Skip to main content Accessibility help
×
Hostname: page-component-cb9f654ff-65tv2 Total loading time: 0 Render date: 2025-08-25T12:43:37.294Z Has data issue: false hasContentIssue false

7 - Spectrum of Digitally Modulated Signals

Published online by Cambridge University Press:  10 March 2025

Tolga M. Duman
Tolga M. Duman
Affiliation:
Bilkent University, Ankara
Get access

Summary

Digital transmission over bandlimited channels is studied. The concept of intersymbol interference (ISI) is described, and the Nyquist criterion for no ISI is derived. The raised cosine pulse, a widely used example of a practical communication pulse resulting in no ISI, is introduced. Both ideal and non-ideal bandlimited channels are considered. In addition, the power spectral density of digitally modulated signals is derived, and the spectral efficiencies of different digital modulation schemes are computed.

Keywords

Bandlimited channelsintersymbol interferenceNyquist rateNyquist criterion for no ISIpower spectral densityspectral efficiency

Information

Type
Chapter
Information
Fundamentals of Digital Communication Systems , pp. 290 - 317
Publisher: Cambridge University Press
Print publication year: 2025

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

Book purchase

Temporarily unavailable

Accessibility standard: Unknown

Accessibility compliance for the PDF of this book is currently unknown and may be updated in the future.

Save book to Kindle

To save this book to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about saving to your Kindle.

Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.

Find out more about the Kindle Personal Document Service.

Available formats
×

Save book to Dropbox

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Dropbox.

Available formats
×

Save book to Google Drive

To save content items to your account, please confirm that you agree to abide by our usage policies. If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account. Find out more about saving content to Google Drive.

Available formats
×