UBC Theses and Dissertations

UBC Theses Logo

UBC Theses and Dissertations

Characterization of persistent multipath components in indoor and outdoor environment at 30 GHz Liya, Badrun Naher

Abstract

Millimeter-wave (mm-wave) frequency bands are under active consideration for use as short-range mobile broadband links in fifth generation (5G) cellular access networks. Although channel characteristics such as path loss, delay spread and fading distributions have been extensively studied for mm-wave channels, the study of the time-varying nature of the channel is still in its early stages. In this work, we studied the lifetime of multipath components of the mm-wave channel, usually referred to as persistence. An important time-varying characteristic of the mm-wave channel, persistence may affect the capacity, and beam training and beam tracking process of mm-wave systems. We developed a 30-GHz vector-network-analyzer-based channel sounder suitable for characterizing multipath persistence and verified its performance through a three-stage verification procedure; time and frequency domain verifications, two-ray verification, and measurements conducted using the National Institute of Standards and Technology (NIST) mm-wave channel sounder verification artifact. The primary goal of this work was to characterize multipath persistence based on measurements conducted at 30 GHz in indoor and outdoor urban microcell environments. Through analysis of our measurement data, we confirmed that the log-logistic distribution provides an accurate description of persistence and showed how the physical attributes of the channel influence the parameters of the distribution. We also verified that a weak correlation exists between average received power and length of the persistent path. We further showed that the rate of angular change of a multipath component throughout its lifetime follows a Laplace distribution and that the angular rate depends on the distance of reflectors from the transmitter-receiver path. We used these results to propose a simulation model that can be used to make simple ray tracing simulations more realistic and to assess the effect of persistence and variations in the angular rate on the capacity, and beam training and tracking process of mm-wave systems.

Item Citations and Data

Rights

Attribution-NonCommercial-NoDerivatives 4.0 International