Methods and nodes for communicating using 3 transmit (TX) partially-coherent codebooks and 3 TX fully coherent codebooks

Abstract

There is provided a method performed by a user equipment (UE) having 3 antenna ports, for performing uplink (UL) codebook-based transmission using one or more 3 Transmit (Tx) partially coherent (PC) precoders from a PC codebook subset. The method comprises: transmitting a reference signal to a network node; receiving an indication of a precoder based on the transmitted reference signal; and transmitting data based on the indicated precoder, wherein the indicated precoder is determined based on the 3 antenna ports, the 3 antenna ports being divided into two antenna-port groups, wherein: a. a first antenna-port group has two antenna ports, and a second antenna port group has one antenna port, b. the two antenna-port groups are mutually non-coherent, and c. the antenna ports in the first antenna port group are fully-coherent. A UE for implementing this method is also provided.

Description

Methods and nodes for communicating using 3 Transmit (Tx) partially-coherent codebooks and 3 Tx Fully coherent codebooks RELATED APPLICATIONS

[0001] This application claims the benefits of priority of U.S. Provisional Patent Application No.63 / 588,528, entitled “Codebook design for 3 Tx partially-coherent UEs” and filed at the United States Patent and Trademark Office (USPTO) on October 6, 2023, and of U.S. Provisional Patent Application No.63 / 543,311, entitled “codebook design for 3 Tx fully- coherent UEs” and filed at the USPTO on October 10, 2023, both of which are hereby incorporated by reference in its entirety. TECHNICAL FIELD

[0002] The present disclosure relates to wireless network communications using codebooks for 3 transmit-antenna Partially Coherent (PC) UEs and 3 transmit-antenna fully- coherent (FC) UEs. BACKGROUND

[0003] Physical Uplink Shared Channel (PUSCH)

[0004] PUSCH scheduling with Configured Grant (CG)

[0005] New Radio (NR) supports two schemes for scheduling PUSCH transmissions without a DG:

[0006] CG type 1: PUSCH transmission parameters, periodicity, and offset is Radio Resource Control (RRC) configured and PUSCH is periodically transmitted.

[0007] CG type 2: PUSCH periodicity and offset is RRC configured but PUSCH transmission is activated / deactivated using dynamic signaling.

[0008] With CG type 1, PUSCH transmission parameters are RRC configured (see ConfiguredGrantConfig IE in 3GPP TS 38.331). The PUSCH periodicity and offset are also RRC configured, which allows the network (NW) to control when the User Equipment (UE) should transmit PUSCH.

[0009] With CG type 2, the PUSCH periodicity and offset are RRC configured. Activation / deactivation of the PUSCH transmission is via Physical Downlink Control Channel (PDCCH) scrambled by Configured Scheduling-Radio Network Temporary Identifier (CS- RNTI) and PUSCH transmission parameters are signaled via Downlink Control Information (DCI) in the PDCCH (e.g., DCI Format 0_0 or DCI Format 0_1).

[0010] PUSCH precoding

[0011] For PUSCH scheduled by a dynamic grant (DG), the NW configures in RRC the transmission scheme by the higher-layer parameter txConfig in PUSCH-Config Information Element (IE) (see below excerpt from 3GPP TS 38.331 version 17.2.0). Two transmission schemes are supported: Codebook (CB)-based precoding and Non CB (NCB)-based precoding. CB-based precoding can be used for non-calibrated UEs and / or for Frequency Division duplex (FDD) (i.e., UL / DL reciprocity does not need to hold). NCB-based precoding, on the other hand, relies on UL / DL reciprocity and is, hence, intended for Time Division Duplexing (TDD). PUSCH-Config ::= SEQUENCE { … txConfig ENUMERATED {codebook, nonCodebook} OPTIONAL, -- Need S … codebookSubset ENUMERATED {fullyAndPartialAndNonCoherent, partialAndNonCoherent,nonCoherent} OPTIONAL, -- Cond codebookBased maxRank INTEGER (1..4) OPTIONAL, -- Cond codebookBased …

[0013] CB-based PUSCH is enabled if the higher-layer parameter txConfig in PUSCH- Config IE is set to codebook. For PUSCH scheduled by a DG, CB-based PUSCH transmission can be summarized in the following steps, which are illustrated in Fig.1.

[0014] In a first step, the UE transmits Sounding Reference Signal (SRS), which is configured in an SRS resource set with higher-layer parameter usage in SRS-Config IE set to codebook. Up to two SRS resources (for testing up to two virtualizations) each with up to four SRS ports, can be configured in the SRS resource set. As such, the UE can transmit up to 2 SRS resources to the gNB.

[0015] In a second step, based on the received SRS resource(s), the gNB selects a Transmit Precoding Matrix indicator (TPMI) value, which specifies a (PUSCH) rank and a precoding matrix, and indicates the selected TPMI to the UE via the DCI field “Precoding information and number of layers”. Demodulation Reference Signal (DMRS) port(s) associated with the layer(s) are also indicated in the DCI via the field “Antenna ports”. If two SRS resources are configured in the SRS resource set (or if more than one SRS resources are received by the gNB), the gNB also indicates the selected SRS resource via the 1-bit SRS Resource Indicator (SRI) field in the DCI scheduling the PUSCH transmission. In other words, the SRI indicates which SRS resource to map the PUSCH to. If only one SRS resource is configured in the SRS resource set, the SRI field is not present in the DCI.

[0016] In a third step, the UE transmits PUSCH according to the received indication. For example, the indicated number of PUSCH layers (and associated DMRS ports) are mapped to the antenna ports corresponding to the SRS ports in the indicated SRS resource via the indicated precoding matrix.

[0017] The rank must be less than a maximum number of layers, which is configured by the higher-layer parameter maxRank in PUSCH-Config IE (see above excerpt from 3GPP TS 38.331 version17.2.0), based on reported UE capability.

[0018] The precoder is selected from a codebook subset, which is configured via the higher-layer parameter codebookSubset in PUSCH-Config IE (see above excerpt from 3GPP TS 38.331 version 17.2.0), based on reported UE capability, and is one of fully coherent, partially coherent, or non-coherent.

[0019] Unless UL full-power mode 1 is configured, the number of bits in DCI used for indicating the number of layers (if transform precoding is enabled, the number of layers is limited to 1) and the precoder (the precoder candidates are tabulated in Clause 6.3.1.5 of 3GPP TS 38.211) is determined as follows:

[0020] - 4, 5, or 6 bits if the number of antenna ports is 4, if transform precoding is disabled, and if the higher-layer parameter maxRank in PUSCH-Config IE is set to 2, 3, or 4 (see Table 7.3.1.1.2-2 of 3GPP TS 38.212 version 17.2.0).

[0021] - 2, 4, or 5 bits if the number of antenna ports is 4, if transform precoding is disabled or enabled, and if the higher-layer parameter maxRank in PUSCH-Config IE is set to 1 (see Table 7.3.1.1.2-3 of 3GPP TS 38.212 version 17.2.0).

[0022] - 2 or 4 bits if the number of antenna ports is 2, if transform precoding is disabled, and if the higher-layer parameter maxRank in PUSCH-Config IE is set to 2 (see Table 7.3.1.1.2- 4 of 3GPP TS 38.212 version 17.2.0).

[0023] - 1 or 3 bits if the number of antenna ports is 2, if transform precoding is disabled or enabled, and if the higher-layer parameter maxRank in PUSCH-Config IE is set to 1 (see Table 7.3.1.1.2-5 of 3GPP TS 38.212 version 17.2.0).

[0024] - 0 bits if 1 antenna port is used for PUSCH transmission. SUMMARY

[0025] There currently exist certain challenge(s). Legacy NR (i.e., up to Rel-18) specification supports UL transmission for 1, 2, 4, or 8 (in NR Rel-18) transmit (Tx) chains. In practice, however, commercial UEs (e.g., smartphones) are restricted to 1-2 Tx chains due to factors such as power amplifier (PA) cost and power consumption, and the limited size ofcommercial smartphones, which limits UL throughput. In other words, UEs with 4 (or more) Tx chains may not appear on the market anytime soon.

[0026] Recently, customer-premises equipment (CPE) devices (targeting FWA deployments) supporting 3 Tx chains (e.g., MediaTek T830 CPE platform) have started to appear on the market. During trials, record-setting UL throughputs have been achieved for such devices via UL Carrier Aggregation (CA), where 1 Tx on a 2.1 GHz FDD band was combined with 2 Tx on a 3.5GHz TDD band. To support such devices, during the RAN#101 plenary meeting, it was agreed that there will be a NR Rel-18 RAN4 work item on supporting 3 Tx UL transmission over two bands (see RP-231719). However, 3 Tx UL transmission in a same band / cell will not be supported in NR Rel-18. For this reason, 3 Tx UL transmission has been proposed as a potential Multiple Input Multiple Output (MIMO) enhancement for NR Rel-19 (RP-232612), with strong support from, in particular, UE vendors and operators. Legacy NR (i.e., up to Rel-18), does not support 3 Tx UL transmission in the same cell. For example, as an SRS resource or a PUSCH transmission can only be configured with 1, 2, 4, or 8 SRS ports, a TPMI field can only indicate a precoder over 1, 2, 4 or 8 SRS ports.

[0027] Hence, codebook design for 3 Tx UL is an open issue. Certain aspects of the disclosure and their embodiments may provide solutions to these or other challenges.

[0028] The codebook configuration depends on the coherency capability of the UE, where the UE can either be fully, partially or non-coherent. In this disclosure, precoder design for a 3 Tx PC codebook is proposed, which considers different possible antenna configurations of how 3 Tx can be implemented in a UE. A precoder design for a 3-Tx FC codebook is also proposed.

[0029] In one aspect, there is provided a method in a UE for transmitting data, in which the UE is configured with 3 transmit chains or 3 antenna ports. Also, the UE is configured to use 3 Tx PC precoders.

[0030] For example, the method comprises: transmitting a reference signal (e.g. SRS) to a network node; receiving an indication of a precoder based on the transmitted reference signal; and transmit data (e.g. PUSCH) based on the indicated precoder, wherein the indicated precoder is determined based on the 3 antenna ports, the 3 antenna ports being divided into two antenna-port groups, wherein, a first antenna-port group has two antenna ports, and a second antenna port group has one antenna port, and the two antenna-port groups are mutually non- coherent, and the antenna ports in the first antenna port group are fully-coherent.

[0031] A UE, comprising processing circuitry and a network interface connected thereto, is also provided to perform the above method.

[0032] In another aspect, there is provided a method in a network node for transmitting data to a UE which is configured with 3 transmit chains / antenna ports and uses 3 Tx PC precoders. The method comprises: receiving a reference signal (e.g. SRS) from a UE; transmitting, to the UE, an indication of a precoder based on the received reference signal; and receiving data based on the indicated precoder, wherein the precoder is determined based on 3 antenna ports in the UE, the 3 antenna ports being divided into two antenna-port groups, wherein, a first antenna-port group has two antenna ports, and a second antenna port group has one antenna port, the two antenna-port groups are mutually non-coherent, and the antenna ports in the first antenna port group are fully-coherent.

[0033] A network node, comprising processing circuitry and a network interface connected thereto, is also provided to perform the above method.

[0034] A readable computer product allowing to perform the above methods is also provided.

[0035] Certain embodiments may provide one or more of the following technical advantage(s).

[0036] The disclosure proposes a PC precoder design for 3 Tx UEs, where the three ports are divided into two groups, which are mutually non-coherent. The proposed solution considers different antenna configurations for arranging the three ports across the two groups. Also, the disclosure introduces a FC precoder design for UEs, which enables FC precoding for 3 Tx UEs. The disclosure further considers restriction of the number of FC precoders to limit the downlink control information (DCI) overhead. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Exemplary embodiments will be described in more detail with reference to the following figures, in which:

[0038] Fig.1 illustrates an example of a signaling diagram between a UE and a gNB, using CB-based precoding.

[0039] Fig.2 illustrates different antenna configurations for PC UEs, with 3 Tx, which are divided into two antenna-port groups, ^^^and ^^^.

[0040] Fig. 3 illustrates a signal diagram between a UE and a gNB for codebook-based transmissions using 3 Tx PC codebook design, according to an embodiment.

[0041] Fig. 4 illustrates an example of a flow chart of a method in a UE, according to an embodiment.

[0042] Fig. 5 illustrates an example of a flow chart of a method in a network node, according to an embodiment.

[0043] Fig.6 illustrates different antenna configurations for FC UEs with 3 Tx.

[0044] Fig. 7 illustrates a signal diagram between a UE and a gNB for codebook-based transmissions using 3 Tx fully coherent codebook design, according to an embodiment.

[0045] Fig.8 shows an example of a communication system, according to an embodiment.

[0046] Fig.9 shows a schematic diagram of a UE, according to an embodiment.

[0047] Fig. 10 shows a schematic diagram of a network node, according to an embodiment.

[0048] Fig.11 illustrates a block diagram illustrating a virtualization environment. DETAILED DESCRIPTION

[0049] Some of the embodiments contemplated herein will now be described more fully with reference to the accompanying drawings. Embodiments are provided by way of example to convey the scope of the subject matter to those skilled in the art.

[0050] In this disclosure, it should be noted that antenna-port group and port group can be used interchangeably, and antenna port and port can be used interchangeably.

