--- In [email protected], Tim Hardy AF1G <har...@...> wrote: > If the bit rate is faster, is not the signal wider as well?
You can trade off bit rate either for bandwidth or the signal-to-noise ratio required for reception, which effectively means range for a given power. There are some games you can play with modulation formats such as hierarchical QAM there there's a main bit stream that gets you, say, "intelligible" audio and an auxiliary bit stream layered "on top" (that's the hierarchical part) that gets you "high fidelity" audio -- these systems are nice in that you have "intelligible" audio out to some reasonable distance, but the folks who are much closer happen to receive "high fidelity" audio. It's a good compromise... (Although as others have pointed out, something like that is in no way D*Star compatible.) > Digital TV looks and sounds great but the signal width is awesome! Yeah, although it actually consumes no more bandwidth than the old NTSC/PAL format (~6MHz). The equivalent application to D*Star here would be switching to a new (more efficient) CoDec -- in the music world, the obvious choice these days is AAC (roughly 1.5-2x as efficient as MP3), although with voice CoDecs are designed inherently differently and I'm not knowledgeable as to the state-of-the-art these days. ---Joel
