Downlink limited-feedback interference alignment with constant amplitude codebooks and rate balance scheduling

摘要

Downlink interference alignment schemes are described which provide, among other things, channel state information (CSI) from the UEs using a constant amplitude codebook. By providing only phase information associated the UEs' channel states, instead of both amplitude and phase information, fewer bits can be used to inform the BSs of the UEs effective channels, thereby reducing the bandwidth requirements associated with the transmission of CSI by UEs for downlink interference alignment purposes. According to other embodiments, feedback information can be used to perform user selection scheduling and rate balancing.

主权项

1. A method for transmitting downlink signals in a radio communication system comprising:
receiving, at a base station, encoded feedback information associated with channels between the base station and a plurality of user equipments, wherein the encoded feedback information is encoded using a constant amplitude codebook; and transmitting, by the base station, downlink signals toward the plurality of user equipments in a manner which is based on a downlink interference alignment scheme that uses the encoded feedback information, wherein the downlink interference alignment scheme involves limiting interfering signals from transmitter-receiver pairs in a group of transceiver-receiver pairs associated with the base station and the plurality of user equipments by relegating the interfering signals to a smaller signal dimension relative to desired signals.