Mobile station apparatus, base station apparatus, MIMO system and data transmission method

摘要

A data transmission method includes, in the mobile station apparatus, selecting a PMI and an RI corresponding to an Hermitian transpose of a channel matrix indicative of channel characteristics and calculating a CQI from the PMI. The method further includes transmitting the PMI, the RI, and the CQI to the base station apparatus as feedback information. The method further includes, in the base station apparatus, calculating a first data rate of a case of performing SU-MIMO transmission based on the PMI transmitted from the mobile station apparatus as feedback and calculating a second data rate of a case of performing ZF MU-MIMO transmission based on the PMI. The method further includes selecting a transmission scheme corresponding to a higher data rate between the first and second data rates.

主权项

1. A mobile station apparatus in a Multi Input Multi Output (MIMO) system in which a base station apparatus switches between Single User MIMO (SU-MIMO) transmission and Zero Forcing MIMO (ZF MU-MIMO) transmission based on feedback information from the mobile station apparatus to perform data transmission, comprising:
a selecting section configured to select Rank Indicator (RI) and to select a Precoding Matrix Indicator (PMI) identifying a precoding matrix minimizing a chordal distance between the precoding matrix and an orthonormalized unitary matrix obtained from an Hermitian transpose of a channel matrix indicative of channel characteristics; a calculating section configured to calculate a Channel Quality Indicator (CQI) from the PMI; and a feedback section configured to transmit the PMI, the RI and the CQI to the base station apparatus as the feedback information.