|
mNo edit summary
|
||
Line 20: | Line 20: | ||
[[Category:Radio resource management]] |
[[Category:Radio resource management]] |
||
[[Category:Interference]] |
[[Category:Interference]] |
||
[[Category:Television terminology]] |
|||
[[ar:تداخل الإشارات]] |
[[ar:تداخل الإشارات]] |
This article does not cite any sources. Please help improve this articlebyadding citations to reliable sources. Unsourced material may be challenged and removed.
Find sources: "Signal-to-interference ratio" – news · newspapers · books · scholar · JSTOR (June 2007) (Learn how and when to remove this message) |
The signal-to-interference ratio (S/I or SIR), also known as the carrier-to-interference ratio (C/I, CIR), is the quotient between the average received modulated carrier power SorC and the average received co-channel interference power I, i.e. cross-talk, from other transmitters than the useful signal.
The CIR resembles the carrier-to-noise ratio (CNR or C/N), which is the signal-to-noise ratio (SNR or S/N) of a modulated signal before demodulation. A distinction is that interfering radio transmitters contributing to I may be controlled by radio resource management, while N involves noise power from other sources, typically additive white gaussian noise (AWGN).
The CIR ratio is studied in interference limited systems, i.e. where I dominates over N, typically in cellular radio systems and broadcasting systems where frequency channels are reused in view to achieve high level of area coverage. The C/N is studied in noise limited systems. If both situations can occur, the carrier-to-noise-and-interference ratio, C/(N+I)orCNIR may be studied.