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

Abstract

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.

Licensing open spectrum systems

“…Those are the cases of the 5 GHz band and the TV band FCC rules. As a general statement, the ubiquitous secondary user communication is difficult in real systems and the interference impact can dramatically degraded the primary user communication link [6]. Indeed, the band holders claim that even if a cognitive radio device detects a free space for transmitting, it can interfere to another primary user due to time-space correlations.…”