By: vijaya

vijaya — Tue, 07 Feb 2012 04:37:30 +0000

plz do explain mimo ofdm mat lab simulation program for inverse fast fourier transform.

By: Krishna Sankar

Krishna Sankar — Mon, 06 Feb 2012 00:16:08 +0000

@Fayeqa: Sorry, was unable to look deep into the code.

By: Fayeqa

Fayeqa — Mon, 30 Jan 2012 08:24:43 +0000

Dear Kirishna, please help me withOFDM amplify and forward in relay schem mathlab codes mine is there but not ok.
%////////////////////////////////////////////////////
% MIMO OFDM BPSK MMSE/ZF Function Multipath – Simplificado
%////////////////////////////////////////////////////

clear,clc

%===================================================
% OFDM Parameters Settings
%===================================================

antennas=1; % Antenas
bit=2048;%4;%2048; % Bit
symbol=bit; % Symbol
carrier=64;%2;%64; % Channels
gil=16;%2;%16; % Guard Interval
delay=1; % Delay
path=16; % Number of Paths
dur=0; % dB Rate
min_err=2000; % Minimum error
min_pckt = 800; % Minimum Packet
sym=symbol/carrier*(carrier+gil);
error=0;
skip=2.5;

%———————–SN Loop———————

for sn=0:skip:30;

%===================================================
% AWGN Setting
%===================================================

snr=10^(sn/10);
sd=sqrt(antennas*0.5/(snr*1*(carrier/(carrier+gil))));
error=0;
pckt=0;
snrtheorical1=(erfc(sqrt(snr)))/2; %BPSK AWGN Theoretical BER
snrtheorical2=0.5.*(1-sqrt(snr/(snr+1)))/(carrier/(carrier+gil)); %BPSK AWGN Multipath Theoretical BER

%—————————-
% packet loop
%—————————-

while(error<=min_err && pckt=0)
% recSD(ch,sk)=1;
% else
% recSD(ch,sk)=-1;
% end
% sk=sk+1;
% end
% end
%************************************************

%************************************************ %************************************************ %************************************************ %************************************************
%************************************************
%%************************************************
%%%************************************************
%%************************************************
%%%************************************************
%%%%************************************************

% Source-Relay LINK

%===================================================
% Multipath Settings
%===================================================

for ch=1:antennas*antennas
gsum(ch)=0;
for k=1:path
pr(ch,k) = (1.0)*sqrt(-log(rand));
prc(ch,k)=pr(ch,k)*exp((2*pi*rand*j));
ga(ch,k)=10^(-dur*(k-1)/20.0);
gsum(ch) = gsum(ch) + abs(ga(ch,k))^2;
end
for k=1:path
ga(ch,k) = ga(ch,k)/sqrt(gsum(ch))*prc(ch,k);
end
end

%===================================================
% Channel Loop
%===================================================
r1=1/sqrt(2);
fsle=0;

for ch=1:antennas*antennas

eqa(ch,1:carrier) = 1;
eqaT=ifft(eqa(ch,:),carrier);
eqaf=eqaT(1);
for k=1:path
eqaT((k-1)*delay+1) = ga(ch,k) * eqaf;
end
eqaF(ch,1:carrier)=fft(eqaT,carrier);

end

hsr=eqaF;

%===================================================
% ZF, MMSE Settings
%===================================================
H1=zeros(antennas,antennas);
sig=1e-6;
for k=1:carrier
for l=1:antennas
H1(l,1:antennas)=eqaF(1+antennas*(l-1):antennas+antennas*(l-1),k);
end
H1T=H1′;
%ZF criteria
%G1=H1T/(H1*H1T+eye(antennas)*sig);
%MMSE criteria
G1=H1T/(H1*H1T+antennas*sd^2*eye(antennas));

for l=1:antennas
for m=1:antennas
G(antennas*(l-1)+m,k)=G1(l,m);
end
end

end

%—————————-
% Transmitter
%—————————-

%*************************
% IFFT – Guard interval
%*************************

% for ch=1:antennas
% for k=1:symbol/carrier
%
% fftmp=map(ch,(k-1)*carrier+1:(k-1)*carrier+carrier);
%
% fftmpT=ifft(fftmp,carrier)*sqrt(carrier);
%
% ggi=fftmpT(:,carrier-gil+1:carrier);
%
% mc=[ggi,fftmpT];
%
% map2(ch,1+(k-1)*(carrier+gil):carrier+gil+(k-1)*(carrier+gil))= mc;
% end
% end

