We have 5g Link Level Simulator. Our research are concerned with NOMA. I analyzed SignalConstellation.m. Here 3GPP MUST composite constellation parameters are present. ( From Line 38 to Line 43) I read MUST Category 2: Superposition transmission with adaptive power ratio section from 3GPP TR 36.859 V13.0.0 (2015-12) document. There I see transmission power ratios ( alpha) for a MUST-near user could be calculated. Below Link On Figure 1, example of the composite constellation of the MUST technique with quadrature phase shift keying (QPSK) modulation is showed.
So I calculated near user power ratios according to above Link for c_QPSK and d_QPSK parameters from SignalConstellation.m. For example for default c_QPSK and d_QPSK parameter ( MUSTIdx==2) , I calculated near user power ratio alpha as 0.1379. I wonder that you select this parameters according to a documentation or you select these parameters to adjust power ratios for near and far users random? How could I change MUST composite constellation parameters to decide different near user power ratios?
The study item 3GPP TR 36.859 V13.0.0 is an old document, and it has already been decided on and included in the standard. The MUST parameters that you find in SignalConstellation.m follow the 3GPP TS 36.211 document in section 7 “Generic functions“. The latest version of this document for Rel-15 is this one: http://www.3gpp.org/ftp//Specs/archive/36_series/36.211/36211-f20.zip.
As you’ve already noticed, MUSTIdx is by default 2; if you would like to change it, you can do so by opening Elements\Link.m and modifying line 265 “MUSTIdx = 2“.
EDIT: As far as I know, there is no rule about which MUSTIdx should be used; it is up to the base station vendors and how they implement their schedulers.