PROVIDING FEEDBACK FOR MULTIPLE DOWNLINK MULTIPLE-INPUT- MULTIPLE-OUTPUT (MIMO) STREAMS

摘要

A wireless-transmit-and-receiving unit (WTRU) supports receiving information via a plurality of multiple-input-multiple-output (MIMO) streams by providing a low-rank feedback report to a base station. The WTRU selects a preferred HS-PDSCH transmission rank, from a subset of ranks that the WTRU supports. The subset includes ranks that are lower than the maximum HS-PDSCH transmission rank supported by the WTRU. For example, for a WTRU that supports rank-4 reception, the subset may include rank-1 and rank-2. The WTRU generates the low-rank feedback report based on the preferred rank, and transmits the report to the base station.