%**************************
%—————————–

%—————————-
% Channel
%—————————-

%**************************
% Multipath
%**************************
smp=zeros(antennas,sym);

for k=1:path
for m=1:antennas
HH(m,1:antennas)=ga(1+antennas*(m-1):antennas+antennas*(m-1),k);
end
for l=1: sym-(k-1)*delay
smp(1:antennas,(k-1)*delay+l)=smp(1:antennas,(k-1)*delay+l)+HH*map2(:,l);
end
end
%***************************

%**************************
% AWGN
%**************************

for ch=1:antennas
for k=1:sym
smp(ch,k)=smp(ch,k)+sd*(randn+j*randn);
end
end

recSR=smp;

%***************************
%—————————–

%——————————
% Receiver
%——————————

%*************************
% FFT – Guard interval
%*************************
%for ch=1:antennas
%for k=1:symbol/carrier
% fftmp=smp(ch,(k-1)*(carrier+gil)+(gil+1):(k-1)*(carrier+gil)+carrier+gil);
% fftmpF=fft(fftmp,carrier)/(sqrt(carrier));
%map3(ch,1+(k-1)*(carrier):k*(carrier))=fftmpF;
%end
%end

%***************************

%*************************
% FDE
%*************************
%map6=zeros(antennas,symbol);

%for k=1:symbol/carrier
% for l=1:carrier
% for m=1:antennas
% GG(m,1:antennas)=G(1+antennas*(m-1):antennas+antennas*(m-1),l);
%end
% map6(1:antennas,(k-1)*carrier+l)=GG*map3(:,(k-1)*carrier+l);

%end
%end

%***************************

%*************************
% BPSK demodulation
%*************************

% for ch=1:antennas
% sk=1;
% for k=1:bit
% if(real(map6(ch,k))>=0)
% recSR(ch,sk)=1;
% else
% recSR(ch,sk)=-1;
% end
% sk=sk+1;
% end
% end
%************************************************

%************************************************
%%************************************************
%%%************************************************
%%%%************************************************
%%%%%************************************************
%%%%%%************************************************
%%%%%%%************************************************
%%%%%%%%************************************************

% Relay-Destination LINK

%===================================================
% Multipath Settings
%===================================================

%===================================================
% Channel Loop
%===================================================
r1=1/sqrt(2);
fsle=0;

for ch=1:antennas*antennas

eqa(ch,1:carrier) = 1;
eqaT=ifft(eqa(ch,:),carrier);
eqaf=eqaT(1);
for k=1:path
eqaT((k-1)*delay+1) = ga(ch,k) * eqaf;
end
eqaF(ch,1:carrier)=fft(eqaT,carrier);

end

hrd=eqaF;

for l=1:antennas
for m=1:antennas
G(antennas*(l-1)+m,k)=G1(l,m);
end
end

end

%—————————-
% Transmitter
%—————————-

map=recSR;

for ch=1:antennas*antennas
beta(ch) = sqrt(1./sum((abs(hsr(ch,1:subcarrier)).^2) +N0));

map2(ch)=beta(ch)*map(ch);
end

%*************************

%*************************
% IFFT – Guard interval
%*************************

%for ch=1:antennas
%for k=1:symbol/carrier

% fftmp=map(ch,(k-1)*carrier+1:(k-1)*carrier+carrier);

% fftmpT=ifft(fftmp,carrier)*sqrt(carrier);

% ggi=fftmpT(:,carrier-gil+1:carrier);

% mc=[ggi,fftmpT];

% map2(ch,1+(k-1)*(carrier+gil):carrier+gil+(k-1)*(carrier+gil))= mc;
%end
%end

%**************************
%—————————–

%—————————-
% Channel
%—————————-

%**************************
% Multipath
%**************************
smp=zeros(antennas,sym);

