SIGNALS
A signal defined only at integer values of time.
Discrete
A system that satisfies superposition.
Linear System
What is sampling?
The process of converting continuous signal to discrete.
An equation that relates input and output of a system.
Difference Equation
Transform used to analyze discrete signals.
DFT
A signal that repeats after a fixed interval.
Periodic Signal
A system whose output depends only on present input.
Static or Memory less Systems
What is Nyquist rate?
Minimum sampling rate required to avoid aliasing.
What is zero-input response?
Response due to system initial conditions.
What is DFT?
The transform used to convert a discrete-time signal into frequency domain.
A signal with infinite duration but finite power.
Power Signal
A system whose behavior does not change with time.
What is aliasing?
Distortion caused due to under-sampling.
What is zero-state response?
Response due to external input.
What is frequency spectrum?
Graph showing frequency content of a signal.
A signal whose value depends on a random variable.
Random Signal
What is a Causal System
A system that uses past and present inputs only.
What is x(n) in sampling?
The discrete-time signal obtained after sampling.
What is impulse response?
The output when input is a unit impulse.
The phase of a frequency-domain signal is obtained
ϕ=tan-1(IMA/REAL)
Any Four classifications of Signals
CAUSAL AND NON CAUSAL
ENERGY AND POWER
PERIODIC AND APERIODIC
EVEN AND ODD
What is a stable system?
A system that gives bounded output for bounded input.
A device that converts analog signal to digital.
ADC
What is step response?
The output when input is a unit step.
Magnitude and Phase response of -3+3J
4.24 and 135 degree