DSP與matlab聯(lián)合設計FIR濾波器

1、設計FIR濾波器作業(yè)報告學號：姓名：設計FIR濾波器作業(yè)報告本設計主要內(nèi)容是利用MATLAB驗證設計思路并用CCS3.3仿真環(huán)境設計一 個FIR濾波器，要求濾除給定的疊加正弦波的兩個較高頻分量。給定波形函數(shù)為：y=si n(2*pi*100*t)+si n(2*pi*250*t)+si n(2*pi*270*t)。1. 設計思路：輸入信號是頻率為 100Hz、250HZ、270Hz的合成正弦等幅信 號，由于給定的諧波分量最高為270Hz，根據(jù)奈奎斯特準則，采樣頻率應大于最 高頻率分量的2倍，即大于2*270，故可以以600Hz的采樣頻率進行采樣，即 fs=600Hz。設計了一個截止頻率為 20

2、0Hz的低通濾波器，目的是通過所設計的 低通bartlett濾波器將信號源中頻率為200Hz以上的信號濾掉，留下頻率為100Hz 的信號，達到濾波的效果。利用 MATLAB設計合適的濾波器實現(xiàn)濾波，然后得 到其濾波器系數(shù)在CCS的simulator方式下編寫濾波程序，調(diào)用波形數(shù)據(jù)，實現(xiàn) 濾波，并觀看濾波前后的信號波形圖、頻譜圖，觀察濾波達到預期效果。2. 設計過程1)在MATLAB中進行算法驗證MATLAB語言由于具有數(shù)值計算功能、符號計算功能、數(shù)據(jù)可視化功能、 建模仿真可視化功能，使得 MATLAB在命題構(gòu)思、模型建立、仿真研究、假想 驗證、數(shù)據(jù)源可視化各環(huán)節(jié)起著強大的作用。因此在設計中必須

3、先在MATLAB語言中設計一個FIR濾波器。本設計采用的是bartlett窗函數(shù)。下面是在MATLAB 中設計的27階FIR型bartlett濾波器程序：clear all ;%請寄存器clf;%青屏N=256;%清數(shù)據(jù)點fs=600;%采樣頻率dt=1/fs;%采樣時間間隔for t=1:Nf仁250;f2=100;f3=270;y(t)=(sin(2*pi*f1*t*dt)+sin(2*pi*f2*t*dt)+sin(2*pi*f3*t*dt);%產(chǎn)生合成信號x(t)=round(10000*y(t);%為DSP匯編程序做數(shù)據(jù)轉(zhuǎn)換endfigure(1)plot(y),title('

4、;濾波前的波形圖像)；fp=200fst=250NL=26f1=200;w1=2*pi*f1/fswindow=bartlett(NL+1)n=1:NL+1%窗函數(shù)hd=sin(w1*(n-NL/2)./(pi*(n-NL/2);hd(NL/2)=0.67; h=hd.*rot90(window) h1=h*32768;h2=fft(h,N); pyy=h2.*conj(h2); f=(0:(N/2-1);for i=1:N/2-1f(i)=f(i)*fs/N;endfigure(2)plot(f,pyy(1:N/2),title( yy 仁 filter(h,1,y); figure(3)%

5、將信號做FFT變換%做功率譜分析'濾波器的頻譜圖像)；%濾波plot(yy1),title('濾波后的波形圖像);y=fft(y,N);pyy=y.*conj(y);f=(0:(N/2-1);for i=1:N/2-1f(i)=f(i)*fs/N;endfigure(4)subplot(1,2,1),plot(f,pyy(1:N/2),title( y=fft(yy1,N);pyy=y.*conj(y);f=(0:(N/2-1);for i=1:N/2-1濾波前的波形頻譜圖像');f(i)=f(i)*fs/N;endsubplot(1,2,2),plot(f,pyy(1

6、:N/2),title('濾波后的波形頻譜圖像)其中采樣點為256個,采樣頻率為600Hz，輸入信號為100Hz、250Hz、270Hz 的合成信號，設定的截止頻率為200Hz，通過FIR濾波器后，期望保留的信號是 100Hz的信號，200Hz以上的頻率基本被濾掉。圖1是濾波前的圖形，圖2是濾波 后的圖形，圖3為濾波器頻譜圖像，圖4濾波前后的波形頻譜圖像。從這四個圖 中可以看住原始信號中的頻率有100Hz、250Hz、270Hz，經(jīng)過濾波后200Hz以上 的信號成分基本上被濾掉。只留下100Hz的信號。濾波前的波形圖像-1-2-3 L050100150200250300圖1濾波前波形圖

7、像濾波后的波形圖像0.8|；10.60.40.2-0.2-0.4-0.6-0.850100150200250300圖2濾波后波形圖像濾波器的頻譜圖像0.90.8 -0.7 -0.6 -0.5 -0.4 -0.3 -0.2 -0.1 -0 L050100150200250300圖3濾波器的頻譜圖像100009000-8000-7000-6000-5000-4000-3000-2000r*1000-1I一丿10濾波后的波形頻譜圖像0100200300圖4濾波前后的波形頻譜圖像2）在CCS環(huán)境的仿真首先配置處理器項，進入 CCStudio v3.3中，編寫程序，程序如下:.mmregs.ref fi

8、lter_start.def _c_int00K_DATA_SIZE.set256K_BUFFER_SIZE.set32K_STACK_SIZE.set256K_B.set27K_CIR.setK_BUFFER_SIZESTACK.usect"stack",K_STACK_SIZESYSTEM_STACK.setK_STACK_SIZE+STACKDATA_DP.usect"filter_vars",0filterdata.usect"filter_vars",K_DATA_SIZEbufferdatay.usect"fil

