认知无线电匹配滤波检测程序问题？

我检测住用户信号为单音信号，就是一个正弦信号%匹配滤波检测clear all;clc;Sim_Times=5000; %Monter-Carlo times   m=5;   W=1;   Fs=4;   N =Fs*m; %此处还是满足采样定理snr_avgdB =-5; snr_avg = power(10,snr_avgdB/10); Pf=0:0.02:1; for i=1:length(Pf)    Over_Num_awgn(i) = 0;     %Monter-Carlo simualtion    for kk = 1:Sim_Times      t = (kk-1)*N+1:kk*N;      A=10;     F0=W;     init_phase = 1/6*pi;     Single1=A*sin(2*pi*F0/Fs*t + init_phase);          %awgn channels 噪声和信号      Noise =0+ sqrt(1) * randn(1,N);%产生均值为0，方差为1的高斯噪声      singal=Single1+Noise         %Detection Process   检测过程        a1=singal;        a2=Single1;       e=sum(a1.*a2);       f=sum(a1.^2);      accum_Num_awgn(i) = e;       lim(i)=qfuncinv(Pf(i))*sqrt(f);%给定的pf反推的lim       lim1(i)=log(lim(i))+0.5*f;             if accum_Num_awgn(i)>lim1(i)          Over_Num_awgn (i)= Over_Num_awgn(i) +1;          end          end       %Calculate Pd and Pm for each scenario   Pd_sim_awgn = Over_Num_awgn / Sim_Times; end%Theory results according Digham and GhasemiPd_theory_awgn = qfunc(qfuncinv(Pf)-sqrt(snr_avg *N)); %pd理论值 Pm_sim_awgn =1-Pd_sim_awgn   %实际pmPm_theory_awgn = 1- Pd_theory_awgn;%理论pmloglog(Pf,Pm_sim_awgn,'*b')hold onloglog(Pf,Pm_theory_awgn,'-r'); grid onaxis([0.0001,1,0.0001,1]);xlabel('虚警概率Pf');ylabel('漏检概率Pm');legend('仿真值','理论值');title('匹配滤波器检测ROC曲线图')仿真后，理论曲线能出来但是仿真曲线出不来求大神找下错误

是不是门限值lim1(i)太小