bao cao xltn _ nhom 11

8/3/2019 Bao Cao XLTN _ Nhom 11

1/13

Li noi u

Ngy nay vi s pht trin nhanh chng ca khoa hc k thut , c bitl ngnh cng ngh thng tin . Cc phng tin truyn thng a phng

tin pht trin cng mnh m v ng vai kh quan trng . Trong x l ting ni ng vai tr then cht .

Bi tp ln ca nhm chng em l v tn hiu p ng tn s ca tuynm c 3 hp cng hng mc ni tip . l 1 ti tht s hu chcho chng em trong hc tp cng nh cho cng vic sau ny . Qua ychng em hiu r hn v tuyn m v cc hm x l fourier .

Cui cng chng em chn thnh cm n : Thy gio Trnh Vn Loan

tn tnh hng dn, gip chng em hon thnh bi tp ln ny .

Nhm sinh vin:

Quang Phong

Hong Trng Tun Anh

Hong Khc Nhn

Hong Nht Nam


2/13

bai:Tuyn m c xem nh cc mch cng hng mc ni tip vi nhau.Hy xy dng tuyn m gm 3 mch cng hng cc tn s F1 =881Hz, F2 = 1532Hz, F3 = 2476Hz. Di thng tng ng l B1 = 177Hz,B2 = 119Hz, B3 = 237Hz.

Tn s ly mu l 10000Hz.

V dng p ng tn s ca tuyn m xy dng trn.

Tn s formant, di thng, tn s v bin cng hng c xem lcc tham s c th thay i. V li dng p ng tn s ca tuyn mmi khi thay i cc tham s trn.


3/13

I. C s l thuyt :

Ting ni l mt c trng ch c con ngi do nghin cu v x lting ni trc tin ta phi hiu c cu trc vt l ca ting ni v c ch toting ni ca con ngi.

m thanh thng c chia thnh ba nhm: m thanh ting ni(voiced sounds),m thanh khng l ting ni( unvoiced sounds) v cc ph m dng (stop-consonants). Cc nguyn m(V d nh /a/,/e/,/i/) v cc m mi(/n/, /m/...) lm thanh ting ni, cc ph m xt (fricatives) (/s/,/h/,/f/) l v d ca m thanhkhng l ting ni , v cc m bt (plosives) (/k/, /p/, /t/) thuc v nhm ph mdng.

Qu trnh to ting ni bt u t phi, ni m lung kh xut pht. m thanhc hnh thnh trong qu trnh lung kh i qua thanh qun v vng pht m(vocal tract). Thanh qun bao gm sn thanh qun, hc pht m v sn phu(arytenoid cartilage). Vng pht m c th c chia thnh ba phn: hng,khoang mi, ming. Li, vm ming, hm di v mi c nh hng nhttrong vng pht m v do to nn s phn bit ca m thanh. S t chc

s to ting ni c biu din Hnh 1.

Tu thuc vo trng thi hot ng ca cc hc pht m, cc m thanh c thc chia thnh hai nhm ln nh sau:

Th nht, khi cc hc pht m ng m theo chu k th s to ra mt chui ccxung (xung thanh mn). iu ny l cho m thanh trong trng hp ny c ctrng ca ting ni l: tnh chu k trong thi gian v cu trc iu ho trongtn s.

Th hai l cc hc pht m ch m, hnh thnh lung kh chuyn ng khngu gia cc hc v m thanh lc ny l nhiu. Cc m thanh m khng phi lting ni c hnh thnh theo cch ny. Cc ph m dng c sinh ra ngaykhi cc hc pht m ng li.

M hnh ting ni c th chia thnh hai khi nim khc nhau: M ho hngsng (waveform coding) v m ho ngun (source coding). Ban u, ngi ta c gng m phng tt c hin tng v tn hiu ca chng nh bn thn

chng vn c; trong x l ting ni iu ny tng ng vi m ho theo dng


4/13

sng. M ho theo dng sng l c gng bo ton hnh dng sng ban u vvic m ho c da vo lng t ho v rt gn dng sng. Mt khc thngi ta thng c xu hng chia mc ch nghin cu thnh cc phn nh hn,v phn tch v m hnh cc phn . T nhng phn m ngi ta tp hp li

thnh ch m cn nghin cu. Chnh iu ny dn ti khi nim m hangun, m hnh ho ting ni bng cc tham s khc nhau.

Mt ngun to ting ni thng c m ho nh sau:

S(z) = E(z)G(z)V(z)L(z), trong E(z) l hm tc ng cho G(z) l m hnhhnh dng ca thanh mn, cho L(z) l m hnh sng ti mi, V(z) l m hnhvng pht m. Thng th G(z), V(z) v L(z) c kt hp thnh h hnh chovng pht m. Hm E(z) trong min thi gian l e(n) c gi l ngun kch v

n c th l chui cc xung hoc nhiu ngu nhin.

