Which types of modulation are used for amateur television DVB-T signals?

DVB-T (Digital Video Broadcasting - Terrestrial) is a widely adopted digital television standard that amateur radio operators use for digital amateur television (DATV). To squeeze high-quality video into a standard RF channel, DVB-T employs Orthogonal Frequency-Division Multiplexing (OFDM). The individual subcarriers within that OFDM signal are modulated using high-efficiency digital modulation schemes, specifically Quadrature Amplitude Modulation (QAM) and Quadrature Phase Shift Keying (QPSK). These complex schemes alter both the phase and amplitude of the carrier to transmit multiple bits per symbol, supporting the high data rates video requires. The distractors feature older or simpler analog and digital modes like AM, FM, and FSK. While these are common in other amateur radio applications, they cannot support the dense data multiplexing requirements of modern digital video.