|
m →See also: alpha, caps
|
m →top: rm space
|
||
| Line 1: | Line 1: | ||
{{Unreferenced|date=June 2007}} |
{{Unreferenced|date=June 2007}} |
||
The '''signal-to-interference ratio''' ('''SIR''' or '''''S/I''''' |
The '''signal-to-interference ratio''' ('''SIR''' or '''''S/I'''''), also known as the '''carrier-to-interference ratio''' ('''CIR''' or '''''C/I'''''), is the quotient between the average received modulated carrier power ''S'' or ''C'' 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 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). |
||
==Carrier-to-noise-and-interference ratio (CNIR)== |
==Carrier-to-noise-and-interference ratio (CNIR)== |
||
 |
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 (SIRorS/I), also known as the carrier-to-interference ratio (CIRorC/I), 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 (CNIRorC/(N+I)) may be studied.
