Inter-cell interference mitigation

Abstract

A method and Coordinated Multi-Point (CoMP) cell controller for reducing interference in a wireless communication network in which a first CoMP cell neighbors a second CoMP cell. The CoMP cell controller in the first CoMP cell gathers scheduling information from border sub-cells in the neighboring second CoMP cell in which transmissions to and from UEs cause inter-CoMP cell interference in at least one sub-cell in the first CoMP cell. The CoMP cell controller augments intra-CoMP cell scheduling information in the first CoMP cell with the scheduling information from the border sub-cells to create augmented scheduling information. The CoMP cell controller then utilizes the augmented scheduling information to schedule transmissions to and from UEs within the at least one sub-cell in the first CoMP cell to reduce the inter-CoMP cell interference.

1 . A method of reducing interference in a wireless communication network comprising a first Coordinated Multi-Point (CoMP) cell and a neighboring second CoMP cell, wherein each CoMP cell comprises a plurality of contiguous sub-cells and a CoMP cell controller operative to manage transmissions within the sub-cells of the CoMP cell to minimize intra-CoMP cell interference, the method comprising the steps of:
 gathering by the first CoMP cell controller, scheduling information for an external sub-cell in the neighboring second CoMP cell, said external sub-cell being located such that transmissions to and from user equipments (UEs) within the external sub-cell cause inter-CoMP cell interference in a given sub-cell in the first CoMP cell;   augmenting intra-CoMP cell scheduling information in the first CoMP cell with the scheduling information for the external sub-cell to create augmented scheduling information; and   utilizing the augmented scheduling information to schedule, by the first CoMP cell controller, transmissions to and from UEs within the given sub-cell in the first CoMP cell to reduce the inter-CoMP cell interference.   
     
     
         2 . The method according to  claim 1 , wherein the external sub-cell in the neighboring second CoMP cell is a border sub-cell adjacent to the given sub-cell in the first CoMP cell. 
     
     
         3 . The method according to  claim 1 , wherein the gathering step includes gathering the scheduling information through one of:
 a switched backbone network that connects the first CoMP cell controller with the second CoMP cell controller; and   a dedicated point-to-point connection between the first CoMP cell controller and the second CoMP cell controller.   
     
     
         4 . The method according to  claim 1 , wherein the gathering step includes gathering a list of the UEs selected to transmit or receive in the external sub-cell in a next transmit/receive phase. 
     
     
         5 . The method according to  claim 4 , wherein the augmented scheduling information also includes one or more of a transmit vector, a receive vector, a pre-coding matrix, channel matrices, or statistics of the Additive White Gaussian Noise (AWGN). 
     
     
         6 . A method of reducing interference in a wireless communication network comprising a first Coordinated Multi-Point (CoMP) cell and a neighboring second CoMP cell, wherein each CoMP cell comprises a plurality of contiguous sub-cells and a CoMP cell controller operative to manage transmissions within the sub-cells of the CoMP cell to minimize intra-CoMP cell interference, the method comprising the steps of:
 gathering by the first CoMP cell controller, scheduling information from a plurality of external sub-cells in the neighboring second CoMP cell, said external sub-cells being located such that transmissions to and from user equipments (UEs) within the external sub-cells cause inter-CoMP cell interference in at least one sub-cell in the first CoMP cell;   augmenting intra-CoMP cell scheduling information in the first CoMP cell with the scheduling information from the plurality of external sub-cells to create augmented scheduling information; and   utilizing the augmented scheduling information to schedule, by the first CoMP cell controller, transmissions to and from UEs within the at least one sub-cell in the first CoMP cell to reduce the inter-CoMP cell interference.   
     
     
         7 . The method according to  claim 6 , wherein the plurality of external sub-cells in the neighboring second CoMP cell are border sub-cells adjacent to the at least one sub-cell in the first CoMP cell. 
     
     
         8 . The method according to  claim 6 , wherein the gathering step includes gathering the scheduling information through one of:
 a switched backbone network that connects the first CoMP cell controller with the second CoMP cell controller; and   a dedicated point-to-point connection between the first CoMP cell controller and the second CoMP cell controller.   
     
     
         9 . The method according to  claim 6 , wherein the gathering step includes gathering a list of the UEs selected to transmit or receive in each of the external sub-cells in a next transmit/receive phase. 
     
     
         10 . The method according to  claim 9 , wherein the augmented scheduling information also includes one or more of a transmit vector, a receive vector, a pre-coding matrix, channel matrices, or statistics of the Additive White Gaussian Noise (AWGN). 
     
