Inter-cell interference coordination for wireless communication systems
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| Název: | Inter-cell interference coordination for wireless communication systems |
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| Patent Number: | 9,042,933 |
| Datum vydání: | May 26, 2015 |
| Appl. No: | 13/438624 |
| Application Filed: | April 03, 2012 |
| Abstrakt: | For each base station, transmit power level variables (I values) for each resource block allocated by the base station are initialized. The I values are used in a model to find sub-gradients for each base station. Neighboring base stations exchange the sub-gradients. For each base station, the base station's sub-gradient and the base station's neighbors' sub-gradients are used in the model to update the I values. Neighboring base stations then exchange the updated I values. For each base station, the base station's updated I value and the base station's neighbors' updated I values are used in the model to update the initial sub-gradients. The updated sub-gradients are then exchanged and used for another update of the I values. After a number of iterations, the I values are used to establish a transmit power level per resource block. |
| Inventors: | Sediq, Akram Bin (Ottawa, CA); Schoenen, Rainer (Ottawa, CA); Yanikomeroglu, Halim (Ottawa, CA); Senarath, Gamini (Ottawa, CA); Chao, Zhijun (Shanghai, CN); Cheng, Ho Ting (Nepean, CA); Zhu, Peiying (Kanata, CA) |
| Assignees: | Futurewei Technologies, Inc. (Plano, TX, US) |
| Claim: | 1. A method for managing a wireless network, the method comprising: accessing, by a communications controller, a first value for a power level variable associated with a first resource block that is allocated by a first base station that serves a first sector of the wireless network; updating, by the communications controller, the first value for the power level variable according to an iterative process having multiple cycles, each cycle of the iterative process comprising: i) receiving a second value from a second base station that serves a second sector of the wireless network, the second value corresponding to the effect of power level for a second resource block allocated by the second base station on a measure of utility for the second sector; and ii) determining an updated value for the power level variable according to the second value; and setting, by the communications controller, a transmit power level for the first resource block according to the updated value. |
| Claim: | 2. The method of claim 1 , further comprising rounding the updated value to the nearest binary value, wherein the first resource block is turned on if the updated value has a first binary value and turned off if the updated value has a second binary value. |
| Claim: | 3. The method of claim 1 , further comprising allocating the first resource block to a user terminal in the first sector according to the updated value. |
| Claim: | 4. The method of claim 1 , wherein the iterative process further comprises: accessing a third value corresponding to the effect of the transmit power level for the first resource block on a measure of utility for the first sector, wherein the third value is determined according to the first value; and determining the updated value for the power level variable according to the sum of the second and third values. |
| Claim: | 5. The method of claim 4 , wherein the third value comprises a sub-gradient value calculated for the first resource block using a minimum network cost flow (MCNF)-structured model, and wherein the second value comprises a sub-gradient value calculated for the second resource block using the MCNF-structured model. |
| Claim: | 6. The method of claim 5 , wherein the iterative process is performed a prescribed number of cycles, each of the cycles comprising: determining a first sub-gradient value for cycle N of the iterative process, the first sub-gradient associated with a resource block that is allocated by the first base station, the first sub-gradient determined according to a power level variable value for the resource block; sending the first sub-gradient value for cycle N of the iterative process to the second base station; receiving a second sub-gradient value for cycle N of the iterative process from the second base station; updating the power level variable value for the resource block according to the sum of the first and second sub-gradient values; sending the updated power level variable value for the resource block to the second base station; and receiving a power level variable value from the second base station, wherein the first sub-gradient value is updated in cycle N+1 of the iterative process according to the updated power level variable value for the resource block and the power level variable value from the second base station. |
| Claim: | 7. The method of claim 1 , further comprising: sending the updated value for the power level variable from the first base station to the second base station; and receiving, from the second base station, a value for a power level variable associated with the second resource block. |
| Claim: | 8. The method of claim 1 , further comprising determining a data transmission rate according to the transmit power level for the first resource block. |
| Claim: | 9. The method of claim 1 , wherein the measure of utility comprises a weighted sum data transmission rate of all user terminals in the first sector. |
| Claim: | 10. The method of claim 1 , wherein the communications controller is implemented by the first base station. |
| Claim: | 11. The method of claim 1 , wherein the communications controller comprises a centralized node configured to communicate with the first and second base stations. |
| Claim: | 12. The method of claim 1 , wherein the first sector comprises a portion of a first cell and the second sector comprises a portion of a second cell that neighbors the first cell. |
