8Tx codebook enhancement

Abstract

An example method includes receiving a configuration from a wireless communication node. The configuration indicates at least one of: a number of one or more port groups, or one or more levels of coherence. The example method also includes determining a precoding for transmission according to the configuration. The example method also includes performing a transmission using precoding. In some embodiments, the total number of ports across the port group is eight.

Description

Technical Field

[0001] The present disclosure relates generally to digital wireless communications. Background Art

[0002] Mobile communication technology is driving the world towards an increasingly connected and networked society. Compared with existing wireless networks, next-generation systems and wireless communication technologies will need to support a wider range of use case features and provide more complex and sophisticated access requirements and flexibility.

[0003] Long Term Evolution (LTE) is a wireless communication standard for mobile devices and data terminals developed by the Third Generation Partnership Project (3GPP). LTE-Advanced (LTE-A) is a wireless communication standard that enhances the LTE standard. The fifth generation wireless system, called 5G, advances the LTE and LTE-A wireless standards and is committed to supporting higher data rates, a large number of connections, ultra-low latency, high reliability, and other emerging business requirements. Summary of the invention

[0004] Techniques for enhancing 8Tx transmission precoding are disclosed. Example embodiments disclosed herein address technical issues related to current codebook issues, overhead of precoding indication, and unclear port indexing for uplink 8Tx. Example embodiments provide solutions related to determining a codebook for uplink 8Tx transmission, reducing the number of candidates for non-coherent codebooks, and port index mapping.

[0005] In an exemplary aspect, a method for wireless communication is described. The method includes receiving a configuration from a wireless communication node, the configuration indicating at least one of: one or more port group numbers, or one or more coherence levels. The method also includes determining a precoding for transmission based on the configuration. The method also includes performing the transmission using the precoding.

[0006] In some embodiments, the total number of ports is eight. In some embodiments, the one or more numbers of port groups indicated by the configuration include one or more of: one port group, two port groups, four port groups, or eight port groups; and the one or more coherence levels indicated by the configuration include one or more of: full coherence, first type of partial coherence, second type of partial coherence, and incoherence.

[0007] In some embodiments, the method further comprises sending information to the wireless communication node, the information indicating the number of one or more port groups supported or the one or more coherence levels supported. In some embodiments, the indicated number of port groups or the indicated coherence level is the highest capability, and the highest capability indicates that one or more capabilities lower than the highest capability are configured or supported. In some embodiments, the order of port group capabilities from highest to lowest is one port group, two port groups, four port groups, and eight port groups; and the order of coherence capabilities from highest to lowest is full coherence, partial coherence of the first type, partial coherence of the second type, and incoherence.

[0008] In some embodiments, determining the precoding for transmission according to the configuration includes: determining the presence or size of an indication of the number of port groups for codebook indication according to the configuration. In some embodiments, determining the precoding for transmission according to the configuration includes: determining one or more numbers of port groups for codebook indication, and determining the presence or size of the indication of the number of port groups according to the determined one or more numbers of port groups for codebook indication. In some embodiments, determining the precoding for transmission according to the configuration includes: determining a given number of port groups according to the indication of the number of port groups, and determining at least one of the following for each port group in the given number of port groups: rank, number of layers, or transmission precoding matrix indicator (TPMI). In some embodiments, determining the precoding for transmission according to the configuration includes: determining a given number of port groups according to the indication of the number of port groups, determining the phase between every two port groups in the given number of port groups, and determining at least one of the following for at least some of the port groups in the given number of port groups: rank, number of layers, or TPMI. In some embodiments, the indication of the number of port groups is included in downlink control information (DCI), media access control (MAC) control element (CE), or radio resource control (RRC) signaling.

[0009] In some embodiments, precoding is determined according to parameters of a scheme of a downlink codebook based on one or more port group numbers being one port group, or precoding is determined according to parameters of a scheme of an uplink codebook based on one or more port group numbers being coherent more than one port group.

[0010] In some embodiments, the method further comprises: determining a value of an oversampling factor in a polarization direction according to the number of antenna elements in the polarization direction.

[0011] In some embodiments, the configuration is received via one of: RRC signaling, MAC CE, or DCI.

[0012] In some embodiments, the precoding is determined based on at least one of the following: the number of port groups, the starting port index, or the order of port indexes. In some embodiments, the precoding is determined based on the number of consecutive port indexes according to at least one of the following: the number of port groups, the starting port index, or the order of port indexes. In some embodiments, the starting port index is determined based on the number of port groups. In some embodiments, the order of port indexes is one of the following: {0,4,1,5,2,6,3,7}, {0,1,2,3,4,5,6,7}, {0,2,1,3,4,6,5,7}, {0,1,4,5,2,3,6,7} or {0,4,2,6,1,5,3,7}.

[0013] In some embodiments, the method further comprises: mapping ports in one or more port groups to precoded ports according to at least one of the one or more predefined mappings. In some embodiments, the one or more predefined mappings comprise: mapping of two port groups to precoded ports {0,1,4,5,2,3,6,7} or to precoded ports {0,2,4,6,1,3,5,7}, each of which has four ports, or mapping of four port groups to precoded ports {0,4,1,5,2,6,3,7}, each of which has two ports.

[0014] In another exemplary aspect, another method for wireless communication is disclosed. The method includes: transmitting a configuration to a wireless communication device, the configuration indicating at least one of: one or more port group numbers, or one or more coherence levels. The method also includes: indicating to the wireless communication device a precoding for transmission according to the configuration, or an indication of the number of port groups. Then, the transmission is performed using the precoding.

[0015] In some embodiments, the method further comprises determining the presence or size of an indication of a number of port groups for a codebook indication.

[0016] In some embodiments, the total number of ports is eight. In some embodiments, the specific number of port groups is one of: one port group, two port groups, four port groups, or eight port groups; the specific coherence level is one of: full coherence, first type of partial coherence, second type of partial coherence, and incoherence.

[0017] In some embodiments, the indicated number of port groups or the indicated level of coherence is a highest capability, and the highest capability indicates that one or more capabilities lower than the highest capability are configured or supported. In some embodiments, the order of port group capabilities from highest to lowest is one port group, two port groups, four port groups, and eight port groups, and the order of coherence capabilities from highest to lowest is full coherence, partial coherence of the first type, partial coherence of the second type, and incoherence.

[0018] In some embodiments, the indication of the number of port groups is included in DCI, MAC CE or RRC signaling.

[0019] In some embodiments, the method further comprises: indicating the number of antenna elements of the polarization direction in the configuration.

[0020] In some embodiments, the configuration is sent via one of: radio resource control (RRC) signaling, a medium access control (MAC) control element, or a downlink control indicator (DCI).

