8 VSB vs 16 VSB

[citan x]

I looked at the wiki for 16 VSB and it states 16 VSB is capable of 38 MBits/s. That is double the bit rate of 8 VSB of 19.3 MBits/s. However, 8 VSB transmits 3 bits at a time and 16 VSB transmits 4 bits at a time. Doesn't that mean the bit rate for 16 VSB is around 25.7 MBits/s and not 39 MBits/s?

The link to the article:16 VSB

Also, I read in another wiki article that the 19.3 MBits/s is considered suitable for 2 HD programs or 5 SD programs. No wonder HDTV looks like crap. Blue rays can easily exceed the 19.3 MBits/s rate.

 

[bsobel]

As your own links point out 8VSB has 3 usable bits, but 4 are sent (forward error correction). 16vsb is more prone to error since the error correction bit isn't apparently used... So if you count the error bit in 8vsb, you can see the bandwidth #s line up.

 

[Modelworks]

The amount of bandwidth suitable for a given amount of channels is really a relative thing to how much you compress. Realize that hdmi when we were testing it could easily push 11-12Gbit/sec so even blu-ray doesn't come close to the capacity of tmds. But to send that kind of bandwidth through the air just isn't practical so concessions have to be made