Precoding matrix indication method, communications apparatus, and storage medium

A communications apparatus, wherein the communications apparatus comprises:

• at least one processor;
• and
• one or more memories coupled to the at least one processor and storing programming instructions for execution by the at least one processor to cause the apparatus to:
• receive third indication information, wherein the third indication information indicates W2(1), W2(2), . . . , W2(K), wherein W(k) is a preceding matrix in a kth frequency-domain unit, W(k) satisfies W(k)=W1×W2(k), W1 is an Nt ×L matrix, W2(k) is an L×R matrix, 0<k≤K, and K is a quantity of frequency-domain units, and L and R are integers;
• the third indication information comprises second indication information and first indication information;
• the second indication information indicates Pi,j elements in a vector Di,j, wherein the vector Di,j and a matrix Fi,j satisfy Vi,j=Fi,j×Di,j, the vector Vi,j corresponds to W2(1)(i,j), W2(2)(i,j), . . . , and W2(K)(i,j), W2(k)(i,j) is a complex number in an ith row and a jth column of the matrix W2(k), and Fi,j is a K×Pi,j matrix, wherein 0<i≤L, 0<j≤R, and Pi,j<K;
• and
• the first indication information indicates a quantity of the elements indicated by the second indication information;
• and
• send downlink data based on t third indication information.

A non-transitory computer-readable storage medium coupled to at least one processor and storing programming instructions for execution by the at least one processor, wherein the programming instructions instruct the at least one processor to:

• receive third indication information, wherein the third indication information indicates W2(1), W2(2), . . . , and W2(K), wherein W(K) is a precoding matrix in a kth frequency- domain unit, W(k) satisfies W(k)=W1×W2(k), W1 is an Nt×L matrix, W2(k) is an L×R matrix, 0<k≤K, and K is a quantity of frequency-domain units, and L and R are integers;
• the third indication information comprises second indication information and first indication information;
• the second indication information indicates Pi,j elements in a vector Di,j, wherein the vector Di,j and a matrix Fi,j satisfy Vi,j=Fi,j×Di,j, the vector Vi,j corresponds to W2(1)(i,j), W2(2)(i,j), . . . , and W2(k), and Fi,j is a K×Pi,j matrix, wherein 0<i≤L, 0<j≤R, and Pi,jK;
• and
• the first indication information indicates a quantity of the elements indicated by the second indication information;
• and
• send downlink data based on the third indication information.