用Matlab实现重叠保留法计算循环卷积的程序实例

				function [y,N0]=circonv(x1,x2,N)
				x0=zeros(N);
				x1_l=length(x1);
				x2_l=length(x2);
				if x1_l>x2_l
				    max=x1_l;
				else
				    max=x2_l;
				end
				if max				    max=N;
				end
				y1=zeros(1,max);
				y2=zeros(1,max);
				y1=[x1,zeros(1,max-x1_l)];
				y2=[x2,zeros(1,max-x2_l)];
				y0=zeros(1,N);
				for i=1:N
				    y0(1,i)=y2(1,i);
				end
				for i=1:N
				    for j=1:N
				        tem=mod(j-i,N)+1;
				        x0(i,j)=y1(1,tem);
				    end
				end
				y=y0*x0;
				N0=0:N-1;