Vic kch ca m thanh ting ni thng c m hnh bng mt chui ccxung, cn vic kch ca m thanh khng l ting ni th s dng kch nhiu ngunhin.

Ting ni c th c xem xt nh qu trnh dng cc b. Tuy nhin, cc phnca ting ni, v d nh cc m thanh ting ni (nh phn chia trn) c thc xem nh cc tn hiu xc nh. Tn hiu ting c chu k ring bit theothi gian li theo mt khun dng, mu th n lin quan ti cc mu gn vin (cc mu c tng quan vi nhau).

Do mu th n c th c d on t cc mu trc , hay mu s(n) c thc biu din bi cc mu s(n-k), 1


5/13

Hnh 1: T chc to ting ni

T vic nghin cu c ch to ting ni ca con ngi, ngi ta m hnh ho

c qu trnh to ting ni trong min thi gian c ri rc ho. (Hnh 2)

Hnh 2: M hnh ri rc theo thi gian ca vic to ting ni


6/13

II. Xy dng tuyn m

Hm truyn t ca b lc s tn s format Fk c cho bi:

Trong :

T: Chu k ly mu

2k : Di thng (Bk)

Tim phng trinh sai phn m ta quan h gi tin hiu ra yk(n) va tinhiu vao xk(n):

T hm truyn t Hk(z) ta c:

S dung bin i z-1:

ta c:

t:


7/13

Ak = -2.|zk|.cosk ; Dk = | zk|2

Ck =

Ta c:

(n) + Ak. (n - 1) + Dk. (n - 2) = Ck. (n)

(n) =Ck. (n) Ak. (n-1) Dk. (n-2)

y l phng trnh sai phn m t quan h gia tn hiu ra (n) v tn

hiu vo (n).

Xy dng tuyn m t phng trinh sai phn:

Tuyn m gm 3 mch cng hng mc ni tip nhau c phng trnhsai phn nh sau:

III. ap ng tn s cua tuyn mT phng trnh sai phn ta c:

yk(n) = Ck.x(n) Ak.yk(n-1) Dk.yk(n-2)

yk(n) + Ak.yk(n-1) + Dk.yk(n-2) = Ck.x(n)

Bin i Fourier:

x(n n0) e-jnow.x(ejw)

Ta c:

Yk(ejw

) + Ake-jw

.Yk(ejw

) + Dk.e-2jw

.Yk(ejw

) = Ck.Xk(ejw

)

+ +

Z-1

Z-1

Z-1 Z-1

Z-1 Z-1

++ +x(n1)

x(n2) x(n3)y(n1) y(n2) y(n3)c1c2 c3

- A1 - A2 - A3

- D1 - D2 - D3


8/13

Vy:

t Pk =

Qk =

Tuyn m gm 3 mch cng hng nn:

IV.Chng trnh m phong:

Chn trnh c vit trn ngn ng VC++ trong mi trngVisual Studio 2005:


9/13

Cc hm tnh chui Fourier ca H1(ejw), H2(ejw), H3(ejw) v H (ejw)nh sau:

private: double Ak(double Fk, double Bk){return (-2 * Math::Exp(-(Bk/2)*Ts) *Math::Cos(2*Math::PI*Fk*Ts));

}private: double Dk(double Fk, double Bk){

return (Sqr(Math::Exp(-(Bk/2)*Ts)));}

private: double Ck(double Fk, double Bk){return (1 + Ak(Fk, Bk) + Dk(Fk, Bk));

}

private: double Reality(double F, double Fk, double Bk){return (1 + Ak(Fk, Bk)*Math::Cos(2*Math::PI*F*Ts)

+ Dk(Fk, Bk)*Math::Cos(4*Math::PI*F*Ts));}private: double Imaginary(double F, double Fk, double Bk){

return (Ak(Fk, Bk)*Math::Sin(2*Math::PI*F*Ts) +Dk(Fk, Bk)*Math::Sin(4*Math::PI*F*Ts));

}private: double AmpHk(int F, double Fk, double Bk){

return (Ck(Fk, Bk)/Math::Sqrt(Sqr(Imaginary(F, Fk,Bk)) + Sqr(Reality(F, Fk, Bk))));

}private: double PhaseHk(double F, double Fk, double Bk){

return (Math::Atan(Imaginary(F, Fk, Bk)/Reality(F,Fk, Bk)));

}private: double AmpH(double F, double F1, double B1, double F2,double B2, double F3, double B3){


10/13

double C, MS, RealNum, ImageNum;C = Ck(F1, B1) * Ck(F2, B2) * Ck(F3, B3);MS = (Sqr(Reality(F, F1, B1)) + Sqr(Imaginary(F,

F1, B1))) * (Sqr(Reality(F, F2, B2)) + Sqr(Imaginary(F, F2, B2))) *(Sqr(Reality(F, F3, B3)) + Sqr(Imaginary(F, F3, B3)));

RealNum = Reality(F, F1, B1)*Reality(F, F2,

B2)*Reality(F, F3, B3) - Reality(F, F1, B1)*Imaginary(F,F2, B2)*Imaginary(F, F3, B3)

