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  2. Modulation - Wikipedia

    en.wikipedia.org/wiki/Modulation

    Digital modulation methods can be considered as digital-to-analog conversion and the corresponding demodulation or detection as analog-to-digital conversion. The changes in the carrier signal are chosen from a finite number of M alternative symbols (the modulation alphabet ).

  3. Keying (telecommunications) - Wikipedia

    en.wikipedia.org/wiki/Keying_(telecommunications)

    The goal of keying is to transmit a digital signal over an analog channel. The name derives from the Morse code key used for telegraph signaling. Modulation is the general technique of shaping a signal to convey information. When a digital message has to be represented as an analog waveform, the technique and term keying (or digital modulation ...

  4. On–off keying - Wikipedia

    en.wikipedia.org/wiki/On–off_keying

    On–off keying (OOK) denotes the simplest form of amplitude-shift keying (ASK) modulation that represents digital data as the presence or absence of a carrier wave. [1] In its simplest form, the presence of a carrier for a specific duration represents a binary one, while its absence for the same duration represents a binary zero.

  5. Phase-shift keying - Wikipedia

    en.wikipedia.org/wiki/Phase-shift_keying

    Phase-shift keying (PSK) is a digital modulation process which conveys data by changing (modulating) the phase of a constant frequency carrier wave. The modulation is accomplished by varying the sine and cosine inputs at a precise time. It is widely used for wireless LANs, RFID and Bluetooth communication.

  6. Amplitude and phase-shift keying - Wikipedia

    en.wikipedia.org/wiki/Amplitude_and_phase-shift...

    Amplitude and phase-shift keying (APSK) is a digital modulation scheme that conveys data by modulating both the amplitude and the phase of a carrier wave. In other words, it combines both amplitude-shift keying (ASK) and phase-shift keying (PSK).

  7. Minimum-shift keying - Wikipedia

    en.wikipedia.org/wiki/Minimum-shift_keying

    In digital modulation, minimum-shift keying (MSK) is a type of continuous-phase frequency-shift keying that was developed in the late 1950s by Collins Radio employees Melvin L. Doelz and Earl T. Heald. [1]

  8. Amplitude-shift keying - Wikipedia

    en.wikipedia.org/wiki/Amplitude-shift_keying

    Amplitude-shift keying (ASK) is a form of amplitude modulation that represents digital data as variations in the amplitude of a carrier wave. [1] In an ASK system, a symbol, representing one or more bits, is sent by transmitting a fixed-amplitude carrier wave at a fixed frequency for a specific time duration.

  9. Differential coding - Wikipedia

    en.wikipedia.org/wiki/Differential_coding

    In digital communications, differential coding is a technique used to provide unambiguous signal reception when using some types of modulation.It makes transmissible data dependent on both the current and previous signal (or symbol) states.