
This simulation code package is mainly used to reproduce the results of the following paper [1]:

[1] Y. Chen and L. Dai, “Non-stationary channel estimation for extremely large-scale MIMO,” IEEE Trans. Wireless Commun., vol. 23, no. 7, pp. 7683-7697, Jul. 2024. 

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If you use this simulation code package in any way, please cite the original paper [1] above. 
 
The author in charge of this simulation code pacakge is: Yuhao Chen (email: chen-yh21@mails.tsinghua.edu.cn).

Reference: We highly respect reproducible research, so we try to provide the simulation codes for our published papers (more information can be found at: 
http://oa.ee.tsinghua.edu.cn/dailinglong/publications/publications.html). 

Please note that the MATLAB R2022b is used for this simulation code package,  and there may be some imcompatibility problems among different MATLAB versions. 

Copyright reserved by the Broadband Communications and Signal Processing Laboratory (led by Dr. Linglong Dai), Beijing National Research Center for Information Science and Technology (BNRist), Department of Electronic Engineering, Tsinghua University, Beijing 100084, China. 

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Abstract of the paper: 

Extremely large-scale multiple-input multiple-output is considered as a key technology for future 6G communications. To realize effective precoding, channel estimation schemes are essential to acquire precise channel state information (CSI), while most existing schemes work relying on the spatial stationary assumption. However, in XL-MIMO systems, the spatial non-stationary effect natually exists. Such effect can hardly be recognized by most existing channel estimation schemes, leading to a severe accuracy loss of channel estimation. In order to deal with this problem, we study the spatial non-stationary channel estimation in XL-MIMO systems in this paper. Specifically, the spatial non-stationary channel in an XL-MIMO system is converted to a series of spatial stationary channels by a proposed group time block code (GTBC) based signal extraction scheme. The key idea is to artificially create the time-domain relevance of non-stationary effect, which brings XL-MIMO the ability to recognize such effect in the space domain.	Based on the extracted signals, an on-grid GTBC-based polar-domain simultaneous orthogonal matching pursuit (GP-SOMP) algorithm and an off-grid GTBC-based polar-domain simultaneous iterative gridless weighted (GP-SIGW) algorithm are proposed to effectively estimate the non-stationary channel. Then, analyses of the complexities and performances of the above two algorithms are carried out. Finally, numerical results reveal that the proposed algorithms can recognize the spatial non-stationary effect and realize a much more accurate channel estimation than existing schemes.
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How to use this simulation code package?

Fig. 6 can be obtained by running main_NMSE_vs_overhead.m by setting "Rmin=5, Rmax=10" and "Rmin=400, Rmax=450" respectively.

Fig. 7 can be obtained by running main_NMSE_vs_SNR.m by setting "Rmin=5, Rmax=10" and "Rmin=400, Rmax=450" respectively.

Fig. 8 can be obtained by running main_NMSE_vs_subarray.m
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Enjoy the reproducible research!