Signal Interference modeling and analysis for heterogeneous wireless networks

Abstract

Recently, the implementation of fourth-generation (4G) cellular systems and the emergence of various types of wireless services have significantly increased the frequency of equipment usage and wireless data usage. Because frequency resources are limited but the demand for wireless bandwidth is increasing, it is important to utilize frequency resources efficiently and various studies are in progress. In particular, for upcoming fifth-generation (5G) cellular systems, wireless transmission techniques, such as small cells, interference alignment, beamforming, and cooperative communications, are being considered and the common element in next-generation technologies is the goal of reducing or avoiding signal interference to maximize capacity. Interference management is the key solution for efficient spectrum utilization, and therefore, the characterization of interference is very important. In this dissertation, the aggregate received interference for wireless networks is modeled statistically, and it is applied to a theoretical analysis of system performance due to interference in heterogeneous wireless networks. The applicable scenarios are the environments, such as ad hoc networks, cognitive radio networks, and heterogeneous systems, that cannot control interference in a centralized way. Because the geometric properties and the statistical characteristics of a wireless propagation channel mainly determine the distribution of the received interference for these uncontrollable-interference scenarios, the aggregate interference is characterized under general geometric and channel environments. For evaluating system performance due to interference, the coexistence scenario of two cellular systems in adjacent bands is used. Because spectrum bands are packed tightly to minimize the unused spectrum between bands, adjacent channel interference (ACI) is considered important. After analyzing system performance, an interference management method for dynamic spec...