QPSK and 8PSK. Whats the difference?

[DishSubLA]

QPSK and 8PSK are modulation schemes, and a separate matter from encoding, which is MPEG . an 8PSK modulation scheme provides for more data to be transmitted without increasing bandwidth nor changing to more efficient encoding (MPEG, etc.)

In fact, there are many tricks or methods of getting more from the same bandwidth besides modulation schemes and encoding. For example, DBS really only have 16 true ConUS down link frequencies or ConUS transponders licensed for DBS, and all the DBS sats currently in orbit can be operated in such a configuration 16 higher powered transponders. However, DBS services also reuse and transmit on the the very same frequencies, but 180 degrees out of phase from each other. The effect is an additional 16 RF channels for an effective total of 32 transponders on which to transmit without interference because of the 180 degree difference of phase. That trick results in doubling the allotted DBS bandwidth, and that is a significant increase and vital to DBS being a robust competitor to cable, AT&T, and Verizon.

Now, add other things like Turbocoding . . . well, all the list of tricks to maximize bandwidth and throughput more data goes on and on.

 

[whatchel1]

The phase out is starting next year. Here is a thread on satguys. http://www.satelliteguys.us/xen/threads/satellite-changes-coming-may-31st-2015.342727/#post-3541150

 

[mike123abc]

Essentially the satellite sends a radio wave to the receiver. In a QPSK system or quad phase, the radio wave could be in one of 4 phases representing 2 bits of information. In an 8PSK system it can be in one of 8 different phases representing 3 bits of information. Essentially 8PSK is 50% more bits, but of course it is harder to tell 8 different wave forms compared to 4, so you get a lot more interference, so they have to increase error correction (or satellite transmit power) to compensate. So, they really get 30% or so more bandwidth.

 

[Claude Greiner]

The 111 was a solid receiver. I believe it was exclusively through retailers. It will still work, since it supports 8PSK.

There is an 8psk chip on the 111, However it makes no since dish treats these like 111's and refuses to activate them

 

[TheKrell]

There is an 8psk chip on the 111, However it makes no since dish treats these like 111's and refuses to activate them

You must have meant to say 301, not 111. Yeah, I had one of those and I fail to see why Dish threw them overboard.