DSP与matlab联合设计FIR滤波器

1、设计FIR滤波器作业报告学号：姓名：设计FIR滤波器作业报告本设计主要内容是利用MATLAB验证设计思路并用CCS3.3仿真环境设计一 个FIR滤波器，要求滤除给定的叠加正弦波的两个较高频分量。给定波形函数为：y=si n(2*pi*100*t)+si n(2*pi*250*t)+si n(2*pi*270*t)。1. 设计思路：输入信号是频率为 100Hz、250HZ、270Hz的合成正弦等幅信 号，由于给定的谐波分量最高为270Hz，根据奈奎斯特准则，采样频率应大于最 高频率分量的2倍，即大于2*270，故可以以600Hz的采样频率进行采样，即 fs=600Hz。设计了一个截止频率为 20

2、0Hz的低通滤波器，目的是通过所设计的 低通bartlett滤波器将信号源中频率为200Hz以上的信号滤掉，留下频率为100Hz 的信号，达到滤波的效果。利用 MATLAB设计合适的滤波器实现滤波，然后得 到其滤波器系数在CCS的simulator方式下编写滤波程序，调用波形数据，实现 滤波，并观看滤波前后的信号波形图、频谱图，观察滤波达到预期效果。2. 设计过程1)在MATLAB中进行算法验证MATLAB语言由于具有数值计算功能、符号计算功能、数据可视化功能、 建模仿真可视化功能，使得 MATLAB在命题构思、模型建立、仿真研究、假想 验证、数据源可视化各环节起着强大的作用。因此在设计中必须

3、先在MATLAB语言中设计一个FIR滤波器。本设计采用的是bartlett窗函数。下面是在MATLAB 中设计的27阶FIR型bartlett滤波器程序：clear all ;%请寄存器clf;%青屏N=256;%清数据点fs=600;%采样频率dt=1/fs;%采样时间间隔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);%产生合成信号x(t)=round(10000*y(t);%为DSP汇编程序做数据转换endfigure(1)plot(y),title('

4、;滤波前的波形图像)；fp=200fst=250NL=26f1=200;w1=2*pi*f1/fswindow=bartlett(NL+1)n=1:NL+1%窗函数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、将信号做FFT变换%做功率谱分析'滤波器的频谱图像)；%滤波plot(yy1),title('滤波后的波形图像);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滤波前的波形频谱图像');f(i)=f(i)*fs/N;endsubplot(1,2,2),plot(f,pyy(1

6、:N/2),title('滤波后的波形频谱图像)其中采样点为256个,采样频率为600Hz，输入信号为100Hz、250Hz、270Hz 的合成信号，设定的截止频率为200Hz，通过FIR滤波器后，期望保留的信号是 100Hz的信号，200Hz以上的频率基本被滤掉。图1是滤波前的图形，图2是滤波 后的图形，图3为滤波器频谱图像，图4滤波前后的波形频谱图像。从这四个图 中可以看住原始信号中的频率有100Hz、250Hz、270Hz，经过滤波后200Hz以上 的信号成分基本上被滤掉。只留下100Hz的信号。滤波前的波形图像-1-2-3 L050100150200250300图1滤波前波形图

7、像滤波后的波形图像0.8|；10.60.40.2-0.2-0.4-0.6-0.850100150200250300图2滤波后波形图像滤波器的频谱图像0.90.8 -0.7 -0.6 -0.5 -0.4 -0.3 -0.2 -0.1 -0 L050100150200250300图3滤波器的频谱图像100009000-8000-7000-6000-5000-4000-3000-2000r*1000-1I一丿10滤波后的波形频谱图像0100200300图4滤波前后的波形频谱图像2）在CCS环境的仿真首先配置处理器项，进入 CCStudio v3.3中，编写程序，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;设置循环缓冲区的大小和步长;设置快循环计数器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%