Yu, Z., An, J., Basar, E., Gan, L., & Yuen, C. (2024). Environment-Aware Codebook Design for RIS-Assisted MU-MISO Communications: Implementation and Performance Analysis. IEEE Transactions on Communications, 72(12), 7466–7479. https://doi.org/10.1109/tcomm.2024.3415619
Abstract:
Reconfigurable intelligent surface (RIS) provides
a new electromagnetic response control solution, which can
proactively reshape the characteristics of wireless channel
environments. In RIS-assisted communication systems, the acquisition
of channel state information (CSI) and the optimization
of reflecting coefficients constitute major design challenges.
To address these issues, codebook-based solutions have been
developed recently, which, however, are mostly environmentagnostic.
In this paper, a novel environment-aware codebook
protocol is proposed, which can significantly reduce both
pilot overhead and computational complexity, while maintaining
expected communication performance. Specifically, first of all,
a channel training framework is introduced to divide the training
phase into several blocks. In each block, we directly estimate
the composite end-to-end channel and focus only on the transmit
beamforming. Second, we propose an environment-aware
codebook generation scheme, which first generates a group
of channels based on statistical CSI, and then obtains their
corresponding RIS configuration by utilizing the alternating
optimization (AO) method offline. In each online training block,
the RIS is configured based on the corresponding codeword
in the environment-aware codebook, and the optimal codeword
resulting in the highest sum rate is adopted for assisting in the
downlink data transmission. Third, we analyze the theoretical
performance of the environment-aware codebook-based protocol
taking into account the channel estimation errors. Finally, numerical simulations are provided to verify our theoretical analysis
and the performance of the proposed scheme. In particular,
the simulation results demonstrate that our protocol is more
competitive than conventional environment-agnostic codebooks.
License type:
Publisher Copyright
Funding Info:
This research / project is supported by the Sichuan Science and Technology Program - NA
Grant Reference no. : 2023YFSY0008, 2023YFG0291
This research / project is supported by the TUBITAK - NA
Grant Reference no. : 120E401
This research / project is supported by the Ministry of Education, Singapore - Academic Research Fund Tier 2
Grant Reference no. : MOE-T2EP50220- 0019
This research / project is supported by the Science and Engineering Research Council of Agency for Science, Technology and Research (A*STAR) Singapore - Manufacturing, Trade, and Connectivity Programmatic Fund
Grant Reference no. : M22L1b0110