Feedback and rate adaptation for MIMO transmission in a time division duplexed (TDD) communication system

An apparatus for wireless communication, comprising:

• means for receiving a first reference signal from a transmitter at a receiver;
• means for selecting a first precoding matrix from a codebook of precoding matrices based on the beamforming matrix based on the first reference signal;
• means for determining channel quality indicator (CQI) or modulation and coding scheme (MCS) information based on the first precoding matrix;
• means for sending the CQI or MCS information to the transmitter;
• means for sending a second reference signal to the transmitter;
• and
• means for receiving, based on the CQI or MCS information and the first precoding matrix, a multiple-input multiple-output (MIMO) transmission sent by the transmitter based on the CQI or MCS information and a second precoding matrix, the second precoding matrix being selected by the transmitter based on the second reference signal.

A computer program product, comprising:

• a non-transitory computer-readable medium comprising:
• code for causing at least one computer to receive a first reference signal from a transmitter at a receiver,
• code for causing at least one computer to select a first precoding matrix from a codebook of precoding matrices based on the beamforming matrix based on the first reference signal,
• code for causing the at least one computer to determine channel quality indicator (CQI) or modulation and coding scheme (MCS) information based on the first precoding matrix,
• code for causing the at least one computer to send the CQI or MCS information to the transmitter,
• code for causing the at least one computer to send a second reference signal to the transmitter, and
• code for causing the at least one computer to receive, based on the CQI or MCS information and the first precoding matrix, a multiple-input multiple-output (MIMO) transmission sent by the transmitter based on the CQI or MCS information and a second precoding matrix, the second precoding matrix being selected by the transmitter based on the second reference signal.