9、ter_vars",K_BUFFER_SIZE*2bufferdatax.usect"filter_vars",K_BUFFER_SIZE*2.data.global inputdatainputdata.WORD 16750, -5878, 18090,-26831,6340, -9511,11750,11443.WORD -6910,0,-16750,5878, 5570,9511,0,-7810.WORD -11750,5878,570, 17321,-6910, -5878,-5570,-9511.WORD 23660, -9511, 18090,-231

10、98, -570,0, 570, 23198,-18090.WORD 9511,-23660,9511,5570, 5878,6910,-17321,-570.WORD -5878,11750,7810,0,-9511,-5570,-5878,16750.WORD 0,6910,-11443,-11750,9511,-6340,26831,-18090.WORD 5878,-16750,0,16750,-5878,18090,-26831,6340.WORD -9511,11750,11443,-6910,0,-16750,5878,5570.WORD 9511,0,-7810,-11750,

11、5878,570,17321,-6910.WORD -5878,-5570,-9511,23660,-9511,18090,-23198,-570.WORD 0,570,23198,-18090,9511,-23660,9511,5570.WORD 5878,6910,-17321,-570,-5878,11750,7810,0.WORD -9511,-5570,-5878,16750,0,6910,-11443,-11750.WORD 9511,-6340,26831,-18090,5878,-16750,0,16750.WORD -5878,18090,-26831,6340,-9511,

12、11750,11443,-6910.WORD 0,-16750,5878,5570,9511,0,-7810,-11750.WORD 5878,570,17321,-6910,-5878,-5570,-9511,23660.WORD -9511,18090,-23198,-570,0,570,23198,-18090.WORD 9511,-23660,9511,5570,5878,6910,-17321,-570.WORD -5878,11750,7810,0,-9511,-5570,-5878,16750.WORD 0,6910,-11443,-11750,9511,-6340,26831,

13、-18090.WORD 5878,-16750,0,16750,-5878,18090,-26831,6340.WORD -9511,11750,11443,-6910,0,-16750,5878,5570.WORD 9511,0,-7810,-11750,5878,570,17321,-6910.WORD -5878,-5570,-9511,23660,-9511,18090,-23198,-570.WORD 0,570,23198,-18090,9511,-23660,9511,5570.WORD 5878,6910,-17321,-570,-5878,11750,7810,0.WORD

14、-9511,-5570,-5878,16750,0,6910,-11443,-11750.WORD 9511,-6340,26831,-18090,5878,-16750,0,16750.WORD -5878,18090,-26831,6340,-9511,11750,11443,-6910.WORD 0,-16750,5878,5570,9511,0,-7810.text_c_int00:.asg AR2,ORIGIN.asg AR3,INPUT.asg AR4,FILTER.asg AR5,OUTPUTSTART:SSBXFRCTSSBXINTMLD#DATA_DRDPSTM#STACK,

15、SPCALLfilter_startNOPNOPNOPLOOPB LOOP.defh0,h1,h2,h3,h4,h5,h6,h7,h8,h9,h10,h11,h12,h13,h14,h15,h16,h17,h18,h19,h20,h21,h22,h23,h24,h25,h26.def filter_starth0.set 0000Hh1.set -003FHh2.set 008AHh3.set 0000Hh4.set -015BHh5.set 01F0Hh6.set 0000Hh7.set -03CDHh8.set 056EHh9.set 0000Hh10.set -0D92Hh11.set

16、1DDBHh12.set 4F2AHh13.set 2349Hh14.set -1049Hh15.set 0000Hh16.set 06C9Hh17.set -04E3Hh18.set 0000Hh19.set 02B7Hh20.set -0209Hh21.set 0000Hh22.set 0116Hh23.set -00BEHh24.set 0000Hh25.set 0035Hh26.set 0000H.textfilter_start:STM#K_CIR,BKSTM#1,AR0STM#inputdata,ORIGINSTM#bufferdatax,INPUTSTM#bufferdatay,

17、FILTERSTM#filterdata,OUTPUTSTM#K_DATA_SIZE-1,BRCRPTBfilter_end-1MVDD*ORIGIN+,*INPUTRPT#K_B-1-1MAR*INPUT-0%MPY*INPUT+0%,#h26,BLD B,A;設置循環(huán)緩沖區(qū)的大小和步長;設置快循環(huán)計數(shù)器MPY *INPUT+0%,#h25,BADD B,AMPY *INPUT+0%,#h24,BADD B,AMPY *INPUT+0%,#h23,BADD B,AMPY *INPUT+0%,#h22,BADD B,AMPY *INPUT+0%,#h21,BADD B,AMPY *INPUT+

18、0%,#h20,BADD B,AMPY *INPUT+0%,#h19,BADD B,AMPY *INPUT+0%,#h18,BADD B,AMPY *INPUT+0%,#h17,BADD B,AMPY *INPUT+0%,#h16,BADD B,AMPY *INPUT+0%,#h15,BADD B,AMPY *INPUT+0%,#h14,BADD B,AMPY *INPUT+0%,#h13,BADD B,AMPY *INPUT+0%,#h12,BADD B,AMPY *INPUT+0%,#h11,BADD B,AMPY *INPUT+0%,#h10,BADD B,AMPY *INPUT+0%,#h9,BADD B,AMPY *INPUT+0%,#h8,BADD B,AMPY *INPUT+0%,#h7,BADD B,AMPY *INPUT+0%,#h6,BADD B,AMPY *INPUT+0%,#h5,BADD B,AMPY *INPUT+0%,#h4,BADD B,AMPY *INPUT+0%