Constant-parameter (time-invariant) and
time-varying-parameter (time-varying) systems
Instantaneous (memoryless or static)
and dynamic (with memory) systems
Causal and noncausal systems
Lumped-parameter and distributed-parameter systems
Continuous-time and discrete-time systems
Analog and digital systems
These are the most common and important classes of systems.
Exercises:
Consider a system that plays an audio tape at half-speed.
Let x(t) represent the audio signal at full-speed, and y(t)
be the output signal from the half-speed system.
Assume x(t) begins at time t=0
and is defined for t>0.
Can the system be modeled as y(t) = x(2t), or
y(t) = x(t/2), or neither?
Is the system linear? Is it time-invariant? Is it causal?
Please explain.
For each of the following system classification properties,
try to think of at least one example of a system with that property.
Linear, nonlinear, time-invariant, time-varying, memoryless,
with memory, causal, non-causal.