认知无线电 能量检测

clear allclcclear figN=600;       %采样个数Sim_Times=1000;%仿真次数 snr_avgdB =-10;%信噪比（dB值）snr_avg=10^(snr_avgdB/10);%信噪比Dn=1;       %噪声功率，高斯噪声的方差Ds=snr_avg*Dn;%信号功率F0=1;Fs=5f=0:0.02:1-0.02;% Pf=0.02;Over_Num_awgn=zeros(1,length(Pf))d=zeros(1,length(Pf));for i=1:length(Pf)    i    for kk = 1:Sim_Times     t = (kk-1)*N+1:kk*N;      %高斯信号     Single1=sqrt(Ds) * randn(1,N); %产生均值为0，方差为Ds的高斯信号     %awgn channels 噪声和信号     Noise =0+ sqrt(Dn) * randn(1,N);%产生均值为0，方差为Dn=1的高斯噪声     singal=Single1+Noise;     %Detection Process   检测过程      power=sum(singal.^2);     Threshold=qfuncinv(Pf(i))*Dn*sqrt(2*N)+N*Dn;%给定的pf反推的Th     if power>Threshold         Over_Num_awgn(i)= Over_Num_awgn(i) +1;     end    end    Pd(i)=Over_Num_awgn (i)/Sim_Times;endThreshold_matrix=qfuncinv(Pf)*Dn*sqrt(2*N)+N*Dnd_theory=qfunc((Threshold_matrix-N*Dn-N*snr_avg*Dn)/(Dn*sqrt(2*N+4*N*snr_avg)));plot(Pf,Pd,'-*r')hold onplot(Pf,Pd_theory,'-*b')hold offxlabel('虚警概率Pf');ylabel('检测概率Pd');legend('仿真值','理论值');title('单用户能量检测ROC曲线图')

正在学习这个，谢谢分享！

判决门限是怎么确定的啊？