modified_modulation.m

B3g_phase2_C语言_Matlab程序及说明

function [Symbols] = modified_modulation(TxBits, ModScheme)
% This function Gray encodes binary bits into QPSK symbols onto antenna.
%
% function [Symbols] = Modulation(TxBits, ModScheme)
%
% Input:
%			TxBits -- Transmit bits
%			ModScheme -- Modulation type
% Output:
%			Symbols       -- Modulated symbols
% Note:
%			Unit energy symbol constellation
% See also:
%			None
% Description:
%			Author(s): Wang Dongming, SEU, NCRL

% TxBits = [  0 0 1 1 ] ;
%              3  
% ModScheme = 4 ;
% 
%
% modified by dupeng 2003 5 15 

j=sqrt(-1);

% Gray coded 16-QAM mapping vector
% MapMatrix16QAM = [-1-j -1-3*j -1+j -1+3*j -3-j -3-3*j -3+j -3+3*j 1-j 1-3*j 1+j 1+3*j 3-j 3-3*j 3+j 3+3*j];
%                   0     1     2    3      4    5      6    7     8    9    10   11   12   13   14   15 

% modified to 
MapMatrix16QAM=[ 1+j -1+j 1-j -1-j  3+j -3+j 3-j -3-j 1+3j -1+3j 1-3j -1-3j 3+3j -3+3j 3-3j -3-3j] ;

 MapMatrix16QAM = MapMatrix16QAM/sqrt(10);

% Binary to Decimal order vector
vecOrder = (2.^(ModScheme-1:-1:0)).';

switch ModScheme
	case 1
		Symbols = TxBits*2 - 1;
	case 2
		Symbols = ((TxBits(:,1:2:end)*2 - 1) + j*(TxBits(:,2:2:end)*2 - 1))/sqrt(2);
	case 4
		matTxBits = vec2mat(TxBits,ModScheme);
		vecTxBits = matTxBits * vecOrder + 1;
		Symbols = MapMatrix16QAM(vecTxBits);
	otherwise
		disp('Modulation options out of range');
end