How to find approximation and detail coefficient from a reconstructed signal?

조회 수: 5 (최근 30일)
Fahim Feroje
Fahim Feroje 2015년 8월 29일
답변: Asfaw Alem 2022년 11월 24일
Hi I want to decompose a signal and by reconstructing this signal try to find approximation and detail coefficient from the reconstructed signal. For decomposition I used single level decomposition(Discrete Wavelet Transform-Db6) and for reconstruction I used inverse discrete wavelet transform. But using idwt I have found only approximation coefficient. But I want to find detail coefficient from original signal or reconstructed signal. How can i do this?
ss=load('Fah_2-L05.mat');
[cA1,cD1] = dwt(ss.data,'db6');
[cA2,cD2] = dwt(cA1,'db6');
[cA3,cD3] = dwt(cA2,'db6');
[cA4,cD4] = dwt(cA3,'db6');
[cA5,cD5] = dwt(cA4,'db6');
[cA6,cD6] = dwt(cA5,'db6');
[cA7,cD7] = dwt(cA6,'db6');
[cA8,cD8] = dwt(cA7,'db6');
A8 = idwt(cA8,cD8,'db6'); %approximation coefficient of level 8

답변 (2개)

Muhammad Ramzan
Muhammad Ramzan 2016년 8월 4일
편집: Walter Roberson 2016년 8월 4일
%%%may be it will help you
ss=load('Fah_2-L05.mat');
[cA1,cD1] = dwt(ss,'db8');
A1 = upcoef('a',cA1,'db8',1,l_s);
D1 = upcoef('d',cD1,'db8',1,l_s);
[C,L] = wavedec(o,8,'db8');
%%Approximattion Coff:
A2 = wrcoef('a',C,L,'db8',2);
A3 = wrcoef('a',C,L,'db8',3);
A4 = wrcoef('a',C,L,'db8',4);
A5 = wrcoef('a',C,L,'db8',5);
A6 = wrcoef('a',C,L,'db8',6);
A7 = wrcoef('a',C,L,'db8',7);
A8 = wrcoef('a',C,L,'db8',8);
%%Details Coff:
D2 = wrcoef('d',C,L,'db8',2);
D3 = wrcoef('d',C,L,'db8',3);
D4 = wrcoef('d',C,L,'db8',4);
D5 = wrcoef('d',C,L,'db8',5);
D6 = wrcoef('d',C,L,'db8',6);
D7 = wrcoef('d',C,L,'db8',7);
D8 = wrcoef('d',C,L,'db8',8);
For reconstruction you can use:
ss= A1+D1;
%%or
ss=A2+D1+D2;
%%or ss= A3+D1+D2+D3; %%and so on

Asfaw Alem
Asfaw Alem 2022년 11월 24일
how can apply dwt and idwt in ofdm to analysis wavelet families in OFDM

카테고리

Help CenterFile Exchange에서 Signal Analysis에 대해 자세히 알아보기

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by