Method and apparatus for interference control in a multi-cell communication system
Methods and apparatus disclosed maximize the capacity of serving cells and minimize inter-cell interferences due to power emission from serving cells in a multi-carrier, multi-cell communication system. The control methods and apparatus take into account various factors such as cell configuration, frequency reuse, geometry and path-loss information, transmission priority, subchannel configuration, feedback from other cells, or any combination thereof, and produce signals that control the transmission power levels and the modulation and coding of transmitted signals.
1. In a multi-cell communication system in which each cell contains a serving base station for providing service to one or more mobile stations, and wherein a communication channel is configured into multiple subchannels, a base station which controls signal transmission on the subchannels in a serving cell to reduce inter-cell interference to other cells from the serving cell, the base station comprising:
a transmitter for transmitting in the serving cell; and
a controller configured to process input information and generate output signals for controlling signal transmission of the transmitter in a manner that reduces inter-cell interference to other cells from the serving cell, wherein:
the output signals generated by the controller control the transmitter in a signal transmission on the subchannels in the serving cell; and
the input information used by the controller comprises:
transmission priority information related to the subchannels, the transmission priority information received from base stations in neighboring cells in the multi-cell communication system; and
other system parameters and measurements, wherein the system parameters and measurements are selected from a group consisting of cell configuration, frequency reuse factor, cell geometry, subchannel configuration, transmission power range, service type, channel quality information, and path loss information from mobile stations to base stations in the multi-cell communication system.
2. The base station of claim 1 , wherein the transmission priority information is based on factors selected from a group consisting of a quality of service of users or applications, transmission delays, and a size of a data transmission buffer.
3. The base station of claim 1 , wherein the transmission priority information indicates an importance of throughput of a corresponding link.
4. The base station of claim 1 , wherein the transmission priority information impacts the limiting of the inter-cell interference on subchannels.
5. The base station of claim 1 , further comprising a resource allocation utility that allocates an appropriate amount of time-frequency resource for a mobile station.
6. The base station of claim 5 , wherein the resource allocation utility reduces the transmission bandwidth of a target link between the serving base station and a mobile station.
7. The base station of claim 1 , wherein the input information further comprises inter-cell interference information that was received from neighboring cells in the multi-cell wireless communication system, the inter-cell interference information including a level of interference experienced by a base station in the corresponding cell.
8. The base station of claim 1 , wherein the input information is repeatedly updated.
9. The base station of claim 1 , wherein the communication channel is further configured in the time domain into multiple time slots; and wherein the controller is further configured to process input information and generate output signals for controlling signal transmission on time-frequency resources made up of time slots and frequency subchannels.
10. In a multi-cell communication system in which each cell contains a serving base station for providing service to one or more mobile stations, and wherein a communication channel is configured into multiple subchannels, a method by a base station for controlling signal transmission on the subchannels in a serving cell to reduce inter-cell interference to other cells from the serving cell, the method comprising:
receiving input information comprising:
transmission priority information related to the subchannels, the transmission priority information received from base stations in neighboring cells to a serving cell in the multi-cell communication system; and
other system parameters and measurements, wherein the system parameters and measurements are selected from a group consisting of cell configuration, frequency reuse factor, cell geometry, subchannel configuration, transmission power range, service type, channel quality information, and path loss information from mobile stations to base stations in the multi-cell communication system; and
generating, based on the received input information, signals for controlling allocation of time-frequency resources to mobile stations in the serving cell in a manner that reduces inter-cell interference to other cells from the serving cell; and
sending the controlling signals to a resource allocation facility for allocating subchannels for transmission in the serving cell.
11. The method of claim 10 , wherein the transmission priority information is based on factors selected from a group consisting of a quality of service of users or applications, transmission delays, and a size of a data transmission buffer.
12. The method of claim 10 , wherein the transmission priority information indicates an importance of throughput of a corresponding link.
13. The method of claim 10 , wherein the transmission priority information impacts the limiting of the inter-cell interference on subchannels.
14. The method of claim 10 , wherein the input information further comprises inter-cell interference information that was received from neighboring cells in the multi-cell wireless communication system, the inter-cell interference information including a level of interference experienced by a base station in the corresponding cell.
15. The method of claim 10 , wherein the input information is repeatedly updated.
16. A method of communicating by a mobile station associated with a serving base station in a multi-cell communication system, wherein a communication channel is configured into multiple subchannels, the method comprising:
receiving information on an allocation of a time-frequency resource from the serving base station; and
transmitting signals in accordance with the time-frequency resource allocated by the serving base station in a manner that reduces inter-cell interference to other cells from the serving cell, wherein the resource allocation is controlled based on input information comprising:
transmission priority information related to the subchannels, the transmission priority information received from base stations in neighboring cells in the multi-cell communication system; and
other system parameters and measurements, wherein the system parameters and measurements are selected from the group consisting of cell configuration, frequency reuse factor, cell geometry, subchannel configuration, transmission power range, service type, channel quality information, and path loss information from mobile stations to base stations in the multi-cell communication system.
17. The method of claim 16 , wherein the communication channel is further configured in the time domain into multiple time slots.
18. The method of claim 16 , further comprising applying transmission power control to the signal transmission on a subchannel basis.
19. The method of claim 16 , further comprising applying modulation and coding schemes to the signal transmission.
20. The method of claim 16 , further comprising transmitting a ranging signal to the serving base station periodically or at the beginning of access.
21. The method of claim 16 , further comprising estimating an uplink channel quality indication (CQI) based on an observed path loss on the downlink.