2连载201:什么是相位(二)
5连载202:如何计算相位
7连载203:如何计算相位(二)
8连载204:如何理解同相和反相
10连载205:同相和反相情况下的相位差
13连载206:如何理解负相位
15连载207:如何确定零相位点
16连载208:如何确定初始相位
18连载209:如何确定初始相位(二)
19连载210:什么是相位差
20连载211:什么是相移
22连载212:相位失真
24连载213:系统的相频特性
25连载214:什么是正交
27连载215:相位超前和滞后(一)
29连载216:相位超前和滞后(二)
30连载217:什么是相干
32连载218:什么是相干解调
33连载219:奈奎斯特第一准则(一)
34连载220:奈奎斯特第一准则(二)
36连载221:奈奎斯特第一准则(三)
38连载222:奈奎斯特第一准则(四)
39连载223:升余弦滚降滤波器
41连载224:脉冲成型滤波器
41连载225:BPSK调制的基带脉冲波形
45连载226:BPSK基带脉冲波形的解调
45连载227:什么是眼图
47连载228:眼图的形成原理
51连载229:频带利用率概念辨析
53连载230:基带系统和频带系统
53连载231:频带带宽与基带带宽的关系
54连载232:双边带调制信号带宽与基带带宽的关系
55连载233:单边带调制信号带宽与基带带宽的关系
57连载234:IQ调制信号带宽与基带带宽的关系
58连载235:数字调制的频带利用率
60连载236:增加信道编码后的频带利用率
62连载237:BPSK调制的频带信号波形
63连载238:QPSK调制的频带信号波形
66连载239:QPSK调制信号的包络
69连载240:利用旋转向量理解BBF+IQ调制
70连载241:旋转向量末端的三维立体轨迹图
76连载242:包络的严格定义
77连载243:包络的严格定义(二)
81连载244:IQ信号的三维立体轨迹图
85连载245:IQ信号在复平面上的投影轨迹
88连载246:通过IQ平面上信号轨迹
分析
定性数据统计分析pdf销售业绩分析模板建筑结构震害分析销售进度分析表京东商城竞争战略分析
包络的变化
89连载247:IQ信号轨迹和星座图的关系
90连载248:相邻码元相同情况下的IQ信号轨迹
93连载249:QPSK调制的相位转移图
94连载250:为什么要研究信号的包络?
94[分享]升余弦滚降滤波器冲击响应的公式推导 from ZTE
连载201:什么是相位(二)
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2010-11-20 23:12
2.jpg (31.1 KB)
2010-11-20 23:12
连载202:如何计算相位
1.jpg (54.27 KB)
2010-11-21 23:20
连载203:如何计算相位(二)
连载204:如何理解同相和反相
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2010-12-6 20:38
连载205:同相和反相情况下的相位差
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2010-12-7 22:27
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2011-2-4 17:44
连载206:如何理解负相位
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2010-12-7 22:41
2.jpg (34.34 KB)
2010-11-26 21:23
连载207:如何确定零相位点
连载208:如何确定初始相位
1.jpg (56.37 KB)
2010-11-29 23:16
连载209:如何确定初始相位(二)
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2010-11-30 23:08
连载210:什么是相位差
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2010-12-2 00:07
>> t=-0.025:0.001:0.025;
>> y1=sin(2*pi*50*t);
>> plot(t,y1, 'r');
>> hold on;
>> y2=sin(2*pi*50*t-2*pi/3);
>> plot(t,y2, 'b');
>> hold on;
>> y3=sin(2*pi*50*t-4*pi/3);
>> plot(t,y3, 'g');
连载211:什么是相移
1.jpg (64.23 KB)
2010-12-8 23:55
连载212:相位失真
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2010-12-9 22:55
连载213:系统的相频特性
连载214:什么是正交
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2010-12-11 22:47
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2010-12-11 22:47
附连载50链接:利用旋转向量理解正交调制
连载215:相位超前和滞后(一)
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2010-12-12 23:48
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2010-12-12 23:48
连载216:相位超前和滞后(二)
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2010-12-14 00:10
2.jpg (32.04 KB)
2010-12-14 00:10
连载217:什么是相干
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2010-12-14 23:55
2.jpg (58.92 KB)
2010-12-14 23:55
附两个链接:
http://www.ngsir.netfirms.com/chinesehtm/Interference.htm
http://www.ngsir.netfirms.com/chinesehtm/Interference2.htm
连载218:什么是相干解调
连载219:奈奎斯特第一准则(一)
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2010-12-19 23:21
连载220:奈奎斯特第一准则(二)
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2010-12-19 22:43
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2010-12-19 01:11
>> subplot(311);
>> n=0:1:7;
>> y=[1,1,1,-1,1,-1,-1,1];
>> stem(n,y) ;
>> axis([ -1 8 -1.5 1.5]);
>> subplot(312);
>> axis([ -1 8 -1.5 1.5]);
>> arrow([0,0],[0,1]);
>> arrow([1,0],[1,1]);
>> arrow([2,0],[2,1]);
>> arrow([3,0],[3,-1]);
>> arrow([4,0],[4,1]);
>> arrow([5,0],[5,-1]);
>> arrow([6,0],[6,-1]);
>> arrow([7,0],[7,1]);
>> line([-1 8],[0 0]);
>> subplot(313);
>> t=-1:0.001:8;
>> y1=sinc(t);
>> plot(t,y1);hold on;
>> y2=sinc(t-1);
>> plot(t,y2);hold on;
>> y3=sinc(t-2);
>> plot(t,y3);hold on;
>> y4=-sinc(t-3);
>> plot(t,y4);hold on;
>> y5=sinc(t-4);
>> plot(t,y5);hold on;
>> y6=-sinc(t-5);
>> plot(t,y6);hold on;
>> y7=-sinc(t-6);
>> plot(t,y7);hold on;
