Unit 1 Introduction to Signals and Systems

A set of vocabulary flashcards covering key concepts from the lecture on Signals and Systems.

Signal

A set of information or data, mathematically defined as a function of one or more independent variables.

Energy Signal

A signal whose energy is finite.

Power Signal

A signal whose power is finite and nonzero.

CT Signal

A signal which is specified for every value of time t.

DT Signal

A signal which is specified only at discrete values of t.

Analog Signal

A signal whose amplitude can take on any value in a continuous range.

Digital Signal

A signal whose amplitude can take on only a finite number of values.

Periodic Signal

A signal for which f(t) = f(t + T0) for a positive constant T0.

Aperiodic Signal

A signal that is not periodic.

Causal Signal

A signal defined as f(t) = 0 for t < 0.

Deterministic Signal

A signal whose values can be predicted precisely.

Random Signal

A signal whose values cannot be predicted precisely, described in probabilistic terms.

Time-Invariant System

A system that does not change with time, obeying y(t-to) = S[x(t-to)].

Causal System

A system whose output depends only on the past and present values of the input.

Memoryless System

A system where the output at the current time depends only on the input at the current time.

Unit Impulse Function

A function delta(t) that is zero everywhere except at t = 0, where it is infinite, with area equal to 1.

Time Transformation

Operations involving time shifting, scaling, or inversion applied to signals.

Amplitude Transformation

Operations involving shifting, scaling, or inversion of the amplitude of signals.

Exponential Function

Function of the form e^(st), where s can be a complex number.

Even Function

A function satisfying x(t) = x(-t), indicating symmetry about the vertical axis.

Odd Function

A function satisfying x(t) = -x(-t), indicating symmetry about the origin.

Superposition Principle

A principle that allows combining inputs in a linear system to find the resultant output.