Precoding weight generation method, mobile station apparatus and base station apparatus

摘要

To increase a data rate (spectral efficiency) of the entire system also in the case of dynamically switching between SU-MIMO transmission and MU-MIMO transmission, it is a feature that a mobile station apparatus (10) selects a PMI associated with a precoding matrix including matrix elements corresponding to a stream that most approximates a channel matrix indicative of a channel state in a channel transmission path to transmit to a base station apparatus (20) as feedback, and that the base station apparatus (20) extracts the matrix elements corresponding to the stream that most approximates the channel state in the channel transmission path from the precoding matrix associated with the PMI transmitted from the mobile station apparatus (10) as feedback, and based on the extracted matrix elements, generates precoding weights.

主权项

1. A precoding weight generation method of generating precoding weights by which transmission data is multiplied, the transmission data being transmitted from a base station apparatus to a mobile station apparatus with a plurality of streams by using Multi Input Multi Output (MIMO) transmission, the method comprising:
in the mobile station apparatus, calculating a throughput expectation value for each of the plurality of streams based on a channel state of each of the plurality of streams, performing the calculating for each of predetermined precoding matrices, and selecting a precoding matrix indicator (PMI) associated with a precoding matrix of the predetermined precoding matrices, the precoding matrix including matrix elements that maximize a throughput expectation value in the calculated throughput expectation values; transmitting the selected PMI to the base station apparatus as channel information; in the base station apparatus, extracting the matrix elements that maximize the throughput expectation value from the precoding matrix associated with the PMI transmitted from the mobile station apparatus as feedback; and generating precoding weights based on the extracted matrix elements.