Systems Engineering and Electronics ›› 2022, Vol. 44 ›› Issue (3): 998-1006.doi: 10.12305/j.issn.1001-506X.2022.03.32

• Communications and Networks • Previous Articles     Next Articles

Progressive channel estimation method for RIS-assisted communication system

Jian DANG1,2, Yewei LI1, Yongdong ZHU3, Rongbin GUO3, Zaichen ZHANG1,2,*, Liang WU1,2   

  1. 1. School of Information Science and Engineering, Southeast University, Nanjing 210096, China
    2. Purple Mountain Laboratories, Nanjing 211111, China
    3. Zhejiang Lab, Hangzhou 311121, China
  • Received:2021-05-10 Online:2022-03-01 Published:2022-03-10
  • Contact: Zaichen ZHANG

Abstract:

Aiming at the problem that the reflection coefficient is randomly configured in the existing channel estimation methods of reconfigurable intelligent surface (RIS), resulting in low signal-to-noise ratio at the receiver, a progressive channel estimation method with specific reflection coefficient is proposed. In this method, the optimal reflection coefficient at the current time is calculated by using the incomplete channel state information (CSI). And then, the optimal reflection coefficient and the random reflection coefficient are used to generate the mixed reflection coefficient according to the weighting coefficient. The RIS configures the hybrid reflection coefficient at the next time, and the receiver uses the relaxed minimum mean square error (RMMSE) channel estimation method to update the incomplete channel state information. Simulation results show that the proposed method can not only obtain accurate channel estimation results, but also continuously increase the signal-to-noise ratio of the receiver and reduce the pilot overhead in the estimation process, so as to improve the spectral efficiency of RIS-assisted wireless communication system.

Key words: reconfigurable intelligent surface (RIS), channel estimation, mixed reflection coefficients, relaxed minimum mean square error (RMMSE), signal-to-noise ratio

CLC Number: 

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