     
         11 . A method of reducing interference in a wireless communication network comprising a first Coordinated Multi-Point (CoMP) cell having a plurality of contiguous sub-cells and a first CoMP cell controller operative to manage transmissions within the sub-cells of the first CoMP cell to minimize intra-CoMP cell interference, a neighboring second CoMP cell having a plurality of contiguous sub-cells and a second CoMP cell controller operative to manage transmissions within the sub-cells of the second CoMP cell to minimize intra-CoMP cell interference, and a neighboring third CoMP cell that neighbors both the first and second CoMP cells and includes a plurality of contiguous sub-cells and a third CoMP cell controller operative to manage transmissions within the sub-cells of the third CoMP cell to minimize intra-CoMP cell interference, the method comprising the steps of:
 defining a hierarchical scheduling order in which the first CoMP cell controller schedules transmissions in the sub-cells of the first CoMP cell, and then the second CoMP cell controller schedules transmissions in the sub-cells of the second CoMP cell, and then the third CoMP cell controller schedules transmissions in the sub-cells of the third CoMP cell;   after the transmissions in the sub-cells of the first CoMP cell are scheduled, gathering by the second CoMP cell controller, scheduling information for sub-cells in the first CoMP cell that border the second CoMP cell;   augmenting intra-CoMP cell scheduling information in the second CoMP cell with the scheduling information from the bordering sub-cells in the first CoMP cell to create augmented scheduling information for the second CoMP cell; and   utilizing the augmented scheduling information for the second CoMP cell to schedule, by the second CoMP cell controller, transmissions to and from UEs within the sub-cells of the second CoMP cell to reduce the inter-CoMP cell interference with the first CoMP cell;   after the transmissions in the sub-cells of the second CoMP cell are scheduled, gathering by the third CoMP cell controller, scheduling information for sub-cells in the first and second CoMP cells that border the third CoMP cell;   augmenting intra-CoMP cell scheduling information in the third CoMP cell with the scheduling information from the bordering sub-cells in the first and second CoMP cells to create augmented scheduling information for the third CoMP cell; and   utilizing the augmented scheduling information for the third CoMP cell to schedule, by the third CoMP cell controller, transmissions to and from UEs within the sub-cells of the third CoMP cell to reduce the inter-CoMP cell interference with the first and second CoMP cells.   
     
     
         12 . A Coordinated Multi-Point (CoMP) cell controller in a first CoMP cell for reducing interference in a wireless communication network in which the first CoMP cell neighbors a second CoMP cell, wherein each CoMP cell comprises a plurality of contiguous sub-cells, the CoMP cell controller comprising:
 means for gathering scheduling information for an external sub-cell in the neighboring second CoMP cell, said external sub-cell being located such that transmissions to and from user equipments (UEs) within the external sub-cell cause inter-CoMP cell interference in a given sub-cell in the first CoMP cell;   means for augmenting intra-CoMP cell scheduling information in the first CoMP cell with the scheduling information for the external sub-cell to create augmented scheduling information; and   means for utilizing the augmented scheduling information to schedule transmissions to and from UEs within the given sub-cell in the first CoMP cell to reduce the inter-CoMP cell interference.   
     
     
         13 . The CoMP cell controller according to  claim 12 , wherein the external sub-cell in the neighboring second CoMP cell is a border sub-cell adjacent to the given sub-cell in the first CoMP cell. 
     
     
         14 . The CoMP cell controller according to  claim 12 , wherein the means for gathering includes an interface to one of:
 a switched backbone network that connects the first CoMP cell controller with the second CoMP cell controller; and   a dedicated point-to-point connection between the first CoMP cell controller and the second CoMP cell controller.   
     
     
         15 . The CoMP cell controller according to  claim 12 , wherein the scheduling information includes a list of the UEs selected to transmit or receive in the external sub-cell in a next transmit/receive phase. 
     
     
         16 . The CoMP cell controller according to  claim 15 , wherein the augmented scheduling information also includes one or more of a transmit vector, a receive vector, a pre-coding matrix, channel matrices, or statistics of the Additive White Gaussian Noise (AWGN). 
     
     
         17 . A Coordinated Multi-Point (CoMP) cell controller in a first CoMP cell for reducing interference in a wireless communication network in which the first CoMP cell neighbors a second CoMP cell, wherein each CoMP cell comprises a plurality of contiguous sub-cells, the CoMP cell controller comprising:
 means for gathering scheduling information from a plurality of external sub-cells in the neighboring second CoMP cell, said external sub-cells being located such that transmissions to and from user equipments (UEs) within the external sub-cells cause inter-CoMP cell interference in at least one sub-cell in the first CoMP cell;   means for augmenting intra-CoMP cell scheduling information in the first CoMP cell with the scheduling information from the plurality of external sub-cells to create augmented scheduling information; and   means for utilizing the augmented scheduling information to schedule transmissions to and from UEs within the at least one sub-cell in the first CoMP cell to reduce the inter-CoMP cell interference.   
     
     
         18 . The CoMP cell controller according to  claim 17 , wherein the plurality of external sub-cells in the neighboring second CoMP cell are border sub-cells adjacent to the at least one sub-cell in the first CoMP cell. 
     
     
         19 . The CoMP cell controller according to  claim 17 , wherein the means for gathering includes an interface to one of:
 a switched backbone network that connects the first CoMP cell controller with the second CoMP cell controller; and   a dedicated point-to-point connection between the first CoMP cell controller and the second CoMP cell controller.   
     
     
         20 . The CoMP cell controller according to  claim 17 , wherein the scheduling information includes a list of the UEs selected to transmit or receive in each of the external sub-cells in a next transmit/receive phase. 
     
     
         21 . The CoMP cell controller according to  claim 20 , wherein the augmented scheduling information also includes one or more of a transmit vector, a receive vector, a pre-coding matrix, channel matrices, or statistics of the Additive White Gaussian Noise (AWGN).