Channel measurement method and communications apparatus
A channel measurement method and a communications apparatus. The method includes: a terminal device receives precoded reference signals from a network device, where the precoded reference signals are obtained by precoding reference signals based on K angle vectors; and generates and sends first indication information, where the first indication information is used to indicate P weighting coefficients corresponding to P angle-delay pairs, the P weighting coefficients are determined based on the precoded reference signals, each of the P angle-delay pairs includes one angle vector and one delay vector corresponding to the angle vector, a delay vector corresponding to each angle vector is preconfigured, each angle vector and the delay vector corresponding to each angle vector are obtained through uplink channel measurement, and the P angle-delay pairs and the P weighting coefficients corresponding to the P angle-delay pairs are used to determine a precoding matrix.
1. An apparatus, comprising at least one processor, and one or more memories coupled to the at least one processor and storing programming instructions that configure the at least one processor to perform operations comprising:
receiving precoded reference signals, wherein the precoded reference signals are obtained by precoding reference signals based on K angle vectors but not based on a delay vector;
generating first indication information, wherein the first indication information is used to indicate P weighting coefficients corresponding to P angle-delay pairs, the P weighting coefficients are determined based on the precoded reference signals, each of the P angle-delay pairs comprises one of the K angle vectors and one of one or more delay vectors corresponding to the one angle vector, one or more delay vectors corresponding to each angle vector are preconfigured, and the P angle-delay pairs and the P weighting coefficients corresponding to the P angle-delay pairs are used to determine a precoding matrix, wherein both K and P are positive integers; and
sending the first indication information.
2. The apparatus according to claim 1 , wherein the at least one processor is further configured to:
receiving second indication information, wherein the second indication information is used to indicate the one or more delay vectors corresponding to each of the K angle vectors.
3. The apparatus according to claim 2 , wherein the second indication information comprises K bitmaps, a k th bitmap in the K bitmaps is used to indicate L k delay vectors that are in a delay vector set and that correspond to a k th angle vector in the K angle vectors, and the delay vector set comprises a plurality of delay vectors, wherein L k ≥1, and L k is an integer.
4. The apparatus according to claim 2 , wherein the second indication information comprises K indexes, a k th index in the K indexes is an index, in a delay vector set, of a combination of L k delay vectors corresponding to a k th angle vector in the K angle vectors, and the delay vector set comprises a plurality of delay vectors, wherein L k ≥1, and L k is an integer.
5. The apparatus according to claim 4 , wherein the second indication information is further used to indicate a quantity of delay vectors corresponding to each angle vector.
6. The apparatus according to claim 2 , wherein the second indication information is used to indicate an index of a combination of the P angle-delay pairs.
7. The apparatus according to claim 1 , wherein in the K angle vectors and one or more delay vectors corresponding to a first angle vector are the same as one or more delay vectors corresponding to a second angle vector, and the first angle vector and the second angle vector are any two angle vectors in the K angle vectors.
8. The apparatus according to claim 1 , wherein the K angle vectors and the one or more delay vectors corresponding to each angle vector are determined through uplink channel measurement.
9. The apparatus according to claim 1 , wherein the P weighting coefficients comprise one or more weighting coefficients fed back for each of the K angle vectors; and for the k th angle vector in the K angle vectors, the first indication information is used to indicate L k weighting coefficients, the L k weighting coefficients correspond to L k angle-delay pairs in the P angle-delay pairs, and each of the L k angle-delay pairs comprises the k th angle vector and one of the L k delay vectors corresponding to the k th angle vector, wherein L k ≥1, and L k is an integer.
10. The apparatus according to claim 1 , wherein the P weighting coefficients correspond to one receive antenna or one transport layer.
11. An apparatus, comprising at least one processor, and one or more memories coupled to the at least one processor and storing programming instructions that configure the at least one processor to perform operations comprising:
sending precoded reference signals, wherein the precoded reference signals are obtained by precoding reference signals based on K angle vectors but not based on a delay vector;
receiving first indication information, wherein the first indication information is used to indicate P weighting coefficients corresponding to P angle-delay pairs, the P weighting coefficients are determined based on the precoded reference signals, each of the P angle-delay pairs comprises one of the K angle vectors and one of one or more delay vectors corresponding to the one angle vector, one or more delay vectors corresponding to each angle vector are preconfigured, and the P angle-delay pairs and the P weighting coefficients corresponding to the P angle-delay pairs are used to determine a precoding matrix, wherein both K and P are positive integers; and
determining the precoding matrix based on the first indication information.
12. The apparatus according to claim 11 , wherein the at least one processor is further configured to:
sending second indication information, wherein the second indication information is used to indicate the one or more delay vectors corresponding to each of the K angle vectors.
