Channel state information Information & Channel state information Links at HealthHaven.com

Channel state information is information about the current value of H, a mathematical value which represents a signal channel. It forms part of the signal model in Telecommunications, the full equation of which is

$R_t = H_t \cdot X_t + N_t$

where $R t$ is the received signal, $X t$ is the transmitted signal, $N t$ is the noise, and $H t$ is the communication channel. The values $R t$ , $X t$ , $N t$ , $H t$ are usually not constant which is indicated by the index $t$ . Especially, $H t$ is fast varying in wireless channels, relative to wireless channels. The system usually needs to have some information regarding $H t$ to figure out what was sent from the transmitter or to enhance system performance, such as increasing transmission speed. The information can be the current value of $H t$ , or the covariance of $H t$ . This type of information is generally referred as channel state information (CSI) and is usually estimated.

[edit] Channel State Information in Wireless Communications

In wireless communications, $H t$ is fast varying relative to wireless channels. Also, the current value of $H t$ is referred as short-term CSI, while the higher order statistics of H are referred as long-term CSI.

[edit] References

[edit] External links

Definition of channel state information at Wikia

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