[zh3]

Agreed, and that's why the "naive" is in my comment :) An even faster is to drop the packerisation and run the transmitter continuously with an appropriate code (self-clocking); the digital radio delay then drops to microseconds. That might in turn make the 48KHz 16-bit ADC seem the limit (21us per sample), one can always use a faster ADC (after appropriate front-end filtering). Out in the real world though error correction is needed, so generally need to use a codec with forward error correction.