Precoding information obtaining method, and device

A precoding information obtaining method, comprising:

• receiving, by a terminal device in any one of W resource block RB groups, a precoded pilot group sent by a network device, wherein the precoded pilot group is obtained by precoding, by the network device by using any one of N sub-codebooks, a pilot group comprising K pilots, the sub-codebooks are subsets of a precoding codebook, the precoding codebook comprises M precoding vectors, each sub-codebook comprises K precoding vectors, K is a positive integer, N and M are integers greater than 1, M is greater than K, and W is a positive integer;
• and
• feeding back, by the terminal device, precoding information of the any precoded pilot group to the network device according to the any received precoded pilot group.

A device, wherein the device is a terminal device and comprises:

• a receiving module, configured to receive, in any one of W resource block RB groups, a precoded pilot group sent by a network device, wherein the precoded pilot group is obtained by precoding, by the network device by using any one of N sub-codebooks, a pilot group comprising K pilots, the sub-codebooks are subsets of a precoding codebook, the precoding codebook comprises M precoding vectors, each sub-codebook comprises K precoding vectors, K is a positive integer, N and M are integers greater than 1, M is greater than K, and W is a positive integer;
• and
• a sending module, configured to feed back precoding information of the any precoded pilot group to the network device according to the any received precoded pilot group.

A device, wherein the device is a terminal device and comprises:

• a receiver, configured to receive, in any one of W resource block RB groups, a precoded pilot group sent by a network device, wherein the precoded pilot group is obtained by precoding, by the network device by using any one of N sub-codebooks, a pilot group comprising K pilots, the sub-codebooks are subsets of a precoding codebook, the precoding codebook comprises M precoding vectors, each sub-codebook comprises K precoding vectors, K is a positive integer, N and M are integers greater than 1, M is greater than K, and W is a positive integer;
• and
• a transmitter, configured to feed back precoding information of the any precoded pilot group to the network device according to the any received precoded pilot group.