Data transmission method and device

A data transmission method, comprising:

• determining, by a transmitting end, a first precoding matrix and a second precoding matrix, the first precoding matrix being selected from a predefined first code book, the second precoding matrix being acquired on the basis of Channel State information (CSI);
• performing, by the transmitting end, precoding processing on a data stream in accordance with the first precoding matrix and the second precoding matrix;
• performing, by the transmitting end, precoding processing on a pilot signal in accordance with the second precoding matrix;
• and
• transmitting, by the transmitting end, the data stream and the pilot signal acquired after the precoding processing to a receiving end,
• wherein the transmitting end is a base station and the receiving end is a UE,
• wherein the step of determining, by the transmitting end, the first precoding matrix comprises:
• determining, by the transmitting end, dimensions of the first precoding matrix in accordance with a quantity of the data streams;
• selecting, by the transmitting end, a first code book which comprises precoding matrices each having dimensions same to the dimensions of the first precoding matrix;
• and
• with respect to each Resource Element (RE), selecting, by the transmitting end, one precoding matrix from the selected first code book as the first precoding matrix for the RE.