1、數(shù)字信號處理基礎(chǔ),基本波形產(chǎn)生的方法 信號的各種運(yùn)算 信號采樣率的各種轉(zhuǎn)換 離散時間系統(tǒng)模型的表示方法與轉(zhuǎn)換,波形的產(chǎn)生,Square方波 Sawtooth鋸齒波 SincSinc函數(shù)波 DiricDirichlet函數(shù)波 Rectpuls非周期方波 Tripuls非周期三角波 Pulstran脈沖序列 Chirp產(chǎn)生調(diào)頻余弦信號,Square: 產(chǎn)生方波,x=square(t) x=square(t,duty), t=0:0.01:5; subplot(211) y=square(2*pi*t); plot(t,y); axis(0 5 -1.2 1.2) subplot(212) y=sq

2、uare(2*pi*t,80); plot(t,y); axis(0 5 -1.2 1.2),方波波形,Sawtooth: 產(chǎn)生鋸齒波和三角波,x=sawtooth(t) x=sawtooth(t,width), t=0:0.01:5; subplot(311) x=sawtooth(2*pi*t); plot(t,x); subplot(312) x=sawtooth(2*pi*t,1); plot(t,x); subplot(313) x=sawtooth(2*pi*t,0.5); plot(t,x);,鋸齒波、三角波波形,Sinc: 產(chǎn)生sinc函數(shù)波形,x=sinc(t), t=-10

3、:0.01:10; x=sinc(t); plot(t,x);,Sinc函數(shù)波形,Diric: 產(chǎn)生Diric或周期Sinc波形,x=Diric(t,n), t=0:0.01:8*pi; x1=diric(t,5); x2=diric(t,4); subplot(211) plot(t,x1); axis tight; subplot(212) plot(t,x2); axis tight;,Dirichlet函數(shù)波形,Rectpuls: 產(chǎn)生非周期方波,x=rectpuls(t) x=rectpuls(t,width), t=0:0.01:1; x=rectpuls(t,0.6); plot

4、(t,x); axis(0 1 -0.2 1.2),非周期方波波形,Tripuls: 產(chǎn)生非周期三角波,x=tripuls(t) x=tripuls(t,width) x=tripuls(t,w,s), t=0:0.01:1; x1=tripuls(t,0.8); x2=tripuls(t,0.4); subplot(211) plot(t,x1); subplot(212) plot(t,x2);,非周期三角波形,Pulstran: 產(chǎn)生沖擊串,x=pulstran(t,d,func) gauspuls rectpuls tripuls x=pulstan(t,d,func) x=pulst

5、ran(t,d,func,p1,p2, ) x=pulstran(t,d,p,Fs), t1=0:1/1e3:1; d1=0:1/3:1; y1=pulstran(t1,d1,tripuls,0.1,-1); subplot(311) plot(t1,y1); t2=0:1/50e3:10e-3; d2=0:1/1e3:10e-3;0.8.(0:10); y2=pulstran(t2,d2,gauspuls,10e3,.5); subplot(312) plot(t2,y2);, p=raylpdf(0:31)/5,1.5); t3=0:320; d3=(0:9)*32; y3=pulstra

6、n(t3,d3,p); subplot(313) plot(t3,y3),脈沖序列波形,Chirp: 產(chǎn)生調(diào)頻余弦信號,x=chirp(t,f0,t1,f1) x=chirp(t,f0,t1,f1,method) Method: linear, quadratic, logarithmic x=chirp(t,f0,t1,f1,method,phi) x=chirp(t,f0,t1,f1,quadratic,phi,concave) x=chirp(t,f0,t1,f1,quadratic,phi,convex), t1=0:0.001:2; y1=chirp(t1,0,1,150); sub

7、plot(221) specgram(y1,256,1E3,256,250); t2=-2:0.001:2; y2=chirp(t2,100,1,200,q); subplot(222) specgram(y2,128,1E3,128,120);, t3=0:0.001:1; fo3=25; f13=100; y3=chirp(t3,fo3,1,f13,q,convex); subplot(223) specgram(y3,256,1000), t4=0:0.001:1; fo4=100; f14=25; y4=chirp(t4,fo4,1,f14,q,concave); subplot(22

8、4) specgram(y4,256,1000),掃頻信號譜圖,信號的運(yùn)算,信號加:x=x1+x2 信號延遲:y(n)=x(n-k) 信號乘:x=x1.*x2 信號變化幅度:y=k*x 信號翻轉(zhuǎn):y=fliplr(x) 信號采樣和:y=sum(x(n1:n2) 信號采樣積:y=prod(x(n1:n2) 信號能量:Ex=sum(abs(x)2) 信號功率:Px=sum(abs(x)2)/N, n1=1:5; x10=1 0.7 0.4 0.1 0; n2=3:8; x20=0.1 0.3 0.5 0.7 0.9 1; n=1:8; x1=x10 zeros(1,8-length(n1); x2

9、=zeros(1,8-length(n2) x20; x=x1+x2; subplot(311); stem(n,x1); subplot(312); stem(n,x2); subplot(313); stem(n,x);,信號相加,采樣率轉(zhuǎn)換,信號整數(shù)倍抽取 信號整數(shù)倍插值 任意倍數(shù)信號重采樣,信號整數(shù)倍抽取,y=decimate(x,r) y=decimate(x,r,n) y=decimate(x,r,fir) y=decimate(x,r,n,fir), t=0:0.00025:2; x=sin(2*pi*50*t)+cos(2*pi*50*t); y=decimate(x,4);

10、subplot(211); stem(x(1:250); subplot(212); stem(y(1:125);,信號整數(shù)倍抽取波形圖,信號整數(shù)倍插值,y=interp(x,r) y=interp(x,r,l,alpha) y,b=interp(x,r,l,alpha), t=0:0.001:2; x=sin(2*pi*50*t)+sin(2*pi*100*t); y=interp(x,4); subplot(211); stem(x(1:125); subplot(212); stem(y(1:250);,信號整數(shù)倍插值波形圖,任意倍數(shù)信號重采樣,y=resample(x,p,q) y=r

11、esample(x,p,q,n) y=resample(x,p,q,n,beta) y=resample(x,p,q,b) y,b=resample(x,p,q, ), t=0:0.001:2; x=sin(2*pi*50*t)+sin(2*pi*100*t); y=resample(x,5,2,8); subplot(211); stem(x(1:125); subplot(212); stem(y(1:250);,信號重采樣波形圖,離散系統(tǒng)模型變換,Tf2ss:傳遞函數(shù)模型轉(zhuǎn)換為狀態(tài)空間模型 Tf2zp:傳遞函數(shù)模型轉(zhuǎn)換為零極點(diǎn)增益模型 Zp2ss:零極點(diǎn)增益模型轉(zhuǎn)換為狀態(tài)空間模型 Zp2tf:零極點(diǎn)增益模型轉(zhuǎn)換為傳遞函數(shù)模型 Zp2sos:零極點(diǎn)增益模型轉(zhuǎn)換為二次分式模型 Ss2tf:狀態(tài)空間模型轉(zhuǎn)換為傳遞函數(shù)