[0051] Design of a PC codebook

[0052] For the design of PC precoders, the 3 ports of a UE can be divided into two non- coherent port groups, ^^^and ^^^, for example. The UE can have different antenna configurations, based on these 2 groups. For example, Fig. 2 illustrates an example of a 3-Tx UE with two possible antenna configurations. The antennas at the UE can be configured as i) “Antenna configuration A” for which antenna-port group with two ports ^^^consists of one dual polarized antenna, and ii) “Antenna configuration B” for which antenna-port group with two ports ^^^consists of two single polarized antennas. In this example, for “Antenna configuration B”, the polarization for the second antenna-port group ^^^is different from the polarization for the first antenna-port group ^^^. Note, however, that the relative polarization between antenna-port groups does not matter for codebook design (except for full power mode 1).

[0053] Whether for configuration A or B, the first group ^^^has two coherent ports and the second group ^^^has a single port. The 2 groups are non-coherent with respect to each other, while the ports within port group ^^^are coherent with respect to each other. Non-coherent groups mean that the antenna ports in the first antenna port group cannot maintain a fixed relative phase with respect to the antenna port in the second antenna port group. The antenna ports in the first group are fully coherent, which means that the two antenna ports can maintain a fixed relative phase with respect to each other. In other words, for a 3 Tx UE, the 2 groupsare not coherent across groups, but the antenna ports are coherent within the first group. This principle can be extended to UEs having other odd numbers of transmit antenna ports, such as 5, 7, 9, etc. For those UEs, one or more antenna-port groups are non-coherent with respect to one or more other antenna-port groups.

[0054] Furthermore, the ports within the first port group with two ports ( ^^^in Fig.2) can be arranged such that the two ports i) belong to different polarization, i.e., ^ ^^^, ^^ଶ, ^^^ ൌ^1,1,2^, or ii) belong to same polarization and arranged as a uniform linear array (ULA), i.e., ^ ^^^, ^^ଶ, ^^^ ൌ^2,1,1^. Accordingly, a maximum rank for groups with two and one port(s) are two and one respectively, giving a maximum rank of three for the 3 Tx UE. Further, a layer cannot be transmitted from ports belonging to more than one of the port groups (unless full power mode 1 is applied).

[0055] Accordingly, in what follows, each layer is assumed to be transmitted from a single port group. The network can indicate to the UE how to map the layer(s) to the two port groups through a TPMI containing the rank, i.e., ^^, and the corresponding PC precoder. The number of possible PC precoders depends on all possible combination of layers in each group, such that ^^^^ ^^^ൌ ^^, ^ ^^^, ^^^^ ^ ^^୫ୟ^, where ^^^and ^^^are the number of layers in port groups G^and G^, possible combinations of layers for the portgroups are given by ^ ^^^, ^^^^ ∈ ^^2,0^, ^1,1^^, where port group G^has two ports.

[0056] It should be noted that a SRS port is mapped to an antenna port. For example, a SRS port can be uniquely mapped to an antenna port. Also, a PUSCH port can be mapped to a SRS port. For example, a UE can send an SRS port with a certain number, e.g., 1000 in different SRS resources (e.g.2 SRS resources) and the gNB can indicate (using SRI) which of these two SRS resources to map a PUSCH port to. Also, a UE can send SRS without ever transmitting PUSCH.

[0057] In practice, a SRS port corresponds to a specific reference signal. The UE and the gNB can assume that this reference signal can be used to estimate the channel corresponding to a specific antenna port. The set of antenna ports defined in 3GPP specification 38.211 for 5G NR for PUSCH / DMRS is Antenna Port Starting from 0 (0 Series), and for SRS, precoded PUSCH is Antenna Port Starting from 1000 (1000 Series). Also, PUSCH layers and DMRS for PUSCH (0 Series) are mapped to SRS ports via TPMI.

[0058] In the following, embodiments for mapping PUSCH ports to SRS ports will be described. These mappings describe the SRS resource indication. For examples, these mappings indicate how the PUSCH layers (e.g. PUSCH ports) are mapped to the SRS ports.

[0059] More specifically, the number of PUSCH layers and the precoder, indicated by the NW via a TPMI value is mapped to SRS ports. Methods to transmit 3 SRS ports for 3 Tx UEs have been proposed, where the 3 SRS ports belong to one or multiple SRS resource(s).

[0060] In one embodiment, if the 3 SRS ports belong to a same SRS resource and:

[0061] - if, e.g., “Antenna configuration A” is assumed, SRS port 1000 and 1002 are assumed by the NW to be mutually coherent when the UE is transmitting PUSCH, and the UE is expected to map PUSCH port 1000 ^ ^^ to SRS port 1000 ^ ^^ in the indicated SRS resource in an SRS resource set with usage codebook;

[0062] - if, e.g., “Antenna configuration B” is assumed, SRS port 1000 and 1001 are assumed by the NW to be mutually coherent when the UE is transmitting PUSCH, and the UE is expected to map PUSCH port 1000 ^ ^^ to SRS port 1000 ^ ^^ in the indicated SRS resource in an SRS resource set with usage codebook.

[0063] In one embodiment, if the 3 SRS ports are spread over a 2-port SRS resource and a 1-port SRS resource in an SRS resource set with usage codebook:

[0064] - If, e.g., “Antenna configuration A” is assumed, the two SRS ports in the 2-port SRS resource are assumed by the NW to be mutually coherent when the UE is transmitting PUSCH. Furthermore, the UE is expected to map PUSCH port 1000 and PUSCH port 1002 to SRS ports in the indicated 2-port SRS resource and PUSCH port 1001 to the SRS port in the 1-port SRS resource.

[0065] - If, e.g., “Antenna configuration B” is assumed, the two SRS ports in the 2-port SRS resource are assumed by the NW to be mutually coherent when the UE is transmitting PUSCH. Furthermore, the UE is expected to map PUSCH port 1000 and PUSCH port 1001 to SRS ports in the indicated 2-port SRS resource and PUSCH port 1002 to the SRS port in the 1-port SRS resource.

[0066] If the SRS ports are spread over a 2-port SRS resource and a 1-port SRS resource in an SRS resource set with usage ‘codebook’, the SRS ports are numbered as follows:

[0067] - in one example, SRS port 1000 to 1000^ ^^ are in the SRS resource with the lowest resource ID and SRS port 1000^ ^^ ^ 1 to 1002 are in the SRS resource with the highest resource ID. Here, ^^ ൌ 0 or ^^ ൌ 1 if the SRS resource with the lowest resource ID has 1 or 2 ports, respectively. a. Furthermore, the 2-port SRS resource should be configured with a lower resource ID than the 1-port SRS resource.

[0068] - in another example, if “Antenna configuration A” is assumed, SRS ports 1000 and 1001 are in the 2-port SRS resource, and SRS port 1002 is in the 1-port SRS resource.

[0069] - in another example, if “Antenna configuration B” is assumed, SRS ports 1000 and 1002 are in the 2-port SRS resource, and SRS port 1001 is in the 1-port SRS resource.

[0070] In one example, if the 3 SRS ports are spread over three 1-port SRS resources in an SRS resource set with usage codebook, PUSCH port 1000 is mapped to a first SRS resource, PUSCH port 1001 is mapped to a second SRS resource, and PUSCH port 1002 is mapped to a third SRS resource.

[0071] In one example, if the SRS ports are spread over three 1-port SRS resources in an SRS resource set with usage ‘codebook’, SRS port 1000 is in the SRS resource with the lowest resource ID, SRS port 1001 is the SRS resource with the second lowest resource ID, and SRS port 1002 is in the SRS resource with the third lowest (i.e., highest) resource ID. For example, the SRS resources are mapped to antenna ports such that, at least the 2 SRS ports in the first and second SRS resources (i.e., the SRS resource with lowest and second lowest resource ID) are mutually coherent under PUSCH transmission. In another example, the SRS resources are mapped to antenna ports such that, at least, the 2 SRS ports in the first and third SRS resources (i.e., the SRS resource with lowest and highest lowest resource ID) are mutually coherent under PUSCH transmission.

[0072] In the following, embodiments related to the design of a PC codebook will be described.

[0073] The design of the PC codebook takes into account different numbers of layers per antenna port and different numbers of antenna ports per layer.

[0074] In the following embodiments, the precoder for the port group with one port is considered to be given by the scalar ‘1’ (ignoring the power scaling), i.e., the layer through the port is transmitted as it is (if a layer is transmitted from that port group, otherwise the scalar ‘0’ will be used). Further, the distribution of the layers for a given rank ^^ is given by the following table (Table 1).

[0075] Table 1: Layer splits ^ ^^^^, ^^^^^ per rank ^^ defining the distribution of layers among two antenna groups ^^^^and ^^^^, where ^^^^and ^^^^have two and one ports each Rank, ^^All layers in one port group Layers split across two port groups1 (1,0), (0,1) 2 (2, 0)2 (1,1) 3 (2,1)

[0076] Here, ^ ^^^, ^^^^ gives the number of layers transmitted from each of the two port groups, ^^^and ^^^, respectively, where ^^^and ^^^have two ports and one port, respectively.

[0077] In one embodiment, the precoders for the group with two ports is generated using the Rel-152 Tx precoders. Accordingly, there are 7, 9 and 3 precoders for rank 1, 2 and 3, such that the number of bits is 3, 4, and 5 bits for max rank 1, 2, and 3, respectively. The generated precoders for antenna configurations A and B are given in 2 and Table 3, respectively. Note that the only difference between the codebooks in Table 2 and Table 3 is a permutation of the 2ndand 3rdrow (PUSCH port 1001 and 1002). As a note, later releases than Rel-15 have separate sets of 2 Tx precoders depending on whether full power mode 1 is configured or not. But 2 Tx precoders were designed in Rel-15 with no further enhancements in later releases.

[0078] Table 2: 3 Tx PC precoders for “Antenna configuration A”, with precoders for antenna group ^^^^generated with Rel-152 Tx precoders^^3-Tx PC Precoders111 1 0 1 1 1 1 1 1 1 00 10 1√3^0൩ ,√3^0൩ ,13^0൩ ,13^0൩ ,െ1 3^ ൩ ,3^ ൩ ,3^1൩0√ √ √ ^^ √ െ ^^ √ 0211 0 1 1 1 1 1 1 0 0 0 1 0 1 0√60 0 , 1 െ1 , 1^^ െ ^^ , 10 0 , 11 0൩ , 1 1 1^ ൩ ^ ൩ ^ ൩ ^ ൩ ^ ^1 0൩ , ^െ ൩ ,01 √6 0 0 √6 0 0 √6 0 1 √6 0 1 √6 0 1 √61 001 √63 1 1 0 0 1 1 0 1 1 03^0 1 0൩ ,1^1 െ1 ൩ ,1^^^ െ ^^ 0൩0 1 3 00 0 0 1 3 0 0 1

[0079] Table 3: 3 Tx PC precoders for “Antenna configuration B”, with precoders for antenna group ^^^^generated with Rel-152 Tx precoders ^^ 3-Tx PC Precoders111 1 0 1 1 1 1 1 1 1 1 1 0√3^0൩ , ^ ൩ , ^ ൩ , ^ , , ,0√310√310√3െ1൩ ^ ^^൩ ^െ ^^ ൩ ^0൩0√3 0 √3 0 √3 1211 0 1 1 1 1 1 1 1 0 0 0 1 0 1 0√6^0 1൩ ^0 ൩ ^0 0 1 1 1 1 1, , ൩ , ^ ൩ , ^ ൩ , ^ ൩ , ^ ൩ ,00 √601െ1 √6 ^^ െ ^^ √60 100 √60 110 √60 110 √60 1െ1 0 √61 1 1 0 1 1 1 03^0 0 1൩ , ^ ൩ , ^0 0 1൩01 0 3 0 0 11 െ1 0 3 ^^ െ ^^ 0

[0080] In another embodiment, the precoders for the group with two ports is generated using Rel-15 Type-I single panel DL codebook (see, e.g., 3GPP TS 38.214 for further details), there are 5, 6, and 2 precoders for rank 1, 2, 3, respectively, requiring 3, 4, and 4 bits for max rank 1, 2, and 3, respectively. Note that this embodiment is equivalent of using only Rel-152 Tx FC precoders for the port group with two ports. It can be noticed that the number of 3 Tx PC precoders in the embodiment is less than the number of Rel-154 Tx PC precoders for rank 1 and 2, while it is equal for rank 3. The generated precoders for antenna configurations A and B are given in Table 4 and Table 5, respectively. Note that the only difference between the codebooks in Table 4 and Table 5 is a permutation of the 2ndand 3rdrow (PUSCH port 1001 and 1002).

