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I am using MatLab to develop the algorithms
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Ok.
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I've also been looking at the DSP builder link between MatLab and Quartus but not sure about that yet.
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I haven't used DSP builder. I prefer to code the VHDL directly.
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The offset correction removes the DC offset, which I believe will make the data easier for the frequency estimation processing.
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That is probably correct; though it would depend on the algorithm you select. If you were to use an FFT, the DC component results in ringing across the frequency response. Its a good idea to remove it. The book "Understanding Digital Signal Processing", by Rick Lyons has example DC removal circuits.
However, if your audio signal is AC coupled to your ADC, there should not be much of a DC offset. You should capture some data and investigate.
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Do I need to determine the input power for the processor?
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No, but you will want to know if your signal is 'loud' enough, otherwise your ADC quantization noise will dominate. I was simply suggesting that you start by figuring out how to design a power measurement circuit, since it is very simple; hint its related to the average of a block of samples squared (simple to implement in hardware).
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For the DSP block your referring to the Quartus megacores right?
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No, I just meant signal processing in general. You might want to use DSP blocks (the FPGA resource), but you can infer those by writing code like a*b, where a and b are appropriate sized std_logic_vectors; the Quartus handbook has coding style recommendations.
Cheers,
Dave
Honored Contributor