13. The apparatus according to claim 12 , wherein the second indication information comprises K bitmaps, a k th bitmap in the K bitmaps is used to indicate L k delay vectors that are in a delay vector set and that correspond to a k th angle vector in the K angle vectors, and the delay vector set comprises a plurality of delay vectors, wherein L k ≥1, and L k is an integer.
14. The apparatus according to claim 12 , wherein the second indication information comprises K indexes, a k th index in the K indexes is an index, in a delay vector set, of a combination of L k delay vectors corresponding to a k th angle vector in the K angle vectors, and the delay vector set comprises a plurality of delay vectors, wherein L k ≥1, and L k is an integer.
15. The apparatus according to claim 14 , wherein the second indication information is further used to indicate a quantity of delay vectors corresponding to each angle vector.
16. The apparatus according to claim 12 , wherein the second indication information is used to indicate an index of a combination of the P angle-delay pairs.
17. The apparatus according to claim 11 , wherein in the K angle vectors, one or more delay vectors corresponding to a first angle vector are the same as one or more delay vectors corresponding to a second angle vector, and the first angle vector and the second angle vector are any two angle vectors in the K angle vectors.
18. The apparatus according to claim 11 , wherein the K angle vectors and the one or more delay vectors corresponding to each angle vector are determined through uplink channel measurement.
19. The apparatus according to claim 11 , wherein the P weighting coefficients comprise one or more weighting coefficients fed back for each of the K angle vectors; and for the k th angle vector in the K angle vectors, the first indication information is used to indicate L k weighting coefficients, the L k weighting coefficients correspond to L k angle-delay pairs in the P angle-delay pairs, and each of the L k angle-delay pairs comprises the k th angle vector and one of the L k delay vectors corresponding to the k th angle vector, wherein L k ≥1, and L k is an integer.
20. The apparatus according to claim 11 , wherein the P weighting coefficients correspond to one receive antenna or one transport layer.
21. A non-transitory computer-readable storage medium, wherein the non-transitory computer-readable storage medium stores a program or instructions that configure the at least one processor to perform operations comprising:
receiving precoded reference signals, wherein the precoded reference signals are obtained by precoding reference signals based on K angle vectors but not based on a delay vector;
generating first indication information, wherein the first indication information is used to indicate P weighting coefficients corresponding to P angle-delay pairs, the P weighting coefficients are determined based on the precoded reference signals, each of the P angle-delay pairs comprises one of the K angle vectors and one of one or more delay vectors corresponding to the one angle vector, one or more delay vectors corresponding to each angle vector are preconfigured, and the P angle-delay pairs and the P weighting coefficients corresponding to the P angle-delay pairs are used to determine a precoding matrix, wherein both K and P are positive integers; and
sending the first indication information.
22. The non-transitory computer-readable storage medium according to claim 21 , wherein the at least one processor is further configured to:
receiving second indication information, wherein the second indication information is used to indicate the one or more delay vectors corresponding to each of the K angle vectors.
23. The non-transitory computer-readable storage medium according to claim 21 , wherein in the K angle vectors and one or more delay vectors corresponding to a first angle vector are the same as one or more delay vectors corresponding to a second angle vector, and the first angle vector and the second angle vector are any two angle vectors in the K angle vectors.
24. A non-transitory computer-readable storage medium, wherein the non-transitory computer-readable storage medium stores a program or instructions that configure the at least one processor to perform operations comprising:
sending precoded reference signals, wherein the precoded reference signals are obtained by precoding reference signals based on K angle vectors but not based on a delay vector;
receiving first indication information, wherein the first indication information is used to indicate P weighting coefficients corresponding to P angle-delay pairs, the P weighting coefficients are determined based on the precoded reference signals, each of the P angle-delay pairs comprises one of the K angle vectors and one of one or more delay vectors corresponding to the one angle vector, one or more delay vectors corresponding to each angle vector are preconfigured, and the P angle-delay pairs and the P weighting coefficients corresponding to the P angle-delay pairs are used to determine a precoding matrix, wherein both K and P are positive integers; and
determining the precoding matrix based on the first indication information.
25. The non-transitory computer-readable storage medium according to claim 24 , wherein the at least one processor is further configured to:
sending second indication information, wherein the second indication information is used to indicate the one or more delay vectors corresponding to each of the K angle vectors.
26. The non-transitory computer-readable storage medium according to claim 24 , wherein in the K angle vectors, one or more delay vectors corresponding to a first angle vector are the same as one or more delay vectors corresponding to a second angle vector, and the first angle vector and the second angle vector are any two angle vectors in the K angle vectors.