Multi-carrier communications with group-based subcarrier allocation
A method and apparatus for subcarrier selection for systems is described. In one embodiment, the system employs orthogonal frequency division multiple access (OFDMA). In one embodiment, a method for subcarrier selection comprises a subscriber measuring channel and interference information for subcarriers based on pilot symbols received from a base station, the subscriber selecting a set of candidate subcarriers, providing feedback information on the set of candidate subcarriers to the base station, and receiving an indication of subcarriers of the set of subcarriers selected by the base station for use by the subscriber.
1. A cellular network using OFDMA channels for communication, the network comprising:
a plurality of cells, each of said cells have a plurality of sectors;
one or more groups of clusters of subcarriers, wherein at least one subcarrier is partitioned into each of said clusters;
a base station in each of the plurality of cells, wherein each base station allocates said one or more groups of clusters of subcarriers to one or more subscribers in at least one of said sectors, wherein said allocation is based on priority assigned to each group of said groups of clusters of subcarriers, said priority being based on the cell of the plurality of cells in which said each base station resides, where each group of clusters of subcarriers is assigned a different priority for use in different cells.
2. The network defined in claim 1 wherein priority orders are designed to enable selective assignment of a cluster of subcarriers to avoid interference while reducing a probability of causing interference with existing assignments of one or more clusters of subcarriers.
3. A method for minimizing inter-cell interference in a cellular network using OFDMA channels for communication, said method comprising:
partitioning each of a plurality of cells into a plurality of sectors;
partitioning subcarriers into a plurality of groups of one or more clusters of subcarriers; and
allocating, at a base station, at least one group in said plurality of groups of one or more clusters of subcarriers to one or more subscribers in at least one of said sectors, said allocating being based on the location of the cell in which said base station is located with respect to other cells in said plurality of cells.
4. The method of claim 3 wherein a first portion of said sectors is allocated a first portion of available clusters of subcarriers and a second portion of said sectors is allocated a second portion of available clusters of subcarriers in said plurality of groups of one or more clusters of subcarriers.
5. The method of claim 4 wherein said first portion of said sectors is one half of said plurality of sectors.
6. The method of claim 4 wherein said first portion of available clusters of subcarriers is one half of said available clusters.
7. The method of claim 4 further comprising:
assigning, at said base station, priority to each of said plurality of groups to be allocated as traffic load increases, wherein the priority is based on the interference the cell in which said base station is located causes to other cells in said plurality of cells and the interference said cell in which said base station is located receives from other cells in said plurality of cells.
8. A cellular network using OFDMA channels for communication, said network comprising:
a plurality of cells, each cell having a plurality of sectors;
a plurality of groups of one or more clusters of subcarriers; and
a base station in each of said plurality of cells, wherein said base station allocates at least one group in said plurality of groups of one or more clusters of subcarriers subscribers in at least one of said sectors, said allocating being based on a location of the cell in which said base station resides with respect to other cells in said plurality of cells.
9. The network of claim 8 wherein said base station allocates a first portion of available clusters of subcarriers in said plurality of groups of one or more clusters of subcarriers to a first portion of said sectors and further allocates a second portion of available clusters of subcarriers in said plurality of groups of one or more clusters of subcarriers to a second portion of said sectors.
10. The network of claim 9 wherein said first portion of said sectors is one half of said plurality of sectors.
11. The network of claim 9 wherein said first portion of available clusters of subcarriers is one half of said available clusters.
12. The network of claim 9 said base station prioritizes each of said plurality of groups in an order to be allocated as traffic load increases, wherein the priority is based on the interference caused by the cell in which said base station is located to other cells in said plurality of cells and the interference received from other cells in said plurality of cells by said cell in which said base station is located.