periodshift.m

这是个扩频仿真的有关程序

%这个函数的用途是什么？
function f=Periodshift(x,row,column)
%row--downshift, column--rightshift
xsize=size(x);
f=x;
remrow=rem(row,xsize(1));
remcolumn=rem(column,xsize(2));
if  remrow>0
   f(1:remrow,:)=x(xsize(1)-remrow+1:xsize(1),:);
   f(remrow+1:xsize(1),:)=x(1:xsize(1)-remrow,:);
elseif remrow<0
   f(xsize(1)+remrow+1:xsize(1),:)=x(1:-remrow,:);
   f(1:xsize(1)+remrow,:)=x(-remrow+1:xsize(1),:);
end
x=f;
if remcolumn>0
   f(:,1:remcolumn)=x(:,xsize(2)-remcolumn+1:xsize(2));
   f(:,remcolumn+1:xsize(2))=x(:,1:xsize(2)-remcolumn);
elseif remcolumn<0
   f(:,xsize(2)+remcolumn+1:xsize(2))=x(:,1:-remcolumn);
   f(:,1:xsize(2)+remcolumn)=x(:,-remcolumn+1:xsize(2));
end