Digitale filtre

6. juni 2005
Digitale filtre
Indholdsfortegnelse
1. INDLEDNING ....................................................................................................................................3
1.1 PROBLEMFORMULERING................................................................................................................3
1.2 TIDSPLAN ......................................................................................................................................3
2. PROBLEMANALYSE.......................................................................................................................4
2.1 PROBLEMSTILLINGEN....................................................................................................................4
2.2 INPUTSIGNAL.................................................................................................................................4
2.3 UDGANGSSIGNALERNE..................................................................................................................5
2.4 EVALUERING AF FILTRE.................................................................................................................6
2.5 ANTAL FILTERKOEFFICIENTER.......................................................................................................6
2.6 SAMPLINGSFREKVENS ...................................................................................................................6
2.7 KONKLUSION.................................................................................................................................7
3. PROJEKTAFGRÆNSNING OG METODER................................................................................8
3.1 AFGRÆNSNING ..............................................................................................................................8
3.2 KRAVSPECIFIKATION.....................................................................................................................8
3.3 TEORIER OG METODER ..................................................................................................................9
3.4 RESSOURCER.................................................................................................................................9
3.5 KONKLUSION...............................................................................................................................10
4. PROBLEMLØSNING .....................................................................................................................11
4.1 DESIGN AF FILTERKRAV ..............................................................................................................11
4.2 VALG AF SAMPLINGSFREKVENS ..................................................................................................13
4.3 BEREGNING AF FILTERKOEFFICIENTER ........................................................................................14
4.4 MATEMATISK SIMULERING AF FIR LØSNING ...............................................................................14
4.5 MATEMATISK SIMULERING AF IIR LØSNING ................................................................................19
4.6 SAMMENLIGNING AF FIR OG IIR LØSNING ..................................................................................31
4.7 SOFTWARE SIMULERING OG IMPLEMENTERING AF FIR LØSNING .................................................32
4.8 FILTER EVALUERING ...................................................................................................................33
4.9 KONKLUSION...............................................................................................................................35
5. KONKLUSION ................................................................................................................................37
5.1 DEN PRODUKTORIENTEREDE DEL ................................................................................................37
5.2 DEN PROCESORIENTEREDE DEL ...................................................................................................37
BILAG 1. PROJEKTOPLÆGGET..................................................................................................39
BILAG 2. ALTERNATIVE FILTERKRAV ...................................................................................46
BILAG 3. SIMULERINGER AF LAV- OG HØJPAS CHEBYSCHEV2 FILTER .....................48
BILAG 4. SIMULERINGSDATA ....................................................................................................50
BILAG 5. KODESTRUKTUR FOR BUFFER OG FOLDNING ..................................................51
BILAG 6. KILDEKODE FOR IMPLEMENTERING ...................................................................52
ITVP4 – Gruppe 5 Side 2 af 53