modsymtable.m

是用matlab编程实现PSK的很好例子

function [Dimen, SymbolTable] = ModSymTable(ModType)

clear Dimen SymbolTable;

%*******************************************************************************************************************
% Modulation Symbols Table
%*******************************************************************************************************************

Mi_BPSK = 2;
U_BPSK(1) = 1;                                  % BPSK symbols table
U_BPSK(2) = -1;

Mi_QPSK  = 4;                                   % QPSK symbols table
Theta0 = pi/4;
for (i=1:Mi_QPSK)
    Theta = (i-1)*2*pi/Mi_QPSK+Theta0;
    U_QPSK(i) = cos(Theta)+j*sin(Theta);        
end;

Mi_8PSK  = 8;                                   % 8PSK symbols table
Theta0 = 0;
for (i=1:Mi_8PSK)
    Theta = (i-1)*2*pi/Mi_8PSK+Theta0;
    U_8PSK(i) = cos(Theta)+j*sin(Theta);        
end;

% QAM Table Generation

IncUnit = 2;
k = 0;
for (i=1:4)
    k = k+1;
    U_QAM(k) = 1+IncUnit*(i-1)+j*(1+IncUnit*(i-1));
    for (n=1:(2*i-1))
        U_QAM(k+1) = U_QAM(k)-IncUnit;
        k = k+1;
    end;
    for (n=1:(2*i-1))
        U_QAM(k+1) = U_QAM(k)-j*IncUnit;
        k = k+1;
    end;
    for (n=1:(2*i-1))
        U_QAM(k+1) = U_QAM(k)+IncUnit;
        k = k+1;
    end;
    for (n=1:(2*i-1)-1)
        U_QAM(k+1) = U_QAM(k)+j*IncUnit;
        k = k+1;
    end;
end;

Mi_16QAM = 16;                                  % 16QAM symbols table
U_16QAM = U_QAM(1:Mi_16QAM);
powerAccu = sum((abs(U_16QAM).^2)/Mi_16QAM);
NormQAM = (1/powerAccu)^0.5;
U_16QAM = NormQAM*U_16QAM;

Mi_32QAM = 32;
U_32QAM(1:16) = U_QAM(1:16);
U_32QAM(17:20) = U_QAM(18:21);
U_32QAM(21:24) = U_QAM(23:26);
U_32QAM(25:28) = U_QAM(28:31);
U_32QAM(29:32) = U_QAM(33:36);
powerAccu = sum((abs(U_32QAM).^2)/Mi_32QAM);
NormQAM = (1/powerAccu)^0.5;
U_32QAM = NormQAM*U_32QAM;

Mi_64QAM = 64;                                  % 64QAM symbols table
U_64QAM = U_QAM(1:Mi_64QAM);
powerAccu = sum((abs(U_64QAM).^2)/Mi_64QAM);
NormQAM = (1/powerAccu)^0.5;
U_64QAM = NormQAM*U_64QAM;

switch ModType
case 'BPSK'
        Dimen = log2(Mi_BPSK);
        SymbolTable = U_BPSK;
    case 'QPSK'
        Dimen = log2(Mi_QPSK);
        SymbolTable = U_QPSK;
    case '8PSK'
        Dimen = log2(Mi_8PSK);
        SymbolTable = U_8PSK;
    case '16QAM'
        Dimen = log2(Mi_16QAM);
        SymbolTable = U_16QAM;
    case '32QAM'
        Dimen = log2(Mi_32QAM);
        SymbolTable = U_32QAM;        
    case '64QAM'
        Dimen = log2(Mi_64QAM);
        SymbolTable = U_64QAM;        
    otherwise
        Dimen = 0;
        SymbolTable = 0;
end;