cp0204_channel_noise.asv

uwb无线电基础书本（电子工业出版社）的MATLAB程序

function [y] = cp0204_Channel_Noise(x,N_los,SNR)
tx = 1;               
c0 = 10^(-47/20);     %47 dB  attenuation 
d = 2;                 %distance between  tx and rx
gamma1 = 1.7;          %attenuation  index
[rx,ag] = cp0801_pathloss(tx,c0,d,gamma1);    % ag is  channel  gain
TMG = ag^2;

if N_los==1 
    LAMBDA = 0.0233e9;      % Cluster Arrival Rate (1/s)
    lambda = 2.5e9;           % Ray Arrival Rate (1/s)
    GAMMA = 7.1e-9;            % Cluster decay factor  
    gamma = 4.3e-9;            % Ray decay factor  
    sigma1 = 10^(3.3941/10);  % Stdev of the cluster fading
    sigma2 = 10^(3.3941/10);  % Stdev of the ray fading
    sigmax = 10^(3/10);       % Stdev of lognormal shadowing
end
if N_los==2 
    LAMBDA = 0.4e9;      % Cluster Arrival Rate (1/s)
    lambda = 0.5e9;           % Ray Arrival Rate (1/s)
    GAMMA = 5.5e-9;            % Cluster decay factor  
    gamma = 6.7e-9;            % Ray decay factor  
    sigma1 = 10^(3.3941/10);  % Stdev of the cluster fading
    sigma2 = 10^(3.3941/10);  % Stdev of the ray fading
    sigmax = 10^(3/10);       % Stdev of lognormal shadowing
end    
if N_los==3 
    LAMBDA = 0.0667e9;      % Cluster Arrival Rate (1/s)
    lambda = 2.1e9;           % Ray Arrival Rate (1/s)
    GAMMA = 14e-9;            % Cluster decay factor  
    gamma = 7.9e-9;            % Ray decay factor  
    sigma1 = 10^(3.3941/10);  % Stdev of the cluster fading
    sigma2 = 10^(3.3941/10);  % Stdev of the ray fading
    sigmax = 10^(3/10);       % Stdev of lognormal shadowing
end
if N_los==4 
    LAMBDA = 0.0667e9;      % Cluster Arrival Rate (1/s)
    lambda = 2.1e9;           % Ray Arrival Rate (1/s)
    GAMMA = 24e-9;            % Cluster decay factor  
    gamma = 12e-9;            % Ray decay factor  
    sigma1 = 10^(3.3941/10);  % Stdev of the cluster fading
    sigma2 = 10^(3.3941/10);  % Stdev of the ray fading
    sigmax = 10^(3/10);       % Stdev of lognormal shadowing
end
fc = 50e9;    
[h0,hf,OT,ts,X] = cp0802_IEEEuwb(fc,TMG,LAMBDA,lambda,GAMMA,gamma,sigma1,sigma2,sigmax);    

X_POWER = var(x);
linear_SNR = 10^(SNR/10);
noise_sigma = X_POWER/linear_SNR;
noise_scale_factor = sqrt(noise_sigma);
noise = randn(1,length(x))*noise_scale_factor;
    
%y = conv(x,hf);
%y = y(1:length(x));
y = y + noise;
t= (length(x)/320)*312.5e-9;
time = linspace(0,t,length(x));

figure(3);
S3=stem(time,y);

    
%UNTITLED1 Summary of this function goes here
%  Detailed explanation goes here