suppose that a digitized tv picture is to be transmitted

We discuss a mathematical approach to sine waves in Appendix C. Sine Wave Wavelength Time and Frequency Domain Composite Signals Bandwidth Topics discussed in this section: A composite periodic analog signal is composed of multiple sine waves. A simple periodic analog signal, a sine wave, cannot be decomposed into simpler signals. Noteģ-2 PERIODIC ANALOG SIGNALS Periodic analog signals can be classified as simple or composite. In data communications, we commonly use periodic analog signals and nonperiodic digital signals.

Noteįigure 3.1 Comparison of analog and digital signals Analog signals can have an infinite number of values in a range digital signals can have only a limited number of values. Digital data have discrete states and take discrete values.

Analog data are continuous and take continuous values. Analog and Digital Data Analog and Digital Signals Periodic and Nonperiodic Signals Topics discussed in this section:ĭata can be analog or digital. The term analog data refers to information that is continuous digital data refers to information that has discrete states. Noteģ-1 ANALOG AND DIGITAL Data can be analog or digital. To be transmitted, data must be transformed to electromagnetic signals. Permission required for reproduction or display. What is the lowest frequency Draw the spectrum if the signal contains all frequencies of the same amplitude.Chapter 3 Data and Signals Copyright © The McGraw-Hill Companies, Inc. Then The spectrum has only five spikes, at 100, 300, 500, 700, and 900 Hz (see Figure 3. Solution Let fh be the highest frequency, fl the lowest frequency, and B the bandwidth. In this case, the composite signal cannot be periodic, because that implies that we are repeating the same word or words with exactly the same tone. It can be the signal created by a microphone or a telephone set when a word or two is pronounced.

The analysis of this signal can give us a good understanding of how to decompose signals. Suppose That A Digitized Tv Picture Is To Be Transmitted How To Decompose Signals We can consider it to be three alarm systems, each with a different frequency. This type of signal is not typical of those found in data communications. T or equivalently f v especially when vc 3.Īll can be represented by three spikes in the frequency domain. What is its phase in degrees and radians Solution We know that 1 complete cycle is 360. If a signal changes instantaneously, its frequency is infinite. The period of this sine wave can be determined as follows: 3. Suppose That A Digitized Tv Picture Is To Be Transmitted How To Decompose SignalsĪnalog signals can have an infinite number of values in a range digital signals can have only a limited number of values.Ī simple periodic analog signal, a sine wave, cannot be decomposed into simpler signals.Ī composite periodic analog signal is composed of multiple sine waves.įor example, the peak value of an AA battery is normally 1.

Suppose that a digitized tv picture is to be transmitted