[0021] In another exemplary aspect, the above method is embodied in the form of processor executable code and stored in a non-transitory computer readable storage medium. When executed by a processor, the code included in the computer readable storage medium causes the processor to implement the method described in this patent document.

[0022] In yet another exemplary embodiment, a device configured or operable to perform the above method is disclosed.

[0023] The above and other aspects and implementations thereof are described in more detail in the drawings, the description and the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figures 1A to 1C Different physical antenna layouts for different numbers of port groups are shown.

[0025] Figure 2 An example grouping of 8 Tx ports is shown.

[0026] Figure 3 An example grouping of 8 Tx ports according to a downlink port indexing scheme is shown.

[0027] Figure 4 An example grouping of 8 Tx ports according to the uplink port indexing scheme is shown.

[0028] Figure 5 An exemplary flow chart related to 8Tx transmission precoding configured by a network is shown.

[0029] Figure 6An exemplary flow chart related to 8Tx transmission precoding including user equipment (UE) capability reporting is shown.

[0030] Figure 7 An exemplary block diagram of a hardware platform is shown, which may be part of a network device or a communication device.

[0031] Figure 8 An example of wireless communication including a base station (BS) and a UE based on some implementations of the disclosed technology is shown. DETAILED DESCRIPTION

[0032] The new radio (NR) technology of the fifth generation (5G) mobile communication system is constantly improving to provide higher quality wireless communication. One of the key features is support for high frequency bands. High frequency bands have abundant frequency domain resources, but wireless signals in high frequency bands attenuate quickly and have a small coverage range. Therefore, transmitting signals in beam mode can concentrate energy in a relatively small spatial range and improve the coverage of wireless signals in high frequency bands.

[0033] However, there are some technical issues, especially regarding signal transmission in beam mode and other example scenarios. First, for a user equipment (UE) configured for full coherence, a downlink (DL) type I codebook or an uplink (UL) 2Tx / 4Tx codebook can be used for transmission, but for some cases including multi-panel coherence scenarios, a downlink type I codebook is not defined. Second, the overhead of precoding indication is large. Third, the port index of uplink (UL) 8Tx is unclear. The example embodiments disclosed herein at least solve these technical problems.

[0034] The example titles of the following sections are used to facilitate understanding of the disclosed subject matter and do not limit the scope of the claimed subject matter in any way. Therefore, one or more features of one example section can be combined with one or more features of another example section. In addition, 5G terminology is used for clarity of explanation, but the technology disclosed in this document is not limited to 5G technology, but can also be used in wireless systems that implement other protocols.

[0035] Example 1

[0036] Embodiments disclosed herein relate to a method for determining a codebook for UL 8Tx.

[0037] As mentioned above, for fully coherent UEs, a DL Type I codebook or a UL 2TX / 4TX codebook may be used, but for some cases of multi-panel coherent scenarios, no DL Type I codebook is defined. In addition, as indicated, the overhead of precoding indication is relatively large.

[0038] Table 1 indicates the supported codebooks and rank indications according to the number of port groups and the coherence capability. Table 1 describes different multi-panel coherence scenarios.

[0039] Table 1

[0040]

[0041] The physical antenna layout corresponding to the physical antenna layout shown in Table 1 is as follows Figures 1A to 1C In some embodiments, Figures 1A to 1C Each square shown in each of the represents a pair of antenna ports, and Figures 1A to 1C The physical antenna layout of 8Tx is shown. For example, Figure 1A shows an example physical layout of a port group, Figure 1B shows an example physical layout of two port groups, Figure 1C An example physical layout of four port groups is shown. As shown in Table 1 and Figure 1B and Figure 1C As shown, at least for the examples of two port groups and four port groups, there are different multi-panel coherence scenarios.

[0042] 1. Design of fully coherent 8-Tx codebook:

[0043] For fully coherent UEs, the following categories are considered:

[0044] CAT-A0: One port group (with 8 Tx ports), coherent within the port group.

[0045] CAT-A1: Two port groups (each with 4Tx ports), coherent within the port group and incoherent across groups.

[0046] CAT-A2: Four port groups (each port group has 2Tx ports), coherent within the port group and incoherent across groups.

[0047] Note that a port group can be implemented by one panel or multiple panels with uniform spacing.

[0048] In some embodiments, for a fully coherent codebook design:

[0049] The DL I type single panel codebook solution can be used for CAT-A0.

[0050] The DL I type multi-panel codebook solution can be used for CAT-A1 and A2.

[0051] For the fully coherent codebook design, CAT-A0 and CAT-A1 can have the same UL 4Tx Transmit Precoding Matrix Indicator (TPMI) based scheme, i.e., one common UL 4Tx TPMI and one additional co-phase. CAT-A2 can have a similar scheme, i.e., one common UL 2Tx TPMI and 3 additional co-phases.

[0052] For example, the UL 4-Tx codebook scheme provides a four-port codebook with a rank of 1 or 2 or 3 or 4, by using an additional phase offset φ n , which can be enhanced to an eight-port codebook of rank 2 or 4 or 6 or 8. Then, the eight-port codebook of rank 1-8 can be determined as a subset of columns, for example, the first R (rank value) columns. The basic W 4×4 The fully coherent codebook can be extended to an eight-port codebook W with a rank of 8 8×8 , as shown in Formula 1.

[0053] Equation 1

[0054]

[0055] Similarly, the basic W 2×2 The fully coherent codebook can be extended to an 8-port codebook W with a rank of 8 8×8 , as shown in Formula 2 below.

[0056] Equation 2

[0057]

[0058] In some examples, φ n The number of candidate values ​​is 2 or 4.

[0059] Therefore, it is possible to consider adopting a DL-based codebook solution for a fully coherent case of one port group (for example, higher than CAT-A0), and adopting a UL-based codebook solution for a fully coherent case of multiple port groups (for example, higher than CAT-A1, A2).

[0060] 2. Design of partially coherent 8-Tx codebook:

[0061] The partially coherent 8-Tx codebook can be used for partially coherent UEs as well as fully coherent and partially coherent UEs.

[0062] The 8Tx ports may be divided into multiple port groups to support partial coherence, wherein ports included in a port group are coherent and ports across port groups may be coherent or incoherent.

[0063] In some embodiments, partially coherent 8Tx considers at least the following types:

[0064] Partially coherent type 1, i.e. 4+4: two port groups, each with four ports, and the individual rank of each port group is 0-4. For example, CAT-B0 includes two port groups, each with 4 Tx ports, and incoherent across groups. For example, CAT-B1 includes four port groups, each with 2 Tx ports, and the four Tx ports within a pair of port groups are coherent and incoherent across two pairs of port groups.

[0065] Partial coherence type 2, i.e. 2+2+2: four port groups, each with two ports, and the individual rank of each port group is 0 to 2. For example, CAT-C0 includes four port groups, each with 2 Tx ports, and the four Tx ports within each port group are coherent and incoherent across port groups.