[0081] Table 4: 3 Tx PC precoders for antenna configuration A, with precoders for antenna group ^^^^generated with DL Type-I codebook ^^ 3-Tx PC Precoders 111 1 1 1 1 1 1 0√30 ,√30൩ , 0 0 1^ ൩ ^√3^ ൩ ,√3^ ൩ ,√3^1൩1െ1 ^^ െ ^^ 0211 1 1 1 1 1 1 0 1 1 0 1 1 0 1 1 0√6^1 െ1൩ , ^ ^^ െ ^^ ൩ , ^ ൩ , ^ ൩ , ^ ^^ 0൩ , ^െ ^^ 0൩00 √6 0 0 √61 001 √6െ1 001 √6 0 1 √6 0 131 1 1 0 1 1 0^,131 െ1 0൩ ^ ^^ െ ^^ 0൩0 0 1 3 0 0 1

[0082] Table 5: 3 Tx PC precoders for antenna configuration B, with precoders for antenna group ^^^^generated with DL Type-I codebook ^^ 3-Tx PC Precoders 11 1 1 1 1 1 1 0െ11 1√3^1൩ , ^ ൩ , ^ ^^൩ , ^െ ^ ,0√3 0 √3 0 √3^ ൩0√3^0൩1 21 1 1 1 1 1 1 0 1 0 1 0 1 00 1 1 1 1^ ൩ , ^ 0൩ , ^ ൩ , ^ ൩ , ^0 1൩ , 0 1√60 0√6 √60 1√60 1√6 √6^ ൩1െ1 ^^ െ ^^ 1 0 െ1 0 ^^ 0 െ ^^ 03 1 1 1 0 1 1 03 ^0 0 1൩ ,10 0 11െ1 0 3^ ൩ ^^ െ ^^ 0

[0083] Furthermore, the number of 3 Tx PC precoders can be further limited by restricting the co-phasing of the two ports in the port group ^^^to ^1,െ1^ . Note that for antenna configuration B, this restriction of the co-phasing of the two ports effectively limits the spatial direction of beams created by port group ^^^. For example, in case Rel-15 Type-1 DL precoders are used for generating precoders for port group G^, this will result in 3, 3, and 1 precoders for rank 1, 2, 3, respectively, requiring 2, 3 and 3 bits for max rank 1, 2, and 3, respectively. Accordingly, the generated precoders for antenna configurations A and B are given in Table 6 and Table 7, respectively.

[0084] Table 6: 3 Tx PC precoders for antenna configuration A, with precoders for antenna group ^^^^generated with DL Type-I codebook ^^ 3-Tx PC Precoders 111 1 1 1 0√3^0൩ ,1√3^0൩ ,െ1 √3^1൩0 211 1 1 1 0 1 0√61 െ1 ,√61 0 , 1^ ൩ ^ ൩√6^െ1 0൩00 0 1 0 131 1 1 03^1 െ1 0൩0 0 1

[0085] Table 7: 3 Tx PC precoders for antenna configuration B, with precoders for antenna group ^^^^generated with DL Type-I codebook ^^ 3-Tx PC Precoders 11 1 1 0, 11, 1^1൩ ^െ൩ ^0√3൩0√3 0 √3 121 1 1 1 1 0 1 1 0√6^0 0൩ ,√6^0 1൩ ,6^0 1൩1െ1 1 0 √ െ1 031 1 1 03^0 0 1൩1 െ1 0

[0086] In another embodiment, the 3 Tx PC precoders for which each of the layers is transmitted on not more than one port is excluded from the codebook. Since these precoders fulfill the criteria of non-coherent precoders, they can be included under the non-coherent precoders for 3 Tx. For example, in case Rel-15 Type-1 DL precoders are used for generating precoders port group G^, the excluded precoders are: ^0 0^an ^√ଷ 1൩ d√ଷ^0൩1 A and B, respectively.two sets of PC precoders, generated for the two antenna configurations, can be included in the same codebook for all or subset of ranks. The PC precoders generated for the two antenna configurations can be included in the same codebook for all or subset of ranks. Note that this is the case when the PC precoders can be nested with fully-coherent (FC) and non-coherent (NC) precoders in one codebook as in legacy Rel-154 Tx codebook in TS 38.211. Accordingly, based on the TPMI indicated by the gNB, this allows the UE to transmit a subset of layers coherently over two ports, such that:

[0088] - (for rank 1) a) the layer is coherently transmitted over PUSCH ports {1000, 1001} or PUSCH ports {1000, 0002} or b) the layer is transmitted over only PUSCH port 1001 or PUSCH port 1002.

[0089] - (for rank 2) a) two layers are coherently transmitted over PUSCH ports {1000, 1001} or PUSCH ports {1000, 1002}, or b) one layer is coherently transmitted over PUSCH ports {1000, 1001} with the second layer over PUSCH port 1002 or PUSCH ports {1000, 1002} with the second layer over PUSCH port 1001.

[0090] - (for rank 3) two layers are coherently transmitted over PUSCH ports {1000, 1001} with the third layer over PUSCH port 1002 or PUSCH ports {1000, 1002} with the third layer over PUSCH port 1001.

[0091] In the following, embodiments related to the design of a PC codebook for full power mode 1 will be described. It should be noted that Mode 1 precoders allow PUSCH transmission with maximum transmit power for UEs where all the antenna ports may not be coherent.

[0092] In this case, one or more additional precoders are included in the UL codebook for full power mode 1 for rank 1.

[0093] Also, a scalar ‘1’ (or other numbers) can be used for the antenna port group with a single antenna port for all the precoders.

[0094] The several different precoders use different co-phasing factors applied over the two antenna ports associated with the antenna port group with two antenna ports. For example, the co-phasing factors of the precoders applied over the two antenna ports of the antenna port group consisting of two antenna ports can be [1,1], [1,-1], [1,j], [1,-j].

[0095] One benefit with using multiple precoders for full power mode 1 for 3 TX is that we can adapt the pointing direction of the spatial beam of the two-port antenna port group (in case the polarizations are the same for the two antenna ports associated with the two-port antenna group) or we can adapt the polarization of the beam of the two-port antenna port group (in case the polarizations e.g. are mutually orthogonal for the two antenna ports associated with the two-port antenna group).

[0096] Now, turning to Fig. 3, a signal diagram between a UE and a gNB for UL transmissions will be described. For example, the UE is configured with 3 antenna ports, as illustrated in Fig.2. The UL transmissions can be UL codebook-based transmissions using a 3 Transmit (Tx) PC codebook, for example.

[0097] In step 110, the gNB may send a SRS configuration to the UE, to configure the UE with SRS parameters and resources, for example. In this disclosure, SRS is used as an example of reference signals, but the teachings in this disclosure equally apply to other reference signals, as well, as known by skilled persons in the art.

[0098] In step 114, the gNB may send a configuration of a 3 Tx PC codebook to the UE. The 3 Tx PC codebook may be designed as described above.

[0099] In step 116, the gNB may send a trigger to the UE, to trigger the UE to send a SRS to the gNB.

[0100] In step 120, the UE transmits a SRS to the gNB, based on the received SRS configuration.

[0101] In step 130, the UE may send a capability message to the network node, the capability being for a 3 Tx PC codebook. This step can be sent to the gNB before the gNB sends the UE the SRS configuration or the 3 Tx PC codebook configuration.

[0102] In step 140, the gNB determines some precoding parameters, like the PMI, rank, layers, etc., based on the codebook generated for 3 antenna ports, as described above.

[0103] In step 150, the gNB sends the determined PMI and parameters, such as the number of layers, to the UE. The gNB can also send an indication to the UE to send a PUSCH transmission to the gNB. For example, the gNB sends a TPMI to the UE.

[0104] In step 160, the UE sends a UL transmission (PUSCH) using the determined PMI and parameters, to the network node.

[0105] It should be noted that the design of the codebooks and precoders based on different configurations of the antenna ports and antenna configuration are as described above.

[0106] Fig. 4 illustrates a flow chart of a method 200 in a UE, for performing UL codebook-based transmission using 3 Tx PC codebook design or using 3 Tx PC precoders from a PC codebook (or from a PC codebook subset). The UE may be configured with 3 antenna ports. The UE may be a UE 812 of Fig.8 or a UE 900 of Fig.9. Method 200 comprises:

[0107] Step 210: transmitting a reference signal (e.g. SRS) to a network node;

[0108] Step 220: receiving an indication of a precoder based on the transmitted SRS;

[0109] Step 230: transmitting data (e.g. PUSCH) based on the indicated precoder, wherein the indicated precoder is determined based on the 3 antenna ports, the 3 antenna ports being divided into two antenna-port groups, wherein a. a first antenna-port group has two antenna ports, and a second antenna port group has one antenna port, b. the two antenna-port groups are mutually non-coherent (e.g. the antenna port in the first antenna port group cannot maintain a fixed relative phase with respect to the antenna port in the second antenna port group); and c. the antenna ports in the first antenna port group with two antenna ports are fully- coherent (e.g., the two antenna ports can maintain a fixed relative phase with respect to each other).

[0110] In some examples, the PC precoder can be designed such that, the precoder for the antenna port group with one antenna port is given by a scalar ‘1’ (or ‘0’ if not used) (ignoring the power scaling), and the precoder for antenna port group with two antenna ports, can be designed as follows:

[0111] - based on Release-152 Transmit (Tx) precoders, or

[0112] - based Release-15 Downlink (DL) Type-I codebook, or

[0113] - a new set of 2 Tx precoders with fully coherent precoder (i.e. with two non-zero elements).

[0114] In some examples, the two antenna ports within one of the antenna port groups can be either i) a dual polarized antenna port (i.e. the two antenna ports are associated with two antenna elements that have mutually orthogonal polarization), or ii) two single polarized antenna port with the same polarization (i.e. the two antenna ports are associated with two antenna elements that have the same polarization).

[0115] In some examples, the number of PC precoders can be restricted by:

[0116] - Limiting the co-phasing between the two coherent ports in the port group with two ports.

[0117] - Removing the PC precoders where each of the configured layers is transmitted from not more than one port, i.e., non-coherent precoders.

[0118] In some examples, the UE may further perform one or more of the following:

[0119] - sending to the network node, a ‘capability of UL transmission using 3 Tx PC codebook (or precoders)’;

[0120] - receiving a message containing configuration of one or more SRS resources;

[0121] - receiving a message containing a 3 Tx PC codebook configuration,

[0122] - receiving a trigger message to transmit the SRS resources,

[0123] - receiving an indication to perform a PUSCH transmission and an indication of which rank and precoder that should be applied on the PUSCH transmission, where the rank and precoder is associated with the 3 Tx PC codebook configuration.

[0124] In some examples, the ‘capability of UL transmission using 3 Tx PC codebook’ indicates support to perform PUSCH transmission using either i) codebook with 3 Tx PC precoders, or ii) codebook with both 3 Tx partially- and non-coherent codebook (precoder nesting as in legacy Rel-15 UL codebooks). In some examples, the UE may further indicate support for 3 Tx PC design with full power mode 1. In some examples, the indication of the precoder is a TPMI. In some examples, more than one precoder can be included in the UL codebook for full power mode 1 for rank 1, and wherein a “1” is used for the antenna port group with a single antenna port, and wherein the several different precoders use different co- phasing factors applied over the two antenna ports associated with the antenna port group with two antenna ports (e.g. the co-phasing factors of the precoders applied over the two antenna ports of the antenna port group consisting of two antenna ports can be [1,1], [1,-1], [1,j], [1,-j] etc.). It should be noted that other values (different from 1) can be used as well.

[0125] In some examples, the precoder indication may map PUSCH layers to single 3-port SRS resource. In some examples, the precoder indication can map PUSCH layers to multiple SRS resources, each with less than 3 SRS ports, wherein: a. A first SRS resource has 2 SRS ports and second SRS resource has 1 SRS port, the 2 SRS ports in the 2-port SRS resource are coherent. b. All SRS resources have 1 SRS port with coherence being maintained over the first two of the 1-port SRS resources.

[0126] In some examples, the first SRS resource or the first two SRS resources in the plurality of SRS resources can be the SRS resource with the lowest ID or the two SRS resourceswith the lowest resource ID and second lowest resource ID. In some examples, a SRS port can be mapped to an antenna port.

[0127] Fig.5 illustrates a flow chart of a method 250 in a gNB, for performing codebook- based transmission using 3 Transmit (Tx) PC codebook design (comprising PC precoders from a PC codebook or a PC codebook subset), with a UE. The UE may be configured with 3 antenna ports. The network node may be the network node 810 of Fig.8 or network node 1000 of Fig. 10. Method 250 comprises:

[0128] Step 260: receiving a reference signal (e.g. SRS) from a UE;

[0129] Step 270: transmitting, to the UE, an indication of a precoder based on the received reference signal; and

[0130] Step 280: receiving data (e.g. PUSCH) based on the indicated precoder, wherein the precoder is determined based on the 3 antenna ports in the UE, the 3 ports being divided into two antenna-port groups, wherein, - a first antenna-port group has two antenna ports, and a second antenna port group has one antenna port, - the two antenna-port groups are mutually non-coherent, e.g. the antenna port in the first antenna port group cannot maintain a fixed relative phase with respect to the antenna port in the second antenna port group, and - the antenna ports in the first antenna port group are fully-coherent, e.g., the two antenna ports can maintain a fixed relative phase with respect to each other.

[0131] In some examples, the precoder can be a PC precoder. In some examples, the PC precoder can be designed such that, the precoder for the antenna port group with one antenna port is given by a scalar ‘1’ (or ‘0’ if not used) (ignoring the power scaling), and the precoder for antenna port group with two antenna ports, can be designed as follows:

[0132] - based on Release-152 Transmit (Tx) precoders, or

[0133] - based Release-15 Downlink (DL) Type-I codebook, or

[0134] - a new set of 2 Tx precoders with fully coherent precoder (i.e. with two non-zero elements).

[0135] It should be noted that other values (different from the scalar 1) can be used as well. In some examples, the two antenna ports within the first antenna port group can be either i) a dual polarized antenna port (i.e. the two antenna ports are associated with two antenna elements that have mutually orthogonal polarization), or ii) two single polarized antenna port with the same polarization (i.e. the two antenna ports are associated with two antenna elements that have the same polarization). In some examples, the number of PC precoders is restricted by:

[0136] - Limiting the co-phasing between the two coherent ports in the first antenna port group;

[0137] - Removing the PC precoders where each of the configured layers is transmitted from not more than one port, i.e., non-coherent precoders.

