In wireless communications, channel state information (CSI) refers to 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. The CSI makes it possible to adapt transmissions to current channel conditions, which is crucial for achieving reliable communication with high data rates in multiantenna systems.
CSI needs to be estimated at the receiver and usually quantized and fed back to the transmitter (although reverse-link estimation is possible in TDD systems). Therefore, the transmitter and receiver can have different CSI. The CSI at the transmitter and the CSI at the receiver are sometimes referred to as CSIT and CSIR, respectively.
Read more about Channel State Information: Different Kinds of Channel State Information, Mathematical Description, Estimation of CSI
Famous quotes containing the words channel, state and/or information:
“This is what the Church is said to want, not party men, but sensible, temperate, sober, well-judging persons, to guide it through the channel of no-meaning, between the Scylla and Charybdis of Aye and No.”
—Cardinal John Henry Newman (18011890)
“Once the state has been founded, there can no longer be any heroes. They come on the scene only in uncivilized conditions.”
—Georg Wilhelm Friedrich Hegel (17701831)
“Phenomenal nature shadows him wherever he goes. Clouds in the staring sky transmit to one another, by means of slow signs, incredibly detailed information regarding him. His inmost thoughts are discussed at nightfall, in manual alphabet, by darkly gesticulating trees. Pebbles or stains or sunflecks form patterns representing in some awful way messages which he must intercept. Everything is a cipher and of everything he is the theme.”
—Vladimir Nabokov (18991977)