Beamforming-Based Transmission Method and Apparatus

A beam forming-based transmission method by a base station, the method comprising:

• obtaining first feedback information of a terminal, wherein the first feedback information of the terminal comprises m first beamforming codewords selected by the terminal;
• determining m second beamforming codewords of the base station based on the m first beamforming codewords selected by the terminal;
• performing beamforming for an antenna group in each polarization direction based on the m second beamforming codewords of the base station;
• generating p antenna ports, wherein antennas in the antenna group in the polarization direction have a same polarization direction, and p is equal to m or p is equal to 2 m;
• and
• sending a second reference signal to the terminal on the p antenna ports.

A beam forming-based transmission method by a terminal, the method comprising;

• obtaining, from a base station, a first reference signal and a message indicating a quantity M of beamforming vectors needing to be reported by the terminal wherein the first reference signal is received from L antenna ports of the base station, wherein M and L each are an integer greater than zero, and wherein L>M;
• estimating downlink channel states on the L antenna ports based on the first reference signal;
• selecting m antenna ports from the 1, antenna ports as beamforming vectors needing to be reported based on the downlink channel states and the quantity M of beamforming vectors needing to be reported;
• calculating a channel quality indicator, wherein m≤M;
• and
• feeding back to the base station sequence numbers of the m antenna ports, the channel quality indicator, and ranks of the downlink channel states.

A beam forming-based transmission device comprising:

• a memory storing information;
• a transceiver configured to obtain, from a base station, a first reference signal and a message indicating a quantity M of beamforming vectors needing to be reported wherein the first reference signal is received from N dual-polarized antenna ports of the base station, and wherein M and N each are an integer greater than zero;
• and
• a processor coupled to the memory and the transceiver and configured to read the information to:
• estimate downlink channel states on the N dual-polarized antenna ports based on the first reference signal obtained by the transceiver;
• and
• select m first beamforming codewords based on the downlink channel states and the quantity M of beamforming vectors needing to be reported, where m≤M, and
• wherein the transceiver is further configured to feed back, to the base station, the m first beamforming codewords selected by the processor and ranks of the downlink channel states.