DFT, Quantisation error, Sinusoid and Triangle.

Cuthbert Nyack
The applets show the effect of Quantisation with Nb bits on the sampled signal spectrum of a Sinusoid and Triangle and the magnitude of the Quantisation Error.
Analytical expressions can be obtained for the Quantisation error assuming a large number of samples and a uniform distribution of the error.

The error distribution is shown in pink and for the small number of samples used, it is far from flat. However by changing T1 and/or T2 a large number of times an average value can be obtained which settles to a value not to far from the analytical value. For the Sinusoid the expression shown should be 2/3 and for the triangle it should be 1.

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COPYRIGHT 2007 Cuthbert Nyack.