[0066] In some embodiments, each port group may have an individual TPMI / precoding vector, or a shared TPMI / precoding vector, depending on the antenna / panel layout assumptions on the UE. If the UE (especially for customer terminal equipment or customer premises equipment (CPE)) has a similar antenna configuration as the network node (e.g., gNodeB), then a shared TPMI / precoding vector is reasonable and the overhead of the TPMI indication is low. If the port groups are coherent, a shared TPMI / precoding vector should be applied.

[0067] Regarding the candidate codebooks for each port group, the UL 4-Tx codebook may be considered for the 4-Tx port group, and the UL 2-Tx codebook may be considered for the 2-Tx port group. Additional considerations are:

[0068] For each port group, the rank may be independent. For each 4-port group, the rank may be 0-4. For each 2-port group, the rank may be 0-2. However, in some embodiments, the rank of each port group is excluded to be all zero.

[0069] Fully coherent 2Tx / 4Tx TPMI vs. fully coherent + partial + incoherent 2Tx / 4Tx TPMI: The combination of all possible ranks + TPMI for each port group may result in a large number of candidate codebooks for partial coherence. Therefore, in some embodiments, fully coherent 2Tx / 4Tx TPMI is preferred.

[0070] The embodiments disclosed herein include UE capability related solutions to the above-mentioned problems and technical issues.

[0071] In some embodiments, to support UL 8Tx transmission, the UE transmits capability information related to port group capability and / or coherence capability to the network. In some embodiments, the capability information includes at least one of the following: information on the number of port groups, or information related to the coherence level.

[0072] For the information about the number of port groups, you can use one of the following solutions:

[0073] 1. The UE indicates the highest port group number level to the network. The indication of the highest port group number level indicates that other port group number levels lower than the highest level can be supported. In some embodiments, the port group number levels can be: one port group, two port groups, four port groups, or eight port groups in descending order. Thus, for example, if the UE indicates the highest port group level as two port groups, the UE indicates that the UE also supports four port groups and eight port groups, but does not support one port group.

[0074] 2. The UE indicates to the network one or more levels of the number of port groups supported. For example, the UE explicitly indicates to the network each number of supported port groups. The one or more levels supported may be indicated from a predefined candidate set, for example, according to Table 2, each candidate set indicating one or more levels. There are 16 entries, each entry for a number of port groups, or a combination of more than one number of port groups. In some embodiments, the candidate entries may include a subset of the entries shown in Table 2.

[0075] Table 2

[0076]

[0077] Therefore, in some embodiments, in either scheme, the UE indicates to the network the number of one or more port groups supported by the UE.

[0078] For the coherence level information, one of the following solutions can be used:

[0079] 1. The highest coherence level is indicated by the UE to the network. The indication of the highest coherence level indicates that other coherence levels lower than the highest level may be supported. In some embodiments, the coherence levels may be, in descending order: full coherence, first type of partial coherence, second type of partial coherence, and incoherence, which may be denoted as coherence levels 1, 2, 3, and 4, respectively. Thus, for example, if the UE indicates the highest coherence level 2, the UE indicates that the UE supports first type of partial coherence, second type of partial coherence, and incoherence, but does not support full coherence.

[0080] 2. The UE indicates to the network one or more supported coherence levels. The supported one or more coherence levels may be indicated from a predefined candidate set, for example, according to Table 3, each candidate set indicating one or more coherence levels. There are 16 entries, each for a coherence level, or a combination of more than one coherence level. In some embodiments, the candidate entries may include a subset of the entries shown in Table 3.

[0081] Table 3

[0082]

[0083]

[0084] Thus, in some embodiments, in either approach, the UE indicates to the network one or more coherence levels supported by the UE.

[0085] In some embodiments, the UE may report information of the number of port groups without coherence level information, and one port group, two port groups, four port groups, or eight port groups correspond to the highest coherence level 1, 2, 3, or 4, respectively.

[0086] In some embodiments, the UE may report information about the number of port groups and coherence level information. In some examples, one port group, two port groups, or four port groups may support coherence levels 1, 2, 3, or 4. Eight port groups may only support coherence level 4.

[0087] In some embodiments, to support UL 8Tx transmission, the network may transmit (or indicate or configure) at least one of the following information to the UE: information on the number of port groups or coherence level information, for example, via RRC signaling, MAC CE or DCI. For example, the network (e.g., a wireless communication node) transmits a configuration indicating the information to the UE. The port group information and the coherence level information may be indicated for UE capabilities as described above.

[0088] In some embodiments, to support UL 8Tx transmission, the network may transmit (or indicate or configure) at least one of the following information to the UE, for example, via RRC signaling, MAC CE or DCI: candidate port group or candidate TPMI / precoding set.

[0089] The candidate port group may include port group information (as described above for UE capabilities). For example, the candidate port group may be the highest port group number level, which indicates that other port group number levels lower than the highest level may be supported. As another example, the candidate port group may be a code point indicating an entry in a predefined table (e.g., a table for one or more port group number levels supported, Table 3). As yet another example, the candidate port group may be a bitmap indicating that a partial port group can be supported. For example, in the case of a four-port group, bitmap 0001 indicates that one of the four port groups (e.g., the first or last, the highest number or the lowest number) is a candidate port group. The candidate port group indication is port group selection information.

[0090] The candidate TPMI / precoding set may include a candidate TPMI / precoding set for restriction or for available. For the UE, only some TPMI / precodings are allowed to be indicated in the DCI.

[0091] In some embodiments, Tx may be a transmission antenna, an antenna port.

[0092] For a UE supporting 8Tx with one port group having full coherence level, it may be by default or indicated to support two port groups (each with 4Tx), four port groups (each with 2Tx), and / or eight port groups (each with 1Tx). It may support full coherence with one port group (part 1 in Table 1), partial coherence of the first type with two port groups (part 2 in Table 1), partial coherence of the second type with four port groups (part 3 in Table 1), and / or incoherence with eight port groups (part 4 in Table 1).

[0093] For a UE supporting 8Tx with two port groups having full coherence levels, it may be defaulted or indicated to support four port groups (each with 2Tx) and / or eight port groups (each with 1Tx). It may support full coherence with two port groups (Part 1 in Table 1), partial coherence of the first type with two port groups (Part 2 in Table 1), partial coherence of the second type with four port groups (Part 3 in Table 1), and / or incoherence with eight port groups (Part 4 as described above).

[0094] For a UE supporting 8Tx with two port groups having partially coherent 1 port, it may by default or be indicated to support four port groups (each with 2Tx) and / or eight port groups (each with 1Tx). It may support partially coherent of the first type with two port groups (Part 2), partially coherent of the second type with four port groups (Part 3), and / or incoherent with eight port groups (Part 4).