>> y8=sinc(t-7);
>> plot(t,y8);hold on;
>> y= y1+y2+y3+y4+y5+y6+y7+y8;
>> plot(t,y, 'r');hold on;
>> n=0:1:7;
>> y9=[1,1,1,-1,1,-1,-1,1];
>> stem(n,y9,'r') ;
>> axis([ -1 8 -2.5 2.5]);
arrow.m和arrow3d.m请到这里去下载:
连载99:复指数信号的傅立叶变换
连载221:奈奎斯特第一准则(三)
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2010-12-20 00:29
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2010-12-20 00:29
>> f=-1.5:0.001:1.5;
>> y1=rectpuls(f,1);
>> plot(f,y1)
>> hold on;
>> f=-1:0.001:1;
>> y2=0.5* (1+cos(pi*f));
>> plot(f,y2,'r') ;
>> axis([-1.5 1.5 -0.5 1.5]);
>> grid on
连载222:奈奎斯特第一准则(四)
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2010-12-21 00:01
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2010-12-21 00:01
>> t=-4:0.001:4;
>> y1=sinc(t).*cos(pi*t)./(1-4.*t.*t);
>> plot(t,y1, 'r');
>> hold on;
>> y2=sinc(t);
>> plot(t,y2);
>> axis([-4 4 -0.5 1.5]);
>> grid on
连载223:升余弦滚降滤波器
1.jpg (48.67 KB)
2010-12-21 23:40
连载224:脉冲成型滤波器
连载225:BPSK调制的基带脉冲波形
1.jpg (54.27 KB)
2010-12-23 23:09
>> subplot(121);
>> t=-4:0.001:4;
>> y=sinc(t).*cos(pi*t)./(1-4.*t.*t);
>> plot(t,y);
>> axis([-4 4 -1.5 1.5]);
>> grid on;
>> subplot(122);
>> t=-4:0.001:4;
>> y=-sinc(t).*cos(pi*t)./(1-4.*t.*t);
>> plot(t,y);
>> axis([-4 4 -1.5 1.5]);
>> grid on
2.jpg (54.04 KB)
2010-12-23 23:09
>> subplot(311);
>> n=0:1:7;
>> y=[1,1,1,-1,1,-1,-1,1];
>> stem(n,y) ;
>> axis([ -1 8 -1.5 1.5]);
>> subplot(312);
>> axis([ -1 8 -1.5 1.5]);
>> arrow([0,0],[0,1]);
>> arrow([1,0],[1,1]);
>> arrow([2,0],[2,1]);
>> arrow([3,0],[3,-1]);
>> arrow([4,0],[4,1]);
>> arrow([5,0],[5,-1]);
>> arrow([6,0],[6,-1]);
>> arrow([7,0],[7,1]);
>> line([-1 8],[0 0]);
>> subplot(313);
>> t=-1:0.001:8;
>> x=t;
>> y1= sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> plot(t,y1);hold on;
>> x=t-1;
>> y2= sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> plot(t,y2);hold on;
>> x=t-2;
>> y3= sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> plot(t,y3);hold on;
>> x=t-3;
>> y4=-sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> plot(t,y4);hold on;
>> x=t-4;
>> y5= sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> plot(t,y5);hold on;
>> x=t-5;
>> y6=- sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> plot(t,y6);hold on;
>> x=t-6;
>> y7=- sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> plot(t,y7);hold on;
>> x=t-7;
>> y8= sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> plot(t,y8);hold on;
>> y= y1+y2+y3+y4+y5+y6+y7+y8;
>> plot(t,y, 'r');hold on;
>> n=0:1:7;
>> y9=[1,1,1,-1,1,-1,-1,1];
>> stem(n,y9,'r') ;
>> axis([ -1 8 -1.5 1.5]);
连载226:BPSK基带脉冲波形的解调
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2010-12-25 00:36
连载227:什么是眼图
:
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2010-12-25 23:40
连载228:眼图的形成原理
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2010-12-26 23:04
连载229:频带利用率概念辨析
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2010-12-28 23:06
连载230:基带系统和频带系统
连载231:频带带宽与基带带宽的关系
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2011-1-1 19:02
连载232:双边带调制信号带宽与基带带宽的关系
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2011-1-1 10:09
连载233:单边带调制信号带宽与基带带宽的关系
1.jpg (38.3 KB)
2011-1-2 07:11
连载234:IQ调制信号带宽与基带带宽的关系
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2011-1-2 22:44
连载235:数字调制的频带利用率
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2011-1-3 22:39
连载236:增加信道编码后的频带利用率
1.jpg (61.53 KB)
2011-1-4 23:36
连载237:BPSK调制的频带信号波形
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2011-1-5 23:15
注:其中红色曲线为基带脉冲波形,蓝色曲线为频带信号波形。
>> t=-1:0.001:8;
>> x=t;
>> y1= sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-1;
>> y2= sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-2;
>> y3= sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-3;
>> y4=-sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-4;