[0138] In some examples, the network node may perform one or more of the following:

[0139] - receiving from the UE, a ‘capability of UL transmission using 3 Tx PC codebook’;

[0140] - transmitting a message containing a configuration of one or more SRS resources;

[0141] - transmitting a configuration of a 3 Tx PC codebook ;

[0142] - transmitting a trigger message to transmit the SRS resources,

[0143] - transmitting an indication to perform a PUSCH transmission and an indication of which rank and precoder that should be applied on the PUSCH transmission, where the rank and precoder is associated with the 3 Tx PC codebook configuration.

[0144] In some examples, the ‘capability of UL transmission using 3 Tx PC codebook’ indicates support to perform PUSCH transmission using either i) a codebook with 3 Tx PC precoders, or ii) codebook with both 3 Tx partially- and non-coherent codebook (precoder nesting as in legacy Rel-15 UL codebooks). In some examples, the indication of the precoder can be given by the TPMI. In some examples, the precoder indication can map PUSCH layers to a single 3-port SRS resource. In some examples, the precoder indication can map PUSCH layers to multiple SRS resources, each SRS resource having less than 3 SRS ports, wherein:

[0145] A. first SRS resource has 2 SRS ports and a second SRS resource has 1 SRS port, the 2 SRS ports in the first SRS resource are coherent.

[0146] B. All SRS resources have 1 SRS port with coherence being maintained over the first two of the 1-port SRS resources.

[0147] In some examples, the first SRS resource or the first two SRS resources in the plurality of SRS resources is the SRS resource with the lowest ID or the two SRS resources with the 2 lowest resource IDs. In some examples, a SRS port can be mapped to an antenna port.

[0148] Design of a FC codebook

[0149] In the following, exemplary 3 Tx FC codebooks (CBs) will be designed assuming different UE antenna configurations. A first set of embodiments introduces FC CB designs for UE antenna configuration shown in Fig. 6, which illustrates a 3-Tx UE with three possible antenna configurations. Specifically, for the design of FC precoders, the 3 ports of a UE can constitute either i) a dual polarized port co-phased with a single polarized port shown in configuration C (302) or ii) three single polarized ports are co-phased together shown inconfiguration D (304). In another example, FC CB designs an antenna configuration E (306) where the 3 mutually orthogonal ports with the same polarization are arranged as an ULA with port configuration of ^N^, Nଶ^ ൌ ^3,1^.

[0150] In antenna configuration C (302), there is one dual polarized port 310 with a single polarized port 312 in a single 2x1 ULA 308. In antenna configuration D (304), there is 2x1 ULA 308 with two single polarized ports 312, and then a 1x1 ULA 308 with a single polarized port 312. In antenna configuration E (306), there is a single 3x1 ULA with three single polarized ports 312.

[0151] Irrespectively of the UE antenna configuration, the FC CB design is such that a layer is transmitted coherently from all the three ports. Accordingly, the network can indicate to the UE how to map the layer(s) to the 3 ports through a TPMI containing the rank, ^^, and the FC precoder. Specifically, the FC precoder maps a number of PUSCH layers (as indicated by the rank, ^^, in the TPMI) to a number of SRS ports via a precoding operation (as indicated by the precoder in the TPMI). Prior to receiving a TPMI indication, the UE transmits a number of SRS ports to allow the NW to pick a suitable precoder.

[0152] In the following, embodiments related to the design of a FC codebook using QPSK symbols will be described. The FC precoder is designed by co-phasing the 3 coherent ports such that no two layers is transmitted with the same co-phasing applied to the 3 coherent ports. For example, the FC precoders for rank 1, 2 and 3 can be generated by the following equations, where the precoders are restricted to QPSK symbols: ^11: ^^^^^^ ^^ ^^^^^ൌ ^^^గ^ / ଶandsymbols (i.e., {1, -1, j, -j}). Based on the above, the generated precoders are given in Table 8, where the 1stand 2ndports are assumed to belong to the same polarization, while the 3rdport can be in the same or orthogonal polarization. Note that the number of precoder candidates can be restrictedby limiting the co-phase factor between the antenna ports for different layers, for instance, by further restricting the values of ^^ and ^^ in the above example. Table 8: Fully-coherent precoder for 3 Tx UE with all ports co-phased differently for each layer ^^  3‐Tx FC Precoders  1 11 1 1 1 1 1 1 1 1 1 1 11 1^^ 1 1^ െ1 െ ^^√31൩ ,√3^ ^^൩ ,√3^െ1൩ ,√3^െ ^^ ൩ ,3^ ൩ ,3^ ൩ ,3^ ൩ ,3^ ൩, 11 1 1 √ ^^ √ ^^ √ ^^ √ ^^ 1 1 1 1 1 1 1, 1, 1 1, 1 1, 11 1^^ 1െ1 1െ ^^√3^1൩√3^ ^^ ൩√3^െ1൩√3^െ ^^൩√3^ ൩ ,√3^ ൩ ,√3^ ൩ ,√3^ ൩ െ1 െ1 െ1 െ1 െ ^^ െ ^^ െ ^^ െ ^^2 11 1 1 1 1 1 1 1 1 1√6^1 ^^൩ , ^ ൩ , ^ , 1, 11 √6^^ െ111 √6െ1 െ ^^ ൩ ^െ ^^ 1൩11 √6 1 1  11 1 1 1 1 1 1 1^1 ^^൩1^^ െ1 1െ1 െ ^^ 1െ ^^ 1√6,^ ൩,^ ൩,^ ൩,  ^^ ^^ √6 ^^ ^^ √6 ^^ ^^ √6 ^^ ^^  11 1 1 1 1 1 1 1 1 1 1√6^ 1 ^^ ൩ , ^ ^^ െ1൩ , ^െ1 െ ^^൩ , ^െ ^^ 1൩, െ1 െ1 √6 െ1 െ1 √6 െ1 െ1 √6 െ1 െ1  11 1 1 1 1 1 1 11 ^^ , 1^^ െ1 , 1െ1 െ ^^ , 1െ ^^ 1√6^ ൩െ^^ െ ^ √6^ ൩√6^ ൩√6^ ൩ ^െ ^^ െ ^^ െ ^^ െ ^^ െ ^^ െ ^^3  1 1 1 1 1 1 1 1 1 1 1 1 111 ^^1^^ ^^1 13^ ൩ ,3 ^ െ1൩ ,3 ^െ1 െ1 െ ^^ ൩ ,3 ^െ ^^ െ ^^ 1൩, 1 ^^ 1 1 ^^ 1 1 ^^ 1 1 ^^ 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 13^1 1 ^^൩ , ^^^ ^^ െ1൩ , ^െ1 െ1 െ ^^൩ , ^െ ^^ െ ^^ 1൩, ^^ െ1 ^^ 3 ^^ െ1 ^^ 3 ^^ െ1 ^^ 3 ^^ െ1 ^^ 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 13^1 1 ^^ ൩ ,3^ ^^ ^^ െ1൩ , െ1 െ1 െ ^^ െ ^^ െ ^^ 1^^ െ1 3^ ൩ , ^ ൩, െ1 െ ^^ െ1 െ1 െ െ1 െ ^^ െ1 3 െ1 െ ^^ െ1 1 1 1 1 1 1 1 1 1 1 1 1 1 131 1 ^^ ^^ ^^ െ 1 1^ ൩ , ^1൩ , ^െ1 െ1 െ ^^൩ , ^െ ^^ െ ^^ 1൩  െ^^ 1 െ ^^ 3 െ ^^ 1 െ ^^ 3 െ ^^ 1 െ ^^ 3 െ ^^ 1 െ ^^

[0154] In the following, the FC codebook design is considered based on the principles of Rel-15 DL single-panel Type-I codebook (codebookMode = 1). Accordingly, the 3 mutually coherent ports are co-phased such that the 3 ports consist of a dual polarized port and a single polarized port (Antenna configuration 302) or 3 single polarized ports (Antenna configuration 304). Based on the above antenna configurations, the following two cases for port implementation is considered:

[0155] Case 1 (three mutually coherent ports with antenna configuration 302): the 3 ports can be denoted by ^^^,^, ^^^,^and ^^^,^, such that ^ ^^^,^, ^^^,^^ are the ports belonging to the dual polarized antenna with polarization ^^ and ^^, with ^^^,^being the port belonging to a single polarized antenna with polarization ^^. Accordingly, ports ^ ^^^,^, ^^^,^^ are firstly co-phased, considering a ULA with port configuration of ^ ^^^, ^^ଶ^ ൌ ^2,1^, which is then co-phased across polarization with port ^^^,^. The key difference between this FC CB design and existing (i.e., in legacy NR) FC CB designs for 2, 4, and 8 Tx chains is that it is asymmetric in the sense that there is a different number of antenna ports per polarization in an antenna array.

[0156] Case 2 (three mutually coherent ports with antenna configuration 304): the 3 ports can be denoted by ^^^,^, ^^^,^and ^^ଶ,^, such that pair of ports ^ ^^^,^, ^^^,^^ is co-phased with port ^^ଶ,^, where all the ports have polarization ^^. Further, the port pair ^ ^^^,^, ^^^,^^ and port ^^ଶ,^can point to different direction as shown in Fig. 7. Accordingly, ports ^ ^^^,^, ^^^,^^ are firstly co-phased, considering a ULA with port configuration of^^^^, ^^ଶ^ൌ^2,1^, which is then co-phased with port ^^ଶ,^. The key difference between this FC CB design and existing (i.e., in legacy NR) FC CB designs for 2, 4, and 8 Tx chains is that it is asymmetric in the sense that there is a different number of antenna ports over the antenna arrays that are co-phased.

[0157] Based on the above, the 3 Tx FC precoders for Case 1 and Case 2 can be designed based on the principles of DL single-panel Type I codebook (codebookMode = 1), which is described below:

[0158] In one example, two ports out of 3 ports are considered to form a ULA with ^ ^^^, ^^ଶ^ ൌ ^2, 1^, which are co-phased with the third port in the opposite polarization (Antenna configuration 302) or in the same polarization (Antenna configuration 304). Accordingly, the FC precoders for rank 1, 2 and 3 can be generated by the following equations, which are based on single-panel Type I DL precoder (codebookMode = 1), given by:

[0159] Rank 1: ^^^^^^,^ ൌ^^^^^^^^^, where ^^ ∈ ^0,1,2,3^, and ^^ ∈ ^0,1,2,3^,

[0160] ∈ ^0,1^,

[0161] Rank 3: ^^^ଷ^ൌ^^^^^ ^^^ᇲ ^^^^^ᇱ^^^^ ^^^^ , where ^^ ∈^0,1,2,3^, ^^ ∈ ^^ ^ 2, and ^^ ∈^0,1^,

[0162] where ^^^^^^,^, ^^ ∈^1,2,3^is the precoders for the ^^ -th rank, ^^^ൌ ഏ^ ்^1, ^^^ೀభ൨ is the DFT beam formed from the ULA with two ports, ^^^is the oversampling factor for the DFT beams along ^^^dimension and ^^^ൌ ^^^గ^ / ଶis the co-phase factor for the third port. The details Rel-15 I DL codebook design can be found in Clause 5.2.2.2.1 of TS 38.214.symbols, the oversampling factor is restricted to ^^^ൌ 2. Note that the primary difference between the proposed 3 Tx FC precoder and legacy Rel-15 DL single-panel Type I precoders is that the DFT beams is generated along one polarization for 3 Tx, while the beam is co-phased with a single port in either orthogonal polarization or same polarization. Based on the above, the FC precoders for rank 1, 2 and 3 with ^^^ൌ 2 are given in Table 9. Table 9: Fully-coherent precoder for 3 Tx UE based on the principles of Rel-15 single-panel Type-I DL codebook with ^^^^ൌ ^^ ^^ 3-Tx FC Precoders 111 1 1 1 1 1 1 1 1 1 1 1 1^ ൩ , ^ ൩ , ^ 1 ^^ 1െ1 1െ ^^√311√3^^1√3െ1൩ ,1√3^െ ^^ ൩ ,1√3^ ൩ , ^ ൩ , ^ ൩ , ^ ൩,^^ √3 ^^ √3 ^^ √3 ^^11 1 1 1 1 1 1 1 1 1 1 1 1^ ൩ , ^ ൩ , ^ ൩ 1 ^^ 1െ1 1െ ^^√31െ1 √3^^െ1 √3െ1 ,െ1 √3^െ ^^൩ ,െ1 √3^ ൩ , ^ ൩ , ^ ൩ , ^ ൩െ^^ √3 െ ^^ √3 െ ^^ √3 െ ^^211 1 1 1 1 1 1 1 1 1 1√6^1 1൩ , ^1 ൩ , ^ ^^ ^^ ൩ , ^ ^^ െ ^^൩,1െ1 √6െ11െ1 √6 1 െ1 √6 1 െ111 1 1 1 1 1 1 1 1 1 1√6^െ1 െ1൩ , ^െ1 1൩ , ^െ ^^ െ ^^൩ , ^െ ^^ ^^ ൩,1െ1 √6 1 െ1 √6 1 െ1 √6 1 െ111 1 1 1 1 1 1 1 1 1 1√6^1 1൩ ,√6^1 െ1൩ , ^^ ^^ , ^^ െ ^^ ,^6^ ൩^^ െ ^^ 6^ ൩^^ െ ^^ ^^ െ ^ √ √ ^^ െ ^^11 1 1 1 1 1 1 1 1 1െ1 െ1 െ1 1 െ ^ 1, , ^ െ ^^ െ ^^ ^^√6^ ൩^^ െ ^^ √6^ ൩√6^ ൩ ,√6^ ൩^^ െ ^^ ^^ െ ^^ ^^ െ ^^31 1 1 1 1 1 1 1 1 1 1 1 1 1 1 13^1 െ1 1൩ , ^ ^^ െ ^^ ^^ ൩ , ^െ1 1 െ1൩ , ^െ ^^ ^^ െ ^^൩,11 െ1 3 1 1 െ1 3 1 1 െ1 3 1 1 െ111 1 13^1 െ1 1൩ ,1 1 1 1 1 1 1 1 1 13^^^ െ ^^ ^^൩ ,13^െ1 1 െ1൩ ,13^െ ^^ ^^ െ ^^൩^^ ^^ െ ^^ ^^ ^^ െ ^^ ^^ ^^ െ ^^ ^^ ^^ െ ^^

[0163] Furthermore, the number of precoders generated can be restricted by limiting all or one or more subsets of the following parameters (defined in Clause 5.2.2.2.1 of TS 38.214) for all or subsets of ranks:

[0164] - oversampling factor ( ^^^): restricting the range of beam index ^^,

[0165] - beam-offset factor ( ^^^): restricting the range of beam index ^^ᇱ, and

[0166] - co-phasing factor index ( ^^): restricting the co-phase factor ^^^between the pair of ports forming the DFT beams and the third port.