[0095] For a UE supporting 8Tx with full coherence level with four port groups, it may by default or be indicated to support eight port groups, each with one port. It may support full coherence with four port groups (Part 1), partial coherence of the first type with four port groups (Part 2), partial coherence of the second type with four port groups (Part 3), and / or incoherence with eight port groups (Part 4).

[0096] For a UE supporting 8Tx with four port groups having partially coherent 1 port, it may by default or be indicated to support eight port groups, each with one port. It may support partially coherent of the first type with four port groups (Part 2), partially coherent of the second type with four port groups (Part 3), and / or non-coherent with eight port groups (Part 4).

[0097] For a UE supporting 8Tx with four port groups having partially coherent 2 ports, it may by default or be indicated to support eight port groups (each with 1 Tx). It may support the second type of partially coherent (Part 3) with four port groups and / or non-coherent (Part 4) with eight port groups.

[0098] For a UE supporting 8Tx with eight port groups having non-coherent ports. It can support non-coherent (Part 4) with eight port groups.

[0099] A port group corresponds to one panel. If more than one port group is coherent, the precoding may be determined based on the small size precoding for one port group and one or more additional phase offsets.

[0100] In some embodiments, the UE determines the precoding for the full coherence level based on the number of port groups. In some embodiments, for a port group, the precoding is determined based on a first set of parameters. For example, the first set of parameters corresponds to a DL codebook-based scheme. For example, the first set of parameters includes at least one of the following: i1 (may include i 1，1 、i 1,2 、i 1,3 or 1，4 ) or i2, N1, N2, O1, O2 values, codebook mode (codebookMode), etc. In some embodiments, for more than one port group, precoding is determined according to a second set of parameters. For example, the second set of parameters corresponds to a UL codebook-based scheme. For example, the second set of parameters includes at least one of the following: TPMI or one or more phase offsets (i.e., co-phase).

[0101] In some embodiments, the UE determines the precoding according to the port group indication. The port group indication (i.e., the indication of the number of port groups indicated for the codebook indication) is indicated in the DCI, MAC CE or RRC signaling, and may indicate the number of port groups. In some embodiments, the port group indication is an indication of the number of port groups. For example, the indication of the number of port groups may be used to select a given number of port groups or more than one number of port groups from a set of numbers of port groups according to a configuration or according to one or more numbers of port groups determined for the codebook indication.

[0102] The number of port groups may be one selected from a set of predetermined numbers, for example, the set of predetermined numbers may be a set (1, 2, 4, 8) or a subset of (1, 2, 4, 8). The set or subset may be determined according to the candidate port group indication, for example, via RRC signaling, MAC CE, or in a predetermined manner.

[0103] For example, if the predetermined number set is a set (1, 2, 4, 8) according to the candidate port group indication via RRC signaling, the port group indication field in the DCI may be 2 bits.

[0104] For example, if the predetermined number set is a set (1, 2) according to the candidate port group indication via RRC signaling or MAC CE, the port group indication field in the DCI may be 1 bit.

[0105] For port group numbers 1, 2, 4, and 8, the precoding indications correspond to full coherence (part 1 in Table 1), first type of partial coherence (part 2 in Table 1), second type of partial coherence (part 3 in Table 1), and incoherence (part 4 as described above), respectively.

[0106] For a port group corresponding to full coherence, a field of rank and TPMI / precoding may be further indicated.

[0107] For two port groups corresponding to the first type of partial coherence, two fields of rank and TPMI / precoding may be further indicated, each field having a rank and TPMI indication corresponding to the port group.

[0108] For the four port groups corresponding to the second type of partial coherence, four fields of rank and TPMI / precoding may be further indicated, each field having a rank and TPMI indication corresponding to the port group.

[0109] For eight port groups corresponding to non-coherence, eight fields of rank may be further indicated, each field corresponding to a port group, or one field of rank combination indication may be indicated.

[0110] For full coherence with DL type I codebook, partial coherence with UL TPMI scheme (two types), the overhead of the precoding indication indicated by "joint indication of each group rank+TPMI" is analyzed according to Table 4 below.

[0111] Table 4

[0112]

[0113]

[0114] In some embodiments, for each port group, the number of Tx ports (configured Tx ports) should be the same; the coherence type should be the same; only fully coherent TPMI / precoding sets can be indicated; the rank parameter is indicated separately; and the port group is disabled by rank = 0 or null. For example, #1: including 0 or null rank value is jointly encoded with TPMI; #2: for rank, including a separate RI indication of 0 or null, or #3: including one or more rank RI combinations with "0 or null".

[0115] If more than one port group is non-coherent, when determining 8Tx precoding, a rank is indicated for each port group, and each port group having a rank layer number is not in the same layer, ie, not in a separate layer.

[0116] In some embodiments, in order to maintain the orthogonal phase shift keying (QPSK) constellation, restrictions should be imposed on N1, N2 and O1, O2: N1*O1<=4, and N2*O2<=4. For example, if N1 or N2 is 4, then O1 or O2 can be 1 respectively; if N1 or N2 is 2, then O1 or O2 can be 1 or 2 respectively.

[0117] In some embodiments, the UE is configured by the network values ​​of N1 and N2. N1 and N2 represent the number of rows and columns of antenna elements in the panel (antenna panel), respectively. In the case where the value of N1 or N2 is 1, O1 or O2 is 1. In the case where the value of N1 or N2 is 2, O1 or O2 can be 1 or 2, depending on the indication for oversampling, for example, 1 bit from the network to indicate 1 or 2. In the case where the value of N1 or N2 is 4, O1 or O2 can be 1.

[0118] N1 is defined as the number of horizontal antenna elements on one polarization. N2 is defined as the number of vertical antenna elements on one polarization. O1 is defined as the value of the oversampling factor on one polarization in the horizontal direction. O2 is defined as the value of the oversampling factor on one polarization in the vertical direction.

[0119] Example 2

[0120] Example embodiments relate to methods for reducing the number of candidates for a non-coherent codebook.

[0121] For non-coherent (as described in Section 4 above), there are 255 cases with sufficient flexibility for the non-coherent case. This number is a relatively large value compared to the number for full coherent precoding, which results in high overhead.

[0122] To address this high overhead problem, the embodiments described below provide a reduction in the number of non-coherent codebook candidates.

[0123] 1) Antenna layout with 8 groups:

[0124] Full flexibility: 255 cases

[0125] Fixed start Tx port (e.g., 0) + consecutive Tx ports: Number of cases: 8

[0126] Any starting Tx port + consecutive Tx ports: number of cases: 8+7+6+…+2+1=36.

