Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Mobile Phone Modulation
Name: Chris
Status: Student
Grade: 9-12
Location: Outside U.S.
Country: Singapore
Date: January 2009


Question:
What type of modulation do mobile phones use? Is it Frequency Modulation, Amplitude Modulation, or Pulse Modulation?



Replies:
Hi Chris,

Unfortunately, your question cannot be answered so simply. Most mobile phones these days are digital. Modulation is of a general type called FSK (Frequency Shift Keying). Details depend on the type of phone network and the country it is used in. For example, in Europe and much of the rest of the world, the GSM standard is commonly used, whereas in the US the most common standard is CDMA. CDMA phones use a type of "Spread Spectrum" modulation. GMS phones use a modulation technique called GMSK (a type of continuous-phase frequency shift keying).

A good overview is here....

http://electronics.howstuffworks.com/cell-phone7.htm

...but as you will see, one thing is for sure: All mobile phone modulation schemes are vastly more complex than the simple ones you have named.

Regards,

Bob Wilson



Click here to return to the Engineering Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory