Method for noise floor and interference estimation

• US 9,071,359 B2
• Filed: 06/29/2007
• Issued: 06/30/2015
• Est. Priority Date: 06/29/2007
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Wigren, Torbjorn
• Primary Examiner(s): Maung, Nay A
• Assistant Examiner(s): FLEMING-HALL, ERICA L
• Application Number:
  US12/666,979
• Publication Number:
  US 20110009070A1
• Time in Patent Office: 2,923 Days
• Field of Search: 455/67.13, 455/67.11, 455/63.1, 455/570, 455/114.2, 455/278.1, 455/283, 455/296
• US Class Current: 1/1
• CPC Class Codes: H04B 17/345 Interference values signal-to-interference ratio [SIR] or carrier-to-interference ratio [CIR] H04B17/336
• CPC Class Codes: H04B 17/354 Adjacent channel leakage power
• CPC Class Codes: H04B 17/382 for resource allocation, admission control or handover

Abstract

The present invention relates to a method and arrangement in a wireless communication system, e.g. an evolved UMTS Terrestrial Radio Access Network, for improved scheduling and admission control of the uplink by providing an improved determining of power-related quantities, e.g. neighbor cell interference levels, for specific tones and providing more accurate determination of noise-related quantities, e.g. noise floor power estimates, for specific tones. The method and arrangement obtains a neighbor cell interference measure for each subset of tones from at least a noise floor measure for each subset of tones based on combined power quantities from the total uplink power per subset of tones and dividing said noise floor measure into sub noise floor measures for each subset of tones, said dividing dependent on the bandwidth of each subset of tones.

Claims

1. A method for neighbor cell interference estimation comprising:

measuring a total uplink power per subset of tones;

measuring a own-channel power per the same subset of tones;

calculating an auxiliary power quantity for each subset of tones as the total uplink power per subset of tones minus the own-channel power per subset of tones minus the leakage of power from other subsets of tones;

combining the auxiliary power quantities for all subsets of tones to obtain a total auxiliary wideband power for the entire uplink band;

calculating a thermal noise floor measure based on said total auxiliary wideband power quantity; and

dividing said calculated thermal noise floor measure into sub noise floor measures for each subset of tones, said dividing dependent on the bandwidth of each subset of tones, for obtaining a neighbor cell interference measure for each subset of tones from at least said sub noise floor measures.

2. The method of claim 1, wherein

the step of combining comprises an addition of the auxiliary power quantities for all subsets of tones;

and

the step of calculating the thermal noise floor measure comprises storing the auxiliary power samples in a sliding window and calculating the minimum j of power samples in said sliding window;

wherein the neighbor cell interference is calculated by scaling the noise floor measure for each of the subsets of tones and calculating the auxiliary power quantity minus the scaled noise floor measure for each subset.

3. The method of claim 2, comprising the step of signaling one or more of the estimated parameters for each subset of tones for

the sum of all contributions of emitted radio frequency power of mobile terminals in neighboring cells,

4. The method of claim 2, whereby said leakage of power is calculated from all channel powers corresponding to other subsets of tones in the own cell.

5. The method of claim 4, whereby said leakage power is calculated according to

6. The method of claim 1, whereby

said auxiliary power quantity constitutes a mean value and a variance corresponding to a Gaussian probability distribution for each subset of tones, said probability distribution obtained by optimum filtering;

said noise floor measure constitutes a conditional probability distribution of the minimum of the total auxiliary power over said sliding window;

and further comprising the steps of

storing the probability distribution of said combined auxiliary power quantities in a sliding window over time; and

said dividing being performed by a transformation of the conditional probability distribution of the minimum of the total auxiliary power over said sliding window; and

said transformation dependent on the bandwidth of each subset of tones.

7. The method of claim 6, further comprising the step of calculating an optimal estimate of the thermal noise floor as a conditional mean of the probability distribution.

8. The method of claim 7, whereby the neighbor cell interference is calculated by

calculating the optimal estimate of the probability distribution dependent on the bandwidth for each subset of tones;

and

calculating the auxiliary power quantity minus the own cell channel power minus the scaled noise floor minus leakage of power for each subset of tones.

9. The method of claim 6, whereby said step of obtaining a neighbor cell interference measure determines the probability distribution of the neighbor cell interference power for each subset of tones according to a difference distribution between said auxiliary power quantity and said divided sub noise floor measures, both for each subset of tones.

10. The method of claim 9, further comprising the step of calculating an optimal estimate of the neighbor cell interference, said estimate calculated as a conditional mean.

11. The method of claim 10, further comprising the step of calculating an optimal estimate of the neighbor cell interference, said estimate calculated as a conditional variance.

12. The method of claim 10, comprising the step of signaling one or more of the estimated parameters for each subset of tones for the sum of all contributions of emitted radio frequency power of mobile terminals in neighboring cells,

13. The method of claim 12, further comprising the step of signaling one or more of the variances for said estimated parameters.

14. The method of claim 6, whereby the auxiliary power is further dependent on a calculated leakage power, said leakage power being obtained from the own-channel power for each subset of tones.

15. The method of claim 14, whereby said leakage power is calculated according to

16. The method of claim 1, whereby said auxiliary power is selected as the total power per subset of tones, and said obtaining of a neighbor cell interference measure is further based on the own-channel power and leakage power, both for each subset of tones.

17. The method of claim 16, comprising the step of signaling one or more of the estimated parameters for each subset of tones for

the sum of all contributions of emitted radio frequency power of mobile terminals in neighboring cells,

18. A node in a wireless communication system, comprising

one or more measurement circuits for measuring the total uplink power per subset of tones, and for measuring the own-channel power per the same subset of tones;

a combining circuit for calculating an auxiliary power quantity for each subset of tones as the total uplink power per subset of tones minus the own-channel power per subset of tones minus the leakage of power from other subsets of tones and combining for all subsets of tones the auxiliary power quantities to obtain a total auxiliary wideband power for the entire uplink band;

a calculation circuit for calculating a thermal noise floor measure based on said combined auxiliary power quantity;

a processing circuit for obtaining a neighbor cell interference measure for each subset of tones from at least said noise floor measure for each subset of tones by dividing said calculated thermal noise floor measure into sub noise floor measures for each subset of tones; and

a signaling circuit for signaling said measure to another function in said node or another node in said wireless communication system.