Aims:
1. Use MATLAB for DFT and FFT implementation
2. Use MATLB for frequency analysis
Suggestion procedure:
All the lab work should be recorded in your logbook.
1. Run MATLAB software from the Desctop. Find and records some functions for FFT in MATLAB.
• The command fft will compute a discrete Fourier transform in Matlab. Type help fft to find out more.
• Two more commands, ifft and ifftshift are needed to compute the inverse Fourier transform. Test the demo fft_demo.m
2. Read and test MATLAB codes dft.m, mydft.m, dsp_fft.m in J:\V_Holmes\NHE2404 DSP Applications\Labs\matlab dsp\dft. Identify the
difference of coding and running time.
3. Use MATLAB to analyse frequency component variations before and after filtering on a sound file of your choice (You may use the
codes in J:\V_Holmes\NHE2404 DSP Applications\Labs\matlab dsp\lab4q8_v.m).
3. Use Internet search engine to search and download a FFT algorithm in C and try to understand the implementation of the
algorithm.
Questions: Discuss the differences of DFT and FFT implementation in MATLAB or C
Tutorial Question
1. A reson filter is required to have a resonant frequency of 5KHz and a bandwidth of 300Hz. The DSP ADC/DAC system has a
sampling frequency of 48KHz.
a) Sketch the poles of the filter on a Z-plane diagram and show that the z-transfer function of the filter is:
where R is the distance from the centre of the z-plane to each pole, is the signal frequency and T the sampling time.
b) Calculate the filter coefficients and write the difference equation for the filter.
c) Determine the peak gain of the filter be in dB.
TAKE ADVANTAGE OF OUR PROMOTIONAL DISCOUNT DISPLAYED ON THE WEBSITE AND GET A DISCOUNT FOR YOUR PAPER NOW!