| Claim: | 13. A communications controller comprising: a processor configured to access a first value for a power level variable associated with a first resource block that is allocated by a first base station that serves a first sector of a wireless network; the processor further configured to update the first value for the power level variable according to an iterative process having multiple interations, each iteration of the iterative process comprising determining an updated value for the power level variable according to a second value, wherein the second value corresponds to the effect of power level for a second resource block allocated by a second base station on a measure of utility for a second sector of the wireless network served by the second base station; the processor further configured to set a transmit power level for the first resource block according to the updated value; and an antenna coupled to the processor and configured to receive the second value from the second base station. |
| Claim: | 14. The communications controller of claim 13 , wherein the processor is further configured to round the updated value to the nearest binary value, wherein the first resource block is turned on if the updated value has a first binary value and turned off if the updated value has a second binary value. |
| Claim: | 15. The communications controller of claim 13 , wherein the processor is further configured to allocate the first resource block to a user terminal in the first sector according to the updated value. |
| Claim: | 16. The communications controller of claim 13 , wherein the iterative process further comprises accessing a third value corresponding to the effect of the transmit power level for the first resource block on a measure of utility for the first sector, wherein the third value is determined according to the first value, and determining the updated value for the power level variable according to the sum of the second and third values. |
| Claim: | 17. The communications controller of claim 16 , wherein the third value comprises a sub-gradient value calculated for the first resource block using a minimum network cost flow (MCNF)-structured model, and wherein the second value comprises a sub-gradient value calculated for the second resource block using the MCNF-structured model. |
| Claim: | 18. The communications controller of claim 13 , wherein the antenna is further configured to send the updated value for the power level variable from the first base station to the second base station, and receive, from the second base station, a value for a power level variable associated with the second resource block. |
| Claim: | 19. The communications controller of claim 13 , wherein the processor is further configured to determine a data transmission rate according to the transmit power level for the first resource block. |
| Claim: | 20. The communications controller of claim 13 , wherein the measure of utility comprises a weighted sum data transmission rate of all user terminals in the first sector. |
| Claim: | 21. The communications controller of claim 13 , wherein the first base station comprises the communications controller. |
| Claim: | 22. The communications controller of claim 13 , wherein the communications controller comprises a centralized node configured to communicate with the first and second base stations. |
| Claim: | 23. An inter-cell interference coordination method for a wireless network, the method comprising: performing, with a communications controller, an iterative process comprising: determining a sub-gradient value according to a value of a transmit power level variable for a resource block allocated by a first base station that services a first sector in the wireless network, wherein the sub-gradient value is determined according to the weighted sum data transmission rate for user terminals in the first sector; sending the sub-gradient value to a second base station in a second sector that neighbors the first sector; receiving a sub-gradient value from the second base station; updating the value of the transmit power level variable according to the sum of the sub-gradient sent to the second base station and the sub-gradient received from the second base station; repeating, by the communications controller, the iterative process a prescribed number of times to generate a final value for the transmit power level variable; and setting, by the communications controller, a transmit power level for the resource block according to the updated value. |
| Claim: | 24. The method of claim 23 , further comprising rounding the final value to the nearest binary value, wherein the resource block is turned on if the updated value has a first binary value and turned off if the updated value has a second binary value. |
| Claim: | 25. The method of claim 23 , further comprising determining a data transmission rate according to the transmit power level for the resource block. |
| Claim: | 26. The method of claim 23 , further comprising allocating the resource block to a user terminal in the first sector according to the final value for the transmit power level variable. |
| Current U.S. Class: | 455/522 |
| Patent References Cited: | 2008/0298486 December 2008 Venturino et al. 2011/0136494 June 2011 Kim et al. 2012/0282889 November 2012 Tanaka et al. |
| Primary Examiner: | Gesesse, Tilahun B |
| Přístupové číslo: | edspgr.09042933 |
| Databáze: | USPTO Patent Grants |
| Abstrakt: | For each base station, transmit power level variables (I values) for each resource block allocated by the base station are initialized. The I values are used in a model to find sub-gradients for each base station. Neighboring base stations exchange the sub-gradients. For each base station, the base station's sub-gradient and the base station's neighbors' sub-gradients are used in the model to update the I values. Neighboring base stations then exchange the updated I values. For each base station, the base station's updated I value and the base station's neighbors' updated I values are used in the model to update the initial sub-gradients. The updated sub-gradients are then exchanged and used for another update of the I values. After a number of iterations, the I values are used to establish a transmit power level per resource block. |
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