[0127] 2) Antenna layout with 4 groups:

[0128] The starting port can be one of each port group (panel), for example {0,2,4,6}

[0129] + Number of continuous rank value Tx ports, number of cases: 8+6+4+2=20

[0130] Or, + the number of "consecutive" rank values ​​of Tx ports with panel and / or polarization order, such as {0,2,4,6,1,3,5,7}, number of cases: 8+6+4+2=20 (from one set or odd or even order)

[0131] 3) Antenna layout with 2 groups:

[0132] The starting port can be one of the ports in each port group (panel), for example {0,4}

[0133] + Number of continuous rank value Tx ports, number of cases: 8+4=12

[0134] Or, + the number of "consecutive" rank values ​​of Tx ports with panel and / or polarization order, such as {0,4,2,6,1,3,5,7}, number of cases: 8+4=12

[0135] 4) Antenna layout with 1 group:

[0136] Fixed starting Tx port (e.g., 0) + consecutive or "continuous" Tx ports: Number of cases: 8.

[0137] In some embodiments, the non-coherent 8-Tx codebook may be used for UEs with non-coherent UEs, partial+non-coherent UEs, and full+partial+non-coherent UEs.

[0138] The non-coherent 8-Tx codebook can be viewed as eight 1-port groups, each with rank 0 or 1, and each 1-port group does not require TPMI. There are 255 codebooks to allow for full flexibility, which is comparable to the flexibility of the fully coherent codebook. For the 8-Tx non-coherent codebook, this high flexibility may not be necessary due to the large overhead. In order to reduce the number of candidate non-coherent codebooks, the UE antenna layout can be considered.

[0139] For example, the starting port index + the number of "continuous" ports can be considered to select the port combination of the non-coherent codebook. Figure 2 The UL 8-Tx port index of one or two or four port groups shown is evaluated as shown in Table 5. For UEs supporting two port groups, the starting port can be port 0 or port 2. For starting port 0, according to the non-circular port order (0,4,1,5,2,6,3,7), it can support (0), (0,4)...(0,4,1,5,2,6,3,7) for rank 1-rank 8 port selection. For starting port 2, according to the non-circular port order (0,4,1,5,2,6,3,7), it can support (2), (2,6)...(2,6,3,7) for rank 1-rank 4 port selection. Therefore, the number of candidates for the non-coherent codebook of two port groups is 8+4=12.

[0140] According to the above rules, a maximum of 36 candidate codebooks are required. If the UE supports one port group, then it only needs eight candidates. The non-cyclic port order (0,4,1,5,2,6,3,7) follows the rule that ports in a smaller (convergent) port group are preferred. If the port groups are prioritized, the port order can also be replaced by another order.

[0141] Table 5

[0142]

[0143] In some embodiments, regarding the non-coherent codebook design, the number of candidate non-coherent codebooks is determined by the UE and the network (e.g., a node of the network) according to at least one of the following:

[0144] - Number of port groups

[0145] - Limited starting port index, e.g. depending on the number of port groups

[0146] - Predefined port index order, for example (0,4,1,5,2,6,3,7)

[0147] For example, for a port group, the starting port may be port 0, and the candidate codebook for non-coherence may have "continuous" R = 1 to 8 ports in a non-cyclic order, for example, (0, 4, 1, 5, 2, 6, 3, 7) for ranks 1-8, respectively. The codebook of rank 1 is the selection of port 0, which means that other ports, i.e., 1-7, are not selected. The codebook may be W 8x1 =[1 0 0 00 0 0 0] T The codebook of rank 4 is a selection of ports 0, 4, 1, 5, which means that other ports, namely 2, 3, 6, 7, are not selected. The codebook can be Equation 3.

[0148] Equation 3

[0149]

[0150] The codebook of rank 6 is a selection of ports 0, 4, 1, 5, 2, 6, which means that other ports, namely 3 and 7, are not selected. The codebook can be Equation 4.

[0151] Equation 4

[0152]

[0153] For example, for two port groups, the starting port may be port 0 or 2, and the candidate codebook for incoherence may have "continuous" R=1 to 8 ports with a non-cyclic order, for example, (0, 4, 1, 5, 2, 6, 3, 7) for ranks 1-8, respectively. The rank 1 codebook with a starting port of 0 is a selection of port 0, which means that the other ports, i.e., 1-7, are not selected. The rank 1 codebook with a starting port of 2 is a selection of port 2, which means that the other ports, i.e., 0, 1, 3-7, are not selected. The rank 4 codebook with a starting port of 0 is a selection of ports 0, 4, 1, 5, which means that the other ports, i.e., 2, 3, 6, 7, are not selected. And the rank 4 codebook with a starting port of 2 is a selection of ports 2, 6, 3, 7, which means that the other ports, i.e., 0, 4, 1, 5, are not selected.

[0154] Note that the precoding above is not normalized. In some embodiments, precoding may require multiplying W by a ratio for normalization.

[0155] Example 3

[0156] Example embodiments disclosed herein relate to methods for port index mapping.

[0157] According to the DL port indexing scheme, such as Figure 3 As shown:

[0158] - For 8Tx full coherence with one port group: ports 0, 1, 2, 3 have the same polarization direction, and ports 4, 5, 6, 7 have another same polarization direction. They belong to one port group or panel.

[0159] -For 8Tx full coherence with two port groups: Ports 0, 1, 2, 3 belong to one port group or panel and are coherent. Ports 0 and 1 have the same polarization direction, and ports 2 and 3 have another same polarization direction. Ports 4, 5, 6 and 7 belong to another port group or panel. Ports 4 and 5 have the same polarization direction, and ports 6 and 7 have another same polarization direction.

[0160] -For 8Tx full coherence with four port groups: Ports 0, 1 belong to one port group or panel and are coherent, they have different polarization directions. Ports 2, 3 belong to another port group or panel and are coherent, they have different polarization directions. Ports 4, 5 belong to another port group or panel and are coherent, they have different polarization directions. Ports 6, 7 belong to another port group or panel and are coherent, they have different polarization directions.

[0161] According to the UL port indexing scheme, such as Figure 4 As shown,

[0162] For 2Tx, it has the same port index for one port group and two port groups,

[0163] For 4Tx, it has the same port index for one port group and two port groups,

[0164] For UL 8Tx, it can follow the UL port index rule or the DL port index rule. If it follows the DL rule, the mapping of port index and port group cannot accommodate 2 groups with 4Tx and 4 groups with 2Tx. If it follows the UL rule, there is no reference for UL 8Tx.

[0165] To address this problem of the UL port indexing scheme, embodiments disclosed herein provide enhanced port index mapping.

[0166] In some embodiments, the UL 8Tx precoding port index follows at least one of the following rules:

[0167] -Polarization pairs are 0-4, 1-5, 2-6, 3-7.