>> y5= sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-5;
>> y6=- sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-6;
>> y7=- sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-7;
>> y8= sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> y= y1+y2+y3+y4+y5+y6+y7+y8;
>> s=y.*cos(2*pi*10*t);
>> plot(t,s);hold on;
>> plot(t,y,'r');
连载238:QPSK调制的频带信号波形
1.jpg (60.28 KB)
2011-1-6 23:33
%输入信号
>> subplot(4,1,1);
>> t=0:0.001:8;
>> d=[0 0 ;0.5 1;1 1;1.5 0;2 1 ;2.5 1;3 0;3.5 0;4 1;4.5 0 ;5 1 ;5.5 1 ;6 0 ;6.5 1 ;7 0 ;7.5 0];
>> s=pulstran(t-0.25,d,'rectpuls',0.5);plot(t,s) ;
>> axis([0 8 -0.5 1.5]);
>> text(0.25,1.2,'0') ; text(0.75,1.2,'1') ; text(1.25,1.2,'1') ; text(1.75,1.2,'0') ;
>> text(2.25,1.2,'1') ; text(2.75,1.2,'1') ; text(3.25,1.2,'0') ; text(3.75,1.2,'0') ;
>> text(4.25,1.2,'1') ; text(4.75,1.2,'0') ; text(5.25,1.2,'1') ; text(5.75,1.2,'1') ;
>> text(6.25,1.2,'0') ; text(6.75,1.2,'1') ; text(7.25,1.2,'0') ; text(7.75,1.2,'0') ;
% I路信号
>> subplot(4,1,2);
>> t=0:0.001:8;
>> a=1/sqrt(2);
>> x=t-0.5;
>> y1= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-1.5;
>> y2= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-2.5;
>> y3= - a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-3.5;
>> y4= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-4.5;
>> y5= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-5.5;
>> y6= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-6.5;
>> y7= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-7.5;
>> y8= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> y01= y1+y2+y3+y4+y5+y6+y7+y8;
>> plot(t,y01);
>> axis([0 8 -2 2]);
>> text(0.5,1.5,'-0.7') ; text(1.5,1.5,'+0.7') ;text(2.5,1.5,'-0.7') ;text(3.5,1.5,'+0.7');
>> text(4.5,1.5,'+0.7') ; text(5.5,1.5,'-0.7') ;text(6.5,1.5,'-0.7') ;text(7.5,1.5,'+0.7');
% Q路信号
>> subplot(4,1,3);
>> t=0:0.001:8;
>> a=1/sqrt(2);
>> x=t-0.5;
>> y1= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-1.5;
>> y2= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-2.5;
>> y3= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-3.5;
>> y4= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-4.5;
>> y5= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-5.5;
>> y6= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-6.5;
>> y7= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-7.5;
>> y8= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> y02= y1+y2+y3+y4+y5+y6+y7+y8;
>> plot(t,y02);
>> axis([0 8 -2 2]);
>> text(0.5,1.5,'+0.7') ; text(1.5,1.5,'-0.7') ; text(2.5,1.5,'-0.7') ; text(3.5,1.5,'+0.7')
>> text(4.5,1.5,'-0.7') ; text(5.5,1.5,'-0.7') ; text(6.5,1.5,'+0.7') ; text(7.5,1.5,'+0.7')
%QPSK调制信号
>> subplot(4,1,4);
>> t=0:0.001:8;
>> s1=y01.*cos(2*pi*10*t) ;
>> s2=y02.*sin(2*pi*10*t);
>> plot(t,s1-s2) ;
>> axis([0 8 -2 2]);
>> text(0.3,1.5,'3\pi/4') ; text(1.3,1.5, '7\pi/4') ; text(2.3,1.5,'5\pi/4') ; text(3.3,1.5,'\pi/4') ;
>> text(4.3,1.5, '7\pi/4') ; text(5.3,1.5, '5\pi/4') ; text(6.3,1.5,'3\pi/4') ; text(7.3,1.5,'\pi/4') ;
连载239:QPSK调制信号的包络
1.jpg (61.97 KB)
2011-1-7 23:07
% I路信号
>> t=0:0.001:8;
>> a=1/sqrt(2);
>> x=t-0.5;
>> y1= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-1.5;
>> y2= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-2.5;
>> y3= - a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-3.5;
>> y4= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-4.5;
>> y5= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-5.5;
>> y6= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-6.5;
>> y7= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-7.5;
>> y8= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> y01= y1+y2+y3+y4+y5+y6+y7+y8;
% Q路信号
>> t=0:0.001:8;
>> a=1/sqrt(2);
>> x=t-0.5;
>> y1= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-1.5;