- Imaginary(F, F1, B1)*Reality(F,F2, B2)*Imaginary(F, F3, B3)

- Imaginary(F, F1,B1)*Imaginary(F, F2, B2)*Reality(F, F3, B3);

ImageNum = Reality(F, F1, B1)*Reality(F, F2,B2)*Imaginary(F, F3, B3)

+ Reality(F, F1, B1)*Imaginary(F,F2, B2)*Reality(F, F3, B3)

+ Imaginary(F, F1, B1)*Reality(F,F2, B2)*Reality(F, F3, B3)

- Imaginary(F, F1,B1)*Imaginary(F, F2, B2)*Imaginary(F, F3, B3);return (C*Math::Sqrt(Sqr(RealNum) +

Sqr(ImageNum))/MS);}

private: double PhaseH(double F, double F1, double B1, double F2,double B2, double F3, double B3){

double RealNum, ImageNum;RealNum = Reality(F, F1, B1)*Reality(F, F2,

B2)*Reality(F, F3, B3)- Reality(F, F1, B1)*Imaginary(F,

F2, B2)*Imaginary(F, F3, B3)- Imaginary(F, F1, B1)*Reality(F,

F2, B2)*Imaginary(F, F3, B3) - Imaginary(F, F1,B1)*Imaginary(F, F2, B2)*Reality(F, F3, B3);

ImageNum = Reality(F, F1, B1)*Reality(F, F2,B2)*Imaginary(F, F3, B3)

+ Reality(F, F1, B1)*Imaginary(F,F2, B2)*Reality(F, F3, B3)

+ Imaginary(F, F1, B1)*Reality(F,F2, B2)*Reality(F, F3, B3)

- Imaginary(F, F1,B1)*Imaginary(F, F2, B2)*Imaginary(F, F3, B3);

return (Math::Atan(ImageNum/RealNum));}

Hm v th:private: System::Void pictureBox1_Paint(System::Object^ sender,

System::Windows::Forms::PaintEventArgs^ e) {Graphics ^ g = e->Graphics;g->Clear(Color::Black);int npoints = Math::Abs(pictureBox1->Left -

pictureBox1->Right);double delta = int(1/(npoints*Ts));

cli::array ^points = gcnewcli::array(npoints);

cli::array ^points1 = gcnewcli::array(npoints);


11/13



double F1, B1, F2, B2, F3, B3;

if(label4->Text == "881") F1 = 881;else F1 = trackBar1->Value*500;if(label16->Text == "177") B1 = 177;else B1 = trackBar6->Value * 50;int x = 0;

if(radioButton1->Checked == 1){for (int i = 0; i < npoints; i++) {

points1[i].X = i;points1[i].Y = - AmpHk(x, F1, B1)/4 +

215.0F;x += delta;

}}else{

for (int i = 0; i < npoints; i++) {

points1[i].X = i;points1[i].Y = - PhaseHk(x, F1, B1)/4 +

215.0F;x += delta;

}}g->SmoothingMode =

Drawing2D::SmoothingMode::HighQuality;g->DrawLines(gcnew Pen(Color::Green, 2.0F),

points1);

if(label3->Text == "1532") F2 = 1532;else F2 = trackBar2->Value*500;if(label14->Text == "119") B2 = 119;else B2 = trackBar5->Value * 50;

x = 0;if(radioButton1->Checked == 1){



215.0F;x += delta;

}}else{



215.0F;x += delta;

}}


12/13

g->DrawLines(gcnew Pen(Color::Blue, 2.0F),points2);

if(label6->Text == "2476") F3 = 1532;else F3 = trackBar3->Value*500;if(label10->Text == "237") B3 = 119;

else B3 = trackBar4->Value * 50;

x = 0;if(radioButton1->Checked == 1){



215.0F;x += delta;

}}else{



215.0F;x += delta;

}}

g->DrawLines(gcnew Pen(Color::Cyan, 2.0F),points3);

x = 0;

if(radioButton1->Checked == 1){for (int i = 0; i < npoints; i++) {

points[i].X = i;points[i].Y = - AmpH(x, F1, B1, F2, B2,

F3, B3)/4 + 215.0F;x += delta;

}}else{


points[i].X = i;

points[i].Y = - PhaseH(x, F1, B1, F2,B2, F3, B3)/4 + 215.0F;

x += delta;}

}

g->DrawLines(gcnew Pen(Color::Red, 2.0F), points);

}


13/13

Kt lun

Chng trnh chy n nh, giao din thn thin, b tr hp l.Tuy nhin trong thi gian ngn, chng em cha hon chinh cchng trnh nh bi yu cu, cha v c p ng pha.Rt mong nhn c nhng li gp ca thy.Chng em xin chn thnh cm n thy!

Nhm sinh vin Quang PhongHong Trng Tun AnhHong Khc Nhn

Hong Nht Nam

bao cao xltn _ nhom 11

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