Patent attributes
In a case where a second reference signal for a second communication system is transmitted in addition to a first reference signal for a first communication system, resources that affect a reception apparatus compatible only with the first communication system can be minimized, and the throughput can be prevented from being deteriorated. As resources for a reference signal CSI-RS for LTE-A, last half symbols in a time direction of a resource unit RB/Sub-frame defined in a frequency-time domain are used, and the CSI-RS is allocated in a position up to the last two symbols or in the last symbol, or the like, of a particular RB/Sub-frame and transmitted when a reference signal 4RS for LTE is transmitted to a reception apparatus in addition to transmitting CSI-RS for LTE-A. The reception apparatus receives CSI-RS allocated in the last half symbol of RB/Sub-frame on the basis of CSI-RS allocation information, measures channel quality such as CQI, PMI or M by using this CSI-RS, and transmits and reports feedback information containing channel quality information to a transmission apparatus.
