Measurements and Analysis of Secondary User Device Effects on Digital Television Receivers

This is the published version. Copyright © 2009 Newman et al.This article presents results from a study of the potential effects of secondary users operating in unoccupied television spectrum. Television spectrum is known within the wireless communications community as being underutilized, making it a prime candidate for dynamic spectrum access. The proposed use of this open spectrum has prompted questions concerning the quantity of available channel space that could be used without negative impact on consumers who view digital television broadcasts and the viability of secondary use of open channels immediately adjacent to a digital television broadcast channel. In this work, we investigate secondary device operation in the channels directly adjacent to a desired television channel, and the effects upon a selection of consumer digital television (DTV) receivers. Our observations strongly suggest that secondary users could operate "White Space Devices" (WSDs) in unoccupied channel bandwidth directly adjacent to a desired digital television (DTV) channel, with no observable adverse impact upon the reception of the desired channel content

A design workflow for software defined radios

Thesis (M.S.)--University of Kansas, Electrical Engineering & Computer Science, 2007.Current technology and policy have created an apparent spectrum scarcity, a situation in which it seems there is not enough available RF spectrum to deploy the next generation of wireless services. It has been shown that this appearance is incorrect because the majority of licensed spectrum is unutilized. In order to address this problem a new technology, the spectrum sensing cognitive radio, has been proposed. Such a radio would be able to locate and use licensed spectrum while avoiding interference with the licensed user, a technique dubbed dynamic spectrum access. This idea has sparked a range of new technologies and algorithms for supporting dynamic spectrum access. Many of the cognitive systems use highly complex algorithms for enabling dynamic spectrum access. With a variety of hardware systems available to run these algorithms, it is becoming necessary to have a common interface to the software defined radio. In order to meet the growing demands for interoperability, this thesis proposes a workflow for developing new software defined radio platforms. This process is verified through development of the University of Kansas Agile Radio platform. Using the knowledge garnered from the development of this system a generic software defined radio control interface is developed. Such a system will allow the development of a hardware agnostic cognitive network stack

Measurements and Analysis of Secondary User Device Effects on Digital Television Receivers

This article presents results from a study of the potential effects of secondary users operating in unoccupied television spectrum. Television spectrum is known within the wireless communications community as being underutilized, making it a prime candidate for dynamic spectrum access. The proposed use of this open spectrum has prompted questions concerning the quantity of available channel space that could be used without negative impact on consumers who view digital television broadcasts and the viability of secondary use of open channels immediately adjacent to a digital television broadcast channel. In this work, we investigate secondary device operation in the channels directly adjacent to a desired television channel, and the effects upon a selection of consumer digital television (DTV) receivers. Our observations strongly suggest that secondary users could operate “White Space Devices” (WSDs) in unoccupied channel bandwidth directly adjacent to a desired digital television (DTV) channel, with no observable adverse impact upon the reception of the desired channel content

Submitted to DySPAN’07 Feasibility of Dynamic Spectrum Access in Underutilized Television Bands

Abstract — This paper presents the preliminary results from a feasibility study regarding the operation of secondary spectrum users within unused television spectrum. Television spectrum is known within the wireless communications community as being underutilized, making it a prime candidate for dynamic spectrum access. Nevertheless, the quality of this spectrum for enabling secondary transmissions has never been assessed. Two unique scenarios are examined:(i) the possibility of unlicensed devices interfering with digital TV reception, and (ii) the possibility of secondary users experiencing interference when operating within close proximity to television towers. With respect to the former, we investigate the critical operating parameters for developing the technical rules for device operation in bands adjacent to a digital television transmission. Regarding the latter, we examine, via measurement campaign, how non-ideal transmission properties of television broadcasts, including intermodulation and saturation effects, can potentially impair the performance of secondary transmissions. Index Terms—Digital TV, spectrum measurements, spectrum white space I