DSP System Toolbox blocks in Simulink - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to create a lowpass FIR filter block using DSP System Toolbox.

Simulink

lpFilt = dsp.FIRFilter('Numerator', [1]);

Drag options to blanks, or click blank then click option'

A[0 1 0 1 0]

B[0.2 0.2 0.2 0.2 0.2]

C[1 2 3 2 1]

D[1 0 0 0 1]

Attempts:

3 left

💡 Hint

Common Mistakes

Using coefficients that do not sum to 1.

Using coefficients that create a highpass filter instead.

The 'Numerator' property defines the filter coefficients. A simple lowpass FIR filter can be created with equal coefficients summing to 1, like [0.2 0.2 0.2 0.2 0.2].

2fill in blank

medium

Complete the code to create a spectrum analyzer block with a sample rate of 1000 Hz.

Simulink

specAnalyzer = dsp.SpectrumAnalyzer('SampleRate', [1]);

Drag options to blanks, or click blank then click option'

A1000

B500

C2000

D50

Attempts:

3 left

💡 Hint

Common Mistakes

Using a sample rate different from the signal's actual rate.

Confusing sample rate with frequency resolution.

The 'SampleRate' property sets the sample rate for the spectrum analyzer. Here, 1000 Hz is the correct value.

3fill in blank

hard

Fix the error in the code to create a decimator block with a decimation factor of 4.

Simulink

decim = dsp.Decimator('DecimationFactor', [1]);

Drag options to blanks, or click blank then click option'

A4

B3

C2

D5

Attempts:

3 left

💡 Hint

Common Mistakes

Using a decimation factor that does not match the desired downsampling.

Using a non-integer decimation factor.

The 'DecimationFactor' must be set to 4 to correctly decimate the signal by a factor of 4.

4fill in blank

hard

Fill both blanks to create a bandpass filter with lower cutoff 100 Hz and upper cutoff 300 Hz.

Simulink

bpFilt = dsp.BandpassFilter('LowerCutoffFrequency', [1], 'UpperCutoffFrequency', [2]);

Drag options to blanks, or click blank then click option'

A100

B200

C300

D400

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping lower and upper cutoff frequencies.

Using frequencies outside the signal bandwidth.

The bandpass filter requires the lower cutoff frequency to be 100 Hz and the upper cutoff frequency to be 300 Hz.

5fill in blank

hard

Fill all three blanks to create a variable bandwidth filter with center frequency 500 Hz, bandwidth 200 Hz, and sample rate 2000 Hz.

Simulink

varFilt = dsp.VariableBandwidthFilter('CenterFrequency', [1], 'Bandwidth', [2], 'SampleRate', [3]);

Drag options to blanks, or click blank then click option'

A400

B500

C2000

D200

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up bandwidth and center frequency values.

Using incorrect sample rate.

The center frequency is 500 Hz, bandwidth is 200 Hz, and sample rate is 2000 Hz as specified.