A periodic signal is **one that repeats the sequence of values exactly after a fixed length of time, known as the period**. In mathematical terms a signal x(t) is periodic if there is a number T such that for all t Equation 10.10 holds.

By Qasim Chaudhari. Classification of continuous-time and discrete-time signals deals with the type of independent variable. **If the signal amplitude is defined for every possible value of time, the signal is called a continuous-time signal**.

**A real signal at any given time takes its value in the set of real numbers**, and a complex signal takes its value in the set of complex numbers.

A periodic signal is **one that repeats the sequence of values exactly after a fixed length of time, known as the period**. In mathematical terms a signal x(t) is periodic if there is a number T such that for all t Equation 10.10 holds.

What is ADC? Analog-to-digital converters, abbreviated as “ADCs,” work to convert analog (continuous, infinitely variable) signals to digital (discrete-time, discrete-amplitude) signals. In more practical terms, an ADC converts an analog input, such as a microphone collecting sound, into a digital signal.

A signal is **a function or a data set representing a physical quantity or variable**. Usually, the signal encapsulates information about the behavior of a physical phenomenon, for example, electrical current flowing through a resistor, sonar sound waves propagating under water, or earthquakes.

**Pulse Width Modulation (PWM) or Pulse Duration Modulation (PDM) or Pulse Time Modulation (PTM)** is an analog modulating scheme in which the duration or width or time of the pulse carrier varies proportional to the instantaneous amplitude of the message signal.

A signal is **an electrical or electromagnetic current that is used for carrying data from one device or network to another**.

Analog signal is **a continuous signal** and digital signal is a discrete signal. A sinusoidal signal is a continuous signal with respect to time. Therefore, sinusoidal signal is a analog signal.

Digital signals are patterns generated by **sampling a stream of continuous data at regular intervals**. The samples or bits of data are converted to a numeric or digit value. The binary code of 1 and 0 used in computers is an example of a digital signal.

An analog input **converts a voltage level into a digital value that can be stored and processed in a computer**. Why would you want to measure voltages? There are a multitude of sensors available which convert things like temperature, pressure, etc.

Inputs to a system may in theory have any form; however, we will concentrate on **four common input types**: impulse, step, ramp, and sinusoidal inputs.

6. Which system uses digital transmission? Explanation: Though the signal type is analog or digital, the transmission takes place in the digital domain in **ISDN and LANs**.

Two main types of signals encountered in practice are **analog and digital**. The figure shows a digital signal that results from approximating an analog signal by its values at particular time instants. Digital signals are quantized, while analog signals are continuous.

A good example of this is an **analogue clock**. An analogue clock shows the time with a smoothly moving seconds hand. The change is continuous. Sound is also a good example of analogue data.

MCQ: Digital data refers to **the information that is**. **continuous**. **discrete**. **bits**. **bytes**.

Noun. 1. input signal - **signal going into an electronic system**. input. signal, signaling, sign - any nonverbal action or gesture that encodes a message; "signals from the boat suddenly stopped"

An analog communication system is **a communication system where the information signal sent from point A to point B can only be described as an analog signal**. An example of this is Monica speaking to Carl over the telephone, as described in Section 1.2.

**digital-to-analog conversion (DAC)**, Process by which digital signals (which have a binary state) are converted to analog signals (which theoretically have an infinite number of states). For example, a modem converts computer digital data to analog audio-frequency signals that can be transmitted over telephone lines.

How are the convolution integral of signals represented? Explanation: We obtain the system output y(t) to an arbitrary input x(t) in terms of the input response h(t). **y(t)= ∫x(α)h(t-α)dα=x(t)*h(t)**.

Analog Signals: Advantages and Disadvantages

Analog signals are **easier to process**. Analog signals best suited for audio and video transmission. Analog signals are much higher density, and can present more refined information. Analog signals use less bandwidth than digital signals.

Dated : 22-Jun-2022

Category : Education