Leveling out of interference in a mobile network using a hopping method

• US 6,587,498 B1
• Filed: 06/27/2000
• Issued: 07/01/2003
• Est. Priority Date: 12/30/1997
• Status: Expired due to Term

• Current Assignee: Nokia Technologies Oy (Nokia Corporation)
• Original Assignee: Nokia Corporation
• Inventors: Sarkola, Eino
• Primary Examiner(s): Pham, Chi
• Assistant Examiner(s): Bayard, Emmanuel
• Application Number:
  US09/604,501
• Time in Patent Office: 1,099 Days
• Field of Search: 375/132, 375/131, 375/133, 375/219, 375/138, 375/220, 375/222, 370/294, 370/295, 370/319, 370/321, 370/330, 370/337, 370/344, 370/347, 370/442, 370/480, 370/331, 455/3.1, 455/62, 455/63, 455/561, 455/507, 455/408, 455/426, 455/430, 455/439, 455/450, 455/451
• US Class Current: 375/132
• CPC Class Codes: H04B 1/713 using frequency hopping
• CPC Class Codes: H04B 2001/7154 with means for preventing interference
• CPC Class Codes: H04B 7/2621 using frequency division multiple access [FDMA] H04B7/2615 takes precedence
• CPC Class Codes: H04W 16/04 Traffic adaptive resource partitioning

Abstract

The idea of the invention is to achieve optimum levelling out of interference by controlling the usage distribution of hopping states. Usage is not necessarily uniformly distributed, but certain hopping states are used more frequently than others. The distribution of hopping states may, for example, be determined by minimizing a pre-determined penalty function. The performance of the distribution can be monitored, for example, on the basis of network geometry, predicted or measured field strength, and traffic data. Once the frequency usage distribution is determined, it is possible to specify the frequency-hopping pattern to be used for the connection. The higher the probability that a frequency is used for a given connection, as determined by the optimization, the more frequently a frequency is used in the hopping sequence.

Claims

1. A method for levelling out interference in a mobile network that comprises at least mobile stations and base stations, that enables the establishment of a radio connection between a mobile station and a base station and that uses a hopping method for levelling out interference,

determining hopping states belonging to the hopping pattern of a connection,

determining usage probabilities of varying values for the hopping states by optimizing the usage distribution of the hopping states, and

determining a hopping pattern essentially implementing the usage probability distribution.

2. The method in accordance with claim 1, wherein density functions for the probability of usage of the hopping states are defined by means of optimization.

3. The method in accordance with claim 2, wherein the density functions are defined by minimizing a function being composed of error probabilities for the connections in the system.

4. The method in accordance with claim 2, wherein information on the network geometry, field strength and traffic volume is used in the optimization.

5. The method in accordance with claim 4, wherein the information on field strength consists of a theoretical prediction of field strength.

6. The method in accordance with claim 4, wherein the information on field strength consists of the result of a measurement on field strength.

7. The method in accordance with claim 4, wherein the information on traffic volume consists of a predicted traffic volume.

8. The method in accordance with claim 4, wherein the information on traffic volume is the result of a measurement of traffic volume.

9. The method in accordance with claim 1, wherein the usage probability distributions of the hopping states are fixedly allocated to the base station transceivers specifically for each individual transceiver.

10. The method in accordance with claim 1, wherein the usage probability distributions of the hopping states are allocated to the transceivers of the base station dynamically in response to traffic load.

11. The method in accordance with claim 1, wherein a number of certain hopping states in the hopping pattern is higher than that of other hopping states.

12. The method in accordance with claim 11, wherein the hopping pattern is a pseudo-random sequence.

13. The method in accordance with claim 11, wherein the hopping pattern is a cyclic sequence.

14. The method in accordance with claim 11, wherein hopping patterns for connections are synchronized so that the connections interfere with one another as little as possible.

15. The method in accordance with claim 14, wherein the hopping patterns are synchronized so that the connections do not simultaneously use channels that cause significant mutual interference when used by the connections.