In telecommunication systems, Carrier frequency is a technical term used to indicate:
Vaguely speaking, the center frequency or the frequency of a carrier wave
The "nominal frequency" or the center frequency of an analog frequency modulation, phase modulation, or double-sideband suppressed-carrier transmission (DSB-SC) (AM-suppressed carrier), radio wave
The frequency of the unmodulated electromagnetic wave at the output of a conventional amplitude-modulated (AM-unsupressed carrier), or frequency-modulated (FM), or phase-modulated (PM) radio transmitter
The nominal frequency or center frequency of various kinds of radio signals with digital modulation -- provided that the message bit stream is a random uncorrelated sequence of equally probable ones and zeroes ("marks" and "spaces")