[0167] For example, to have the same number of FC precoders as in Rel-154 Tx codebook and follow the design principle similar to Rel-154 Tx codebook, the FC precoders for rank 1, 2 and 3 can be generated by the following equations, where the oversampling factor is restricted to ^^^ൌ 2 with ^^^ൌ 0 (or ^^^,ଷൌ 0) for rank 2:

[0168] Rank 1: ^^^^^ ^ ^^^,^ ൌ^√ଷ ^ ^^^^, where ^^ ∈^0,1,2,3^and ^^ ∈^0,1,2,3^.Table 10: Fully-coherent precoder for 3 Tx UE based on the principles of Rel-15 single-panel Type-I DL codebook with ^^^^ൌ ^^ with ^^^^ൌ ^^ (or ^^^^, ^^ൌ ^^) for rank 2. ^^3-Tx FC Precoders111 1 1 1 1 1 1 1 1 1 1 1 1^^ 1 1^ ൩ , ^ ൩ , ^ ൩ , ^ ൩ , ^1൩ , ^ െ1 െ ^^√311√3^^1√3െ11√3െ ^^1√3൩ , ^ ൩ , ^ ൩,^^ √3 ^^ √3 ^^ √3 ^^11 1 1 1 1 1 1 1 1 1 1 11 1^^ 1െ1 1^ ൩ , ^ ^^ ൩ , ^ ൩ , ^െ ^^ , , , , െ ^^√313െ1 3െ113൩െ1 3^ ൩3^ ൩3^ ൩3^ ൩െ1 √ √ െ √ √ െ ^^ √ െ ^^ √ െ ^^ √ െ ^^211 1 1 1 1 1 1 1 1 1 1√6^1 1൩ , ^ ^^ ^^ ൩ , ^െ1 ൩ , ^െ ^^ െ ^^൩,1െ1 √6 1 െ1 √6െ11െ1 √6 1 െ111 1 1 1 1 1 1 1 11 1 ^^ ^^ 1െ1 െ 1√6^ ൩ ,^^ െ ^^ √6^ ൩ ,^^ െ ^^ √6^ 1൩ , ^െ ^^ െ ^^൩,^^ െ ^^ √6 ^^ െ ^^31 1 1 13^1 െ1 1൩ ,1 1 1 1^൩ ,1 1 1 1 1 1 1^1 െ1 1൩ ,1^െ1 1 െ1൩1 1 െ1 3 െ1 1 െ11 1 െ1 3 ^^ ^^ െ ^^ 3 ^^ ^^ െ ^^

[0172] In the following, embodiments related to the design of a FC codebook using non- QPSK symbols will be described.

[0173] For the antenna configuration in antenna configuration 306 of Fig. 7, it is not possible to design a precoder, which maps each PUSCH layer to all 3 antenna ports, with two (or more) orthogonal beams, where each beam can carry one layer using QPSK symbols. Therefore, in one embodiment, the FC precoder will use non-QPSK symbols (which is different from existing UL codebooks designed for Rel-15 2 and 4 Tx and Rel-18 8 Tx precoders). Accordingly, 3-point DFT vectors can be used to form 3 or more orthogonal beams to transmit up to 3 layers for 3 Tx UL transmission. Specifically, the 3-point DFT matrix is: మ்^ ഏ^ రഏ^

[0174] ^^^ൌ ^1, ^^యೀభ, ^^^యೀభ൨ , ^^ ∈ ^0,1, … ,3 ^^^െ 1^, in ^^^set of 3 orthogonal beams, i.e.,, ^^ ∈ ^0, 1, … , ^^^െ 1^ are orthogonal. Accordingly, the FC precoders for rank 1, 2 and 3 can be generated the following equations,which transmit each layer on an orthogonal beam generated by 3- DFT, given by:

[0176] Rank 1: ^^^^^^ ൌ^√ଷ^^^, where ^^ ∈ ^0, 1, … , 3 ^^^െ 1^,

[0177] 2 ^^^ െ 1^ and ^^ᇱ∈ ^^ ^ ^^ ^^^, suchthat ^^ ∈ ^1, 2^,

[0178] Rank 3: ^ ൌ ଷ^ ^^^^^^ᇲ ^^^ᇲᇲ^, where ^^ ∈^0, 1, … , ^^^ െ 1^, ^^ᇱ∈ ^^ ^ ^^^, and^^ᇱᇱ∈ ^^ ^ 2 ^^^.

[0179] Based on the above, the FC precoders for rank 1, 2 and 3 with ^^^ൌ 2 are given in Table 11. Table 11: Fully-coherent precoder for 3 Tx UE based on 3-point DFT with ^^^^ൌ ^^ ^^  3‐Tx FC Precoders  1 11 1 1 10.50 ^ ^^0.87 1√3^1൩ ,1√3^ ൩ , ^െ0.50 ^ ^^0.87൩, െ0.50 ^ ^^0.87 √3 െ0.50 െ ^^0.8711 1 1 1െ0.50 െ ^^0. 1√3^െ1൩ , ^ 87൩ , ^ 0.50 െ ^^0.87 ൩ 1√3 െ0.50 ^ ^^0.87 √3 െ0.50 െ ^^0.872 11 1 1 11 െ0.50 ^ ^ 1^ ^0.87൩ , ^1 െ0.50 െ ^^0.87൩, √6 1 െ0.50 െ ^^0.87 √6 1 െ0.50 ^ ^^0.8711 111 1^0.50 ^ ^^0.87 െ1൩ , ^ 0.50 ^ ^^0.87 0.50 െ ^^0.87 ൩, √6 െ0.50 ^ ^^0.87 1 √6 െ0.50 ^ ^^0.87 െ0.50 െ ^^0.87  11 1 1 1 1െ0.50 ^ ^^0.87 െ0.50 െ ^^0.87 െ1 0.50 െ ^^0.87√6^ ൩ ,√6^ ൩ െ0.50 െ ^^0.87 െ0.50 ^ ^^0.87 1 െ0.50 െ ^^0.873  1 1 1 11 െ0.50 ^ ^^0.87 െ0.50 െ ^^03 ^ .87൩, 1 െ0.50 െ ^^0.87 െ0.50 ^ ^^0.8711 1 10.50 ^ ^^0.87 െ1 0.50 െ ^^3 ^ 0.87 ൩ െ0.50 ^ ^^0.87 1 െ0.50 െ ^^0.87

[0180] Furthermore, the number of precoders generated can be restricted by limiting all or one or more subsets of the following parameters for all or one or more subsets of ranks:

[0181] - oversampling factor ( ^^^): restricting the range of beam index ^^, and

[0182] - beam-offset factor ( ^^): restricting the range of beam index ^^ᇱ.

[0183] In one example, for the coherent ports in the same polarization (antenna configuration 304 and 306), the UE can support QPSK or non-QPSK CB and reports its capability to the NW, which can then infer the FC CB that the UE supports and is expected to be configured with.

[0184] Furthermore, the UE can signal an indication of its antenna-array configuration to the gNB.

[0185] Depending on the scenario, antenna configuration 302, antenna configuration 304 or antenna configuration 306 may be favorable for a device. E.g., in an FWA scenario, it may be possible to align a CPE device such that it is pointing towards the gNB, in which case it is better to arrange all antennas in a ULA of single-polarized antenna elements (antenna configuration 306), such that beamforming gain (EIRP) can be maximized. For other handheld devices, it may be better to distribute antenna elements over the UE and / or map different antenna ports to different polarizations for achieving diversity (antenna configuration 302 or 304).

[0186] Therefore, the UE can report antenna configuration to the NW.

[0187] Also, the UE can report support for one or more FC CBs associated with antenna configuration 302, 304, or 306. Based on the indicated capability, the UE can be configured with one or more of the corresponding FC CBs.

[0188] In another example, the UE can report directly an antenna configuration (e.g., antenna configuration 302, 304, or 306) from which the network can infer the FC CB that the UE supports and is expected to be configured with.

[0189] Furthermore, the UE can report a number of antenna arrays (or antenna-port groups) and the number of elements (possibly per polarization) for each antenna array.

[0190] Fig. 7 illustrates a message sequence chart for a UE communicating with a gNB, using a FC codebook configuration designed for 3 transmit chain port, according to embodiments of the present disclosure.

[0191] For example, the method can begin at step 402 where the UE 104 sends to the base station device 102, an antenna array configuration report. The UE can also send an indication of capability of UL transmission using a 3 Tx FC codebook. In an example, the indication of capability of UL transmission using the 3 Tx FC codebook indicates support to perform the PUSCH transmission using either a codebook with 3 FC precoders or a codebook with 3 Tx fully, partially, and non-coherent codebooks. In an example, the indication of capability of UL transmission using 3 Tx FC codebook indicates support for one or more of a plurality of 3 Tx FC codebooks. In another example, the indication of capability of UL transmission using 3 Tx FC codebook comprises an antenna configuration at the UEs. In an example, the indication of capability of UL transmission using 3 Tx FC codebook comprises an indication of support of a codebook subset based on the UE antenna configuration.

[0192] At step 404, the UE 104 can receive a message containing a reference signal configuration, for example a SRS resource configuration, from the base station device 102.

[0193] At step 406, the UE 104 receives a 3 Tx FC codebook configuration. The 3 Tx FC codebook is designed as described above.

[0194] At step 408, the UE 104 receives, from the base station device, a trigger message to transmit the SRS resources, and at 410 receives an indication to perform a PUSCH transmission and an indication indicating a rank and precoder for the PUSCH transmission. The precoder and rank are determined based on the SRS and the 3 TX FC codebook configuration. The indication for indicating the precoder and rank can be the TPMI, for example.

[0195] At step 412, the UE transmits the PUSCH to the base station device 102, based on the received precoder (and rank).

[0196] In the following, some examples are provided. For example, a method implemented in a base station device 102 in communication with a UE, which has 3 antenna ports and using a 3 Tx FC codebook is provided. The method comprises sending a SRS configuration and a 3 Tx FB codebook configuration to the UE 104, wherein the 3 TX FC codebook configuration comprises one of:

[0197] - a first mapping comprising 2 ports mapped to a dual polarized antenna with 2 antenna ports and one port mapped to a single polarized antenna with a single antenna port; or

[0198] - a second mapping comprising 3 ports respectively mapped to three single polarized antennas with single antenna ports each, wherein three antenna ports with the three single polarized antennas are mapped to different antenna arrays each having different numbers of antenna elements or the three antenna ports are mapped to a same antenna array with three antenna ports.

[0199] In some examples, the precoder associated with the 3 Tx FC codebook comprises QPSK symbols or non QPSK symbols.

[0200] In some examples, the 3 ports are co-phased such that two layers associated with the 3 ports do not share the same co-phasing between the ports. For example, the co-phasing can be restricted to ^1, ^^,െ1,െ ^^^.

[0201] In some examples, the precoders can be designed based on the principles of Rel-15 DL single-panel Type I codebook (with codebookMode = 1), where two ports with same polarization can be considered as an ULA, for example ^ ^^^, ^^ଶ^ ൌ ^2,1^ (with oversampling factor restricted to ^^^ൌ 2), which is co-phased with the 3rdport either in same or orthogonal polarization, such that no two layers share the same co-phasing between the ports.

[0202] In some examples, 2 ports with a same polarization are a uniform linear array( ULA) which is co-phased with a third port in a same or orthogonal polarization such that two layers associated with the three ports do not share the same co-phasing between the ports.

[0203] In some examples, precoder candidates are restricted based on limiting co-phasing between the ports, or based on limiting an oversampling factor for beams available for the ports forming the ULA, or based on limiting beams selected for a first layer.

