Introduction to Systems

Moving Average Filter

Coefficients of a moving average filter in time domain

The most commonly used filter in DSP applications is a moving average filter. In today’s world with extremely fast clock speeds of the microprocessors, it seems strange that an application would require simple operations. But that is exactly the case…
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Finite Impulse Response (FIR) Filters

Time and frequency response of a lowpass FIR filter designed with Parks-McClellan algorithm for N=33

We learned in the concept of frequency that most signals of practical interest can be considered as a sum of complex sinusoids oscillating at different frequencies. The amplitudes and phases of these sinusoids shape the frequency contents of that signal…
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What is a System?

A system with input and output

In wireless communications and other applications of digital signal processing, we often want to modify a generated or acquired signal. A device or algorithm that performs some prescribed operations on an input signal to generate an output signal is called…
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Additive White Gaussian Noise (AWGN)

Computing noise power within a specified bandwidth

The performance of a digital communication system is quantified by the probability of bit detection errors in the presence of thermal noise. In the context of wireless communications, the main source of thermal noise is addition of random signals arising…
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System Characterization

Magnitude of frequency response |H[k]| in response to complex sinusoids at all N frequencies

After learning some properties of the system, the question is: how should we characterize a system in both time and frequency domains? Impulse response is a tool to characterize a system in time domain and frequency response to do the…
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