2021/06/02 by Anish Pradhan, Pradhan, Anish, J. Kartheek Devineni +5 · 1 citation
Engineering · Materials Science · #Advanced Wireless Communication Technologies #FOS: Computer and information sciences #FOS: Electrical engineering #Information Theory (cs.IT) #Metamaterials and Metasurfaces Applications #Millimeter-Wave Propagation and Modeling #Signal Processing (eess.SP) #electronic engineering #information engineering
paper · pdf · doi:10.48550/arxiv.2106.01225
openalex publication_date 2021/06/02 · openalex created_date 2022/07/25 · openalex updated_date 2026/07/28
The operation of Terahertz (THz) communication can be significantly impacted\nby the interaction between the transmitted wave and the molecules in the\natmosphere. In particular, it has been observed experimentally that the signal\nundergoes not only molecular absorption, but also molecular re-radiation. Two\nextreme modeling assumptions are prevalent in the literature, where the\nre-radiated energy is modeled in the first as additive Gaussian noise and in\nthe second as a scattered component strongly correlated to the actual signal.\nSince the exact characterization is still an open problem, we provide in this\npaper the first comparative study of the performance of a reconfigurable\nintelligent surface (RIS) assisted THz system under these two extreme models of\nre-radiation. In particular, we employ an RIS to overcome the large pathloss by\ncreating a virtual line-of-sight (LOS) path. We then develop an optimization\nframework for this setup and utilize the block-coordinate descent (BCD) method\nto iteratively optimize both RIS configuration vector and receive beamforming\nweight resulting in significant throughput gains for the user of interest\ncompared to random RIS configurations. As expected, our results reveal that\nbetter throughput is achieved under the scattering assumption for the molecular\nre-radiation than the noise assumption.\n