%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%?lmsalgo?:?LMS?algorithm?demo
%?Author?:?Tamer?abdelazim?Mellik
%?Contact?information?:?
%Department?of?Electrical?&?Computer?Engineering
%University?of?Calgary
%2500?University?Drive?N.W.?
%Calgary?AB?T2N?1N4?
%Canada?.
%?email?:abdelasi@enel.ucalgary.ca??
%?email?:?tabdelaz@ucalgary.ca
%?Webpage?:?http://www.enel.ucalgary.ca/~abdelasi/
%?Date????:?20-4-2003
%?Version?:?1.0.0
%?Reference?:?S.?Haykin?Adaptive?Filter?Theory.?3rd?edition?Upper?Saddle?River?NJ:?Prentice-Hall?1996.?
%?Note?:?The?author?doesn‘t?take?any?responsibility?for?any?harm?caused?by?the?use?of?this?file
clear?all
close?all
hold?off
%channel?system?order
sysorder?=?5?;
%?Number?of?system?points
N=2000;
inp?=?randn（N1）;
n?=?randn（N1）;
[ba]?=?butter（20.25）;
Gz?=?tf（ba-1）;
%This?function?is?submitted?to?make?inverse?Z-transform?（Matlab?central?file?exchange）
%The?first?sysorder?weight?value
%h=ldiv（basysorder）‘;
%?if?you?use?ldiv?this?will?give?h?:filter?weights?to?be
h=??[0.0976;
????0.2873;
????0.3360;
????0.2210;
????0.0964;];
y?=?lsim（Gzinp）;
%add?some?noise
n?=?n?*?std（y）/（10*std（n））;
d?=?y?+?n;
totallength=size（d1）;
%Take?60?points?for?training
N=60?;	
%begin?of?algorithm
w?=?zeros?（?sysorder???1?）?;
for?n?=?sysorder?:?N?
	u?=?inp（n:-1:n-sysorder+1）?;
????y（n）=?w‘?*?u;
????e（n）?=?d（n）?-?y（n）?;
%?Start?with?big?mu?for?speeding?the?convergence?then?slow?down?to?reach?the?correct?weights
????if?n?????????mu=0.32;
????else
????????mu=0.15;
????end
	w?=?w?+?mu?*?u?*?e（n）?;
end?
%check?of?results
for?n?=??N+1?:?totallength
	u?=?inp（n:-1:n-sysorder+1）?;
????y（n）?=?w‘?*?u?;
????e（n）?=?d（n）?-?y（n）?;
end?
hold?on
plot（d）
plot（y‘r‘）;
title（‘System?output‘）?;
xlabel（‘Samples‘）
ylabel（‘True?and?estimated?output‘）
figure
semilogy（（abs（e）））?;
title（‘Error?curve‘）?;
xlabel（‘Samples‘）
ylabel（‘Error?value‘）
figure
plot（h?‘k+‘）
hold?on
plot（w?‘r*‘）
legend（‘Actual?weights‘‘Estimated?weights‘）
title（‘Comparison?of?the?actual?weights?and?the?estimated?weights‘）?;
axis（[0?6?0.05?0.35]）

?屬性????????????大小?????日期????時間???名稱
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?????文件???????2072??2009-02-05?09:38??lms.m

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?????????????????2072????????????????????1