Television Activity Detection: A Statistical-Based Opportunistic Spectrum Use Approach-Edición Única

Abstract

The following thesis document develops a research proposal that can be though of as an alternate Cognitive Radio method, designed for the detection of periodic patterns embedded on Analog Television Composite Video Signals. The method strives for reliable and efficient spectrum reutilization through the assertion of TV activity on any particular spectrum frequency. In order to take advantage of the properties of Barker Codes autocorrelation functions, an expansion is proposed based on a pre-processing scheme using signal masking. Once it is masked, the baseband composite video signal will then be passed through a filter matched to a Barker Code-type pattern and a correlation spike will appear as an indicator whenever a valid pattern is found on the incoming signal. The proposed technique will serve as a television activity detection tool and will be capable of operating conditions in noisy environments where the SNR may drop down to -20dB. It represents a low cost and high efficiency method to promote spectrum reutilization, as all secondary devices will have a reliable tool for spectrum sensing that will allow TV activity awareness before transmitting and causing harmful inband interference to licensed broadcasting stations/devices. The following proposal to be developed provides useful contributions to the state-of-the-art developments on Cognitive Radio and TV activity detection as it: Guarantees the feasibility for the implementation of new wireless networks within areas that are already covered by other wireless service providers. • Will be applicable to assess the presence/absence of analog television activity on the 700MHz frequency band, and will also be expandable to other spectrum allocations. • Offers implementation flexibility as it can be applied to any wireless standard technology. • Provides an objective criterion to support or disincline decisions for projects in the wireless service market. • Provides tools to improve spectrum utilization. The designed technique is based on a simple idea and supported by decades of proven mathematical and statistical theories. For such reason, it represents a strong alternative for future field applications; besides, it provides further improvement areas that might be considered in future research works.