[0168] - For partial coherence, 2 groups: one 4TX group with ports (0,1,2,3) and another 4TX group with ports (0,1,2,3) are mapped to 8TX(0,1,4,5,2,3,6,7) or 8TX(0,2,4,6,1,3,5,7).

[0169] -For partial coherence, 4 groups: 2TX group 1, 2, 3, 4: port (0,1), port (0,1), port (0,1), port (0,1) are mapped to 8TX (0,4,1,5,2,6,3,7).

[0170] Example Operation

[0171] As described herein, example embodiments describe in detail UE capability reporting and / or network configuration to identify different modes (coherent and port groups). Example embodiments restrict candidate codebooks to reduce overhead for port group indication. Example embodiments reduce overhead for non-coherent codebook candidates. Example embodiments provide unified port indexing for UL 8Tx with one or two or four port groups.

[0172] Figure 5 An exemplary flow chart related to network configuration of 8Tx transmission precoding is shown.

[0173] At operation 502, a wireless communication device (eg, UE) receives a configuration from a wireless communication node (eg, base station), the configuration indicating at least one of: one or more port group numbers or one or more coherence levels.

[0174] At operation 504, the wireless communication device determines precoding for transmission according to the configuration.

[0175] At operation 506, the wireless communication device performs transmission using precoding.

[0176] In some embodiments, the total number of ports is eight. For example, a total of eight ports are divided into a given number of port groups (eg, one port group, two port groups, four port groups, and eight port groups).

[0177] In some embodiments, the one or more port group numbers indicated by the configuration include one or more of the following: one port group, two port groups, four port groups, or eight port groups. In some embodiments, the one or more coherence levels indicated by the configuration include one or more of the following: full coherence, first type of partial coherence, second type of partial coherence, and incoherence. In some embodiments, the first type of partial coherence refers to splitting all ports (e.g., eight ports) into two port groups that are incoherent with each other, while the ports within a given port group are coherent with each other. For example, the first type of partial coherence refers to Part 2 in Table 1. In some embodiments, the second type of partial coherence refers to splitting all ports (e.g., eight ports) into four port groups that are incoherent with each other, while the ports within a given port group are coherent. For example, the second type of partial coherence refers to Part 3 in Table 1.

[0178] In some embodiments, the wireless communication device also transmits information indicating the number of one or more port groups supported or the one or more coherence levels supported (eg, capability information). In some embodiments, at operation 502, the wireless communication device transmits the capability information before receiving the configuration from the wireless communication node.

[0179] In some embodiments, the indicated number of port groups or the indicated level of coherence is the highest capability, and the highest capability indicates that one or more capabilities lower than the highest capability are configured (e.g., in the configuration received in operation 502) or supported (e.g., in the capability information transmitted to the network). For example, one or more given capabilities are selected from the remaining capability set, and the one or more given capabilities have capabilities lower than the highest capability. The one or more given capabilities may have the highest or lowest capabilities in the remaining capability set. Assuming that the highest capability is one port group, the given capability may be two port groups. Then, the capability of one port group may include one port group and two port groups. In some embodiments, the order of port group capabilities from highest to lowest is one port group, two port groups, four port groups, and eight port groups. In some embodiments, the order of coherence capabilities from highest to lowest is full coherence, partial coherence of the first type, partial coherence of the second type, and incoherence.

[0180] In some embodiments, determining the precoding for transmission according to the configuration (e.g., at operation 504) includes determining the presence or size of an indication of a number of port groups for a codebook indication according to the configuration. The indication of the number of port groups can be used to select one or more port group numbers from a set of port group numbers according to the configuration or according to one or more port group numbers determined for the codebook indication.

[0181] In some embodiments, determining the precoding for transmission according to the configuration (e.g., at operation 504) includes: determining one or more port group numbers for the codebook indication, and determining the presence or size of an indication of the number of port groups (e.g., a port group indication) according to the one or more port group numbers determined for the codebook indication. Thus, these embodiments provide a field for determining a candidate codebook indicated by the DCI. The presence or size of the port group indication can be determined according to the one or more port group numbers determined for the codebook indication.

[0182] In some examples, the determined one or more port group numbers may be one or more port group numbers received (e.g., in the configuration). In other examples, the determined one or more port group numbers are different (e.g., inferred or determined via the configuration). For example, the wireless communication device may receive only one port group number, but one or more related port group numbers (e.g., all lower capabilities, all one or more port group numbers) are determined according to a predetermined rule.

[0183] For example, if only full coherence or only one port group is determined, the DCI does not include a port group indication, but includes rank (1-8) and TPMI. Precoding can be determined based on the rank and TPMI in the DCI.

[0184] For example, if full coherence and partial coherence of the first type or one port group and two port groups are determined, the DCI includes a 1-bit "port group number indication" to indicate one port group or two port groups. Then, for each port group, there should be a rank and TPMI or a set of parameters for determining the codebook. This means that for each port group, there is a set of rank + TPMI.

[0185] The TPMI may be an index for indicating a codebook from a predefined codebook set, or a parameter set for determining a codebook / precoding.

[0186] In some embodiments, determining precoding for transmission according to the configuration includes determining a given number of port groups according to an indication of the number of port groups, and determining at least one of the following for each port group in the given number of port groups: rank, number of layers, or TPMI.

[0187] In some embodiments, determining the precoding for transmission according to the configuration includes: determining a given number of port groups according to an indication of the number of port groups, determining a phase between every two port groups in the given number of port groups, and determining at least one of the following for at least some of the port groups in the given number of port groups: rank, number of layers, or TPMI. In some embodiments, the indication of the number of port groups is included in DCI, MAC CE, or RRC signaling.

[0188] For example, if there are two coherent port groups, one phase is determined, for example, received from the network via DCI or MAC CE. For example, if there are four coherent port groups, three phases are determined, for example, received from the network via DCI or MAC CE. In this case, the rank and / or TPMI may be indicated for more than one port group in a given number of port groups (i.e., all or part of the port groups in a given number of port groups). In other words, the rank and / or TPMI may be shared for multiple port groups in a given number of port groups. For example, in these embodiments, when all or part of the port groups are coherent, at least one of the ranks or TPMIs of at least some of the port groups is determined.

[0189] In some embodiments, precoding is determined according to parameters of a scheme of a downlink codebook based on one or more port group numbers being one port group, or precoding is determined according to parameters of a scheme of an uplink codebook based on one or more port group numbers being coherent more than one port group.

[0190] In some embodiments, the wireless communication device further determines a value of an oversampling factor in a polarization direction according to the number of antenna elements in the polarization direction. In some examples, the polarization direction includes a horizontal direction or a vertical direction.

[0191] In some embodiments, the configuration is received via one of: radio resource control (RRC) signaling, a medium access control (MAC) control element, or a downlink control indicator (DCI).

