function y = modulate(x,b,e, s2,s4,s16,s64,s256)% function y = modulate(x,b,e, s2,s4,s16,s64,s256)%%    y - modulated output, in the form of a row vector%    x - a vector of input bits, for all the subcarriers (row vector)%    b - subcarrier bit allocation (64 elements in this matrix, each one%        corresponding to the number of bits to be allocated to the subcarrier%        having the same index)%    e - subcarrier energy allocation (64 elements in this matrix, each one%        corresponding to the energy to be allocated to the subcarrier%        having the same index)%    s_ - the encoder for a given constellation sizey=[];b2 = zeros(1,length(b));b2(1) = 1;for i = 1:length(b)    b2(i+1) = b(i) + b2(i);endfor i = 1:length(b)    switch b(i)    case {1}        y = [y s2(x(b2(i))+1)*sqrt(e(i))];    case {2}        y = [y s4(x(b2(i):(b2(i+1)-1))*[2;1]+1)*sqrt(e(i))];    case {4}        y = [y s16(x(b2(i):(b2(i+1)-1))*[8;4;2;1]+1)*sqrt(e(i))];    case {6}        y = [y s64(x(b2(i):(b2(i+1)-1))*[32;16;8;4;2;1]+1)*sqrt(e(i))];    case {8}        y = [y s256(x(b2(i):(b2(i+1)-1))*[128;64;32;16;8;4;2;1]+1)*sqrt(e(i))];    otherwise        % must be zero bits allocated        y = [y 0];    endend