The modification of current cellular networks, operating in ultra-high frequency (UHF) bands, to support high data rates with optimum coverage is leading to severe bandwidth congestion. As millimeter waves holding large unoccupied bandwidth are among the solutions, an investigation into the wideband characteristics of millimeter wave propagation is paramount. Results from such an investigation can be used for planning and designing indoor 5G wireless communication networks. The main objective of the paper was therefore to simulate and analyze the propagation characteristics of millimeter wave propagation in an indoor complex environment considering the geometry and motion of objects. Intelligent Ray Tracing (IRT) model was employed to predict wideband parameters that affect the propagation of millimeter waves on the second floor of Building-412 of Haramaya University. Propagation considered in this research was mainly from the direct path, single and two-times reflections, and diffraction from moving objects, walls, and indoor objects. The simulation results demonstrated that human shadows near receiver locations significantly obstructed and affected signal strength. Furthermore, the movement of persons in the corridor of the building caused temporal variations of received power, path loss, and delay spread in NLOS. Results were compared with CI path loss model parameters are derived from measurement and indicated that CI path loss model fits the best in indoor environments when compared to other models. As a result, the CI path loss model is chosen to validate the path loss predicted in this paper. This implies that the geometry and motion of objects impact indoor propagation, and hence indoor geometry and motion of objects need to be considered in planning and designing indoor wireless networks.

Future high densification wireless networks come with high handoff rates, which require knowledge of mobile speed. Mobile speed estimation is crucial for optimizing handover to reduce call drops and network signaling flow, optimize traffic scheduling, improve quality of service, achieve resource optimization, mobility load balancing, channel quality feedback enhancement, and energy efficiency. In this paper, we present a low complexity mobile speed estimation model using count of peaks and troughs of the received signal envelop. We simulated the model in Matlab® and our result shows that the model has a maximum error of 0.25 m/sec. The model has two advantages. First, it does not require measurement of the received signal power; it only counts envelop peaks and troughs. Second, the model is independent of dc offset inherent in the radio receivers. However, the model has one limitation- it does not give the crossing component of a mobile’s velocity.

Millimeter waves hold strong promise for future multi-Giga wireless communication due to the large available bandwidth. Due to the short wavelength of millimeter waves traveling a short distance, experiencing severe multipath, leading to large delay spread and path loss. i.e. large inter-symbol interference. However, the wideband propagation characteristics of these E-bands are not well studied. Therefore, in this paper, we aim to investigate the propagation characteristics of millimeter waves in the outdoor market at E-Band. In our paper, the Intelligent Ray Tracing model is used to predict wideband parameters that affect the propagation of millimeter waves by considering the geometry of environments. In this research, the biggest marketplace in Africa, Merkato is considered as a case study. We have found out that the propagation is mainly due to direct path as well as single and two-times reflections and diffractions from building walls. In particular, we have observed that 73 GHz produces the best outcome for path loss and received power when compared with other frequencies. A good agreement is observed between the simulation, ABG, and CI path loss model.