qam_ab2bits.m

64QAM matlab s programs.

function bits=QAM_ab2bits(a,b)
%
% bits=QAM_ab2bits(a,b)

L = length(a);

bits = zeros(1,L*4);

for k = 1 : L

    % Determine the first 2 bits from a

    if a(k) >= 2/3
        bits((k-1)*4+1:(k-1)*4+2)=[1 1];
    elseif a(k) > 0 & a(k) < 2/3
        bits((k-1)*4+1:(k-1)*4+2)=[1 0];
    elseif a(k) <= 0 & a(k) > -2/3
        bits((k-1)*4+1:(k-1)*4+2)=[0 1];
    else
        bits((k-1)*4+1:(k-1)*4+2)=[0 0];
    end

    % Determine the second two bits from b

    if b(k) >= 2/3
        bits((k-1)*4+3:(k-1)*4+4)=[1 1];
    elseif b(k) > 0 & b(k) < 2/3
        bits((k-1)*4+3:(k-1)*4+4)=[1 0];
    elseif b(k) <= 0 & b(k) > -2/3
        bits((k-1)*4+3:(k-1)*4+4)=[0 1];
    else
        bits((k-1)*4+3:(k-1)*4+4)=[0 0];
    end


end