Fourier Domain Analysis performances of a RESPER probe - Amplitude and Phase inaccuracies due to the Round-Off noise of FFT processors

Alessandro Settimi

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arXiv · 1009.1832

Fourier Domain Analysis performances of a RESPER probe - Amplitude and Phase inaccuracies due to the Round-Off noise of FFT processors

Alessandro Settimi

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Abstract

This report proposes to discuss the Fourier domain analysis performances of a RESPER probe. A uniform ADC, which is characterized by a sensible phase inaccuracy depending on frequency, is connected to a Fast Fourier Transform (FFT) processor, that is especially affected by a round-off amplitude noise linked to both the FFT register length and samples number. If the register length is equal to 32 bits, then the round-off noise is entirely negligible, else, once bits are reduced to 16, a technique of compensation must occur. In fact, oversampling can be employed within a short time window, reaching a compromise between the needs of limiting the phase inaccuracy due to ADC and not raising too much the number of averaged FFT values sufficient to bound the round-off. Finally, the appendix presents an outline of somewhat lengthy demonstrations needed to calculate the amplitude and especially phase inaccuracies due to the round-off noise of FFT processors.

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Alessandro Settimi. 2010-09-10. Fourier Domain Analysis performances of a RESPER probe - Amplitude and Phase inaccuracies due to the Round-Off noise of FFT processors. https://arxiv.org/abs/1009.1832

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