[0192] In some embodiments, the precoding is determined based on at least one of the number of port groups, the starting port index, or the order of the port indexes. In some embodiments, the precoding is determined based on at least one of the number of port groups, the starting port index, or the order of the port indexes, including: determining the precoding from a codebook set determined based on at least one of the number of port groups, the starting port index, or the order of the port indexes. The codebook set includes codebooks that each reflect a port selection. If a port is selected, a vector of layers having non-zero elements for the port and zero elements for other ports is determined.

[0193] In some examples, the precoding is determined according to the incoherence level indicated by the configuration. In some embodiments, the precoding is determined based on the number of consecutive port indexes according to at least one of the number of port groups, the starting port index, or the port index order. In some embodiments, the starting port index is determined based on the number of port groups. In some embodiments, the port index order is one of {0,4,1,5,2,6,3,7}, {0,1,2,3,4,5,6,7}, {0,2,1,3,4,6,5,7}, {0,1,4,5,2,3,6,7} or {0,4,2,6,1,5,3,7}.

[0194] In some embodiments, the wireless communication device further maps ports of one or more port groups to precoded ports according to at least one of the one or more predefined mappings. In some embodiments, the one or more predefined mappings include: mapping of two port groups to precoded ports {0,1,4,5,2,3,6,7} or to precoded ports {0,2,4,6,1,3,5,7}, each of which has four ports, or mapping of four port groups to precoded ports {0,4,1,5,2,6,3,7}, each of which has two ports.

[0195] Figure 6 An exemplary flow chart related to capability reporting for 8Tx transmission precoding is shown.

[0196] At operation 602, a wireless communication node (eg, a base station) transmits a configuration to a wireless communication device, the configuration indicating at least one of: one or more numbers of port groups or one or more coherence levels.

[0197] At operation 604, the wireless communication node indicates to the wireless communication device the precoding or the indication of the number of port groups used for the transmission according to the configuration. The transmission is then performed using the precoding. In some embodiments, the wireless communication node receives the transmission and decodes the transmission according to the precoding.

[0198] In some embodiments, the wireless communication node also determines the presence or size of an indication of a number of port groups for a codebook indication. In some embodiments, the indication of the number of port groups can be used to select a given number of port groups (or more than one number of port groups based on a given number of port groups) from a set of number of port groups according to the configuration or according to one or more number of port groups determined for the codebook indication.

[0199] In some embodiments, the total number of ports is eight. In some embodiments, the specific number of port groups is one of: one port group, two port groups, four port groups, or eight port groups; the specific coherence level is one of: full coherence, first type of partial coherence, second type of partial coherence, and incoherence.

[0200] In some embodiments, the wireless communication node also indicates the number of antenna elements of the polarization direction in the configuration.

[0201] In some embodiments, the indicated number of port groups or the indicated level of coherence is the highest capability, which indicates that one or more capabilities below the highest capability are configured or supported. In some embodiments, the order of port group capabilities from highest to lowest is one port group, two port groups, four port groups, and eight port groups. The order of coherence capabilities from highest to lowest is full coherence, first type of partial coherence, second type of partial coherence, and incoherence.

[0202] In some embodiments, the indication of the number of port groups is included in DCI, MAC CE or RRC signaling.In some embodiments, the wireless communication node also indicates the number of antenna elements of polarization directions in the configuration.

[0203] In some embodiments, the wireless communication node transmits the configuration via one of: RRC, MAC CE, or DCI.

[0204] Figure 7 1 shows an exemplary block diagram of a hardware platform 700, which may be part of a network device (e.g., a base station) or a communication device (e.g., a user equipment (UE)). The hardware platform 700 includes at least one processor 710 and a memory 705, on which instructions are stored. When the instructions are executed by the processor 710, the hardware platform 700 is configured to perform the various embodiments described in FIG. 1 to FIG. Figure 4The operations described in the above. Transmitter 715 transmits or sends information or data to another device. For example, a network device transmitter can send a message to a user device. Receiver 720 receives information or data transmitted or sent by another device. For example, a user device can receive a message from a network device.

[0205] The implementation described above will be applied to wireless communications. Figure 8 An example of a wireless communication system (e.g., a 5G or NR cellular network) including a base station 820 and one or more user equipments (UEs) 811, 812, and 813 is shown. In some embodiments, the UE uses a communication link to the network (sometimes referred to as an uplink direction, as shown by dashed arrows 831, 832, 833) to access the BS (e.g., the network), which then enables subsequent communication from the BS to the UE (e.g., shown in the direction from the network to the UE, sometimes referred to as a downlink direction, as shown by arrows 841, 842, 843). In some embodiments, the BS sends information to the UE (sometimes referred to as a downlink direction, as shown by arrows 841, 842, 843), which then enables subsequent communication from the UE to the BS (e.g., the direction from the UE to the BS, sometimes referred to as an uplink direction, as shown by dashed arrows 831, 832, 833). The UE can be, for example, a smart phone, a tablet, a mobile computer, a machine-to-machine (M2M) device, an Internet of Things (IoT) device, etc.

[0206] In this document, the term "exemplary" is used to mean "an example of," and not to indicate an ideal or preferred embodiment unless otherwise stated.

[0207] Some of the embodiments described herein are described in the general context of methods or processes, which in one embodiment can be implemented by a computer program product, which is implemented in a computer-readable medium, and the computer-readable medium includes computer-executable instructions, such as program codes, executed by a computer in a networked environment. Computer-readable media may include removable and non-removable storage devices, including but not limited to read-only memory (ROM), random access memory (RAM), compact disk (CD), digital versatile disk (DVD), etc. Therefore, computer-readable media may include non-transitory storage media. Generally, program modules may include routines, programs, objects, components, data structures, etc. that perform specific tasks or implement specific abstract data types. Computer or processor executable instructions, associated data structures, and program modules represent examples of program codes for executing the steps of the methods disclosed herein. Such specific sequences of executable instructions or associated data structures represent examples of corresponding actions for implementing the functions described in such steps or processes.

[0208] Some of the disclosed embodiments may be implemented as devices or modules using hardware circuits, software, or a combination thereof. For example, a hardware circuit implementation may include discrete analog and / or digital components that are, for example, integrated as a part of a printed circuit board. Alternatively or additionally, the disclosed components or modules may be implemented as application specific integrated circuits (ASICs) and / or field programmable gate arrays (FPGAs) devices. Some implementations may additionally or alternatively include a digital signal processor (DSP), which is a dedicated microprocessor with an architecture optimized for the operational requirements of digital signal processing associated with the disclosed functions of the present application. Similarly, various components or subcomponents within each module may be implemented with software, hardware, or firmware. The connection between the modules and / or components within the modules may be provided using any of the connection methods and media known in the art, including but not limited to communications using appropriate protocols over the Internet, wired, or wireless networks.

