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  2. Fading - Wikipedia

    en.wikipedia.org/wiki/Fading

    In wireless systems, fading may either be due to multipath propagation, referred to as multipath-induced fading, weather (particularly rain), or shadowing from obstacles affecting the wave propagation, sometimes referred to as shadow fading. A fading channel is a communication channel that experiences fading.

  3. Channel state information - Wikipedia

    en.wikipedia.org/wiki/Channel_state_information

    In wireless communications, channel state information (CSI) is the known channel properties of a communication link.This information describes how a signal propagates from the transmitter to the receiver and represents the combined effect of, for example, scattering, fading, and power decay with distance.

  4. Rayleigh fading - Wikipedia

    en.wikipedia.org/wiki/Rayleigh_fading

    Rayleigh fading is a statistical model for the effect of a propagation environment on a radio signal, such as that used by wireless devices.. Rayleigh fading models assume that the magnitude of a signal that has passed through such a transmission medium (also called a communication channel) will vary randomly, or fade, according to a Rayleigh distribution — the radial component of the sum of ...

  5. Shadowing - Wikipedia

    en.wikipedia.org/wiki/Shadowing

    Shadow fading in wireless communication, caused by obstacles; File shadowing, to provide an exact copy of or to mirror a set of data; Job shadowing, learning tasks by first-hand observation of daily behavior; Projective shadowing, a process by which shadows are added to 3D computer graphics

  6. Coherence bandwidth - Wikipedia

    en.wikipedia.org/wiki/Coherence_bandwidth

    Therefore, when fading occurs it occurs only over a relatively small fraction of the total CDMA signal bandwidth. The portion of the signal bandwidth over which fading does not occur typically contains enough signal power to sustain reliable communications. This is the bandwidth over which the channel transfer function remains virtually constant.

  7. Path loss - Wikipedia

    en.wikipedia.org/wiki/Path_loss

    Path loss normally includes propagation losses caused by the natural expansion of the radio wave front in free space (which usually takes the shape of an ever-increasing sphere), absorption losses (sometimes called penetration losses), when the signal passes through media not transparent to electromagnetic waves, diffraction losses when part of the radiowave front is obstructed by an opaque ...

  8. Free-space path loss - Wikipedia

    en.wikipedia.org/wiki/Free-space_path_loss

    In telecommunications, the free-space path loss (FSPL) (also known as free-space loss, FSL) is the attenuation of radio energy between the feedpoints of two antennas that results from the combination of the receiving antenna's capture area plus the obstacle-free, line-of-sight (LoS) path through free space (usually air). [1]

  9. Fade margin - Wikipedia

    en.wikipedia.org/wiki/Fade_margin

    In telecommunications, the term fade margin (fading margin) has the following meanings: A design allowance that provides for sufficient system gain or sensitivity to accommodate expected fading , for the purpose of ensuring that the required quality of service is maintained.