【matlab编程代做】matlab实现bpsk+ofdm.pdf

%BPSK simulation using a carrier cosine wave with ISI clc; close all; clear all; %figure(1) n=160 for i=1:n data(i)= 2*round(rand)-1; end %create modulated BPSK signal %first expand the bit stream exdata=[]; for i=1:length(data) for rep=1:5 exdata= [exdata data(i)]; end end ts=.1; t=1:ts:; carrier=cos(pi*t); %multiply expanded bitstream by cosine wave with carrier frequency %this is the BPSK that is to be transmitted over the channel bpsk=carrier.*exdata; %bpsk=[bpsk(length(bpsk)-1) bpsk(length(bpsk)) bpsk]; %plot(bpsk) % generating the noise % p=rand(1,800)*2*pi; p=rand*2*pi; snr=10; r=sqrt(-1*(1/snr*log(1 -rand))); % no = 5*(r.* exp(j*p)); no = (r.* exp(j*p)); % value of alpha al=rand+j*rand; %al=1; % Spreading channel with the alpha as the variable for k=5:5:795 for l = 1:5 %al=round(rand)+j*round(rand) rec(k+l)=bpsk(k+l)+al*bpsk(k-5+l); end end rxdata=rec+ no ; %begin demodulation %first multiply recieved bitstream by cosine wave with carrier frequency %figure(2) uncarry=rxdata.*carrier; %plot(uncarry) %demodulate by integrating dec1=[]; for inc=1:5:length(uncarry) dec=trapz(inc:inc+4,uncarry(inc:inc+4)); dec1=[dec1 dec]; end %make decision with a threshold of zero demod=[]; for i=1:length(dec1) if dec1(i)>0 demod=[demod 1]; elsedemod=[demod -1]; end end %stem(demod) %calculate errors error=0; for i=1:length(demod) if data(i)~=demod(i) error=error+1; end e