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  2. Baseband - Wikipedia

    en.wikipedia.org/wiki/Baseband

    A baseband signal or lowpass signal is a signal that can include frequencies that are very near zero, by comparison with its highest frequency (for example, a sound waveform can be considered as a baseband signal, whereas a radio signal or any other modulated signal is not). [2] A baseband bandwidth is equal to the highest frequency of a signal ...

  3. Bandwidth (signal processing) - Wikipedia

    en.wikipedia.org/wiki/Bandwidth_(signal_processing)

    Baseband bandwidth is equal to the upper cutoff frequency of a low-pass filter or baseband signal, which includes a zero frequency. Bandwidth in hertz is a central concept in many fields, including electronics , information theory , digital communications , radio communications , signal processing , and spectroscopy and is one of the ...

  4. Orthogonal frequency-division multiplexing - Wikipedia

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

    If no guard interval was applied, this would result in a base band complex valued signal with a sample rate of 1 MHz, which would require a baseband bandwidth of 0.5 MHz according to Nyquist. However, the passband RF signal is produced by multiplying the baseband signal with a carrier waveform (i.e., double-sideband quadrature amplitude ...

  5. 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]

  6. Spectral efficiency - Wikipedia

    en.wikipedia.org/wiki/Spectral_efficiency

    If digital single-sideband modulation is used, the passband signal with bandwidth W corresponds to a baseband message signal with baseband bandwidth W, resulting in a maximum symbol rate of 2W and an attainable modulation efficiency of 2N (bit/s)/Hz. Example 3: A 16QAM modem has an alphabet size of M = 16 alternative symbols, with N = 4 bit ...

  7. Frequency-division multiplexing - Wikipedia

    en.wikipedia.org/wiki/Frequency-division...

    The modulator alters some aspect of the carrier signal, such as its amplitude, frequency, or phase, with the baseband signal, "piggybacking" the data onto the carrier. The result of modulating (mixing) the carrier with the baseband signal is to generate sub-frequencies near the carrier frequency, at the sum (f C + f B) and difference (f C − f ...

  8. Amplitude modulation - Wikipedia

    en.wikipedia.org/wiki/Amplitude_modulation

    The message signal determines the envelope of the transmitted waveform. In the frequency domain, amplitude modulation produces a signal with power concentrated at the carrier frequency and two adjacent sidebands. Each sideband is equal in bandwidth to that of the modulating signal, and is a mirror image of the other. Standard AM is thus ...

  9. Frequency modulation - Wikipedia

    en.wikipedia.org/wiki/Frequency_modulation

    The technology is used in telecommunications, radio broadcasting, signal processing, and computing. In analog frequency modulation, such as radio broadcasting, of an audio signal representing voice or music, the instantaneous frequency deviation , i.e. the difference between the frequency of the carrier and its center frequency, has a ...