test_uwb.m

FCCUWB

clc;
clear;
Ts=1e-7;
smp = 1024;             % number of samples
Tmin =-4e-9;           % lower time limit
Tmax = 4e-9;            % upper time limit
alpha=0.25e-9;
alphastep=0.043e-9;
dt = (Tmax - Tmin) / smp; % sampling period
fs = 1 / dt;
frequencysmoothingfactor=8;
N=frequencysmoothingfactor*smp;  %N=8*1024=8192 
df=1/(N*dt);  
positivefrequency=linspace(0,(fs/2),N/2);
t=linspace(Tmin,Tmax,smp);% initialization of the time axis
emissionmask=cp0703_generate_mask(N,fs);
for n=1:6;
    a=alpha;
    pulse1(1,:) = 48*2^(1/2)*(1/a)^(1/2)*pi^2/a^4*exp(-2*pi*t.^2/a^2)-...
        384*2^(1/2)*(1/a)^(1/2)*pi^3/a^6*t.^2.*exp(-2*pi*t.^2/a^2)+...
        256*2^(1/2)*(1/a)^(1/2)*pi^4*t.^4/a^8.*exp(-2*pi*t.^2/a^2);
    pulse1(1,:)=pulse1(1,:)/max(abs(pulse1(1,:)));
    
    X=fft(pulse1(1,:),N);
    X=X/N;
    E=fftshift(abs(X).^2/(df^2));
    Ess=2*E((N/2+1):N);
    singlederivativePSD=10*log10((1/Ts)*Ess/377)+90;
    figure(1);
    plot(positivefrequency/1e6,emissionmask,'r','linewidth',[1]);
    hold on
    plot(positivefrequency/1e6,singlederivativePSD);
    X=xlabel('Frequency [MHz]');
    set(X,'fontname','Arial','fontsize',10.5);
    Y=ylabel('ESD [dBm/MHz]');
    set(Y,'fontname','Arial','fontsize',10.5);
    axis([0 12e3 -120 0]);
   
    text(4e3,-35,'FCC UWB indoor emission mask','fontname','Arial','fontsize',10.5);
    text(4.3e3,-105,'\alphamax\rightarrow','fontname','Arial','fontsize',10.5);
    text(10e3,-100,'\leftarrow\alphamin','fontname','Arial','fontsize',10.5);
    
    alpha=alpha+alphastep;
end
 title('高斯函数的4阶导函数的ESD与\alpha的关系和FCC掩蔽的比较');
 grid