When people talks about whether a system is analog or digital, it refers to its base-band modulation. DJI/OpenHD/HDZero uses OFDM modulation, while analog wireless video uses traditional CVBS (NTSC/PAL) modulation. OFDM is a digital way, and CVBS is an analog way.

The traditional digital wireless video transmission uses video encoder for compression to reduce data rate and OFDM as baseband modulation. HDZero uses Joint Source Channel Coding (JSCC) technolgy for directly mapping incoming video data to OFDM constellation as baseband modulation.