-Rao Factorization (KRF) and bilinear alternating least squares (BALS) are applied to the signal model. Numerical results show that both KRF and BALS are superior to the LS estimator by 10 dB SNR for the correlated Rayleigh fading channel model.

Keywords

• Reconfigurable Intelligent Surfaces
• Multi-User MISO
• Channel Estimation
• Least Squares
• Khatri-Rao Factorization
• Parallel Factor Decomposition

References

1. [1] C. Huang, A. Zappone, G. C. Alexandropoulos, M. Debbah and C. Yuen, "Reconfigurable Intelligent Surfaces for Energy Efficiency in Wireless Communication," in IEEE Trans. Wireless Commun., vol. 18, no. 8, pp. 4157-4170, Aug. 2019.
2. [2] M. Di Renzo et al., "Smart Radio Environments Empowered by Reconfigurable Intelligent Surfaces: How It Works, State of Research, and The Road Ahead," in IEEE J. Sel. Areas Commun., vol. 38, no. 11, pp. 2450-2525, Nov. 2020.
3. [3] W. U. Khan, E. Lagunas, A. Mahmood, B. M. ElHalawany, S. Chatzinotas and B. Ottersten, "When RIS Meets GEO Satellite Communications: A New Sustainable Optimization Framework in 6G," IEEE VTC2022-Spring, Helsinki, Finland, 2022, pp. 1-6.
4. [4] YILMAZ Ü, Güler Ü "On Orbit Demonstration of Pointing Accuracy of Ground Antennas by a Flying GEO Satellite." Sakarya University Journal of Computer and Information Sciences (Online), 6, ss.32 - 36, 2023.
5. [5] Elorbany K, BAYILMIS C, BALTA S "A Smart Socket Equipped With IoT Technologies for Energy Management of Electrical Appliances." Sakarya University Journal of Computer and Information Sciences (Online), 4, ss.347 - 353, 2021.
6. [6] ARAT F, Demirci S "Experimental Analysis of Energy Efficient and QoS Aware Objective Functions for RPL Algorithm in IoT Networks." Sakarya University Journal of Computer and Information Sciences (Online), 4, ss.192 - 203, 2021.
7. [7] M. Di Renzo et al., "Reconfigurable Intelligent Surfaces vs. Relaying: Differences, Similarities, and Performance Comparison," in IEEE Open J. Commun. Soc., vol. 1, pp. 798-807, 2020.
8. [8] T. L. Jensen and E. De Carvalho, "An Optimal Channel Estimation Scheme for Intelligent Reflecting Surfaces Based on a Minimum Variance Unbiased Estimator," in Proc. IEEE ICASSP, Barcelona, Spain, 2020, pp. 5000-5004.

9. [9] Q. -U. -A. Nadeem, H. Alwazani, A. Kammoun, A. Chaaban, M. Debbah and M. -S. Alouini, "Intelligent Reflecting Surface-Assisted Multi-User MISO Communication: Channel Estimation and Beamforming Design," in IEEE Open J. Commun. Soc., vol. 1, pp. 661-680, 2020.
10. [10] R. V. Şenyuva, "Channel Estimation for RIS aided MISO System," SIU, Istanbul, Turkiye, 2023, pp. 1-4.
11. [11] Z. Wang, L. Liu and S. Cui, "Channel Estimation for Intelligent Reflecting Surface Assisted Multiuser Communications," in IEEE WCNC, Seoul, Korea (South), 2020, pp. 1-6.
12. [12] G. T. de Araújo, A. L. F. de Almeida and R. Boyer, "Channel Estimation for Intelligent Reflecting Surface Assisted MIMO Systems: A Tensor Modeling Approach," in IEEE J. Sel. Topics in Signal Process., vol. 15, no. 3, pp. 789-802, April 2021.
13. [13] L. Wei, C. Huang, G. C. Alexandropoulos and C. Yuen, "Parallel Factor Decomposition Channel Estimation in RIS-Assisted Multi-User MISO Communication," in IEEE SAM, Hangzhou, China, 2020, pp. 1-5.
14. [14] L. Wei, C. Huang, G. C. Alexandropoulos, C. Yuen, Z. Zhang and M. Debbah, "Channel Estimation for RIS-Empowered Multi-User MISO Wireless Communications," in IEEE Trans. Commun., vol. 69, no. 6, pp. 4144-4157, June 2021.
15. [15] C. Beldi, A. Dziri, F. Abdelkefi and H. Shaiek, "PARAFAC Decomposition based Channel Estimation for RIS-aided Multi-User MISO Wireless Communications," in IWCMC, Marrakesh, Morocco, 2023, pp. 1537-1542.
16. [16] K. Ardah, S. Gherekhloo, A. L. F. de Almeida and M. Haardt, "Double-RIS Versus Single-RIS Aided Systems: Tensor-Based MIMO Channel Estimation and Design Perspectives," in Proc. IEEE ICASSP, Singapore, 2022, pp. 5183-5187.
17. [17] T. G. Kolda and B. W. Bader, "Tensor decompositions and applications," SIAM Rev., vol. 51, no. 3, pp. 455-500, 2009.
18. [18] P. Comon, X. Luciani, and A.L.F. de Almeida, "Tensor decompositions, alternating least squares and other tales," J. Chemometrics, vol. 23, no. 7-8, pp. 393-405, 2009.