MatLab Project for Filler Digital Signals

EE 463 - Matlab Project 3 - Spring 2020

Here we will use filtering to identify and separate two audio signals that have been added together into a single wav file. Download the audio signal twosigb.wav from the course webpage. One of the two signals in this single wav file is a highpass signal, so it can be extracted using a highpass filter. The other signal is a lowpass signal that can be extracted using a lowpass filter. They do not overlap in frequency enough to be a concern.

1. Using the fft function, plot the magnitude of the DTFT of the audio signal (in dB units) using 1024 frequency samples over [0, π] radians. Using the sampling rate, transform the frequency axis into Hz instead of radians, and plot only positive frequencies.

2. Design a low-pass filter using the window method to extract the low-pass audio signal from twosig.wav. Find an appropriate cut-off frequency using trial-and-error using the sound function. There is no exact right answer for the cutoff frequency, but there is a range of acceptable answers. Plot the frequency response of the filter and the filtered signal.

3. Design a high-pass filter to extract the high-pass audio signal from twosig.wav. The cutoff frequency will be the same as for part 3. Plot the frequency response of the filter and the filtered signal.

Send 5 pdf figures and your matlab script to [email protected] with the subject line "EE 463 Project 3":

• A single .pdf figure with 1 curve, as described in part 1 above.

• Two .pdf figures with 1 curve each, as described in part 2 above.

• Two .pdf figures with 1 curve each, as described in part 3 above.

• A single Matlab script that will automatically produce the figures above (without any input from the user) and indicate the location of the useful portion of the sig- nal.

Use only primitive Matlab commands in your script; avoid the use of any toolboxes.

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