function error_ratio = err_staric(sig_code,demap_out);
global Ofdm_bits Mod_type Tx_num
    pqam_length = Ofdm_bits*Mod_type;
    error_ratio = 0;
    error_num = 0;
    sig_all_num = pqam_length*Tx_num;
    
    error_matrix = zeros(Tx_num-1,pqam_length);
    for t = 1:Tx_num-1 
        for n = 1:pqam_length   
            if demap_out(t,n)~=sig_code(t,n)
                error_num = error_num+1;
                error_matrix(t,n) = 1;
            end
        end
    end
    error_ratio = error_num/sig_all_num;