>> y2= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-2.5;
>> y3= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-3.5;
>> y4= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-4.5;
>> y5= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-5.5;
>> y6= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-6.5;
>> y7= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-7.5;
>> y8= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> y02= y1+y2+y3+y4+y5+y6+y7+y8;
%QPSK调制信号
>> t=0:0.001:8;
>> s1=y01.*cos(2*pi*5*t) ;
>> s2=y02.*sin(2*pi*5*t);
>> plot(t,s1-s2) ;
>> axis([0 8 -2 2]);
>> grid on;
>> text(0.3,1.5,'3\pi/4') ; text(1.3,1.5, '7\pi/4') ; text(2.3,1.5,'5\pi/4') ; text(3.3,1.5,'\pi/4') ;
>> text(4.3,1.5, '7\pi/4') ; text(5.3,1.5, '5\pi/4') ; text(6.3,1.5,'3\pi/4') ; text(7.3,1.5,'\pi/4') ;
%包络
>> y03=sqrt(power(y01,2)+power(y02,2));
>> hold on;
>> plot(t,y03, 'r:');
>> hold on;
>> plot(t,-y03, 'r:');
连载240:利用旋转向量理解BBF+IQ调制
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2011-1-8 22:50
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2011-1-8 22:50
蓝色向量在实轴上的投影就是IQ调制后的信号。
连载241:旋转向量末端的三维立体轨迹图
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2011-1-9 23:08
% I路信号
>> t=0:0.001:8;
>> a=1/sqrt(2);
>> x=t-0.5;
>> y1= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-1.5;
>> y2= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-2.5;
>> y3= - a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-3.5;
>> y4= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-4.5;
>> y5= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-5.5;
>> y6= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-6.5;
>> y7= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-7.5;
>> y8= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> y01= y1+y2+y3+y4+y5+y6+y7+y8;
% Q路信号
>> t=0:0.001:8;
>> a=1/sqrt(2);
>> x=t-0.5;
>> y1= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-1.5;
>> y2= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-2.5;
>> y3= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-3.5;
>> y4= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-4.5;
>> y5= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-5.5;
>> y6= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-6.5;
>> y7= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-7.5;
>> y8= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> y02= y1+y2+y3+y4+y5+y6+y7+y8;
%BBF+IQ调制信号
>> t=0:0.001:8;
>> s1=y01+y02*i;
>> s2=cos(2*pi*5*t) +sin(2*pi*5*t)*i;
>> s=s1.*s2;
>> plot3(real(s) ,t,imag(s)) ;
>> ylabel('t');
>> zlabel('y');
>> xlabel('x');
>> set(gca,'YDir','reverse');
>> axis([-1.5 1.5 0 8 -1.5 1.5]);
>> grid on;
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>> clf;
>> plot(t,real(s));
>> axis([0 8 -1.5 1.5]);
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>> clf;
>> plot(t,imag(s));
>> axis([0 8 -1.5 1.5]);
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>> clf;
>> plot(real(s),imag(s));
>> axis([-1.5 1.5 -1.5 1.5]);
连载242:包络的严格定义
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2011-1-11 00:43
连载243:包络的严格定义(二)
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2011-1-12 23:35
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2011-1-12 23:35
% I路信号
>> delta=8/160;
>> t=0:delta:8;
>> a=1/sqrt(2);
>> x=t-0.5;
>> y1= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-1.5;
>> y2= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-2.5;
>> y3= - a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-3.5;
>> y4= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-4.5;
>> y5= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-5.5;
>> y6= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-6.5;
>> y7= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-7.5;
