BER for BPSK in ISI channel with MMSE equalization in Rayleigh channel (Matlab code)
Dear, check this link:
http://www.dsplog.com/2010/01/24/ber-bpsk-isi-channel-mmse-equalization/
BER for BPSK in ISI channel with Zero Forcing equalization in Rayleigh channel (Matlab code)
http://www.dsplog.com/2009/11/29/ber-bpsk-isi-channel-zero-forcing-equalization/
Hi I dont know much about how to do equalization. But following code gives you Rayleigh fading channel with Shadowing and path loss
%Pr = (sigma)^2*(10^(X/2))*(lambda/4pi*d)^2*Pt
r = randn + i*randn; % sigma = abs(r)
%Due to Pathloss
Very_slow_effect = 20*log10(lambda) - 20*log10(4*pi) - 10*ch_param.pathlossExp*log10(User.d);
%Shadaowing effect
Pr_slowfade(ii) = Pr_very_slowfade(ii) + std_dev*randn;
%Rayleigh fading
Pr_Rayleigh(ii) = Pr_slowfade(ii) + 20*log10(abs(r));
%%
%-------------------------- Zero Forcing Equalizer ------------------------
% Zero Forcing Equalizer is a type of linear equalizers used to combat ISI
% A typical channel is model in discrete domain as:
% y[n]=h[n]*x[n]+z[n]
% where y[n] is channel output,
% x[n] is channel input,
% h[n] is channal impulse response,
% z[n] is AWGN nosise
%---------------- To convert channel to frequency domain ------------------
% Y(f)=H(f)X(f)+Z(f)
% Zero-forcing equalizer multiplies Y(f) by inv(H(f))
% inv(H(f))Y(f)=X(f)+inv(H(f))Z(f)
function Xh = ZF(h,r)
% r ------------ is the signal at the receiver
% h ------------ is the impulse response of the channel
%------------------ Computing inverse impulse response --------------------
g = tf(h,1); % taking impulse response and transforming it to S domain
f = 1/g; % taking inverse of a transfer function
[num,den] = tfdata(f,'v');% extracting numerator and denominator coefficients
%----------------------------- Zero forcing -------------------------------
Xh = filter(num,den,r); % filtering
end
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