基于MATLAB的FSK调制解调仿真,含仿真操作录像

clc; clear all; close all; x=[ 1 0 1 0 1 0 1]; % Binary Information bp=.0001; % bit period disp(' Binary information at Trans mitter :'); disp(x); %XX representation of transmitting binary information as digital signal XXX bit=[]; for n=1:1:length(x) if x(n)==1; se=ones(1,50); else x(n)==0; se=zeros(1,50); end bit=[bit se]; end t1=bp/50:bp/50:50*length(x)*(bp/50); subplot(3,1,1); plot(t1,bit,'lineWidth',2.0);grid on; axis([ 0 bp*length(x) -.5 1.5]); ylabel('amplitude(volt)'); xlabel(' time(sec)'); title('transmitting information as digital signal'); %XXXXXXXXXXXXXXXXXXXXXXX Binary-FSK modulation XXXXXXXXXXXXXXXXXXXXXXXXXXX% A=5; % Amplitude of carrier signal br=1/bp; % bit rate f1=br*8; % carrier frequency for information as 1 f2=br*2; % carrier frequency for information as 0 t2=bp/99:bp/99:bp; ss=length(t2); m=[]; for (i=1:1:length(x)) if (x(i)==1) y=A*cos(2*pi*f1*t2); else y=A*cos(2*pi*f2*t2); end m=[m y]; end t3=bp/99:bp/99:bp*length(x); subplot(3,1,2); plot(t3,m); xlabel('time(sec)'); ylabel('amplitude(volt)'); title('waveform for binary FSK modulation coresponding binary information'); %XXXXXXXXXXXXXXXXXXXX Binary FSK demodulation XXXXXXXXXXXXXXXXXXXXXXXXXXXXX mn=[]; for n=ss:ss:length(m) t=bp/99:bp/99:bp; y1=cos(2*pi*f1*t); % carrier signal for information 1 y2=cos(2*pi*f2*t); % carrier signal for information 0 mm=y1.*m((n-(ss-1)):n); mmm=y2.*m((n-(ss-1)):n); t4=bp/99:bp/99:bp; z1=trapz(t4,mm) % intregation z2=trapz(t4,mmm) % intregation zz1=round(2*z1/bp) zz2= round(2*z2/bp) if(zz1>A/2) % logic lavel= (0+A)/2 or (A+0)/2 or 2.5 ( in this case) a=1; else(zz2>A/2) a=0; end mn=[mn a]; end disp(' Binary information at Reciver :'); disp(mn); %XXXXX Representation of binary information as digital signal which achived %after demodulation XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX bit=[]; for n=1:length(mn); if mn(n)==1; se=ones(1,100); else mn(n)==0; se=zeros(1,100); end bit=[bit se]; end t4=bp/100:bp/100:100*length(mn)*(bp/100); subplot(3,1,3) plot(t4,bit,'LineWidth',2.5);grid on; axis([ 0 bp*length(mn) -.5 1.5]); ylabel('amplitude(volt)'); xlabel(' time(sec)'); title('recived information as digital signal after binary FSK demodulation');