www.pudn.com > maximumcapacityofamimochannelisconsideredhere.zip > WaterFilling_alg.m

function [Capacity PowerAllo] = WaterFilling_alg(PtotA,ChA,B,N0); 
% 
% WaterFilling in Optimising the Capacity 
%=============== 
% Initialization 
%=============== 
ChA = ChA + eps; 
NA = length(ChA);     % the number of subchannels allocated to 
 
H = ChA.^2/(B*N0);  % the parameter relate to SNR in subchannels 
% assign the power to subchannel 
PowerAllo = (PtotA + sum(1./H))/NA - 1./H; 
while(length(find(PowerAllo < 0 ))>0) 
    IndexN = find(PowerAllo <= 0 ); 
    IndexP = find(PowerAllo > 0); 
    MP = length(IndexP); 
    PowerAllo(IndexN) = 0; 
    ChAT = ChA(IndexP); 
    HT = ChAT.^2/(B*N0); 
    PowerAlloT = (PtotA + sum(1./HT))/MP - 1./HT; 
    PowerAllo(IndexP) = PowerAlloT; 
end 
PowerAllo = PowerAllo.';     
Capacity  = sum(log2(1+ PowerAllo.' .* H));