>> y8= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> I= y1+y2+y3+y4+y5+y6+y7+y8;
% Q路信号
>> t=0:delta:8;
>> a=1/sqrt(2);
>> x=t-0.5;
>> y1= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-1.5;
>> y2= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-2.5;
>> y3= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-3.5;
>> y4= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-4.5;
>> y5= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-5.5;
>> y6= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-6.5;
>> y7= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-7.5;
>> y8= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> Q= y1+y2+y3+y4+y5+y6+y7+y8;
%包络曲面
>> =find(isnan(I));I(i)=0;
>> =find(isnan(Q));Q(i)=0;
>> I(81)=0.708;I(121)=-0.708;
>> Q(41)=-0.708;Q(101)=-0.708;Q(141)=0.708;
>> r=sqrt(power(I,2)+power(Q,2));
>> u=linspace(-pi,pi,50);
>> y=linspace(0,8,161);
>> [U,Y]=meshgrid(u,y);
>> [U,R]=meshgrid(u,r);
>> X=R.*cos(U);
>> Z=R.*sin(U);
>> surf(X,Y,Z);
>> axis equal
>> ylabel('t');
>> zlabel('y');
>> xlabel('x');
>> set(gca,'YDir','reverse');
>> axis([-1.5 1.5 0 8 -1.5 1.5]);
>> grid on;
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2011-1-12 23:35
连载244:IQ信号的三维立体轨迹图
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2011-2-17 19:35
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2011-1-13 23:30
% I路信号
>> delta=8/160;
>> t=0:delta:8;
>> a=1/sqrt(2);
>> x=t-0.5;
>> y1= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-1.5;
>> y2= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-2.5;
>> y3= - a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-3.5;
>> y4= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-4.5;
>> y5= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-5.5;
>> y6= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-6.5;
>> y7= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-7.5;
>> y8= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> I= y1+y2+y3+y4+y5+y6+y7+y8;
% Q路信号
>> t=0:delta:8;
>> a=1/sqrt(2);
>> x=t-0.5;
>> y1= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-1.5;
>> y2= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-2.5;
>> y3= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-3.5;
>> y4= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-4.5;
>> y5= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-5.5;
>> y6= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-6.5;
>> y7= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-7.5;
>> y8= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> Q= y1+y2+y3+y4+y5+y6+y7+y8;
%包络曲面
>> =find(isnan(I));I(i)=0;
>> =find(isnan(Q));Q(i)=0;
>> I(81)=0.708;I(121)=-0.708;
>> Q(41)=-0.708;Q(101)=-0.708;Q(141)=0.708;
>> r=sqrt(power(I,2)+power(Q,2));
>> u=linspace(-pi,pi,50);
>> y=linspace(0,8,161);
>> [U,Y]=meshgrid(u,y);
>> [U,R]=meshgrid(u,r);
>> X=R.*cos(U);
>> Z=R.*sin(U);
>> surf(X,Y,Z);
>> axis equal
>> ylabel('t');
>> zlabel('y');
>> xlabel('x');
>> set(gca,'YDir','reverse');
>> axis([-1.5 1.5 0 8 -1.5 1.5]);
>> grid on;
>> shading interp
% I路信号
>> t=0:0.001:8;
>> a=1/sqrt(2);
>> x=t-0.5;
>> y1= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-1.5;
>> y2= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-2.5;
>> y3= - a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-3.5;
>> y4= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-4.5;
>> y5= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-5.5;
>> y6= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-6.5;
>> y7= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-7.5;
>> y8= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> y01= y1+y2+y3+y4+y5+y6+y7+y8;
% Q路信号
>> t=0:0.001:8;
>> a=1/sqrt(2);
>> x=t-0.5;
>> y1= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-1.5;
