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Complex Coefficients with FIR Compiler II

Altera_Forum
Honored Contributor II
766 Views

Is it possible to use complex coefficients with the FIR Compiler II? If so, what notation is used to specify this when loading coefficients from a file into the wizard? I've tried i and j, but the wizard is complaining about invalid coefficients.

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3 Replies
Altera_Forum
Honored Contributor II
66 Views

 

--- Quote Start ---  

Is it possible to use complex coefficients with the FIR Compiler II? If so, what notation is used to specify this when loading coefficients from a file into the wizard? I've tried i and j, but the wizard is complaining about invalid coefficients. 

--- Quote End ---  

 

 

I know dspbuilder doesn't support complex filter but you can use four real filters and do the complex addition/subtraction manually. 

remember for every tap the following multiplication is needed: 

 

yr = xr.hr - xi.hi 

yi = xr.hi + xi.hr 

 

thus the terms xr.hr becomes one filter for these inputs and the term xi.hi a second filter and so on. Finally you add/subtract the outputs of two pair filters to get real and imag output. 

 

You can alsouse three filters by some trick.
Altera_Forum
Honored Contributor II
66 Views

i don't think FIR II supports complex data paths

Altera_Forum
Honored Contributor II
66 Views

thanks guys

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