Types of radio emissions

The modulation of a radio signal is classified according to a scheme of the International Telecommunication Union (ITU). For this purpose, a scheme of nine symbol is used which is constructed as follows:

BBBBMSIDX

  • BBBB: bandwidth of the signal, for example, 6K00 (6.00 kHz)
  • M: modulation type, for example, A (amplitude modulation)
  • S: signal type, for example, 3 (analog signal )
  • I: information type, for example, E (telephony, radio-broadcast transmission )
  • D: detail (optional ), eg G ( monophonic )
  • X: multiplexing ( optional), for example N (no division )

Example 6K00A3EGN features such as an amplitude modulated analog, broadcasting monophonic signal having a bandwidth of 6 kHz, as is typical for medium-wave and short-wave radio transmitter.

Frequently bandwidth, detailing and multiplexing methods are omitted so that the term of only three characters is (MSI ), eg A3E.

It should be noted that some Modulationsbezeichner equivalent and indistinguishable. The difference comes from the type of treatment. Thus it can be palpated for example for a frequency shift of the oscillator of a transmitter, whereby the frequency between two values ​​jumps back and forth ( FSK Frequency Shift Keying). The same is achieved by a low-frequency oscillator is sampled and this analog signal is modulated with a J3E transmitter ( AFSK, Audio Frequency Shift Keying).

Bandwidth

The range is designated by three digits and a letter. The letter may be a H (Hertz ), a K (kHz ), a M (MHz) or a G (GHz). The letter takes the place of the comma.

Modulation of the main carrier

Modulation of amplitude, frequency / phase or pulse characteristics are based.

Signal

Use of a sub-carrier

Is modulated

A subcarrier

Modulates a Einseitenbandsender

Of information

Detailing (optional)

A distinction is made between signals with two or more discrete states, sound and television signals.

Or one or more bits

Information for amplitude control

Multiplexing information

Commonly used types of modulation

  • A1A: Morse code with getastetem support ( old A1)
  • A2A: Morse code modulated subcarrier ( old A2)
  • A3E: amplitude modulated telephony signal ( old A3)
  • A3F: amplitude- modulated video signal ( old A5)
  • J3E: SSB single sideband (LSB / USB) ( old a3j )
  • F1B: frequency modulated by Fernschreibtelegrafie shift keyed carrier ( old F1)
  • F1C: frequency modulated by facsimile transmission shift keyed carrier ( old F4)
  • F1D: frequency modulated remote operation by shift keyed carrier ( old F9)
  • F2A: frequency-modulated Morse code with a modulated subcarrier ( old F2)
  • F2B: frequency modulated Fernschreibtelegrafie with a modulated subcarrier ( old F2)
  • F2C: frequency-modulated facsimile transmission with a modulated subcarrier ( old F4)
  • F2D: frequency modulated remote control with a modulated subcarrier ( old F9)
  • F3C: analog frequency-modulated facsimile signal ( old F4)
  • F3E: frequency modulated telephony ( old F3)
  • F3F: frequency modulated video signal ( old F5)
  • G1A: phase-modulated Morse code without subcarrier
  • G1B: phase-modulated telex without subcarrier
  • G1C: phase-modulated fax transmission without subcarrier
  • G1D: phase-modulated data transmission without subcarrier
  • G2A: phase-modulated Morse code with subcarrier
  • G2B: phase-modulated telex subcarrier
  • G2C: phase-modulated fax transmission subcarriers
  • G2D: phase-modulated data transmission using subcarrier
  • G3C: phase-modulated fax transmission
  • G 3E: phase-modulated telephony
  • G3F: phase-modulated video transmission
Analogsignal Bandwidth (signal processing) Medium frequency Single-sideband modulation Single-sideband modulation#Vestigial sideband .28VSB.29 Angle modulation Modem
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