Zusammenfassung der Ressource
Signals and Systems
- Signal: A fn which contains some
information or the physical variation of one
quantity w.r.t. other
- Continuous Time and
Discrete Time
- CT : x (t)
- DT: x [n]
- CT -> Sampling -> DT
- Conjugate Symmetric and
Conjugate Skew Symmetric
- CS: x(t) = x*(-t);
x [n] = x* [-n]
- CSS: x(t) = -x* (-t);
x [n] = -x* [-n]
- Period and Non-periodic
- P: x (t) --> x(t+T) = x(t); for all t & T element of R-{0};
x [n] --> x[n+N] = x[n]; for all n; N element of Z-{0}
- Energy and Power Signals
- Energy Signal : 0 < E < infinity;
P --> 0
- Power Signal: 0 < P < infinity;
E --> infinity
- Real and Complex
- Real : If the signal contains only real value
- Else Complex Signal
- System: An entity which extracts useful
information from the signal or it processes
the signal
- Linear System
- Obeys Superposition Principle
- Time Invariant System
- delayed version of i/p gives
delayed version of o/p
- Causal System
- O/p depends on present and
past i/p s
- Stable System (BIBO)
- Bounded i/p should give bounded o/p
- Invertible System
- x(t) must be able to be obtained from y(t)
- Memoryless
- O/p depend only on the present i/p