www.pudn.com > tanlansuanfa.rar > tanlansuanfa.m

clc 
clear 
BER=1.3e-3; 
rate=60; 
numbertotalsub=18; 
sigma=rand(1,numbertotalsub); 
%%%%初始化%%%%%%%%% 
subcarrierallocate=zeros(1,numbertotalsub); 
powerallocate=zeros(1,numbertotalsub); 
bitallocation=zeros(1,numbertotalsub); 
%%%第一次分配，增加一个比特，增加功率最少功率的子载波被选择%%%%%%%%% 
%%%同时这个完成该子载波的功率加载，同时用户的速率需求降低1比特到19%% 
%%假设使用QAM调制 
%delta=+inf; 
%numbersub=1; 
for n=1:numbertotalsub 
     bitallocation(n)=bitallocation(n)+1; 
     powerallocate(n)=1/3*sigma(n)*erfcinv(BER/2)* erfcinv(BER/2)*(2^bitallocation(n)-1); 
end 
minpower=min(powerallocate); 
minindex=find(powerallocate~=minpower); 
bitallocation(1,minindex)=0; 
powerallocate(1,minindex)=0; 
rate=rate-1; 
 
while rate>0 
     rate; 
    for n=1:numbertotalsub 
     powerallocate(n)=1/3*sigma(n)*erfcinv(BER/2)* erfcinv(BER/2)*(2^bitallocation(n)-1);   
     bitallocation01(n)=bitallocation(n)+1; 
     powerallocate01(n)=1/3*sigma(n)*erfcinv(BER/2)* erfcinv(BER/2)*(2^bitallocation01(n)-1); 
     chazhi(n)=powerallocate01(n)-powerallocate(n); 
    end 
   minchazhi=min(chazhi); 
   minindex=find(chazhi==minchazhi); 
   bitallocation(minindex)=bitallocation(minindex)+1; 
   powerallocate(minindex)=powerallocate(minindex)+minchazhi; 
   rate=rate-1; 
   minchazhi=0; 
end 
bitallocation