认知无线电频谱感知之功率检测matlab代码

能量检测仿真实验代码：clear all;clc;n = 5;ps = 1;SNR1 = -5;SNR2 = -8;SNR3 = -10;% Sim_Times=10000; %Monter-Carlo times% m=5;T=0.001;% 信号带宽W W=5*10^4;% 采样频率Fs = 2*W;m = T*W;n = 2*T*W;% F0=W;% Fs=2;% Sig=sqrt(2)*sin(2*pi*F0/Fs*t); %single tone samples, Fs=2F0% 实际信噪比snr1 = 10.^(SNR1/10);snr2 = 10.^(SNR2/10);snr3 = 10.^(SNR3/10);pn = (1/snr1)*ps;mu0 = n*pn;sigma0 = sqrt(2*n)*pn;mu = n*(pn+ps);sigma = sqrt(2*n*(pn^2+2*pn*ps));% [noi,x0,mu0,sigma0,m0] = cnoi( n,pn );% sig = randn(n,1);sig = 1;% 重复次数count = 5000;% 能量检测判决门限lambda = [200:20:600];lambda1 = [500:20:900];lambda2 = [700:30:1300];% 置信度判决参数% tt = [-5:0.4:3];% cc = 10.^tt;% tt1 = [-1:0.1:1];% cc1 = 10.^tt;% cc2 = [-0.01:0.001:0.01];for kk = 1:1:length(lambda);ff = 0;dd = 0;ff1 = 0;dd1 = 0;ff2 = 0;dd2 = 0;for ii=1:1:count;t = (kk-1)*n+1:kk*n;init_phase = 1/6*pi;sig=2*sin(2*pi*W/Fs*t+init_phase);%sig=1;%dot(sig,sig)/nnoi1 = randn(1,n);noi1 = sqrt(1/snr1)*noi1;rec1 = noi1 + sig;noi2 = randn(1,n);noi2 = sqrt(1/snr2)*noi2;rec2 = noi2 + sig;noi3 = randn(1,n);noi3 = sqrt(1/snr3)*noi3;rec3 = noi3 + sig;sum0_1 = dot(noi1,noi1);sum0_2 = dot(noi2,noi2);sum0_3 = dot(noi3,noi3);sum1_1 = dot(rec1,rec1);sum1_2 = dot(rec2,rec2);sum1_3 = dot(rec3,rec3);%单用户能量检测判决if (sum0_1 > lambda(kk));ff = ff+1;endif (sum1_1 > lambda(kk));dd = dd+1;endif (sum0_2 > lambda1(kk));ff1 = ff1+1;endif (sum1_2 > lambda1(kk));dd1 = dd1+1;end if (sum0_3 > lambda2(kk));ff2 = ff2+1;endif (sum1_3 > lambda2(kk));dd2 = dd2+1;endendPd_1(kk) = dd/count;Pf_1(kk) = ff/count;Pd_2(kk) = dd1/count;Pf_2(kk) = ff1/count;Pd_3(kk) = dd2/count;Pf_3(kk) = ff2/count;endplot(Pf_1,Pd_1,'-o',Pf_2,Pd_2,'-s',Pf_3,Pd_3,'-*');hold on;grid on;xlabel('False alarm probability, P_{Fa}');ylabel('Detection probability, P_{d}');legend('能量检测 SNR=-5dB,n=100','能量检测 SNR=-8dB,n=100','能量检测 SNR=-10dB,n=100');grid on;hold on;