%?A?second?order?DPLL?design
%?Block?diagram
%?????????????+---+??e????+-----------+??????y
%????x?------>|?+?|------>|???H1（z）???|---------+??
%?????????????+---+???????+-----------+?????????|
%???????????????^???????????????????????????????|
%???????????????|???z?????+-----------+?????????|
%???????????????|---------|??H2（z）????|<--------+
%?????????????????????????+-----------+
%?
clear?all

%?number?of?bits?in?the?quantizer
b?=?15;
q?=?1/2^b;
phase?=?0;
amplitude?=?5;

%?DPLL?parameters?from?closed-loop?transfer?function
g1?=?0.0147;
g2?=?0.0001;

%?gain?of?the?phase?detector
Gpd?=?1;
%?VCO?gain
Gvco?=?1;
G1?=?g1/（Gpd*Gvco）;
G2?=?g2/（Gpd*Gvco）;
G?=?G1?+?G2;

%?input?（reference）?signal
t?=?0:0.0001:?1;
f?=?10;
%x?=?ones（1?1000）;?????%?step?response?only
if?mod（t100）?==?0
	%phase?=?phase?+?rand（）*360?;
	phase?=?phase?+?100?;
	if?phase?>?360
		phase?=?（phase-360）;
	end
end

%x?=?sin?（amplitude?*?exp（j?*?（2*pi*f*t?+?phase）?）?）;
x?=?amplitude?*?sin?（2*pi*f*t?+?phase?）
%x?=?AWGN（temp_sine50）;????%AWGN（XSNR）?adds?white?Gaussian?noise?to?X.?The?SNR?is?in?dB.?
%x?=?chirp（t01150）;


figure
plot（x）;

%?quantize?x?into?b?bits?（Can?take?the?following?3?lines?out?to?compare
%?with?and?without?quantizer）
signs?=?sign（x）;
signs（~signs）?=?ones（size（signs（~signs）））;
x?=?q?.*?floor（abs（x./q）?+?0.5）?.*?signs;

y（1）?=?（G1?+?G2）?*?x（1）;
z（1）?=?y（1）;

%?quantize?y?and?z?into?b?bits?（Can?take?the?following?6?lines?out?to
%?compare?with?and?with?quantizer）
sign_y?=?sign（y（1））;
sign_y（~sign_y）?=?ones（size（sign_y（~sign_y）））;
y（1）?=?q?.*?floor（abs（y（1）./q）?+?0.5）?.*?sign_y;

sign_z?=?sign（z（1））;
sign_z（~sign_z）?=?ones（size（sign_z（~sign_z）））;
z（1）?=?q?.*?floor（abs（z（1）./q）?+?0.5）?.*?sign_z;

e（1）?=?x（1）?-?z（1）;

for?i?=?2?:?length（x）
????%?phase?detector
????e（i）?=?x（i）?-?z（i-1）;
????
????%?loop?filter?H1（z）?an?IIR?filter
????y（i）?=?G?*?e（i）?-?G1?*?e（i-1）?+?y（i-1）;
????
????%?Can?take?the?following?3?lines?out?to?compare
????%?with?and?without?quantizer
????sign_y?=?sign（y（i））;
????sign_y（~sign_y）?=?ones（size（sign_y（~sign_y）））;
????y（i）?=?q?.*?floor（abs（y（i）./q）?+?0.5）?.*?sign_y;
????
????%?VCO?filter?an?IIR?accumulator
????z（i）?=?z（i-1）?+?Gvco?*?y（i）;
????
????%?Can?take?the?following?3?lines?out?to?compare
????%?with?and?without?quantizer
????sign_z?=?sign（z（i））;
????sign_z（~sign_z）?=?ones（size（sign_z（~sign_z）））;
????z（i）?=?q?.*?floor（abs（z（i）./q）?+?0.5）?.*?sign_z;
end



figure
plot（e）;

figure
plot（y）;

%?equivalent?close-loop?transfer?function?the?ideal?case
Z?=?tf（‘z‘1）;
H?=?（0.0148*Z?-?0.0147）/（Z^2?-1.9852*Z?+0.9853）;
step?=?ones（11000）;
step_response?=?lsim（H?step?1:length（step））;

?屬性????????????大小?????日期????時間???名稱
-----------?---------??----------?-----??----

?????文件???????2734??2009-03-01?16:18??dpll.m

-----------?---------??----------?-----??----

?????????????????2734????????????????????1