How to calculate amplitude and phase of a digital/analog sig

I am a student who is doing a project in VHDL... I need to find the
amplitude and phase of an analog and digital signal in VHDL ...

I am using an ADC to convert the analog to digital which then goes into
the simple computer module in VHDL which calculates it frequency and
all that...

I want to know given the initial analog signal or the converted digital
signal, how can I find the original signals amplitude and phase?

If anyone has any suggestions or code that can be useful please reply
ASAP!!

 

[jens]

I want to know given the initial analog signal or the converted digital
signal, how can I find the original signals amplitude and phase?

Assuming you're looking for the dominant signal's frequency, amplitude
& phase... do an FFT of the input, calculate the magnitudes
(sqrt(real^2 + imag^2)), find the largest magnitude, then calculate the
phase (atan(imag/real)). Note that the phase might be meaningless,
depending on what the FFT's time period is related to. Also note
you'll probably want to apply a window before the FFT, and the
amplitude will have to be scaled accordingly.

You're probably better off beginning to understand what you're trying
to do from a DSP perspective, then figuring out how to code it in VHDL.
FFT cores are widely available from FPGA vendors, also check
opencores.org.

 

[Dave Higton]

In message <1164941892.408594.123140@f1g2000cwa.googlegroups.com>
ronak283@gmail.com wrote:

I want to know given the initial analog signal or the converted digital
signal, how can I find the original signals amplitude and phase?

Phase is a measurement between two signals. What is the other signal
in your case?

Dave

 

Take a look at the CORDIC algorithm.
This algorithm can be implemented with adders and shifters.

-cmw