[0204] In some examples, three ports with a same polarization are a ULA which is co- phased with a third port in a same or orthogonal polarization such that each layer is transmitted on orthogonal beams generated by the precoder, in case the precoder comprises non QPSK symbols.

[0205] Furthermore, the UE sends to the network node a ‘capability of UL transmission using 3 Tx fully coherent codebook’, where the ‘capability of UL transmission using 3 Tx fully coherent codebook’ indicates support to perform PUSCH transmission using either i) codebook with 3 Tx FC precoders, or ii) codebook with 3 Tx fully-, partially- and non-coherent codebook (precoder nesting as in legacy Rel-15 UL codebooks).

[0206] When sending the ‘capability of UL transmission using 3 Tx fully coherent codebook’, the UE indicates support for one or more of a plurality of 3 Tx FC codebooks.

[0207] Furthermore, the UE may send the network node information / configuration about the antenna configuration at the UE.

[0208] The indication can further involve informing the network node about support of a codebook subset depending on the UE antenna configuration.

[0209] Fig.8 shows an example of a communication system 800 in accordance with some embodiments.

[0210] In the example, the communication system 800 includes a telecommunication network 802 that includes an access network 804, such as a radio access network (RAN), and a core network 806, which includes one or more core network nodes 808. The access network 804 includes one or more access network nodes, such as network nodes 810a and 810b (one or more of which may be generally referred to as network nodes 810), or any other similar (3GPP) access nodes or non-3GPP access points. Moreover, as will be appreciated by those of skill in the art, a network node is not necessarily limited to an implementation in which a radio portion and a baseband portion are supplied and integrated by a single vendor. Thus, it will be understood that network nodes include disaggregated implementations or portions thereof. For example, in some embodiments, the telecommunication network 802 includes one or more Open-RAN (ORAN) network nodes. An ORAN network node is a node in the telecommunication network 802 that supports an ORAN specification (e.g., a specification published by the O-RAN Alliance, or any similar organization) and may operate alone or together with other nodes to implement one or more functionalities of any node in the telecommunication network 802, including one or more network nodes 810 and / or core network nodes 808.

[0211] Examples of an ORAN network node include an open radio unit (O-RU), an open distributed unit (O-DU), an open central unit (O-CU), including an O-CU control plane (O- CU-CP) or an O-CU user plane (O-CU-UP), a RAN intelligent controller (near-real time or non-real time) hosting software or software plug-ins, such as a near-real time control application (e.g., xApp) or a non-real time control application (e.g., rApp), or any combination thereof (the adjective “open” designating support of an ORAN specification). The network node may support a specification by, for example, supporting an interface defined by the ORAN specification, such as an A1, F1, W1, E1, E2, X2, Xn interface, an open fronthaul user plane interface, or an open fronthaul management plane interface. Moreover, an ORAN access node may be a logical node in a physical node. Furthermore, an ORAN network node may be implemented in a virtualization environment (described further below) in which one or more network functions are virtualized. For example, the virtualization environment may include anO-Cloud computing platform orchestrated by a Service Management and Orchestration Framework via an O-2 interface defined by the O-RAN Alliance or comparable technologies. The network nodes 810 facilitate direct or indirect connection of user equipment (UE), such as by connecting UEs 812a, 812b, 812c, and 812d (one or more of which may be generally referred to as UEs 812) to the core network 806 over one or more wireless connections.

[0212] Example wireless communications over a wireless connection include transmitting and / or receiving wireless signals using electromagnetic waves, radio waves, infrared waves, and / or other types of signals suitable for conveying information without the use of wires, cables, or other material conductors. Moreover, in different embodiments, the communication system 800 may include any number of wired or wireless networks, network nodes, UEs, and / or any other components or systems that may facilitate or participate in the communication of data and / or signals whether via wired or wireless connections. The communication system 800 may include and / or interface with any type of communication, telecommunication, data, cellular, radio network, and / or other similar type of system.

[0213] The UEs 812 may be any of a wide variety of communication devices, including wireless devices arranged, configured, and / or operable to communicate wirelessly with the network nodes 810 and other communication devices. Similarly, the network nodes 810 are arranged, capable, configured, and / or operable to communicate directly or indirectly with the UEs 812 and / or with other network nodes or equipment in the telecommunication network 802 to enable and / or provide network access, such as wireless network access, and / or to perform other functions, such as administration in the telecommunication network 802.

[0214] In the depicted example, the core network 806 connects the network nodes 810 to one or more hosts, such as host 816. These connections may be direct or indirect via one or more intermediary networks or devices. In other examples, network nodes may be directly coupled to hosts. The core network 806 includes one more core network nodes (e.g., core network node 808) that are structured with hardware and software components. Features of these components may be substantially similar to those described with respect to the UEs, network nodes, and / or hosts, such that the descriptions thereof are generally applicable to the corresponding components of the core network node 808. Example core network nodes include functions of one or more of a Mobile Switching Center (MSC), Mobility Management Entity (MME), Home Subscriber Server (HSS), Access and Mobility Management Function (AMF), Session Management Function (SMF), Authentication Server Function (AUSF), Subscription Identifier De-concealing function (SIDF), Unified Data Management (UDM), Security EdgeProtection Proxy (SEPP), Network Exposure Function (NEF), and / or a User Plane Function (UPF).

[0215] The host 816 may be under the ownership or control of a service provider other than an operator or provider of the access network 804 and / or the telecommunication network 802, and may be operated by the service provider or on behalf of the service provider. The host 816 may host a variety of applications to provide one or more service. Examples of such applications include live and pre-recorded audio / video content, data collection services such as retrieving and compiling data on various ambient conditions detected by a plurality of UEs, analytics functionality, social media, functions for controlling or otherwise interacting with remote devices, functions for an alarm and surveillance center, or any other such function performed by a server.

[0216] As a whole, the communication system 800 of Fig.8 enables connectivity between the UEs, network nodes, and hosts. In that sense, the communication system may be configured to operate according to predefined rules or procedures, such as specific standards that include, but are not limited to: Global System for Mobile Communications (GSM); Universal Mobile Telecommunications System (UMTS); Long Term Evolution (LTE), and / or other suitable 2G, 3G, 4G, 5G standards, or any applicable future generation standard (e.g., 6G); wireless local area network (WLAN) standards, such as the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standards (WiFi); and / or any other appropriate wireless communication standard, such as the Worldwide Interoperability for Microwave Access (WiMax), Bluetooth, Z-Wave, Near Field Communication (NFC) ZigBee, LiFi, and / or any low-power wide-area network (LPWAN) standards such as LoRa and Sigfox.

[0217] In some examples, the telecommunication network 802 is a cellular network that implements 3GPP standardized features. Accordingly, the telecommunications network 802 may support network slicing to provide different logical networks to different devices that are connected to the telecommunication network 802. For example, the telecommunications network 802 may provide Ultra Reliable Low Latency Communication (URLLC) services to some UEs, while providing Enhanced Mobile Broadband (eMBB) services to other UEs, and / or Massive Machine Type Communication (mMTC) / Massive IoT services to yet further UEs.

[0218] In some examples, the UEs 812 are configured to transmit and / or receive information without direct human interaction. For instance, a UE may be designed to transmit information to the access network 804 on a predetermined schedule, when triggered by an internal or external event, or in response to requests from the access network 804. Additionally, a UE may be configured for operating in single- or multi-RAT or multi-standard mode. Forexample, a UE may operate with any one or combination of Wi-Fi, NR and LTE, i.e. being configured for multi-radio dual connectivity (MR-DC), such as E-UTRAN (Evolved-UMTS Terrestrial Radio Access Network) NR – Dual Connectivity (EN-DC).

[0219] In the example, the hub 814 communicates with the access network 804 to facilitate indirect communication between one or more UEs (e.g., UE 812c and / or 812d) and network nodes (e.g., network node 810b). In some examples, the hub 814 may be a controller, router, content source and analytics, or any of the other communication devices described herein regarding UEs. For example, the hub 814 may be a broadband router enabling access to the core network 806 for the UEs. As another example, the hub 814 may be a controller that sends commands or instructions to one or more actuators in the UEs. Commands or instructions may be received from the UEs, network nodes 810, or by executable code, script, process, or other instructions in the hub 814. As another example, the hub 814 may be a data collector that acts as temporary storage for UE data and, in some embodiments, may perform analysis or other processing of the data. As another example, the hub 814 may be a content source. For example, for a UE that is a VR headset, display, loudspeaker or other media delivery device, the hub 814 may retrieve VR assets, video, audio, or other media or data related to sensory information via a network node, which the hub 814 then provides to the UE either directly, after performing local processing, and / or after adding additional local content. In still another example, the hub 814 acts as a proxy server or orchestrator for the UEs, in particular if one or more of the UEs are low energy IoT devices.

[0220] The hub 814 may have a constant / persistent or intermittent connection to the network node 810b. The hub 814 may also allow for a different communication scheme and / or schedule between the hub 814 and UEs (e.g., UE 812c and / or 812d), and between the hub 814 and the core network 806. In other examples, the hub 814 is connected to the core network 806 and / or one or more UEs via a wired connection. Moreover, the hub 814 may be configured to connect to an M2M service provider over the access network 804 and / or to another UE over a direct connection. In some scenarios, UEs may establish a wireless connection with the network nodes 810 while still connected via the hub 814 via a wired or wireless connection. In some embodiments, the hub 814 may be a dedicated hub – that is, a hub whose primary function is to route communications to / from the UEs from / to the network node 810b. In other embodiments, the hub 814 may be a non-dedicated hub – that is, a device which is capable of operating to route communications between the UEs and network node 810b, but which is additionally capable of operating as a communication start and / or end point for certain data channels.

[0221] Fig. 9 shows a UE 900 in accordance with some embodiments. As used herein, a UE refers to a device capable, configured, arranged and / or operable to communicate wirelessly with network nodes and / or other UEs. Examples of a UE include, but are not limited to, a smart phone, mobile phone, cell phone, vehicle-mounted or vehicle embedded / integrated wireless device, etc. Other examples include any UE identified by the 3GPP, including a narrow band internet of things (NB-IoT) UE, a machine type communication (MTC) UE, and / or an enhanced MTC (eMTC) UE.

[0222] A UE may support device-to-device (D2D) communication, for example by implementing a 3GPP standard for sidelink communication, Dedicated Short-Range Communication (DSRC), vehicle-to-vehicle (V2V), vehicle-to-infrastructure (V2I), or vehicle- to-everything (V2X). In other examples, a UE may not necessarily have a user in the sense of a human user who owns and / or operates the relevant device. Instead, a UE may represent a device that is intended for sale to, or operation by, a human user but which may not, or which may not initially, be associated with a specific human user (e.g., a smart sprinkler controller). Alternatively, a UE may represent a device that is not intended for sale to, or operation by, an end user but which may be associated with or operated for the benefit of a user (e.g., a smart power meter).

[0223] The UE 900 includes processing circuitry 902 that is operatively coupled via a bus 904 to an input / output interface 906, a power source 908, a memory 910, a communication interface 912, and / or any other component, or any combination thereof. Certain UEs may utilize all or a subset of the components shown in Fig.9. The level of integration between the components may vary from one UE to another UE. Further, certain UEs may contain multiple instances of a component, such as multiple processors, memories, transceivers, transmitters, receivers, etc.

[0224] The processing circuitry 902 is configured to process instructions and data and may be configured to implement any sequential state machine operative to execute instructions stored as machine-readable computer programs in the memory 910. The processing circuitry 902 may be implemented as one or more hardware-implemented state machines (e.g., in discrete logic, field-programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), etc.); programmable logic together with appropriate firmware; one or more stored computer programs, general-purpose processors, such as a microprocessor or digital signal processor (DSP), together with appropriate software; or any combination of the above. For example, the processing circuitry 902 may include multiple central processing units (CPUs).Further, the processing circuitry 902 is configured to perform any steps of method 200 of Fig. 4.

[0225] In the example, the input / output interface 906 may be configured to provide an interface or interfaces to an input device, output device, or one or more input and / or output devices. Examples of an output device include a speaker, a sound card, a video card, a display, a monitor, a printer, an actuator, an emitter, a smartcard, another output device, or any combination thereof. An input device may allow a user to capture information into the UE 900. Examples of an input device include a touch-sensitive or presence-sensitive display, a camera (e.g., a digital camera, a digital video camera, a web camera, etc.), a microphone, a sensor, a mouse, a trackball, a directional pad, a trackpad, a scroll wheel, a smartcard, and the like. The presence-sensitive display may include a capacitive or resistive touch sensor to sense input from a user. A sensor may be, for instance, an accelerometer, a gyroscope, a tilt sensor, a force sensor, a magnetometer, an optical sensor, a proximity sensor, a biometric sensor, etc., or any combination thereof. An output device may use the same type of interface port as an input device. For example, a Universal Serial Bus (USB) port may be used to provide an input device and an output device.

[0226] In some embodiments, the power source 908 is structured as a battery or battery pack. Other types of power sources, such as an external power source (e.g., an electricity outlet), photovoltaic device, or power cell, may be used. The power source 908 may further include power circuitry for delivering power from the power source 908 itself, and / or an external power source, to the various parts of the UE 900 via input circuitry or an interface such as an electrical power cable. Delivering power may be, for example, for charging of the power source 908. Power circuitry may perform any formatting, converting, or other modification to the power from the power source 908 to make the power suitable for the respective components of the UE 900 to which power is supplied.

