Update README.md

README.md

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 |18|[Near-field Localization with a Reconfigurable Intelligent Surface Acting as Lens](https://github.com/henkwymeersch/RISLensLocalization)|Zohair Abu-Shaban, etal.|
 |19|[Channel Estimation for RIS Assisted Wireless Communications: Part II - An Improved Solution Based on Double-Structured Sparsity](http://oa.ee.tsinghua.edu.cn/dailinglong/publications/code/Channel%20estimation%20for%20RIS%20assisted%20wireless%20communications.zip)| Linglong Dai, etal.|
 |20|[Passive Beamforming and Information Transfer Design for Reconfigurable Intelligent Surfaces Aided Multiuser MIMO Systems](https://github.com/Yuan-Xiaojun/MIMO_SingleRIS)|W. Yan, etal.|
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+|21|[Passive Beamforming and Information Transfer via Large Intelligent Surface](https://github.com/Yuan-Xiaojun/Matlab_SIMO)|W. Yan, etal.|
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