The Design And Implementation Of Indoor TV White Spaces Software Defined Radio System

With the decreasing of wireless spectrum resources,especially the exhaustion of available spectrum resources,it is a promising vision to exploit white spaces,that is,vacant VHF and UHF TV channels,to meet the rapidly growing demand for wireless data services in both outdoor and indoor scenarios.Band 470MHz-806 MHz has low frequency and the characteristics of wide signal coverage and strong penetration.It is suitable for wide network coverage and low cost of networking.Therefore,it is internationally recognized as "digital dividend" band.While most prior works have focused on outdoor white space,the indoor story is largely open for investigation.Motivated by this observation and discovering that 70% of the spectrum demand comes from indoor environment,this work conducted a comprehensive study to explore indoor available spectrum space.Through hardware design and software radio technology,this thesis develops a set of radio detection platform suitable for China,carries out field testing and obtains valuable research data.The main work done in this thesis includes these items below:1.Aiming at the problem that the spectrum formats of TV spectrum in China(including Hong Kong)are different from those in Europe and the United States,this thesis analyses the digital and analog signal format in China(Hong Kong adopts Chinese digital TV signal standard).Then designs a complete White Space detection system,which can accurately measure the TV spectrum in Hong Kong,which solves the problem that the commonly used energy detection methods cannot detect weak signals.2.Carry out a comprehensive study to explore indoor white spaces.This work firstly conduct a large-scale measurement study and compare outdoor and indoor TV spectrum occupancy at 30+ diverse locations in a typical metropolis—Hong Kong.The results showed that abundant white spaces are available in different areas in Hong Kong,which account for more than 50% and 70% of the entire TV spectrum in outdoor and indoor scenarios,respectively.3.Although there are substantially more white spaces indoors than outdoors,there have been very few solutions for identifying indoor white space.To fill in this gap,this work develops a data-driven,low-cost indoor white space identification system for White-space Indoor Spectrum EnhanceR(WISER),to allow secondary users to identify white spaces for communication without sensing the spectrum themselves.The test results show that WISER can identify 30%–40% more indoor white spaces with negligible false alarms,as compared to alternative baseline approaches.WISER saves a lot of hardware cost of spectrum detection and achieves very satisfactory results.Later,large-scale tests will be carried out in different buildings in order to obtain more test data to improve the system and algorithm.