www.pudn.com > MultiuserOFDM_0_1.zip > shenpowerallo.m

% Copyright (c) 2003-2004 The University of Texas 
% All Rights Reserved. 
%   
% This program is free software; you can redistribute it and/or modify 
% it under the terms of the GNU General Public License as published by 
% the Free Software Foundation; either version 2 of the License, or 
% (at your option) any later version. 
%   
% This program is distributed in the hope that it will be useful, 
% but WITHOUT ANY WARRANTY; without even the implied warranty of 
% MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
% GNU General Public License for more details. 
%   
% The GNU Public License is available in the file LICENSE, or you 
% can write to the Free Software Foundation, Inc., 59 Temple Place - 
% Suite 330, Boston, MA 02111-1307, USA, or you can find it on the 
% World Wide Web at http://www.fsf.org. 
%   
% Programmers:	Zukang Shen 
%  
% The authors are with the Department of Electrical and Computer 
% Engineering, The University of Texas at Austin, Austin, TX. 
% They can be reached at shen@ece.utexas.edu. 
 
function [p,outage]= shenpowerallo(channel,suballo,N,K,Ptot,noise,gamma) 
 
for i=1:K 
	n(i)=sum(suballo(i,:));    
end 
 
for user=1:K 
   used=[]; 
	for j=1:N 
   	if suballo(user,j)>0 
      	used=[used channel(user,j)]; 
   	end 
	end 
 
	usedlength=length(used); 
	for i=1:length(used) 
   	[minvalue minindex]=min(used); 
   	usedordered(user,i)=minvalue; 
   	used=[used(1:minindex-1) used(minindex+1:length(used))]; 
	end 
   usedordered(user,:)=usedordered(user,:)/noise;	 
    
   h(user)=usedordered(user,1); 
   vtemp=0; 
   for m=2:usedlength 
   	vtemp=vtemp+(usedordered(user,m)-usedordered(user,1))/(usedordered(user,1)*usedordered(user,m));    
   end 
   v(user)=vtemp; 
    
   ytemp=1; 
   for m=2:usedlength 
   	ytemp=ytemp*usedordered(user,m)/usedordered(user,1);    
   end 
   y(user)=ytemp; 
    
end 
 
 
 
coef(1)=1; 
power(1)=1; 
 
for i=2:K 
    coef(i)=n(i)/(h(i)*y(i)^(1/n(i)))*(h(1)*y(1)^(1/n(1))/n(1))^(n(1)*gamma(i)/(n(i)*gamma(1))); 
    power(i)=n(1)*gamma(i)/(n(i)*gamma(1)); 
end 
 
infcheck=0; 
for i=1:K 
    if coef(i)==inf 
        infcheck=1; 
    end 
end 
if (infcheck==1) 
   for i=1:K 
      p(i)=Ptot/N*n(i); 
   end 
   outage=1; 
   return; 
end 
 
 
fun=['x']; 
for i=2:K 
	fun=[fun,'+',num2str(coef(i)),'*x^',num2str(power(i))];    
end 
 
for i=1:101 
   guessx=0.01*(i-1)*Ptot; 
   guess(i)=guessx; 
   for j=2:K 
   	guess(i)=guess(i)+coef(j)*guessx^power(j);    
   end 
    
   guess(i)=guess(i)-Ptot;    
end 
 
 
[guessvalue,guessindex]=min(abs(guess)); 
 
fun=[fun,'-',num2str(Ptot)]; 
 
p(1)=fzero(fun,0.01*(guessindex-1)*Ptot); 
 
if isnan(p(1))==1 
   for i=1:K 
      p(i)=Ptot/N*n(i); 
   end 
   outage=1; 
else  
   for i=2:K 
      p(i)=coef(i)*p(1)^power(i); 
   end 
   outage=0; 
end