recurse_other.m

Hierarchical－QAM的程序

function [err_value] = recurse_other(position, theta_input_vector, angle_vector, phase_error,snr)

% This function recursively finds out the ber of bits in positions i_{1} 
% to i_{n-1}

x=length(angle_vector);

n=length(theta_input_vector);
if(n>1)
    theta_output_vector1=zeros(n-1,1);
    theta_output_vector2=zeros(n-1,1);
end;

if(n>1)
    if( position<n+1)
	alpha=theta_input_vector(n-1)+theta_input_vector(n);
	beta=theta_input_vector(n-1)-theta_input_vector(n);
        if (n > 2)
		for i=1:n-2
    	                theta_output_vector1(i,1)=theta_input_vector(i);
		        theta_output_vector2(i,1)=theta_input_vector(i);
  		end;
        end;
        theta_output_vector1(n-1,1)=alpha;
        theta_output_vector2(n-1,1)=beta;
        theta_output_vector1;
        theta_output_vector2;
        position;
        snr;
    	err_value=0.5*recurse_other(position, theta_output_vector1, angle_vector, phase_error,snr)+0.5*recurse_other(position, theta_output_vector2, angle_vector,phase_error,snr);
    else
	if(position == x+1)	
        	err_value=lsb_error_new(angle_vector, phase_error, snr);
	else
		feed_vector=theta_input_vector;
		feed_vector(1)=angle_vector(1);
		err_value=lsb_error_new(feed_vector, phase_error, snr);
	end;
    end;

elseif( n==1 )
        if(position == 1)
            err_value = F_func(snr, -theta_input_vector(1))-F_func(snr, pi-theta_input_vector(1));
%	        err_value = 0.5*erfc(sin(theta_input_vector(1))/snr);
        elseif(position == 2)
            err_value = F_func(snr, theta_input_vector(1)-pi/2)-F_func(snr, pi/2+theta_input_vector(1));
%            err_value= 0.5*erfc(cos(theta_input_vector(1))/snr);
        end;  
    end;