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How do I find an aliased signal?
For example, suppose that fs = 65 Hz, fN = 62.5 Hz, which corresponds to 8-ms sampling rate. The alias frequency then is fa = |2 × 62.5 − 65| = 60 Hz.
What is an aliased signal?
In signal processing and related disciplines, aliasing is an effect that causes different signals to become indistinguishable (or aliases of one another) when sampled. Aliasing can occur in signals sampled in time, for instance digital audio, and is referred to as temporal aliasing.
How do you find the frequency of a sampled signal?
The sampling frequency or sampling rate, fs, is the average number of samples obtained in one second (samples per second), thus fs = 1/T.
How do you calculate aliased frequency?
A simple rule to predict this aliased frequency is: decrement fo by fs enough times to get within the observable frequency range of [−fN , fN ]. The absolute value of this result is the aliased frequency. Sampling at 5.5kHz gives a time step of 0.182 milliseconds.
How is the aliasing frequency of a signal determined?
This aliasing frequency calculator determines the perceived (reconstructed) frequency fp of any signal frequency f, which is sampled at any sampling frequency fs. The calculator also determines the Nyquist frequency for the given sampling frequency.
Why do we use rs for frequency aliasing?
Frequency aliasing is a common problem in signal conversion systems whose sampling rate is too slow to read input signals of a much higher frequency. Note down the value of sampling rate of your data acquisition system. Call it “Rs” for simplicity.
What is the alias frequency of 60 Hz?
The alias frequency then is fa = |2 × 62.5 − 65| = 60 Hz. In conclusion, undersampling has two effects: contamination of the digital signal spectrum by high frequencies beyond the Nyquist, which may have been present in the continuous signal. Nothing can be done about the first problem. The second problem is of practical importance.
How does an alias signal work in audio?
My understanding of an alias signal is that if you undersample your input signal (i.e. sample at a rate which is less than twice the maximum frequency) then we can get aliasing because we’re not sampling frequently enough to capture the high frequency details.