Intra-Cell Common Reuse for a Wireless Communication System

Abstract

To avoid or reduce intra-cell interference, each sector of a cell is associated with a sector-specific set of system resources (e.g., subbands) and at least one non-overlapping common set of system resources. Each common set for each sector includes system resources observing little or no interference from at least one other sector in the cell. The channel condition for a terminal in a given sector x is ascertained based on forward and/or reverse link measurements for the terminal. The terminal is assigned system resources from a common set or a sector-specific set for sector x based on the terminal's channel condition. For example, if the terminal observes high interference from another sector y, then the terminal is assigned system resources from a common set that observes little or no interference from sector y. The techniques may be used for an OFDMA system that uses frequency hopping.

What is claimed is: 
     
         1 . A method for assigning system resources in a wireless communication system by a base station, comprising:
 determining a channel condition of a terminal served by a first cell of the base station and located near or in a boundary region of the first cell and a second cell of the base station; and   assigning the terminal with one of a first set of resources or a second set of resources based on the channel condition, the first set of resources and the second set of resources being mutually exclusive, the first set of resources being for terminals served by the first cell, the second set of resources being a common set of resources for terminals served by any one of the first cell and the second cell.   
     
     
         2 . The method of  claim 1 , wherein the channel condition is a signal to interference plus noise ratio (SINR), and the terminal is assigned with the first set of resources when the SINR is greater than a threshold and is assigned the second set of resources when the SINR is less than the threshold. 
     
     
         3 . The method of  claim 1 , wherein the determining the channel condition comprises:
 obtaining pilot measurements for the terminal; and   determining an interference observed by the terminal from the second sell based on the obtained pilot measurements, wherein the terminal is assigned the first set of resources when the determined interference is less than a threshold and is assigned the second set of resources when the determined interference is greater than the threshold.   
     
     
         4 . The method of  claim 1 , wherein the base station includes the first cell, the second cell, and a third cell, and the second set of resources are assigned to terminals served by any one of the first cell, the second cell, and the third cell. 
     
     
         5 . The method of  claim 1 , wherein the first set of resources and the second set of resources includes resources that hop based on a time period to different subbands, the first set of resources and the second set of resources including the same subbands at different time periods. 
     
     
         6 . An apparatus for assigning system resources in a wireless communication system, the apparatus being a base station, comprising:
 means for determining a channel condition of a terminal served by a first cell of the base station and located near or in a boundary region of the first cell and a second cell of the base station; and   means for assigning the terminal with one of a first set of resources or a second set of resources based on the channel condition, the first set of resources and the second set of resources being mutually exclusive, the first set of resources being for terminals served by the first cell, the second set of resources being a common set of resources for terminals served by any one of the first cell and the second cell.   
     
     
         7 . The apparatus of  claim 6 , wherein the channel condition is a signal to interference plus noise ratio (SINR), and the terminal is assigned with the first set of resources when the SINR is greater than a threshold and is assigned the second set of resources when the SINR is less than the threshold. 
     
     
         8 . The apparatus of  claim 6 , wherein the means for determining the channel condition is configured to:
 obtain pilot measurements for the terminal; and   determine an interference observed by the terminal from the second sell based on the obtained pilot measurements,   wherein the terminal is assigned the first set of resources when the determined interference is less than a threshold and is assigned the second set of resources when the determined interference is greater than the threshold.   
     
     
         9 . The apparatus of  claim 6 , wherein the base station includes the first cell, the second cell, and a third cell, and the second set of resources are assigned to terminals served by any one of the first cell, the second cell, and the third cell. 
     
     
         10 . The apparatus of  claim 6 , wherein the first set of resources and the second set of resources includes resources that hop based on a time period to different subbands, the first set of resources and the second set of resources including the same subbands at different time periods. 
     
     
         11 . An apparatus for assigning system resources in a wireless communication system, the apparatus being a base station, comprising:
 a controller for determining a channel condition of a terminal served by a first cell of the base station and located near or in a boundary region of the first cell and a second cell of the base station; and   a scheduler for assigning the terminal with one of a first set of resources or a second set of resources based on the channel condition, the first set of resources and the second set of resources being mutually exclusive, the first set of resources being for terminals served by the first cell, the second set of resources being a common set of resources for terminals served by any one of the first cell and the second cell.   
     
     
         12 . The apparatus of  claim 11 , wherein the channel condition is a signal to interference plus noise ratio (SINR), and the terminal is assigned with the first set of resources when the SINR is greater than a threshold and is assigned the second set of resources when the SINR is less than the threshold. 
     
     
         13 . The apparatus of  claim 11 , wherein the controller is configured to determine the channel condition by:
 obtaining pilot measurements for the terminal; and   determining an interference observed by the terminal from the second sell based on the obtained pilot measurements,   wherein the terminal is assigned the first set of resources when the determined interference is less than a threshold and is assigned the second set of resources when the determined interference is greater than the threshold.   
     
     
         14 . The apparatus of  claim 11 , wherein the base station includes the first cell, the second cell, and a third cell, and the second set of resources are assigned to terminals served by any one of the first cell, the second cell, and the third cell. 
     
     
         15 . The apparatus of  claim 11 , wherein the first set of resources and the second set of resources includes resources that hop based on a time period to different subbands, the first set of resources and the second set of resources including the same subbands at different time periods. 
     
     
         16 . A non-transitory computer-readable medium within a base station, the computer-readable medium comprising code for:
 determining a channel condition of a terminal served by a first cell of the base station and located near or in a boundary region of the first cell and a second cell of the base station; and   assigning the terminal with one of a first set of resources or a second set of resources based on the channel condition, the first set of resources and the second set of resources being mutually exclusive, the first set of resources being for terminals served by the first cell, the second set of resources being a common set of resources for terminals served by any one of the first cell and the second cell.   
     
     
         17 . The computer-readable medium of  claim 16 , wherein the channel condition is a signal to interference plus noise ratio (SINR), and the terminal is assigned with the first set of resources when the SINR is greater than a threshold and is assigned the second set of resources when the SINR is less than the threshold. 
     
     
         18 . The computer-readable medium of  claim 16 , wherein the code for determining the channel condition:
 obtains pilot measurements for the terminal; and   determines an interference observed by the terminal from the second sell based on the obtained pilot measurements,   wherein the terminal is assigned the first set of resources when the determined interference is less than a threshold and is assigned the second set of resources when the determined interference is greater than the threshold.   
     
     
         19 . The computer-readable medium of  claim 16 , wherein the base station includes the first cell, the second cell, and a third cell, and the second set of resources are assigned to terminals served by any one of the first cell, the second cell, and the third cell. 
     
     
         20 . The computer-readable medium of  claim 16 , wherein the first set of resources and the second set of resources includes resources that hop based on a time period to different subbands, the first set of resources and the second set of resources including the same subbands at different time periods.