Channel Orthogonalization in Panel-Based LIS
<|reference_start|>Channel Orthogonalization in Panel-Based LIS: Large intelligent surface (LIS) has gained momentum as a potential 6G-enabling technology that expands the benefits of massive multiple-input multiple-output (MIMO). On the other hand, orthogonal space-division multiplexing (OSDM) may give a promising direction for efficient exploitation of the spatial resources, analogous as what is achieved with orthogonal frequency-division multiplexing (OFDM) in the frequency domain. To this end, we study how to enforce channels orthogonality in a panel-based LIS scenario. Our proposed method consists of having a subset of active LIS-panels coherently serving a set of users, and another subset of LIS-panels operating in semi-passive mode by implementing a receive and re-transmit (RRTx) process. This results in an inter-symbol interference (ISI) channel, where we characterize the semi-passive processing required to achieve simultaneous orthogonality in time and space. We then employ the remaining degrees of freedom (DoFs) from the orthogonality constraint to minimize the semi-passive processing power, where we derive a closed-form global minimizer, allowing for efficient implementation of the proposed scheme.<|reference_end|>
@article{alegría2024channel,
    title={Channel Orthogonalization in Panel-Based LIS},
    author={Juan Vidal Alegr'ia, Ove Edfors},
    journal={arXiv preprint arXiv:2405.01919},
    year={2024},
    archivePrefix={arXiv},
    eprint={2405.01919},
    primaryClass={cs.IT eess.SP math.IT}
}