HDTV: Ghosts out of the machine

Communications giant Motorola claims it has solved a potentially serious glitch in high-definition and digital television (HDTV) broadcasting that prevents quality viewing in cities.

The company on Monday released details of the US side of the development -- a new digital signal processing architecture built-in to its latest MCT2100 demodulator chip. A similar architecture targeting UK and mainland European users is expected to ship on 20 September, Motorola said.

The manufacturer confirmed it was already sampling the technology to key TV, tuner and set-top-box players across the UK and Europe. It explained the developments were necessary to eliminate multipath reflections -- or ghost signals -- traditionally caused by obstacles to reception, such as large buildings.

James Spansberry, director of marketing development for Motorola's Entertainments Solutions division explained the need for the two distinct approaches to the US and European markets. "In the US, digital and high definition broadcasts use the Advanced Television Systems Committee (ATSC) transmission standard, whereas in Europe and in other areas such as Latin America or Australia, the Digital Video Broadcast (DVB) Committee standard is used.

"Each uses its own modulation scheme. The ATSC uses Vestidual Site Band (VSB), whereas the DVB adopted a version of Orthogonal Frequency Division Multiplex (OFDM)."

Video resolution is somewhat independent to modulation. Each approach has a trade off in terms of functionality. Motorola claims it has good intentions furthering the development of both standards, in an effort to keep high definition broadcasting moving forward worldwide.