>> y2= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-2.5;
>> y3= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-3.5;
>> y4= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-4.5;
>> y5= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-5.5;
>> y6= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-6.5;
>> y7= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-7.5;
>> y8= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> y02= y1+y2+y3+y4+y5+y6+y7+y8;
% IQ信号
>> t=0:0.001:8;
>> s=y01+y02*j;
>> hold on;
>> plot3(real(s) ,t,imag(s)) ;
连载245:IQ信号在复平面上的投影轨迹
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2011-1-14 23:26
% I路信号
>> t=0:0.001:8;
>> a=1/sqrt(2);
>> x=t-0.5;
>> y1= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-1.5;
>> y2= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-2.5;
>> y3= - a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-3.5;
>> y4= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-4.5;
>> y5= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-5.5;
>> y6= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-6.5;
>> y7= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-7.5;
>> y8= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> y01= y1+y2+y3+y4+y5+y6+y7+y8;
% Q路信号
>> t=0:0.001:8;
>> a=1/sqrt(2);
>> x=t-0.5;
>> y1= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-1.5;
>> y2= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-2.5;
>> y3= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-3.5;
>> y4= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-4.5;
>> y5= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-5.5;
>> y6= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-6.5;
>> y7= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-7.5;
>> y8= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> y02= y1+y2+y3+y4+y5+y6+y7+y8;
% IQ信号
>> t=0:0.001:8;
>> s=y01+y02*j;
>> hold on;
>> plot(real(s) ,imag(s)) ;
连载246:通过IQ平面上信号轨迹分析包络的变化
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2011-1-15 22:43
连载247:IQ信号轨迹和星座图的关系
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2011-1-16 23:03
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2011-1-16 23:03
连载248:相邻码元相同情况下的IQ信号轨迹
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2011-1-18 07:21
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% I路信号
>> t=0:0.001:8;
>> a=1/sqrt(2);
>> x=t-0.5;
>> y1= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-1.5;
>> y2= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-2.5;
>> y3= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-3.5;
>> y4= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-4.5;
>> y5= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-5.5;
>> y6= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-6.5;
>> y7= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-7.5;
>> y8= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> y01= y1+y2+y3+y4+y5+y6+y7+y8;
% Q路信号
>> t=0:0.001:8;
>> a=1/sqrt(2);
>> x=t-0.5;
>> y1= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-1.5;
>> y2= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-2.5;
>> y3= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-3.5;
>> y4= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-4.5;
>> y5= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-5.5;
>> y6= -a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-6.5;
>> y7= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> x=t-7.5;
>> y8= a.*sinc(x).*cos(pi*x)./(1-4.*x.*x);
>> y02= y1+y2+y3+y4+y5+y6+y7+y8;
% IQ信号
>> t=0:0.001:8;
>> s=y01+y02*j;
>> hold on;
>> plot(real(s) ,imag(s)) ;
连载249:QPSK调制的相位转移图
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2011-1-18 23:31
连载250:为什么要研究信号的包络?
[分享]升余弦滚降滤波器冲击响应的公式推导 from ZTE