DVB-S2 - Getting Signal Constellations and Bit Mappings

The function returns constellation points and bit mappings specified in the DVB-S2 Standard.

%DVBS2Constellation Signal Constellations taken from ETSI EN 302 307
% [CONSTELLATION, BITMAPPING] = DVBS2Constellation(MODSCHEME,GAMMA)
% returns the constellation points and the bit mapping specified in the DVB-S2
% Standard ETSI EN 302 307. The output vector CONSTELLATION contains the
% constellation points and the output vector BITMAPPING contains the associated
% bit mapping. The data of these vectors is organized such that the vectors
% can directly fed into the sigmapper or llr_demod_mex constructor.
%
% The DVB-S2 Standard ETSI EN 302 307 specifies signal constellations for
% four different modulation schemes: QPSK, 8PSK, 16APSK and 32APSK.
%
% MODSCHEME denotes the modulation scheme. GAMMA sets the constellation radius
% ratios which are required when using the constellation schemes 16APSK and
% 32APSK. If the modulation schemes QPSK and 8PSK are used, no additional
% input GAMMA is needed.
% (for more information:
% http://www.etsi.org/deliver/etsi_en/302300_302399/302307/01.02.01_60/en_302307v010201p.pdf)
%
% Important: The radius of the inner circle of the modulation schemes 16APSK
% and 32 APSK always has unit length. If the signal power should be normalized
% to one, the constellations points must be scaled accordingly.
%
% Input: MODSCHEME [char] 'QPSK', '8PSK', '16APSK', '32APSK'
% GAMMA [1x1] (16APSK), [1x2] (32APSK)
%
% Output: CONSTELLATION [1xM]
% MAPPING [1xM]

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These are the basic commands lines:

[constellation, bitMapping] = DVBS2Constellation('QPSK')

[constellation, bitMapping] = DVBS2Constellation('8PSK')

[constellation, bitMapping] = DVBS2Constellation('16APSK', [3.15])

[constellation, bitMapping] = DVBS2Constellation('32APSK', [2.84 5.27])

Note: There is a text file included which contains the optimum constellation radius ratios for several code rates. These radius ratios are only needed when using 16APSK or 32APSK.