TV 화이트 스페이스에서 인식 라디오 네트워크이 전송범위 추정에 관한 연구

Abstract

This thesis presents a simulation model to calculate coverage of TV band devices (TVBDs) in TV white space (TVWS), considering the presence of interference by Digital TV (DTV). Recently, the Federal Communications Commission (FCC) proceedings have considered the notion of unlicensed device operation in the television broadcast bands due to the lack of bandwidth at the low frequency spectrum. In January 2010, the IEEE established a new standard task group to develop a standard for 802.11 WLANs operating in the TV white space (TVWS). This approval brings the ever increasing interest in cognitive radio techniques. The performance loss of DTV has concerned in the previous works for TVWS since incumbent services must be protected from interference by TVBDs. Compared to the previous works, this thesis concentrates on the performance of the secondary system such as TVBD. Based on the standard of IEEE 802.11 af, this thesis have considered the realistic simulation environments and developed the software for TVBD. For the accurate estimation of the achievable data rate, additional features should be in the simulation. The co-channel or adjacent interferences aroused from DTV signal are also taken into account with pass loss models. The packet error rate (PER) of TVBD of each modulation and coding scheme (MCS) is estimated and combined with the link budget analysis. This thesis estimate the TVBD service coverage for different ranges of TVBD transmit antenna height by using a large scale fading channel model and the proposed scheme. The estimation of TVBD service coverage applies the keep-out distance specified in the Federal Communication Commission (FCC) rule. Simulation results based on both methods show that the TVBD service coverage located outside the DTV protected contour is reduced due to neighboring DTV service and the reducing trend about the large scale fading channel is similar to that of the proposed scheme. These results demonstrate that the proposed scheme can be used to estimate the service coverage of TVBD networks with low complexity and contribute to determine regulatory policies.