MATLAB中频分多址的仿真.zip

% Design and simulation of Frequency Division Multiplexing in MATLAB clc; clear all close all samples=1000; % number of users nos=8; % modulating signal frequency in Hz mfreq=[30 40 50 60 70 80 90 100]; % carrier frequency allocated to the different users in Hz cfreq=[300 600 900 12000 1500 1800 2100 2400]; % choose frequency deviation freqdev=10; % generate modulating signal t=linspace(0,1000,samples); parfor i=1:nos m(i,:)=sin(2*pi*mfreq(1,i)*t)+2*sin(pi*8*t); end % Generate the modulated signal parfor i=1:nos y(i,:)=fmmod(m(i,:),cfreq(1,i),10*cfreq(1,i),freqdev); end % pass the modulated signal through the channel ch_op=awgn(sum(y),0,'measured'); % demodulate the received signal at the base station parfor i=1:nos z(i,:)=fmdemod(y(i,:),cfreq(1,i),10*cfreq(1,i),freqdev); end % display the transmitted signal and received signal at the base station % figure C = {'k','b','r','g','y',[.5 .6 .7],[.8 .2 .6],[.3 .2 .2]}; % Cell array of colros. for i=1:nos figure (1) hold on plot(y(i,:),'color',C{i}); xlabel('time index'); ylabel('amplitude'); title('Signal from different users combined in the channel'); figure subplot(3,1,1) plot(m(i,:)) % modulating signal xlabel('time index'); ylabel('amplitude'); title('modulating Signal from user'); subplot(3,1,2) plot(y(i,:),'color',C{i}); % modulated signal xlabel('time index'); ylabel('amplitude'); title('modulated Signal from user'); subplot(3,1,3) plot(z(i,:),'color',C{i}); % demodulated signal xlabel('time index'); ylabel('amplitude'); title('demodulated Signal from user at the base station'); end figure plot(ch_op) % combination of all modulated signals passed through the channel xlabel('time index'); ylabel('amplitude'); title('Signal after passing through the channel');