Terms Flashcards
Any physical quantity that varies with time, space, or any other independent variable/s.
Signal
A pattern of variations of a physical quantity that can be manipulated, stored, or transmitted by a physical process.
Signal
An information variable represented by a physical quantity. (For digital systems, the variable takes on discrete values.)
Signal
A physical device that performs an operation on a signal.
System
Deals with the enhancement, extraction, and representation of information for communication or analysis.
Signal Processing
A field of numerical mathematics that is concerned with the processing of discrete signals.
Digital Signal Processing
This area of mathematics deals with the principles that underlie all digital systems.
Digital Signal Processing
Multichannel and Multidimensional Signals vs Single Chanel
MC: stereos, TV audios
MD: earthquake (depth, coverage)
Single: combined into one
Continuous-Time vs Discrete-Time
Continuous: present anywhere
Discrete: specific signal at a particular parameter
Discrete-Valued vs Continuous-Valued
Discrete: value of peak at that instant of time
Continuous: target range of operation at a given parameter
Random vs Deterministic
Random: present anywhere, anytime, aka stochastic signal
Deterministic: specific range, corresponding interpretation
Conversion of continuous-time signal into a discrete-time signal obtained by taking samples of CT signals at DT instants
Sampling
Conversion of DT continuous-valued signal into a DT, discrete-valued (digital) signal.
Quantization
Difference between the unquantized sample x(n) and the quantized output x_q(n)
Quantization Error
Each discrete value x_q(n) is represented by a b-bit binary sequence
Coding
The time interval T between successive samples
Sampling period o sample interval
Reciprocal of time interval T = 1/T = Fs
Sampling rate (samples/second) or sampling frequency (Hz)
Two conditions must be met under the Sampling Theorem.
The signal x(t) must be bandlimited, and the sampling rate fs must be chosen to be at least twice the maximum frequency fmax.
Converts a binary digital number into an analog representation, such as voltage or current.
DAC
Smallest observable change in the analog output that can be effected by a single step change in the digital input.
Resolution
A measurement of the maximum speed at which the DAC’s
circuitry can operate and still produce the correct output.
Sampling Rate
Determined by the time it takes to perform the
conversion process.
Conversion Speed
Interval between a command to update (change) its output value and the instant it reaches its final value, within a specified percentage.
Settling Time
Specifies the accuracy.
Linearity
The degree to which each output step (or code width) varies from the ideal step, which is generally more critical when outputting small signals.
Differential Nonlinearity
Measures the deviation of the entire transfer function from the ideal function and is generally more critical for outputting large signals.
Integral nonlinearity
Minimum rate at which a signal can be sampled without introducing errors, which is twice the highest frequency present in the signal.
Nyquist frequency
An effect that makes different signals indistinguishable when sampled.
Aliasing
It also refers to the difference between a signal reconstructed from samples and the original continuous signal, when the resolution is too low.
Aliasing
Aliasing depends on…
the sampling rate and frequency content of the signal.
Passes all the appropriate input frequencies and cuts off all the undesired frequencies.
Anti-Aliasing Filters
Something that conveys information, represented mathematically as functions of one or more independent variables.
Signal
The output y[n] at every value of n depends only on the input x[n] at the same value of n.
Memoryless System
A system is _____ if, for every choice of N0 the output sequence value at the index n = n0 depends only on the input sequence value for n≤n0.
Causal
Representation of general sequence as a linear combination of delayed impulse
Convolution
