Spectral leakage, Electrical Engineering

This assignment is intended to provide an easier analysis of how windows work. Begin by looking at individual spectrum bins as affected by off-bin-centred frequency components with different windows.

A sine wave component of the test signal is bin-centred if it has an integer number of periods in the data segment being analyzed. This almost never happens without planning.

When the signal is periodic and an integer number of periods fill the acquisition time interval, the FFT turns out such that the signal frequency matches one of the FFT frequency bins. When the number of periods in the acquisition is not an integer, the endpoints are discontinuous. The result is the high side lobes seen in the un-windowed spectrum plot. This phenomenon is called Spectral Leakage.

Consider the case of a sampling rate of 1024 Hz being used to look at a 16 Hz. Clearly 16 is a divisor of 1024, but how many samples are needed to uniquely identify the component.

a) using different sample lengths as shown, produce the corresponding FFT of the signal, explaining your results.

b) Repeat this exercise for frequencies 16.5 Hz, 17.0 Hz & 17.5 Hz

It is now necessary to consider the effects of windowing the data set with a view to minimizing leakage effects of a non bin-centered signal on the spectra computed.

c) repeat parts a) & b) by applying windowing to the data sets.

This has been illustrated graphically below using von Hann (Hanning) & Hamming windows, although clearly other could be used.. Graphs are shown for 16 Hz and again for 16.5 Hz.

Posted Date: 3/16/2013 2:54:50 AM | Location : United States

Related Discussions:- Spectral leakage, Assignment Help, Ask Question on Spectral leakage, Get Answer, Expert's Help, Spectral leakage Discussions

Write discussion on Spectral leakage
Your posts are moderated
Related Questions
Effect of Supply  Voltage a.As the applied  as voltage  is increased hysteresis loss increases. b.Eddy current losses are given by W e α f 2 t 2 B 2 m Where B m =

States Ohm's law Ohm's law describes that the current I flowing in a circuit is directly proportional to the applied voltage V and inversely proportional to the resistance R, g

oscilloscope probes specification & performance

Perform a Hartree-Fock geometry optimization calculation of butadiene using a minimal basis set. Repeat with the 6-311G(d,p) basis set, using the optimized minimal basis set geomet

Explain the Working of Asynchronous (Ripple) Counters? An external clock is connected to the clock input of the first flip-flop (FF0) only. Thus FF0 changes state at the falli

The new kitchen is to be 20feet long and it''s width is 75% of it''s length. The door to the kitchen is on the short wall and is 10% of the width of that wall. you want to put in m

any Boolean function can be realized using multiplexer.(true/false).

Compute the efficiency of the transformer of Example corresponding to (a) full load, 0.8 power factor lagging, and (b) one-half load, 0.6 power factor lagging, given that the input

Ask questertion #Minimum 100 words accepted#

Describe properties of the conducting materials . Conducting materials are classified by low resistivity materials and high resistivity materials. Low resistivity mater