IP Library › Granted Patent US 12,676,651

Granted Patent B2

US 12,676,651 · App. 18/653,371 · Granted Jul 7, 2026

Codebook subset design for uplink data transmission

Inventors: Sigen Ye (San Diego, CA); Haitong Sun (Cupertino, CA); Ankit Bhamri (Haar, DE); Wei Zeng (Saratoga, CA); Dawei Zhang (Saratoga, CA); Huaning Niu (San Jose, CA)

Assignee: Apple Inc.

H04B7/0478 H04B7/0417 H04B7/0639

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Quick Facts

Patent No.: US 12,676,651
App. No.: 18/653,371
Granted: Jul 7, 2026
Kind: B2

External Links

USPTO Patent Center↗ Full Patent PDF↗

Abstract

A user equipment (UE), a base station, a baseband processor or other network device can determine a codebook subset configuration of a plurality of multiple-input multiple-output (MIMO) layers for antenna ports of a codebook. The codebook subset configuration can include a nested structure based on a codebook configured for a fully-coherent UE, or a codebook configured for a partially-coherent UE. Fully-coherent precoders, a set of partially-coherent precoders or a set of non-coherent precoders can be configured in the codebook subset configuration to reduce a number of precoders from the partially-coherent precoders or the non-coherent precoders.

Claims (41)

1 . A baseband processor for a user equipment (UE), the baseband processor comprising:

one or more processors configured to, when executing instructions stored in a memory, perform operations comprising:

receiving, in radio resource control (RRC) signaling or a medium access control (MAC) control element (CE), an indication of a number of antenna groups, wherein each antenna group of the number of antenna groups comprises a set of coherent antennas, and wherein the sets of coherent antennas across antenna groups are non-coherent with one another;

determining a codebook subset configuration of a plurality of multiple-input multiple-output (MIMO) layers based on a codebook configured for the UE and the indicated number of antenna groups, wherein the codebook comprises at least one of: a set of fully-coherent precoders, a set of partially-coherent precoders, or a set of non-coherent precoders; and

providing data to a radio frequency (RF) interface for transmission based on the codebook subset configuration.

2 . The baseband processor of claim 1 , wherein the codebook is configured for a fully-coherent UE, or wherein the codebook is configured for a partially-coherent UE.

3 . The baseband processor of claim 2 , wherein a nested precoder structure of the codebook configured for the fully-coherent UE comprises fully-coherent precoders and one or more precoders of: the set of partially-coherent precoders or the set of non-coherent precoders, that use a subset of antenna ports compared to the set of fully-coherent precoders.

4 . The baseband processor of claim 2 , wherein a nested precoder structure of the codebook configured for the partially-coherent UE comprises a first set of partially-coherent precoders and one or more of: a second set of partially-coherent precoders or the set of non-coherent precoders that use a subset of antenna ports compared to the first set of partially-coherent precoders with a same rank, wherein the first set of partially-coherent precoders is associated with a different number of antenna groups than the second set of partially-coherent precoders.

5 . The baseband processor of claim 1 , wherein the operations further comprise:

receiving a downlink control information (DCI) indicating one or more precoders to use from the set of fully-coherent precoders or the set of partially-coherent precoders according to the codebook subset configuration.

6 . The baseband processor of claim 5 , wherein the operations further comprise:

reducing a number of precoders in the codebook subset configuration relative to the codebook configured for the UE based on whether a pair of cross-polarized antennas is both used or not used at a same time in each precoder of the codebook configured for the UE.

7 . The baseband processor of claim 1 , wherein the operations further comprise:

configuring the set of fully-coherent precoders only based on a UE capability; or

configuring the set of fully-coherent precoders and at least one of: a subset of the set of partially-coherent precoders or a subset of the set of non-coherent precoders that only use a subset of antenna ports.

8 . The baseband processor of claim 1 , wherein the operations further comprise:

configuring the codebook for a partially-coherent UE with at least one of: a subset of partially-coherent precoders or a subset of non-coherent precoders that use a subset of antenna ports within at least one antenna group of the UE.

9 . The baseband processor of claim 1 , wherein the codebook subset configuration includes:

an entirety of the set of non-coherent precoders;

a subset of the set of non-coherent precoders to further reduce the number of precoders; or

a plurality of non-coherent precoders associated with predefined transmitter precoder matrix indicator (TPMI) indices.

10 . The baseband processor of claim 1 , wherein the number of antenna groups comprises an Ng value, and wherein the RRC signaling or the MAC CE includes an indication to switch to the Ng value from a previous Ng value.

11 . A baseband processor for a base station, the baseband processor configured to, when executing instructions stored in a memory, perform operations comprising:

providing, for transmission via radio frequency (RF) circuitry, an indication of a number of antenna groups for a user equipment (UE), wherein the indication is included in radio resource control (RRC) signaling or a medium access control (MAC) control element (CE), wherein each antenna group of the number of antenna groups comprises a set of coherent antennas, and wherein the sets of coherent antennas across antenna groups are non-coherent with one another;

generating a codebook subset configuration of a plurality of multiple-input multiple-output (MIMO) layers for a codebook configured for the UE based on the indicated number of antenna groups for the UE; and

communicating, via the RF circuitry, with the UE based on the codebook subset configuration.

12 . The baseband processor of claim 11 , wherein the codebook subset configuration is generated with the set of fully-coherent precoders or the set of partially-coherent precoders based on a UE capability information, and wherein the plurality of MIMO layers comprises up to 8 MIMO layers.

13 . The baseband processor of claim 11 , wherein the codebook subset configuration configures fully-coherent precoders with at least one of: a subset of partial-coherent precoders, or a subset of non-coherent precoders, that use a subset of antenna ports relative to the fully-coherent precoders, in response to receiving UE capability information indicating support for the fully-coherent precoders.

14 . The baseband processor of claim 11 , wherein the codebook subset configuration configures only partially-coherent precoders or the partially-coherent precoders with at least one of: a subset of partially-coherent precoders, or a subset of non-coherent precoders, that only use a subset of antenna ports in at least one antenna group of a number of antenna groups, in response to receiving UE capability information indicating support for the partially-coherent precoders.

15 . The baseband processor of claim 10 , wherein different Ng values are configured at different times.

16 . A method of a user equipment (UE) comprising:

determining a codebook subset configuration of a plurality of multiple-input multiple-output (MIMO) layers based on whether a pair of cross-polarized antennas are both used or not used at a same time in each precoder of a codebook configured for the UE, wherein the codebook comprises at least one of: a set of fully-coherent precoders, a set of partially-coherent precoders, or a set of non-coherent precoders, and wherein the codebook subset configuration comprises a reduced number of precoders from the set of partially-coherent precoders or the set of non-coherent precoders; and

transmitting data based on the codebook subset configuration.

17 . The method of claim 16 , further comprising:

including a subset of non-coherent precoders in the codebook configured for a partially-coherent UE, wherein the codebook subset configuration configures use of all non-coherent precoders except for ones using every antenna port within an antenna group.

18 . The method of claim 16 , further comprising:

19 . The method of claim 16 , further comprising:

providing UE capability information indicating a support for a number of antenna groups of partially-coherent precoders or fully-coherent precoders; and

receiving an indication of precoders to use in the codebook configured for the UE based on the codebook subset configuration and on the UE capability information, wherein the UE comprises a fully-coherent UE or a partially-coherent UE.

20 . The method of claim 16 , wherein the codebook subset configuration includes one or more partially-coherent precoders and one or more fully-coherent precoders, and wherein each of the one or more partially-coherent precoders uses a reduced number of antenna ports relative to each of the one or more fully-coherent precoders.