Name: discrete-time signal basics and shapes
Uploaded: 2024-09-26T13:16:53.000Z
Duration: 1 min 16 s
Channel: JoVE

A sequência de passos unitários é expressa como 1 para zero e valores positivos do inteiro 'n'. Isso pode ser exibido graficamente usando um conjunto de oito pontos de amostragem.
O impulso unitário ou sequência de amostra é expresso matematicamente para todos os valores discretos de n. É zero para todos os 'n' valores, exceto em zero.
O impulso unitário é a primeira diferença do passo unitário, enquanto o passo unitário é a soma cumulativa da amostra unitária. Essa correlação é demonstrada visualmente por meio de um gráfico.
A sequência de impulso unitário pode efetivamente amostrar o valor do sinal em n igual a zero, uma vez que é diferente de zero apenas nesse ponto.
A sequência de rampa unitária exibe um escalonamento linear no valor com o aumento no número de amostras. Para uma sequência de 12 amostras em uma rampa unitária, o gráfico mostra um aumento linear na amplitude com o número da amostra.
Uma sequência senoidal é definida por seus parâmetros de amplitude e fase.
A sequência exponencial é definida usando números complexos, com sequências exponencialmente decrescentes e crescentes representadas em um gráfico.

sinais básicos de tempo discreto

Basic Discrete Time Signals

A sequência de passos unitários é definida como 1 para valores zero e positivos do inteiro n. Essa sequência pode ser exibida graficamente usando um conjunto de oito pontos de amostra, mostrando uma função de passo começando em n=0 e permanecendo constante depois disso.

O impulso unitário ou sequência de amostra é matematicamente expresso como zero para todos os valores de n, exceto em n=0, onde é um. A sequência de impulso unitário, denotada por δ(n), é a primeira diferença da sequência de passos unitários, enquanto a sequência de passos unitários u(n) é a soma cumulativa da sequência de impulsos unitários. Essa relação pode ser demonstrada visualmente por meio de um gráfico, destacando como o impulso unitário pode efetivamente amostrar o valor do sinal em n=0.

A sequência de rampa unitária exibe um aumento linear no valor com o aumento no número da amostra. Por exemplo, uma sequência de 12 amostras em uma rampa unitária mostrará um aumento linear na amplitude com cada número de amostra, representado graficamente como uma linha reta.

Uma sequência sinusoidal é definida por seus parâmetros de amplitude e fase. Esta sequência pode ser representada como,

<img alt="Equation1" src="/files/ftp_upload/16043/16043_PT%20EQUATION_1.svg" style="text-align: center; height: 14px;">

onde A é a amplitude, ω é a frequência angular e φ é a fase.

A sequência exponencial é definida usando números complexos, com sequências crescentes e decrescentes exponencialmente representadas em um gráfico. Uma sequência decrescente exponencialmente pode ser escrita como,

<img alt="Equation2" src="/files/ftp_upload/16043/16043_PT%20EQUATION_2.svg" style="text-align: center; height: 14px;">

enquanto uma sequência crescente exponencialmente é expressa como,

<img alt="Equation3" src="/files/ftp_upload/16043/16043_PT%20EQUATION_3.svg" style="text-align: center; height: 14px;">

onde A é a amplitude inicial e <span style="font-size: 11pt; font-family: Arial, sans-serif; color: rgb(0, 0, 0); background-color: transparent; font-variant-numeric: normal; font-variant-east-asian: normal; font-variant-alternates: normal; font-variant-position: normal; font-variant-emoji: normal; vertical-align: baseline; white-space-collapse: preserve;">α é uma constante positiva. Essas sequências são fundamentais na análise de diversas aplicações de processamento de sinais devido às suas propriedades e comportamentos únicos.

Sinais Básicos de Tempo Discreto

A sequência de passos unitários é expressa como 1 para zero e valores positivos do inteiro 'n'. Isso pode ser exibido graficamente usando um conjunto de oito ...

Education

JoVE Core

Electrical Engineering

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Unit 1

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Introduction to Signals and Systems

Introdução a Sinais e Sistemas

KEY TERMS AND CONCEPTS

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discrete-time signal basics and shapes

Discrete-time signals include several basic sequences used in signal processing. The unit step sequence is 1 for zero and positive values of the integer n. A graph of eight sample points shows it as a step that begins at n = 0 and stays constant after that.

The unit impulse, also called the sample sequence, is 0 for every n except at n = 0, where it equals 1. This sequence is written as δ(n). It is the first difference of the unit step sequence, and the unit step sequence u(n) is the cumulative sum of the unit impulse sequence. A graph can show how the impulse samples the signal value at n = 0.

The unit ramp sequence increases linearly as the sample number increases. For example, a 12-sample ramp rises by the same amount at each sample, so its graph appears as a straight line. This makes the ramp easy to recognize on a plot.

A sinusoidal sequence is set by its amplitude and phase. In the expression for this sequence, A is the amplitude, ω is the angular frequency, and Φ is the phase. An exponential sequence uses complex numbers. It can describe both exponentially decaying and exponentially increasing sequences. The decaying form and the increasing form are both shown on graphs, with A as the initial amplitude and α as a positive constant. These basic sequences are important because they help describe many signal-processing applications.

Discrete-Time Signal Basics and Shapes

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basic discrete time signals

Discrete-time signals include several basic sequences used in signal processing. The unit step sequence is 1 for zero and positive values of the integer n. A graph of eight sample points shows it as a step that begins at n = 0 and stays constant after that. The unit impulse, also called the sample sequence, is 0 for every n except at n = 0, where it equals 1. This sequence is written as δ(n). It is the first difference of the unit step sequence, and the unit step sequence u(n) is the...

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Discrete-Time Signal Basics and Shapes

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