**6. Summary**

This chapter "multiplexing" deals with different multiplexing techniques commonly used in both analog and digital communication systems and their classifications. This chapter contains the detailed description of analog modulation techniques like FDM, WDM, etc. It also describes about OFDM techniques and various digital modulation schemes like TDM and its variants. It also focuses on

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**Author details**

Vijayakumar Nandalal\* and M.S. Sumalatha

provided the original work is properly cited.

Engineering and Technology, Coimbatore, Tamilnadu, India

\*Address all correspondence to: nandalalskcet@gmail.com

Department of Electronics and Communication Engineering, Sri Krishna College of

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

*Multiplexing*

diagrams.

*DOI: http://dx.doi.org/10.5772/intechopen.85866*

CDM multiplexing techniques and different digital multiplexers and demultiplexers and varies in digital demodulation techniques like ASK, PSK, and FSK with detailed

*Multiplexing DOI: http://dx.doi.org/10.5772/intechopen.85866*

*Multiplexing*

**5.3 Phase shift keying**

**Figure 22.** *Phase shift keying.*

*5.3.2 Application*

**6. Summary**

*5.3.1 Advantages and disadvantages of PSK*

1.Used in our ADSL broadband modem

2.Used in satellite communication

3.Used in our mobile phones

offers lower bandwidth efficiency than ASK modulation type.

The principle of phase shift keying is that the phase of the carrier wave is modulated in accordance with the digital message signal, i.e., PSK signal represents the binary data in the form of variations in the phase of the carrier signal. Here the carrier signal changes its phase depending on the nature of the transmitted bit, i.e., 0 or 1. In two levels of PSK, the difference of 180-phase shift is used between binary 1 and binary 0 (**Figure 22**).

It is a more power-efficient modulation technique than the ASK and FSK as it is less susceptible to errors than ASK modulation and occupies the same bandwidth as ASK. The disadvantage of PSK includes lower bandwidth efficiency. The binary data is decoded by estimation of phase states of the signal. These detection and recovery algorithms are very complex. It is also one form of FSK, and hence it also

This chapter "multiplexing" deals with different multiplexing techniques commonly used in both analog and digital communication systems and their classifications. This chapter contains the detailed description of analog modulation techniques like FDM, WDM, etc. It also describes about OFDM techniques and various digital modulation schemes like TDM and its variants. It also focuses on

**26**

CDM multiplexing techniques and different digital multiplexers and demultiplexers and varies in digital demodulation techniques like ASK, PSK, and FSK with detailed diagrams.