[0227] The memory 910 may be or be configured to include memory such as random access memory (RAM), read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically EPROM (EEPROM), magnetic disks, optical disks, hard disks, removable cartridges, flash drives, and so forth. In one example, the memory 910 includes one or more application programs 914, such as an operating system, web browser application, a widget, gadget engine, or other application, and corresponding data 916. The memory 910 may store, for use by the UE 900, any of a variety of various operating systems or combinations of operating systems.

[0228] The memory 910 may be configured to include a number of physical drive units, such as redundant array of independent disks (RAID), flash memory, USB flash drive, external hard disk drive, thumb drive, pen drive, key drive, high-density digital versatile disc (HD- DVD) optical disc drive, internal hard disk drive, Blu-Ray optical disc drive, holographic digital data storage (HDDS) optical disc drive, external mini-dual in-line memory module (DIMM), synchronous dynamic random access memory (SDRAM), external micro-DIMM SDRAM, smartcard memory such as tamper resistant module in the form of a universal integrated circuit card (UICC) including one or more subscriber identity modules (SIMs), such as a USIM and / or ISIM, other memory, or any combination thereof. The UICC may for example be an embedded UICC (eUICC), integrated UICC (iUICC) or a removable UICC commonly known as ‘SIM card.’ The memory 910 may allow the UE 900 to access instructions, application programs and the like, stored on transitory or non-transitory memory media, to off-load data, or to upload data. An article of manufacture, such as one utilizing a communication system may be tangibly embodied as or in the memory 910, which may be or comprise a device-readable storage medium.

[0229] The processing circuitry 902 may be configured to communicate with an access network or other network using the communication interface 912. The communication interface 912 may comprise one or more communication subsystems and may include or be communicatively coupled to an antenna 922. The communication interface 912 may include one or more transceivers used to communicate, such as by communicating with one or more remote transceivers of another device capable of wireless communication (e.g., another UE or a network node in an access network). Each transceiver may include a transmitter 918 and / or a receiver 920 appropriate to provide network communications (e.g., optical, electrical, frequency allocations, and so forth). Moreover, the transmitter 918 and receiver 920 may be coupled to one or more antennas (e.g., antenna 922) and may share circuit components, software or firmware, or alternatively be implemented separately.

[0230] In the illustrated embodiment, communication functions of the communication interface 912 may include cellular communication, Wi-Fi communication, LPWAN communication, data communication, voice communication, multimedia communication, short-range communications such as Bluetooth, near-field communication, location-based communication such as the use of the global positioning system (GPS) to determine a location, another like communication function, or any combination thereof. Communications may be implemented in according to one or more communication protocols and / or standards, such as IEEE 802.11, Code Division Multiplexing Access (CDMA), Wideband Code DivisionMultiple Access (WCDMA), GSM, LTE, NR, UMTS, WiMax, Ethernet, transmission control protocol / internet protocol (TCP / IP), synchronous optical networking (SONET), Asynchronous Transfer Mode (ATM), QUIC, Hypertext Transfer Protocol (HTTP), and so forth.

[0231] Regardless of the type of sensor, a UE may provide an output of data captured by its sensors, through its communication interface 912, via a wireless connection to a network node. Data captured by sensors of a UE can be communicated through a wireless connection to a network node via another UE. The output may be periodic (e.g., once every 15 minutes if it reports the sensed temperature), random (e.g., to even out the load from reporting from several sensors), in response to a triggering event (e.g., when moisture is detected an alert is sent), in response to a request (e.g., a user initiated request), or a continuous stream (e.g., a live video feed of a patient).

[0232] As another example, a UE comprises an actuator, a motor, or a switch, related to a communication interface configured to receive wireless input from a network node via a wireless connection. In response to the received wireless input the states of the actuator, the motor, or the switch may change. For example, the UE may comprise a motor that adjusts the control surfaces or rotors of a drone in flight according to the received input or to a robotic arm performing a medical procedure according to the received input.

[0233] A UE, when in the form of an IoT device, may be a device for use in one or more application domains, these domains comprising, but not limited to, city wearable technology, extended industrial application and healthcare. Non-limiting examples of such an IoT device are a device which is or which is embedded in: a connected refrigerator or freezer, a TV, a connected lighting device, a fitness tracker, a head-mounted display for Augmented Reality (AR) or Virtual Reality (VR), a wearable for tactile augmentation or sensory enhancement, an Unmanned Aerial Vehicle (UAV), and any kind of medical device, like a heart rate monitor or a remote controlled surgical robot. A UE in the form of an IoT device comprises circuitry and / or software in dependence of the intended application of the IoT device in addition to other components as described in relation to the UE 900 shown in Fig.9.

[0234] As yet another specific example, in an IoT scenario, a UE may represent a machine or other device that performs monitoring and / or measurements, and transmits the results of such monitoring and / or measurements to another UE and / or a network node. The UE may in this case be an M2M device, which may in a 3GPP context be referred to as an MTC device. As one particular example, the UE may implement the 3GPP NB-IoT standard. In other scenarios, a UE may represent a vehicle, such as a car, a bus, a truck, a ship and an airplane, orother equipment that is capable of monitoring and / or reporting on its operational status or other functions associated with its operation.

[0235] In practice, any number of UEs may be used together with respect to a single use case. For example, a first UE might be or be integrated in a drone and provide the drone’s speed information (obtained through a speed sensor) to a second UE that is a remote controller operating the drone. When the user makes changes from the remote controller, the first UE may adjust the throttle on the drone (e.g. by controlling an actuator) to increase or decrease the drone’s speed. The first and / or the second UE can also include more than one of the functionalities described above. For example, a UE might comprise the sensor and the actuator, and handle communication of data for both the speed sensor and the actuators.

[0236] Fig. 10 shows a network node 1000 in accordance with some embodiments. As used herein, network node refers to equipment capable, configured, arranged and / or operable to communicate directly or indirectly with a UE and / or with other network nodes or equipment, in a telecommunication network. Examples of network nodes include, but are not limited to, access points (APs) (e.g., radio access points), base stations (BSs) (e.g., radio base stations, Node Bs (NBs), evolved NBs (eNBs) and NR NBs (gNBs)), O-RAN nodes or components of an O-RAN node (e.g., O-RU, O-DU, O-CU).

[0237] Base stations may be categorized based on the amount of coverage they provide (or, stated differently, their transmit power level) and so, depending on the provided amount of coverage, may be referred to as femto base stations, pico base stations, micro base stations, or macro base stations. A base station may be a relay node or a relay donor node controlling a relay. A network node may also include one or more (or all) parts of a distributed radio base station such as centralized digital units, distributed units (e.g., in an O-RAN access node) and / or remote radio units (RRUs), sometimes referred to as Remote Radio Heads (RRHs). Such remote radio units may or may not be integrated with an antenna as an antenna integrated radio. Parts of a distributed radio base station may also be referred to as nodes in a distributed antenna system (DAS).

[0238] Other examples of network nodes include multiple transmission point (multi-TRP) 5G access nodes, multi-standard radio (MSR) equipment such as MSR BSs, network controllers such as radio network controllers (RNCs) or base station controllers (BSCs), base transceiver stations (BTSs), transmission points, transmission nodes, multi-cell / multicast coordination entities (MCEs), Operation and Maintenance (O&M) nodes, Operations Support System (OSS) nodes, Self-Organizing Network (SON) nodes, positioning nodes (e.g., Evolved Serving Mobile Location Centers (E-SMLCs)), and / or Minimization of Drive Tests (MDTs).

[0239] The network node 1000 includes a processing circuitry 1002, a memory 1004, a communication interface 1006, and a power source 1008. The network node 1000 may be composed of multiple physically separate components (e.g., a NB component and a RNC component, or a BTS component and a BSC component, etc.), which may each have their own respective components. In certain scenarios in which the network node 1000 comprises multiple separate components (e.g., BTS and BSC components), one or more of the separate components may be shared among several network nodes. For example, a single RNC may control multiple NBs. In such a scenario, each unique NB and RNC pair, may in some instances be considered a single separate network node. In some embodiments, the network node 1000 may be configured to support multiple radio access technologies (RATs). In such embodiments, some components may be duplicated (e.g., separate memory 1004 for different RATs) and some components may be reused (e.g., a same antenna 1010 may be shared by different RATs). The network node 1000 may also include multiple sets of the various illustrated components for different wireless technologies integrated into network node 1000, for example GSM, WCDMA, LTE, NR, WiFi, Zigbee, Z-wave, LoRaWAN, Radio Frequency Identification (RFID) or Bluetooth wireless technologies. These wireless technologies may be integrated into the same or different chip or set of chips and other components within network node 1000.

[0240] The processing circuitry 1002 may comprise a combination of one or more of a microprocessor, controller, microcontroller, central processing unit, digital signal processor, application-specific integrated circuit, field programmable gate array, or any other suitable computing device, resource, or combination of hardware, software and / or encoded logic operable to provide, either alone or in conjunction with other network node 1000 components, such as the memory 1004, to provide network node 1000 functionality.

[0241] In some embodiments, the processing circuitry 1002 includes a system on a chip (SOC). In some embodiments, the processing circuitry 1002 includes one or more of radio frequency (RF) transceiver circuitry 1012 and baseband processing circuitry 1014. In some embodiments, the radio frequency (RF) transceiver circuitry 1012 and the baseband processing circuitry 1014 may be on separate chips (or sets of chips), boards, or units, such as radio units and digital units. In alternative embodiments, part or all of RF transceiver circuitry 1012 and baseband processing circuitry 1014 may be on the same chip or set of chips, boards, or units. Further, the processing circuitry 1002 is configured to perform any steps of method 250 of Fig. 5.

[0242] The memory 1004 may comprise any form of volatile or non-volatile computer- readable memory including, without limitation, persistent storage, solid-state memory, remotely mounted memory, magnetic media, optical media, random access memory (RAM), ROM, mass storage media (for example, a hard disk), removable storage media (for example, a flash drive, a Compact Disk (CD) or a Digital Video Disk (DVD)), and / or any other volatile or non-volatile, non-transitory device-readable and / or computer-executable memory devices that store information, data, and / or instructions that may be used by the processing circuitry 1002. The memory 1004 may store any suitable instructions, data, or information, including a computer program, software, an application including one or more of logic, rules, code, tables, and / or other instructions capable of being executed by the processing circuitry 1002 and utilized by the network node 1000. The memory 1004 may be used to store any calculations made by the processing circuitry 1002 and / or any data received via the communication interface 1006. In some embodiments, the processing circuitry 1002 and memory 1004 is integrated.

[0243] The communication interface 1006 is used in wired or wireless communication of signaling and / or data between a network node, access network, and / or UE. As illustrated, the communication interface 1006 comprises port(s) / terminal(s) 1016 to send and receive data, for example to and from a network over a wired connection. The communication interface 1006 also includes radio front-end circuitry 1018 that may be coupled to, or in certain embodiments a part of, the antenna 1010. Radio front-end circuitry 1018 comprises filters 1020 and amplifiers 1022. The radio front-end circuitry 1018 may be connected to an antenna 1010 and processing circuitry 1002. The radio front-end circuitry may be configured to condition signals communicated between antenna 1010 and processing circuitry 1002. The radio front-end circuitry 1018 may receive digital data that is to be sent out to other network nodes or UEs via a wireless connection. The radio front-end circuitry 1018 may convert the digital data into a radio signal having the appropriate channel and bandwidth parameters using a combination of filters 1020 and / or amplifiers 1022. The radio signal may then be transmitted via the antenna 1010. Similarly, when receiving data, the antenna 1010 may collect radio signals which are then converted into digital data by the radio front-end circuitry 1018. The digital data may be passed to the processing circuitry 1002. In other embodiments, the communication interface may comprise different components and / or different combinations of components.

[0244] In certain alternative embodiments, the network node 1000 does not include separate radio front-end circuitry 1018, instead, the processing circuitry 1002 includes radio front-end circuitry and is connected to the antenna 1010. Similarly, in some embodiments, allor some of the RF transceiver circuitry 1012 is part of the communication interface 1006. In still other embodiments, the communication interface 1006 includes one or more ports or terminals 1016, the radio front-end circuitry 1018, and the RF transceiver circuitry 1012, as part of a radio unit (not shown), and the communication interface 1006 communicates with the baseband processing circuitry 1014, which is part of a digital unit (not shown).

[0245] The antenna 1010 may include one or more antennas, or antenna arrays, configured to send and / or receive wireless signals. The antenna 1010 may be coupled to the radio front- end circuitry 1018 and may be any type of antenna capable of transmitting and receiving data and / or signals wirelessly. In certain embodiments, the antenna 1010 is separate from the network node 1000 and connectable to the network node 1000 through an interface or port.

[0246] The antenna 1010, communication interface 1006, and / or the processing circuitry 1002 may be configured to perform any receiving operations and / or certain obtaining operations described herein as being performed by the network node. Any information, data and / or signals may be received from a UE, another network node and / or any other network equipment. Similarly, the antenna 1010, the communication interface 1006, and / or the processing circuitry 1002 may be configured to perform any transmitting operations described herein as being performed by the network node. Any information, data and / or signals may be transmitted to a UE, another network node and / or any other network equipment.

