What digital modulation method is mandated by the FCC for use in the United States?

The mandated digital modulation method for television broadcasting in the United States by the FCC is 8-VSB (eight-level vestigial sideband). This modulation scheme is specifically designed for transmitting digital television (DTV) signals over the airwaves. It allows for efficient signal transmission in the UHF band, optimizing the use of available bandwidth while minimizing interference and distortion.

8-VSB was selected as the U.S. standard mainly due to its robustness in the presence of multipath interference, which is a common issue in broadcasting environments. The method operates effectively for over-the-air reception, ensuring that viewers receive high-quality broadcasts. This modulation technique supports the needs of DTV broadcasting, including both standard and high-definition content, thus providing a reliable viewing experience.

Other modulation methods, though useful in various contexts such as satellite or cable transmission, do not apply to the specific regulatory framework established for terrestrial DTV transmission in the United States.