(A) study on channel assignment, interference analysis and 4-port TEM cell in digital broadcasting frequency bands

Abstract

A study on the channel assignment, interference analysis and 4-port TEM cell in digital broadcasting frequency bands is presented in this thesis. We analyze the interference effect caused by introduction of new broadcasting system and design efficient broadcasting network. Also, we propose a method to improve the electromagnetic field distribution of 4-port transverse electromagnetic (TEM) cell, which is a test device to measure electromag-netic interference and electromagnetic compatibility (EMC) of the broadcasting equipment, and evaluate re-ceiver performance in the near-field environment. With evolution from analog to digital broadcasting, from fixed to mobile broadcasting and from high definition to ultra-high definition broadcasting, frequencies to intro-duce new broadcasting services are indispensable. However, as new broadcasting systems continue to appear, influence of mutual interference between existing and new broadcasting devices increases further, and the fre-quency issues become more and more serious. The influence of interference between the newly introduced system and the existing system is analyzed, and broadcasting channels are assigned so that the frequency for broadcasting services can be efficiently used. New broadcasting system has to operate within the frequency band used by existing broadcasting system due to limited frequency resources. Therefore, we have assigned broadcasting channels to meet the radio frequency (RF) interference constraints and reception requirements of both systems while minimizing interference effects. As an alternative standard electromagnetic field generator, a 4-port TEM cell can be used for an EMC emission and immunity test. A new method to suppress unwanted field components in a 4-port TEM cell is pre-sented to improve the accuracy of EMC test of the broadcasting devices. By introducing the narrow slits in in-ternal septa, which are transverse with respect to the direction of wave propagation, the 4-port TEM cell can provide improved standard electromagnetic field distribution with the much-lowered unwanted field component inside the usable test volume. A performance assessment for the protection of broadcasting equipment due to different interference in near- and far-field environments is presented. A terrestrial ultra-high definition (UHD) transceiver system based on the Advanced Television System Committee (ATSC) 3.0 standard is modeled and the interference effect according to the shape and direction of the receiving antenna is analyzed.