Which terrestrial transmission technology did the Advanced Television Systems Committee select?

Which terrestrial transmission technology did the Advanced Television Systems Committee select?

• A. 8 level vestigial sideband
• B. Quadrature amplitude modulation
• C. Orthogonal frequency division multiplexing
• D. Amplitude modulation

Answer: (A)

Eight-level vestigial sideband modulation was chosen for terrestrial ATSC. It fits a 6 MHz broadcast channel and supports the digital data rate needed for TV content using a single-carrier approach, keeping receiver design practical and cost-effective. The eight amplitude levels provide enough bits per symbol, while vestigial sideband shaping preserves bandwidth efficiently. QAM is typically used in cable and can be more sensitive to channel conditions in a broadcast environment; OFDM is used in other standards (and in the newer ATSC 3.0), but not in the original terrestrial ATSC; Amplitude modulation in its basic form is analog and cannot deliver digital TV at the required rates.

Eight-level vestigial sideband modulation was chosen for terrestrial ATSC. It fits a 6 MHz broadcast channel and supports the digital data rate needed for TV content using a single-carrier approach, keeping receiver design practical and cost-effective. The eight amplitude levels provide enough bits per symbol, while vestigial sideband shaping preserves bandwidth efficiently. QAM is typically used in cable and can be more sensitive to channel conditions in a broadcast environment; OFDM is used in other standards (and in the newer ATSC 3.0), but not in the original terrestrial ATSC; Amplitude modulation in its basic form is analog and cannot deliver digital TV at the required rates.