Hacker News new | ask | show | jobs
by IshKebab 496 days ago
I think graceless degradation isn't an inherent property of digital radio. You definitely could have some kind of digital modulation that takes advantage of FEC etc. but gracefully degrades.

I'm sure it exists, there probably just not much market for it.
1 comments
bri3d 496 days ago
Almost all existing digital FPV systems gracefully degrade as much as they possibly can, both by using FEC and walking down a large number of available MCS as link quality gets worse (and reducing bitrate to match). But when they do eventually fail, re-sync is a much harder problem for them than it is for analog.
link
IshKebab 496 days ago
Right, but I don't see any reason why that must be the case. It's not a fundamental limitation.
link
bri3d 496 days ago
To a great extent you trade statefulness (inter-frame compression, FEC, HARQ, sounding parameters, overhead) for efficiency, so improving link recoverability comes at a cost. There is an existing solution which makes this trade - HDZero. It works amazingly at close range in clean RF environments and has good analog-esque falloff characteristics, but in terms of absolute efficiency it is very bad and therefore does not have the same quality or range as other solutions. Certainly a better hybrid approach is possible but to your point, niche.
link
IshKebab 495 days ago
> but in terms of absolute efficiency it is very bad

Worse than analogue?

link