Comment by jasonwatkinspdx
5 hours ago
Yup, it shifts but it's a minor shift and easily handled in the receiver. Receivers already need a little ability to tune the carrier frequency to account for ordinary variations in the circuits. From memory GPS's doppler shift is on the scale of a single digit khz, so Starlink's probably double that. A few khz of shift is no big deal for ghz carriers.
How does the receiver know how to shift?!
All RF protocols have some provision for signal acquisition. It can take a bunch of forms but what it nets out to is the oscillator in the receiver can acquire the signal from the sender. A simple example of this is "pilot" signals or prefixes that have an easily recognizable structure and allow the receiver to align to the sender in the clock recovery sense. So the receiver needs a little extra tunable bandwidth and to run the messy intermediates through something like a convolution filter, but it can latch on easily. This is early days of radio technology, like mid century post war.