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Digital signal processing

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signal
thumb|right|In The Signal by William Powell Frith, a woman sends a signal by waving a white handkerchief.
analog-to-digital converter
system that converts an analog signal, such as a sound picked up by a microphone or light entering a digital camera, into a digital signal; device converting a physical quantity to a digital number
Dirac delta function
pseudo-function δ such that an integral of δ(x-c)f(x) always takes the value of f(c)
codec
A codec is a computer hardware or software component that encodes or decodes a data stream or signal. Codec is a portmanteau of coder/decoder.
digital signal processing
mathematical signal manipulation by computers
digital-to-analog converter
electronic device that converts a digital signal into an analog signal (mixed signal device), mostly realized as part of an integrated circuit (IC)
digital signal processor
specialized microprocessor optimized for digital signal processing in real time, mainly used for audio and/or video applications
Fourier analysis
branch of mathematics regarding periodic and continuous signals
sampling
measurement of a signal at discrete time intervals
Nyquist–Shannon sampling theorem
theorem in signal processing describing discrete samples of a continuous signal
quantization
process of mapping a continuous set to a countable set
multi-core processor
microprocessor with more than one processing unit
aliasing
In digital signal processing, aliasing is a phenomenon that a reconstructed signal from samples of the original signal contains low frequency components that are not present in the original one. This is caused when, in the original signal, there are components at frequency exceeding a certain frequency called Nyquist frequency, f_s / 2, where f_s is the sampling frequency (undersampling). This is because typical reconstruction methods use low frequency components while there are a number of frequency components, called aliases, which sampling result in the identical sample. It also often refer
discrete cosine transform
technique representing data as sums of cosine functions
fast Fourier transform
𝑂(𝑁 log 𝑁) divide‐and‐conquer algorithm to calculate the discrete Fourier transforms
anti-aliasing
proces used before a signal sampler to prevent aliasing
discrete Fourier transform
technique used in advanced mathematics
Finite Impulse Response filter
type of filter in signal processing
SIMD
class of parallel computers in Flynn's taxonomy, with multiple processing elements that perform the same operation on multiple data points simultaneously
Nyquist frequency
in signal processing, the frequency whose cycle-length is twice the interval between samples
very long instruction word
type of instruction set architecture
digital filter
mechanism to reduce or enhance aspects of a sampled, discrete-time signal
dither
450px|thumb|right|Image on left is original. Center image is reduced to 16 colors. Right image also 16 colors, but dithered to reduce banding effect.
linear time-invariant system
mathematical model of system that produces an output signal from any input signal subject to the constraints of linearity and time-invariance
infinite impulse response filter
property of many linear time-invariant (LTI) systems
Talk box
effects unit that allows musicians to modify the sound of a musical instrument
window function
function used in signal processing
Linear predictive coding
speech analysis and encoding technique
downsampling
process of reducing the sampling rate of a signal
direct digital synthesis
method for creating waveforms
delta modulation
signal conversion technique
discrete-time Fourier transform
Fourier analysis technique applied to sequences
delta-sigma modulation
Method for converting signals between digital and analog
pitch shift
audio processing technique that changes the original pitch of a sound
Adaptive filter
system with self-optimizing transfer function
almost periodic function
function that "converges" to periodicity
audio normalization
application of gain to a recording to achieve a target level
Zero-order hold
model of signal reconstruction in digital-to-analog (DAC) converters
BIBO stability
process control theorem
Ramer–Douglas–Peucker algorithm
line simplification algorithm
Multiply–accumulate operation
or multiplier–accumulator, in digital signal processing
sample and hold
digital control system
bilinear transform
method used in digital signal processing and discrete-time control theory to transform continuous-time system representations to discrete-time and vice versa
Whittaker–Shannon interpolation formula
signal (re-)construction algorithm
discrete wavelet transform
transform in numerical harmonic analysis
Recursive least squares filter
adaptive filter algorithm for digital signal processing
multiple signal classification
algorithm used for frequency estimation and radio direction finding
all-pass filter
filter that passes signals of all frequencies with same gain, but changes the phase relationship among various frequencies
filter bank
tool for Digital Signal Processing
sinc filter
idealized filter that removes all signal frequency components above a given frequency
audio time-scale/pitch modification
changing the speed or duration of an audio signal without affecting its pitch
causal system
system where the output depends only on past and current inputs
Nyquist rate
twice the bandwidth of a bandlimited function or channel
numerically controlled oscillator
digital signal generator creating a synchronous (clocked), discrete-time, discrete-valued representation of a waveform, usually sinusoidal
Successive approximation ADC
type of analog-digital conversion
pitch correction
technique for calibrating the pitch of an audio recording to match musical notes
Goertzel algorithm
algorithm
sample-rate conversion
changing the sampling rate of a discrete signal to obtain a new discrete representation of the underlying continuous signal
oversampling
In signal processing, oversampling is the process of sampling a signal at a sampling frequency significantly higher than the Nyquist rate. Theoretically, a bandwidth-limited signal can be perfectly reconstructed if sampled at the Nyquist rate or above it. The Nyquist rate is defined as twice the bandwidth of the signal. Oversampling is capable of improving resolution and signal-to-noise ratio, and can be helpful in avoiding aliasing and phase distortion by relaxing anti-aliasing filter performance requirements.
voice activity detection
technique used in speech processing in which the presence or absence of human speech is detected