Matlab模拟基于能量检测的协作频谱感知

clear all close all clc N = 10^2; %?????????? Pf = 0.001; %虚警概率 K = 3;%节点数 SNR = -15:1:5; %信噪比 SNR1 = power(10,SNR/10); lambda = norminv(1-Pf,K*N*1,sqrt(2*K*N)*1); %检测概率对应的门限值 Pd_ana = 1-normcdf(lambda,K*N*(1+SNR1),sqrt(2*K*N)*(1+SNR1)); %未检测 Np=10^3; Pd_sim = zeros(1,length(SNR)); for i = 1:length(SNR) d = 0; for n = 1:Np s = sqrt(SNR1(i))*randn(K,N); noise = randn(K,N); r = s + noise; r_power = sum(sum(abs(r).^2)); if (r_power > lambda) d = d+1; end end Pd_sim(i) = d/Np; end plot(SNR,Pd_ana,'r-+',SNR,Pd_sim,'r-s'); hold on; K = 1; %单节点 lambda = K*N+sqrt(2*K*N)*sqrt(2)*erfcinv(2*Pf); Pd_ana = 1-normcdf(lambda,K*N*(1+SNR1),sqrt(2*K*N)*(1+SNR1)); Np=10^3; Pd_sim = zeros(1,length(SNR)); for i = 1:length(SNR) d = 0; for n = 1:Np s = sqrt(SNR1(i))*randn(K,N); noise = randn(K,N); r = s + noise; r_power = sum(sum(abs(r).^2)); if (r_power > lambda) d = d+1; end end Pd_sim(i) = d/Np; end plot(SNR,Pd_ana,'g-*',SNR,Pd_sim,'g-o'); grid on; xlabel('SNR(dB)'); ylabel('Pd'); title('ROC of Energy Detector'); legend('3节点理论值','3节点仿真值','单节点理论值','单节点仿真值');