A Review on Comparative Study of Indoor Propagation Model Below and Above 6 GHz for 5G Wireless Networks

To satisfy the demand for ever-increasing data rates in the mobile networks, and that the high demands for the future applications in the 5G system require more capacity. In the microwave band below 6 GHz, most of the available bands are occupied; hence, the microwave band above 6 GHz and mmWave band can be used for the 5G system to cover the bandwidth required for all 5G applications. In this paper, the propagation characteristics at three different bands above 6 GHz (19, 28, and 38 GHz) are investigated in an indoor corridor environment for line of sight (LOS) and non-LOS (NLOS) scenarios. Five different path loss models are studied for this environment, namely, close-in (CI) free space path loss, floating-intercept (FI), frequency attenuation (FA) path loss, alpha-beta-gamma (ABG), and close-in free space reference distance with frequency weighting (CIF) models. Important statistical properties, such as power delay profile (PDP), root mean square (RMS) delay spread, and azimuth angle spread, are obtained and compared for different bands. The paper studied and discusses the comparative propagation model below and above 6 GHz characteristics for 5G wireless networks channels at two different frequency bands. In which two different wireless networks models have been proposed and analyzed to study the loss due to the diffraction from wall edge and the loss of high frequency band. The wideband measurements were summarized and conducted at 3.5 GHz and 28 GHz using a 5G channel sounder including the gains of antennas, with a high chip rate of 1000 Mcps. All the key system parameters are summarized for path loss; excess delay and power delay profile were calculated. The frequency response of the entire system and signal loss due to the edge shadow and high frequency was monitored, investigated and discussed accordingly. Two separate models have been proposed to study and calculate the loss due to the diffraction from wall edge and the loss of high frequency band/ antennas. The wideband including waveguide horn antenna measurements were conducted and calculated at 3.5 GHz and 28 GHz using a 5G channel sounder including the gains of antennas with a high chip rate of 1000 Mcps. The 5G channel parameters for path loss, excess delay and power delay profile were investigated, summarized and calculated. The signal loss due to the edge shadow and high frequency was also investigated.