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  2. 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).

  3. 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.

  4. Constellation diagram - Wikipedia

    en.wikipedia.org/wiki/Constellation_diagram

    A constellation diagram is a representation of a signal modulated by a digital modulation scheme such as quadrature amplitude modulation or phase-shift keying. [1] It displays the signal as a two-dimensional xy-plane scatter diagram in the complex plane at symbol sampling instants.

  5. Modulation - Wikipedia

    en.wikipedia.org/wiki/Modulation

    PSK (phase-shift keying): a finite number of phases are used. FSK (frequency-shift keying): a finite number of frequencies are used. ASK (amplitude-shift keying): a finite number of amplitudes are used. QAM (quadrature amplitude modulation): a finite number of at least two phases and at least two amplitudes are used.

  6. Modulation order - Wikipedia

    en.wikipedia.org/wiki/Modulation_order

    Examples of these are quadrature phase shift keying and its generalisation as m-ary quadrature amplitude modulation (m-QAM). Because existing computers and automation systems are based on binary logic most of the modulations have an order which is a power of two: 2, 4, 8, 16, etc.

  7. Orthogonal frequency-division multiplexing - Wikipedia

    en.wikipedia.org/wiki/Orthogonal_frequency...

    An OFDM carrier signal is the sum of a number of orthogonal subcarriers, with baseband data on each subcarrier being independently modulated commonly using some type of quadrature amplitude modulation (QAM) or phase-shift keying (PSK). This composite baseband signal is typically used to modulate a main RF carrier.

  8. Phase modulation - Wikipedia

    en.wikipedia.org/wiki/Phase_modulation

    A(t) represents the time-varying amplitude of the sinusoidal carrier wave and the cosine-term is the carrier at its angular frequency, and the instantaneous phase deviation (). This description directly provides the two major groups of modulation, amplitude modulation and angle modulation.

  9. 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.