Scalable process for indicating beam selection

Patent metadata

Field	Value
Publication number	US-12003307-B2
Application number	US-202217744373-A
Country	US
Kind code	B2
Filing date	May 13, 2022
Priority date	Aug 11, 2017
Publication date	Jun 4, 2024
Grant date	Jun 4, 2024

Abstract

Methods, systems, and devices for wireless communication are described. In wireless systems supporting multiple-input, multiple-output (MIMO) transmissions, devices may implement beam-forming to improve reliability of communications. A user equipment (UE) may select a set of beams, and corresponding beam indices, for communication based on reference signals received from a base station. The UE may determine values corresponding to each of the beam indices using a scalable set of tables. For example, the UE may select a subset of the tables based on the number of selected beams, and may determine the values based on these tables. In this way, the UE may efficiently store sets of tables for multiple different configurations. The UE may sum the corresponding values to obtain a combination index value, and may transmit the combination index value to the base station. The base station may determine the selected beams based on this combination index value.

First claim

What is claimed is:

1. A method for wireless communication, comprising:
receiving a combination index value that is a single integer uniquely indicating each beam of a set of selected beams for a user equipment (UE);
determining a greatest beam index for a first selected beam of the set of selected beams based at least in part on a current table and the combination index value; and
determining an additional beam index for each additional selected beam of the set of selected beams based at least in part on one or more additional tables and a respective update to the combination index value.

2. The method of claim 1 , further comprising:
transmitting a configuration of a codebook type for a codebook for channel state information reporting; and
transmitting a set of reference signals associated with one or more antenna ports, wherein the set of selected beams is based at least in part on the codebook, the set of reference signals, or both.

3. The method of claim 2 , wherein the greatest beam index and the additional beam index for each additional selected beam of the set of selected beams correspond to codeword indices of the codebook if the codebook type comprises a beam selection codebook or to antenna port indices if the codebook type comprises a port selection codebook.

4. The method of claim 3 , wherein:
each codeword of the beam selection codebook comprises a base sequence; and
the beam selection codebook comprises one or more sets of orthogonal base sequences.

5. The method of claim 1 , wherein the current table and the one or more additional tables are selected from a set of tables stored in a memory.

6. The method of claim 5 , wherein the set of tables comprises a first table and one or more subsequent tables, wherein a set of values stored in each of the one or more subsequent tables is based at least in part on a preceding set of values stored in a preceding table of the set of tables.

7. The method of claim 6 , wherein a value of the set of values is a sum of a preceding value of the set of values and a preceding table value of the preceding set of values, wherein the preceding value and the preceding table value are associated with a same beam index.

8. The method of claim 5 , further comprising:
selecting a first set of tables comprising a quantity of tables equal to a quantity of the set of selected beams, wherein determining the greatest beam index and the additional beam index for each additional selected beam is based at least in part on the first set of tables.

9. The method of claim 8 , further comprising:
receiving a second combination index value indicating a second set of selected beams for the UE, wherein a quantity of the second set of selected beams is greater than the quantity of the set of selected beams; and
selecting a second set of tables comprising a second quantity of tables equal to the quantity of the second set of selected beams, wherein the first set of tables is a subset of the second set of tables.

10. The method of claim 1 , wherein each additional beam index decreases in a descending order with respect to a previous additional beam index.

11. The method of claim 1 , wherein determining the greatest beam index for the first selected beam further comprises:
identifying a greatest value of the current table that is less than or equal to the combination index value, wherein the greatest beam index is set to an index corresponding to the identified greatest value; and
updating the combination index value by subtracting the identified greatest value from the combination index value.

12. The method of claim 11 , wherein determining the additional beam index for each additional selected beam further comprises:
identifying an additional greatest value of a next table of the one or more additional tables that is less than or equal to the updated combination index value, wherein the additional beam index is set to an additional index corresponding to the identified additional greatest value; and
updating the updated combination index value by subtracting the identified additional greatest value from the updated combination index value.

13. The method of claim 11 , wherein a smallest beam index for a last selected beam of the set of selected beams is equal to a last updated combination index value.

14. The method of claim 1 , wherein each table of a set of tables stored in memory comprises a same length and wherein a quantity of active entries for each table is based at least in part on a configured quantity of antenna ports, configured quantity of beams, or combination thereof.

15. The method of claim 1 , further comprising:
identifying a first configured quantity of antenna ports, configured quantity of beams, or combination thereof; and
selecting a first set of active entries for each table of a set of tables stored in memory based at least in part on the first configured quantity of antenna ports, configured quantity of beams, or combination thereof.

16. The method of claim 15 , further comprising:
identifying a second configured quantity of antenna ports, configured quantity of beams, or combination thereof, wherein the second configured quantity of antenna ports, configured quantity of beams, or combination thereof is greater than the first configured quantity of antenna ports, configured quantity of beams, or combination thereof; and
selecting a second set of active entries for each table of the set of tables based at least in part on the second configured quantity of antenna ports, configured quantity of beams, or combination thereof, wherein the first set of active entries is a subset of the second set of active entries.

17. The method of claim 1 , wherein each table of a set of tables stored in memory comprises a quantity of active entries based at least in part on a configured quantity of antenna ports transmitting channel state information reference signals (CSI-RS), a configured quantity of beams, or a combination thereof.

18. The method of claim 1 , further comprising:
calculating, for a beam index, a first sub-beam index corresponding to a first dimension and a second sub-beam index corresponding to a second dimension.

19. The method of claim 18 , wherein calculating the first sub-beam index comprises:
dividing the beam index by a size of the second dimension to obtain an intermediate value; and
rounding the intermediate value down to a nearest integer to obtain the first sub-beam index.

20. The method of claim 18 , wherein calculating the second sub-beam index comprises:
dividing the beam index by a size of the second dimension to obtain the second sub-beam index, wherein the second sub-beam index is a remainder of the division.

21. The method of claim 1 , further comprising:
identifying the set of selected beams based at least in part on a codebook and the greatest beam index and each additional beam index.

22. The method of claim 21 , wherein the codebook used for the identifying is based at least in part on a configuration of a quantity of antenna ports.

23. An apparatus for wireless communication, comprising:
means for receiving a combination index value that is a single integer uniquely indicating each beam of a set of selected beams for a user equipment (UE);
means for determining a greatest beam index for a first selected beam of the set of selected beams based at least in part on a current table and the combination index value; and
means for determining an additional bea

Assignees

• Qualcomm Inc

Inventors

• Hao Chenxi
• Wu Liangming
• Zhang Yu
• Xu Hao
• Wei Chao
• Chen Wanshi

Classifications

• H04L5/0048

  Allocation of pilot signals, i.e. of signals known to the receiver (allocation of control signalling H04L5/0053; use of control signalling H04L5/0091) · CPC title

• H04B7/0478

  Special codebook structures directed to feedback optimisation · CPC title

• H04B7/0695 Primary

  using beam selection · CPC title

• H04B7/0481

  using subset selection of codebooks · CPC title

• H04B7/048

  using three or more PMIs · CPC title