Patent ID: 8391876

Claim:
A central base station for interference management in a distributed antenna system which includes a plurality of users and a plurality of remote radio heads, the central base station comprising: a processor; a memory; a frequency partition module configured to divide the remote radio heads into clusters and allocate a frequency band to each cluster so that remote radio heads in each cluster have the same frequency band, wherein multiple clusters use the same frequency band and groups of clusters are formed, each group of clusters using the same frequency band; a joint scheduler configured, for each group, to activate at most two clusters at any given time and deactivate remaining clusters in the group, one of the at most two activated clusters being a serving cluster of the group, and to associate one or more users with the serving cluster in the group; and an interference alignment module configured to apply downlink interference alignment between the at most two activated clusters in each group to align transmit directions of all interferences between the at most two activated clusters; wherein each group has one serving cluster and at most one interfering cluster, the serving cluster having first strongest Reference Signal Received Power in the group and the at most one interfering cluster having the second strongest Reference Signal Received Power in the group.