Signals: Spectra & Processing Flashcards
The most important piece that needs to be shared and safeguarded from noise.
Signal
An action, a gesture, or sign used as a means of communcation
Means of Communication
A piece of information communicated by an action, gesture, or sign
Communicated Infromation
Something that incites somebody to action
Incitement
Information transmitted by means of a modulated current or an electromagnetic wave and received by telephone, telegraph, etc.
Electronics Transmitted Infromation
It is defined as ta single-valued function of time that conveys information
Signal
Describes the frequency content of the signal
Spectra
Condition that is not limited to a specific set of values but can vary infinitely within a continuum
Spectrum
Separation of visible light through a prism forming a rainbow
Prismatic Diffraction
Any variable signal continuous in both time and amplitude
Analog Signal
Electrical properties used to a signal
Voltage
Frequency
Current
Charge
The digital representation of discrete-time signal which is often derived from analog signal
Digital Signal
A sampled version of an analog signal
Discrete-time Signal
The result of individual time values of the discrete-time signal being approximated to a certain precision
Digital Signal
The process of approximating the precise value within a fixed number of digits or bits
Quantization
It is quantized discrete-time signal
Digital Signal
Any signal processing conducted on analog signals by analog means
Analog Signal Processing
The study of signals in a digital representation and the processing methods of these signals
Digital Signal Processing
The four major subfields of DSP
Audio Signal Processing
Control Engineering
Digital Image Processing
Speech Processing
The domains of digital signals
Time Domain Spatial Domain Frequency Domain Autocorrelation Domain Wavelet Domain
It can be produced by a sequence of samples from a measuring device
Time and Spatial domain Representation
Can be obtained by a discrete Fourier transform
Frequency Domain Information
The cross-correlation of the signal with itself over varying intervals of time or space
Autocorrelation
The most common enhancement processing approach of the input signal in the time or space domain
Filtering
It is a linear transformation of input samples
Linear Filter
A filter that uses only previous samples of the input or output signals
Causal Filters
A filter that uses only future input samples
Non-causal
Means to change a non-causal filter to a causal filter
Adding a delay
A filter that has constant properties over time
Time-invariant Filter
A filter that changes in time
Adaptive Filter
A filter that produces an output that converges to a constant value with time or remains bounded within a finite interval
Stable Filter
A filter that produces output that diverges
Unstable
A filter that is always stable and only uses the input signals
Finite Impulse Response (FIR) Filter
A filter that uses both the input signal and previous samples of the output signal and can be unstable
Infinite Impulse Response (IIR) Filter
Converts the signal information to a magnitude and phase component of each frequency
Fourier Transform
A function that satisfies the condition:
x(t)=x(t+To)
where,
t = time
To = a constant
Periodic Signal
Any signal for which there is no value of To to satisfy the equation
x(t)=x(t+To)
Nonperiodic or Aperiodic Signal
A signal where there is no uncertainty with respect to ts value at any time
Deterministic Signal
A signal about which there is uncertainty before its actual occurrence
Random Signal
The condition of an energy signal
It is an energy signal IF AND ONLY IF the total energy of the signal satisfies the condition
0
The condition of a power signal
It is a power signal IF AND ONLY IF the average power of the signal satisfies the condition
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