[0247] The power source 1008 provides power to the various components of network node 1000 in a form suitable for the respective components (e.g., at a voltage and current level needed for each respective component). The power source 1008 may further comprise, or be coupled to, power management circuitry to supply the components of the network node 1000 with power for performing the functionality described herein. For example, the network node 1000 may be connectable to an external power source (e.g., the power grid, an electricity outlet) via an input circuitry or interface such as an electrical cable, whereby the external power source supplies power to power circuitry of the power source 1008. As a further example, the power source 1008 may comprise a source of power in the form of a battery or battery pack which is connected to, or integrated in, power circuitry. The battery may provide backup power should the external power source fail.

[0248] Embodiments of the network node 1000 may include additional components beyond those shown in Fig. 10 for providing certain aspects of the network node’s functionality, including any of the functionality described herein and / or any functionality necessary to support the subject matter described herein. For example, the network node 1000 may include user interface equipment to allow input of information into the network node 1000and to allow output of information from the network node 1000. This may allow a user to perform diagnostic, maintenance, repair, and other administrative functions for the network node 1000.

[0249] Fig.11 is a block diagram illustrating a virtualization environment 1100 in which functions implemented by some embodiments may be virtualized. In the present context, virtualizing means creating virtual versions of apparatuses or devices which may include virtualizing hardware platforms, storage devices and networking resources. As used herein, virtualization can be applied to any device described herein, or components thereof, and relates to an implementation in which at least a portion of the functionality is implemented as one or more virtual components. Some or all of the functions described herein may be implemented as virtual components executed by one or more virtual machines (VMs) implemented in one or more virtual environments 1100 hosted by one or more of hardware nodes, such as a hardware computing device that operates as a network node, UE, core network node, or host. Further, in embodiments in which the virtual node does not require radio connectivity (e.g., a core network node or host), then the node may be entirely virtualized. In some embodiments, the virtualization environment 1100 includes components defined by the O-RAN Alliance, such as an O-Cloud environment orchestrated by a Service Management and Orchestration Framework via an O-2 interface.

[0250] Applications 1102 (which may alternatively be called software instances, virtual appliances, network functions, virtual nodes, virtual network functions, etc.) are run in the virtualization environment Q400 to implement some of the features, functions, and / or benefits of some of the embodiments disclosed herein.

[0251] Hardware 1104 includes processing circuitry, memory that stores software and / or instructions executable by hardware processing circuitry, and / or other hardware devices as described herein, such as a network interface, input / output interface, and so forth. Software may be executed by the processing circuitry to instantiate one or more virtualization layers 1106 (also referred to as hypervisors or virtual machine monitors (VMMs)), provide VMs 1108a and 1108b (one or more of which may be generally referred to as VMs 1108), and / or perform any of the functions, features and / or benefits described in relation with some embodiments described herein. The virtualization layer 1106 may present a virtual operating platform that appears like networking hardware to the VMs 1108.

[0252] The VMs 1108 comprise virtual processing, virtual memory, virtual networking or interface and virtual storage, and may be run by a corresponding virtualization layer 1106. Different embodiments of the instance of a virtual appliance 1102 may be implemented on oneor more of VMs 1108, and the implementations may be made in different ways. Virtualization of the hardware is in some contexts referred to as network function virtualization (NFV). NFV may be used to consolidate many network equipment types onto industry standard high volume server hardware, physical switches, and physical storage, which can be located in data centers, and customer premise equipment.

[0253] In the context of NFV, a VM 1108 may be a software implementation of a physical machine that runs programs as if they were executing on a physical, non-virtualized machine. Each of the VMs 1108, and that part of hardware 1104 that executes that VM, be it hardware dedicated to that VM and / or hardware shared by that VM with others of the VMs, forms separate virtual network elements. Still in the context of NFV, a virtual network function is responsible for handling specific network functions that run in one or more VMs 1108 on top of the hardware 1104 and corresponds to the application 1102.

[0254] Hardware 1104 may be implemented in a standalone network node with generic or specific components. Hardware 1104 may implement some functions via virtualization. Alternatively, hardware 1104 may be part of a larger cluster of hardware (e.g. such as in a data center or CPE) where many hardware nodes work together and are managed via management and orchestration 1110, which, among others, oversees lifecycle management of applications 1102. In some embodiments, hardware 1104 is coupled to one or more radio units that each include one or more transmitters and one or more receivers that may be coupled to one or more antennas. Radio units may communicate directly with other hardware nodes via one or more appropriate network interfaces and may be used in combination with the virtual components to provide a virtual node with radio capabilities, such as a radio access node or a base station. In some embodiments, some signaling can be provided with the use of a control system 1112 which may alternatively be used for communication between hardware nodes and radio units.

[0255] Although the computing devices described herein (e.g., UEs, network nodes, hosts) may include the illustrated combination of hardware components, other embodiments may comprise computing devices with different combinations of components. It is to be understood that these computing devices may comprise any suitable combination of hardware and / or software needed to perform the tasks, features, functions and methods disclosed herein. Determining, calculating, obtaining or similar operations described herein may be performed by processing circuitry, which may process information by, for example, converting the obtained information into other information, comparing the obtained information or converted information to information stored in the network node, and / or performing one or more operations based on the obtained information or converted information, and as a result of saidprocessing making a determination. Moreover, while components are depicted as single boxes located within a larger box, or nested within multiple boxes, in practice, computing devices may comprise multiple different physical components that make up a single illustrated component, and functionality may be partitioned between separate components. For example, a communication interface may be configured to include any of the components described herein, and / or the functionality of the components may be partitioned between the processing circuitry and the communication interface. In another example, non-computationally intensive functions of any of such components may be implemented in software or firmware and computationally intensive functions may be implemented in hardware.

[0256] In certain embodiments, some or all of the functionality described herein may be provided by processing circuitry executing instructions stored on in memory, which in certain embodiments may be a computer program product in the form of a non-transitory computer- readable storage medium. In alternative embodiments, some or all of the functionality may be provided by the processing circuitry without executing instructions stored on a separate or discrete device-readable storage medium, such as in a hard-wired manner. In any of those particular embodiments, whether executing instructions stored on a non-transitory computer- readable storage medium or not, the processing circuitry can be configured to perform the described functionality. The benefits provided by such functionality are not limited to the processing circuitry alone or to other components of the computing device, but are enjoyed by the computing device as a whole, and / or by end users and a wireless network generally.

[0257] Those skilled in the art will recognize improvements and modifications to the embodiments of the present disclosure. All such improvements and modifications are considered within the scope of the concepts disclosed herein.

Claims

Claims 1. A method (200) performed by a user equipment (UE, 812, 900) having 3 antenna ports, for performing uplink (UL) codebook-based transmission using one or more 3 Transmit (Tx) partially coherent (PC) precoders from a PC codebook, the method comprising: - transmitting (210) a reference signal to a network node; - receiving (220) an indication of a precoder based on the transmitted reference signal; and - transmitting (230) data based on the indicated precoder, wherein the indicated precoder is determined based on the 3 antenna ports, the 3 antenna ports being divided into two antenna- port groups, wherein: a. a first antenna-port group has two antenna ports, and a second antenna port group has one antenna port, b. the two antenna-port groups are mutually non-coherent, and c. the antenna ports in the first antenna port group are fully-coherent.

2. The method of claim 1, wherein the one or more 3Tx PC precoders are designed such that, a precoder for the second antenna port group is given by a scalar and a precoder for the first antenna port group is given by one of the following: a. based on Release-152 Transmit (Tx) precoders, or b. based Release-15 Downlink (DL) Type-I codebook, or c. a new set of 2 Tx precoders with fully coherent precoders.

3. The method of any one of claims 1 to 2, wherein the two antenna ports within the first antenna port group are one of a dual polarized antenna port and two single polarized antenna ports with the same polarization.

4. The method of any one of claims 1 to 3, wherein a number of 3 Tx PC precoders is restricted by: a. limiting a co-phasing between the two antenna ports in the first antenna-port group; or b. removing PC precoders for which each configured layer is transmitted from not more than one antenna port.

5. The method of any one of claims 1 to 4, further comprising one or more of the following: a. sending to the network node, a capability of UL transmission using 3 Tx PC precoders; b. receiving a message containing a configuration of one or more sounding reference signal (SRS) resources;c. receiving a configuration of a 3 Tx PC codebook; d. receiving a trigger message to transmit the SRS resources; and e. receiving an indication to perform a Physical Uplink Shared Channel (PUSCH) transmission and an indication of which rank and precoder that should be applied on the PUSCH transmission, where the rank and precoder are associated with the 3 Tx PC codebook configuration.

6. The method of claim 5, wherein the capability of UL transmission using 3 Tx PC codebook indicates support to perform PUSCH transmission using either i) a codebook with 3 Tx PC precoders, or ii) a codebook with both 3 Tx partially- and non-coherent codebooks.

7. The method of any one of claims 1 to 6, wherein the indication of the precoder is a Transmit Precoding Matric Indicator (TPMI).

8. The method of claim 1, further comprising indicating support for a 3 Tx PC codebook with full power mode 1.

9. The method of claim of 8, wherein more than one precoder is included in the 3 Tx PC codebook for full power mode 1 for rank 1, and wherein a “1” is used for the second antenna port group, and wherein different precoders use different co-phasing factors applied over the two antenna ports associated with the first antenna-port group 10. The method of any one of claims 1 to 9, wherein the indication of the precoder indicates mapping of PUSCH layers to a single 3-port SRS resource.

11. The method of any one of claims 1 to 9, wherein the indication of the precoder indicates mapping of PUSCH layers to multiple SRS resources, each SRS resource having less than 3 SRS ports, wherein: a. a first SRS resource has 2 SRS ports and a second SRS resource has 1 SRS port, the 2 SRS ports in the first SRS resource being coherent; or b. all SRS resources have 1 SRS port, with coherence being maintained over first two SRS resources.

12. The method of claim 11, wherein the first SRS resource or the first two SRS resources in the plurality of SRS resources is a SRS resource with the lowest ID or two SRS resources with the lowest resource ID and second lowest resource ID.

13. The method of any one of claims 1 to 12, wherein a SRS port is mapped to an antenna port.

14. A method (250) performed by a network node (810, 1000) for receiving uplink (UL) codebook-based transmission using 3 Transmit (Tx) partially coherent (PC) precoders from a PC codebook, the method comprising:- receiving (260) a reference signal from a user equipment (UE); - transmitting (270), to the UE, an indication of a precoder based on the received reference signal; and - receiving (280) data based on the indicated precoder, wherein the precoder is determined based on 3 antenna ports in the UE, the 3 antenna ports being divided into two antenna-port groups, wherein: a. a first antenna port group has two antenna ports, and a second antenna port group has one antenna port, b. the two antenna port groups are mutually non-coherent, and c. the antenna ports in the first antenna port group are fully-coherent.

15. The method of claim 14, wherein the 3 Tx PC precoders are designed such that, a precoder for the second antenna port group is given by a scalar and a precoder for the first antenna port group is given by one of the following: a. based on Release-152 Transmit (Tx) precoders, or b. based Release-15 Downlink (DL) Type-I codebook, or c. a new set of 2 Tx precoders with fully coherent precoder.

16. The method of any one of claims 14 to 15, wherein the two antenna ports within the first antenna port group are one of a dual polarized antenna port and two single polarized antenna port with the same polarization.

17. The method of any one of claims 14 to 16, wherein the number of partially-coherent precoders is restricted by: a. limiting a co-phasing between the two coherent ports in the first antenna port group; or b. removing PC precoders for which each configured layer is transmitted from not more than one antenna port.

18. The method of any one of claims 14 to 17, further comprising one or more of the following: f. receiving from the UE, a capability of UL transmission using 3 Tx PC codebook; g. transmitting a message containing a configuration of one or more sounding reference signal (SRS) resources; h. transmitting a configuration of a 3 Tx PC codebook; i. transmitting a trigger message to transmit the SRS resources; j. transmitting an indication to perform a Physical Uplink Shared Channel(PUSCH) transmission and an indication of which rank and precoder that should be applied on the PUSCH transmission, where the rank and precoder are associated with the 3 Tx PC codebook configuration.

19. The method of claim 18, wherein the capability of UL transmission using 3 Tx PC codebook indicates support to perform PUSCH transmission using either i) a codebook with 3 Tx PC precoders, or ii) a codebook with both 3 Tx partially- and non-coherent codebook.

20. The method of any one of claims 14 to 19, wherein the indication of the precoder is a TPMI.

21. The method of any one of claims 14 to 20, wherein the indication of the precoder indicates mapping of PUSCH layers to a single 3-port SRS resource.

22. The method of any one of claims 14 to 21, wherein the indication of the precoder indicates mapping of PUSCH layers to multiple SRS resources, each SRS resource having less than 3 SRS ports, wherein: a. a first SRS resource has 2 SRS ports and a second SRS resource has 1 SRS port, the 2 SRS ports in the first SRS resource being coherent. b. all SRS resources have 1 SRS port, with coherence being maintained over first two SRS resources.

23. The method of any one of claims 14 to 22, wherein a SRS port is mapped to an antenna port.

24. A user equipment (812, 900), comprising processing circuitry (902) and a network interface (912) connected thereto, the processing circuitry (902) configured to perform the method of any one of claims 1 to 13.

25. A network node (810, 1000) comprising processing circuitry (1002) and a network interface (1006) connected thereto, the processing circuitry (1002) configured to perform the method of any one of claims 14 to 23.

26. A computer program product comprising a computer readable memory storing computer executable instructions thereon that when executed by a computer perform any one of the methods of any one of claims 1 to 23.

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