Line 30: Line 30:
 
Determine and sketch the convolution of the following signals:
 
Determine and sketch the convolution of the following signals:
 
x(t) = t+1 for <math> 0 \le  t \le 1</math>
 
x(t) = t+1 for <math> 0 \le  t \le 1</math>
 +
 
x(t) = 2-t for <math> 1 <  t \le 2</math>
 
x(t) = 2-t for <math> 1 <  t \le 2</math>
 +
 
x(t) = 0 everywhere else
 
x(t) = 0 everywhere else
  
Line 43: Line 45:
  
 
[[Image:bonus1.jpg]]
 
[[Image:bonus1.jpg]]
 
 
  
 
y(t) = t+3 for <math> -2 <  t \le -1</math>
 
y(t) = t+3 for <math> -2 <  t \le -1</math>
 +
 
y(t) = t+4 for <math> -1 <  t \le -0</math>
 
y(t) = t+4 for <math> -1 <  t \le -0</math>
 +
 
y(t) = 2-2t for <math> 0 <  t \le 1</math>
 
y(t) = 2-2t for <math> 0 <  t \le 1</math>
 +
 
y(t) = 0 everywhere else
 
y(t) = 0 everywhere else
  
 
[[Category:period]]
 
[[Category:period]]
 +
==Question==
 +
Determine the fundamental period of the signal x(t) = 5cos(14t)+sin(6t-2).
 +
 +
==Solution==
 +
Period of first term = <math>\frac{2\pi}{14}</math> = <math>\frac{\pi}{7}</math>
 +
 +
Period of second term = <math>\frac{2\pi}{6}</math> = <math>\frac{\pi}{3}</math>
 +
 +
Least common multiple = Fundamental period = <math> \pi </math>
 +
 +
  
  

Revision as of 15:59, 10 February 2013

Linearity

Linear system: y[n] = 8x[n/4]

Non-linear system: y(t) = 5x^2(t) + 11

Causality

Causal system: y[n] = x[n] + x[n-4]

Non-causal system: y(t) = 3x(-t/6)

Memory

System w/ memory: y[n] = 3t^2x[n-9]

Memoryless system: y(t) = (4x(t))^2

Invertibility

Invertible system: y[n] = 2x[n+4]

Non-invertible system: y(t) = x^4(t) -5

Stability

Stable system: y[n] = x^2[n] +4x[n] -1

Non-stable system: y(t) = d^2x(t)/dt^2 + dx(t)/dt + 6x(t)

Time Invariance

Time-variant system: y[n] = 3n^2x[n] + 5

Time-invariant system: y(t) = 2x(t) + x(t-3)

Question

Determine and sketch the convolution of the following signals: x(t) = t+1 for $ 0 \le t \le 1 $

x(t) = 2-t for $ 1 < t \le 2 $

x(t) = 0 everywhere else

h(t) = $ \delta(t+2) $ + $ 2\delta(t+1) $

Solution

x(t)*h(t) = $ \int x(\tau)h(t-\tau)d\tau $ = $ \int h(\tau)x(t-\tau)d\tau $

Becomes x(t)*h(t) = x(t+2)+2x(t+1)

Sketches:

Bonus1.jpg

y(t) = t+3 for $ -2 < t \le -1 $

y(t) = t+4 for $ -1 < t \le -0 $

y(t) = 2-2t for $ 0 < t \le 1 $

y(t) = 0 everywhere else

Question

Determine the fundamental period of the signal x(t) = 5cos(14t)+sin(6t-2).

Solution

Period of first term = $ \frac{2\pi}{14} $ = $ \frac{\pi}{7} $

Period of second term = $ \frac{2\pi}{6} $ = $ \frac{\pi}{3} $

Least common multiple = Fundamental period = $ \pi $



Please place solutions and/or comments below.

Back to first bonus point opportunity, ECE301 Spring 2013

Alumni Liaison

Ph.D. 2007, working on developing cool imaging technologies for digital cameras, camera phones, and video surveillance cameras.

Buyue Zhang