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  2. Modulation - Wikipedia

    en.wikipedia.org/wiki/Modulation

    Categorization for signal modulation based on data and carrier types. In electronics and telecommunications, modulation is the process of varying one or more properties of a periodic waveform, called the carrier signal, with a separate signal called the modulation signal that typically contains information to be transmitted. [1]

  3. 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.

  4. 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).

  5. Eb/N0 - Wikipedia

    en.wikipedia.org/wiki/Eb/N0

    where is the energy per symbol in joules and ρ is the nominal spectral efficiency in (bits/s)/Hz. [2] E s / N 0 {\displaystyle E_{s}/N_{0}} is also commonly used in the analysis of digital modulation schemes.

  6. Phase-shift keying - Wikipedia

    en.wikipedia.org/wiki/Phase-shift_keying

    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. Any digital modulation scheme uses a finite number of distinct signals to represent digital data. PSK uses a finite number of phases, each assigned a unique pattern of binary digits ...

  7. Orthogonal frequency-division multiple access - Wikipedia

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

    Orthogonal frequency-division multiple access (OFDMA) is a multi-user version of the popular orthogonal frequency-division multiplexing (OFDM) digital modulation scheme. Multiple access is achieved in OFDMA by assigning subsets of subcarriers to individual users. This allows simultaneous low-data-rate transmission from several users.

  8. 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 ...

  9. 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.