Modulation

HomePage | Recent changes | View source | Discuss this page | Page history | Log in |

Printable version | Disclaimers | Privacy policy

Modulation describes a range of techniques for encoding information on a carrier signal, typically a sine-wave signal.

Modulation techniques include:

When OFDM is used in conjunction with channel coding techniques, it is described as 'Coded orthogonal frequency division modulation' (COFDM).

Pulse modulation techniques include:

Where the signal is a simple low speed on-off indication, as in morse code or radioteletype (RTTY) transmission, modulation is often known as 'keying' as in the terms

RTTY can also be regarded as a simple kind of pulse code modulation.

Where Morse code is used to turn the carrier wave on and off, the term used is not 'amplitude keying', but 'continuous wave' (CW) operation.

Modulation is frequently used in conjunction with various channel access methods, such as

Where these methods are used for dividing forward and reverse communication channels, they are known as duplexing methods, such as:

See also: