Channel Characterization for RIS-enabled Indoor mmWave Communications

Transmission at Millimeter-wave (mmWave) frequencies is an essential technology in 5G systems and seen to be the same for 6G and beyond. The importance of utilizing mmWave stems from the larger bandwidth and also the less-congested spectrum of this high-frequency band. However, this comes at the cost of having unfavorable propagation features like higher path loss, associated with the higher frequency, and higher blockage probability due to shorter wavelengths and less diffraction and scattering capabilities. It is therefore necessary to obtain a valid model for mmWave channels since propagation features, which impact system performance largely, are different from signals at lower frequencies (<10 GHz). The shortcoming of mmWave being easily blocked is more pronounced in indoor environments where more closely-spaced physical obstacles exist. Accordingly, this work first suggests a channel model simulator for indoor mmWave links using the NYUSIM channel simulator. Then, we propose to incorporate the RIS technique to improve the coverage of indoor mmWave signals by manipulating the directions of the signals. The performance investigations, via numerical results, show that RIS-assisted receivers can compensate effectively for the higher blockage loss in mmWave band.