%**************************
% AWGN
%**************************

for ch=1:antennas
for k=1:sym
smp(ch,k)=smp(ch,k)+sd*(randn+j*randn);
end
end

%***************************
%—————————–

%——————————
% Receiver
%——————————

%*************************
% FFT – Guard interval
%*************************
for ch=1:antennas
for k=1:symbol/carrier
fftmp=smp(ch,(k-1)*(carrier+gil)+(gil+1):(k-1)*(carrier+gil)+carrier+gil);
fftmpF=fft(fftmp,carrier)/(sqrt(carrier));
map3(ch,1+(k-1)*(carrier):k*(carrier))=fftmpF;
end
end

%***************************

%*************************
% FDE
%*************************
map6=zeros(antennas,symbol);

for k=1:symbol/carrier
for l=1:carrier
for m=1:antennas
GG(m,1:antennas)=G(1+antennas*(m-1):antennas+antennas*(m-1),l);
end

map6(1:antennas,(k-1)*carrier+l)=GG*map3(:,(k-1)*carrier+l);

end
end

recRD=map6;
combRD=recSD+recRD;

%***************************

%*************************
% BPSK demodulation
%*************************

% for ch=1:antennas
% sk=1;
% for k=1:bit
% if(real(map6(ch,k))>=0)
% recRD(ch,sk)=1;
% else
% recRD(ch,sk)=-1;
% end
% sk=sk+1;
% end
% end
%************************************************

%*************************
% Combining demodulation
%*************************

for ch=1:antennas
sk=1;
for k=1:bit
if(real(combRD(ch,k)+combSD(ch,k))>=0)
final(ch,sk)=1;
else
final(ch,sk)=-1;
end
sk=sk+1;
end
end
%************************************************

%=====================================================================
% ERROR COUNT
%=====================================================================
for ch=1:antennas
for k=1:bit
if(final(ch,k)~=tx(ch,k))
error=error+1;
end
end
end

end

%—————————–End packet loop

%=====================================================================
% BER
%=====================================================================

BER(sn/skip+1,1)=error/(antennas*bit*pckt);
sn,BER
%error,pckt
sn1(sn/skip+1)=sn;
sn2(sn/skip+1)=snrtheorical2;

if(BER(sn/skip+1,1)<=1.e-6)
break;
end
end

%=====================================================================
% Graphic
%=====================================================================

semilogy(sn1,BER,'*b-',sn1,sn2,'r-'); title('OFDM BPSK Multipath'); xlabel('Eb/N0 (dB)'); ylabel('BER'); grid;
AXIS([0 30 1e-6 1]);legend('Simulated Result','Theoretical Result',1);

%
%

By: Researcher

Researcher — Sun, 21 Aug 2011 08:00:26 +0000

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Matlab Code as well as the full paper will be sent to the individual after acceptance of paper from the conference.
Fee submission will be through Freelancer and elance. Candidate name will be included in Paper after milestone payment is released by him/her. Milestone payment is one which is in the custody of broker (Freelancer or Elance authority) and not in the custody of either party. After the paper is accepted and the client is conformed about the acheivement, only then he will be allowed to pay. Time is short so the policy of 1st come 1st serve will be entertained.

By: Krishna Sankar

Krishna Sankar — Thu, 26 May 2011 00:55:47 +0000

@MIKA: The BPSK in Rayleigh simulation does not have multipath. And in OFDM case though it has multipath, as long as it’s contained within cyclic prefix, there is no performance impact

By: Krishna Sankar

Krishna Sankar — Sun, 22 May 2011 21:40:17 +0000

@vasanth: What was your intent – to normalize the variance to unity?

By: vasanth

vasanth — Wed, 18 May 2011 10:37:51 +0000

can u pls tel me the equation for taps representation in ofdm…
is dis d correct eqn
h=(1/sqrt(2^taps))*(randn+i*randn)???
or
h=(1/sqrt(2*taps))*(randn+i*randn)???

Comments on: BER for BPSK in OFDM with Rayleigh multipath channel

By: vijaya

By: Krishna Sankar

By: Fayeqa

By: Researcher

By: Krishna Sankar

By: Krishna Sankar

By: vasanth