[0209] Although this document includes many details, these details should not be interpreted as limitations on the scope of the claimed invention or the content that can be claimed, but rather as descriptions of the features of a particular embodiment. Certain features described in this document in the context of a separate embodiment may also be implemented in combination in a single embodiment. On the contrary, the various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments. In addition, although features may be described above as working in certain combinations, and even initially claimed as such, in some cases, one or more features from the claimed combination may be deleted from the combination, and the claimed combination may involve a sub-combination or a variant of a sub-combination. Similarly, although operations are described in a particular order in the accompanying drawings, this should not be understood as requiring such operations to be performed in the particular order shown or in sequence or requiring all the operations shown to be performed to achieve the desired result.

[0210] Only a few implementations and examples are described, and other implementations, enhancements, and variations may be made based on what is described and illustrated in this disclosure.

Claims

1. A method for wireless communication, comprising: receiving a configuration from a wireless communication node, the configuration indicating at least one of: one or more numbers of port groups, or one or more coherence levels; Determining precoding for transmission according to the configuration; and The transmitting is performed using the precoding.

2. The method of claim 1, wherein the total number of ports is eight.

3. A method according to claim 1, wherein the one or more port group numbers indicated by the configuration include one or more of the following: one port group, two port groups, four port groups, or eight port groups; and wherein the one or more coherence levels indicated by the configuration include one or more of the following: full coherence, partial coherence of a first type, partial coherence of a second type, and incoherence.

4. The method according to claim 1, further comprising: Information is sent to the wireless communication node, the information indicating one or more supported numbers of port groups or one or more supported coherence levels. 5 . The method according to claim 1 , wherein the indicated number of port groups or the indicated coherence level is a highest capability, the highest capability indicating that one or more capabilities lower than the highest capability are configured or supported.

6. The method according to claim 5, wherein the order of port group capabilities from highest to lowest is one port group, two port groups, four port groups, and eight port groups; and wherein the order of coherence capabilities from highest to lowest is full coherence, partial coherence of the first type, partial coherence of the second type, and incoherence.

7. The method of claim 1 , wherein determining a precoding for transmission based on the configuration comprises: The presence or size of the indication of the number of port groups for the codebook indication is determined according to the configuration.

8. The method of claim 1 , wherein determining a precoding for transmission based on the configuration comprises: determining one or more port group numbers for codebook indication; as well as Based on the one or more port group numbers determined for the codebook indication, the presence or size of an indication of a number of port groups is determined.

9. The method of claim 1 , wherein determining a precoding for transmission based on the configuration comprises: determining a given number of port groups according to an indication of the number of port groups; as well as For each port group in the given number of port groups, at least one of the following is determined: a rank, a number of layers, or a transmit precoding matrix indicator (TPMI).

10. The method of claim 1, wherein determining a precoding for transmission based on the configuration comprises: determining a given number of port groups according to an indication of the number of port groups; determining a phase between every two port groups of the given number of port groups; as well as For at least some of the port groups in the given number of port groups, at least one of the following is determined: rank, number of layers, or TPMI.

11. The method according to any one of claims 7 to 10, wherein the indication of the number of port groups is included in DCI, MAC CE or RRC signaling.

12. The method of claim 3, wherein the precoding is determined according to parameters of a downlink codebook-based scheme based on the one or more port group numbers being one port group, or the precoding is determined according to parameters of an uplink codebook-based scheme based on the one or more port group numbers being coherent more than one port group.

13. The method according to claim 1, further comprising: The value of the oversampling factor for a polarization direction is determined according to the number of antenna elements in the polarization direction.

14. The method of claim 1, wherein the configuration is received via one of: radio resource control (RRC) signaling, a medium access control (MAC) control element, or downlink control information (DCI).

15. The method of claim 1, wherein the precoding is determined based on at least one of: a port group number, a starting port index, or a port index order.

16. The method of claim 1, wherein the precoding is determined based on a consecutive number of port indexes according to at least one of: the port group number, a starting port index, or a port index order. The method of claim 15 , wherein the starting port index is determined based on the port group number.

18. The method of any one of claims 15 to 17, wherein the port index order is one of the following: {0,4,1,5,2,6,3,7}, {0,1,2,3,4,5,6,7}, {0,2,1,3,4,6,5,7}, {0,1,4,5,2,3,6,7}, or {0,4,2,6,1,5,3,7}.

19. The method of claim 1, further comprising: Ports in one or more port groups are mapped to the precoded ports according to at least one predefined mapping of the one or more predefined mappings.

20. The method of claim 19, wherein the one or more predefined mappings include: a mapping of two port groups to the precoded ports {0,1,4,5,2,3,6,7} or to the precoded ports {0,2,4,6,1,3,5,7}, the two port groups each having four ports, or A mapping of four port groups to the precoded ports {0, 4, 1, 5, 2, 6, 3, 7}, the four port groups each having two ports.

21. A method for wireless communication, comprising: sending a configuration to a wireless communication device, the configuration indicating at least one of: one or more numbers of port groups, or one or more coherence levels; as well as The wireless communication device is indicated with an indication of the precoding or the number of port groups used for transmission according to the configuration.

22. The method according to claim 21, further comprising: The presence or size of an indication of a number of port groups for a codebook indication is determined.

23. The method of claim 21, wherein the total number of ports is eight.

24. A method according to claim 21, wherein the one or more port groups include one or more of the following: one port group, two port groups, four port groups, or eight port groups; and wherein the one or more coherence levels include one or more of the following: full coherence, partial coherence of a first type, partial coherence of a second type, and incoherence.

25. The method of any one of claims 21 to 24, wherein the indicated number of port groups or the indicated coherence level is a highest capability, the highest capability indicating that one or more capabilities lower than the highest capability are supported or configured.

26. A method according to claim 25, wherein the order of port group capabilities from highest to lowest is one port group, two port groups, four port groups, and eight port groups; and wherein the order of coherence capabilities from highest to lowest is full coherence, partial coherence of the first type, partial coherence of the second type, and incoherence.

27. The method of claim 21, wherein the indication of the number of port groups is included in DCI, MAC CE, or RRC signaling.

28. The method of claim 21, further comprising: The number of antenna elements used for the polarization direction is indicated in the configuration.

29. The method of claim 21, wherein the configuration is sent via one of: DCI, MAC CE, or RRC signaling.

30. An apparatus for wireless communication, comprising a memory and a processor, wherein the processor executes instructions stored on the memory to implement the method according to any one or more of claims 1 to 29.

31. A non-transitory computer readable medium having stored thereon codes which, when executed by a processor, cause the processor to implement the method according to any one or more of claims 1 to 29.

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