In telecommunication, the term carrier shift has the following meanings: Note 1: The carrier shift results in a change in carrier power. Note 2: The carrier shift may be a shift to a higher or to a lower frequency. ... Found on http://en.wikipedia.org/wiki/Carrier_shift
1) Radio modulation mode 
In telecommunication, the term carrier shift has the following meanings: Note 1: The carrier shift results in a change in carrier power. Note 2: The carrier shift may be a shift to a higher or to a lower frequency. ...