SRS ENHANCEMENTS FOR COHERENT JOINT TRANSMISSIONS

Abstract

Disclosed are systems and methods for enhancing sounding resource signal (SRS) communications. In some embodiments, power control parameters and/or spatial relation information is determined prior to transmissions of the SRS signal. The determination may include a dynamic determination or a selection of a power control parameter set from a plurality of power control parameter sets. In some embodiments, cross-SRS interference is reduced when multiple transmissions utilize a same resource by applying orthogonal cover codes (OCC) to the resources prior to transmission.

Claims

1. A method, comprising: determining, at a user equipment (UE), that a Sounding Reference Signal (SRS) resource is to be transmitted to a base station (gNB); in response to determining that the SRS resource is to be transmitted to the gNB, determining one or more power control parameters of the SRS resource; and transmitting the SRS resource with the determined one or more power control parameters to the gNB.

2. The method of claim 1, further comprising, in response to determining that the SRS resource is to be transmitted to the gNB, determining spatial relation information of the SRS resource.

3. The method of claim 1, wherein determining the one or more power control parameters of the SRS resource comprises determining a fractional power control multiplier.

4. The method of claim 3, wherein a nominal UE transmit power and a pathloss reference signal are configured for an SRS resource set that includes the SRS resource based on a worst transmission and reception point (TRP) transmission.

5. The method of claim 1, wherein determining the one or more power control parameters of the SRS resource comprises measuring a path loss for transmitting to the gNB and determining a pathloss reference signal from the measured path loss.

6. The method of claim 1, wherein determining the one or more power control parameters of the SRS resource comprises determining a nominal UE transmit power for a TRP transmission.

7. The method of claim 6, wherein a single pathloss reference signal and a single fractional power control multiplier are configured for an SRS resource set that includes the SRS resource.

8. The method of claim 1, further comprising updating the one or more power control parameters using a medium access control (MAC) control element (MAC-CE) or dynamic control element (DCI).

9. The method of claim 1, wherein multiple options for the one or more power control parameters are configured for an SRS resource set that includes the SRS resource and wherein determining the one or more power control parameters of the SRS resource comprises selecting the one or more power control parameters from the multiple options for the one or more power control parameters that are configured for the resource set.

10. The method of claim 1, wherein the SRS resource is shared between a first TRP transmission and a second TRP transmission, wherein the UE applies an Orthogonal Cover Code (OCC) to the SRS to maintain orthogonality in use of the SRS resource between the first TRP transmission and the second TRP transmission.

11. The method of claim 10, wherein the first TRP transmission is sent from the UE to a particular TRP and the second TRP transmission is sent from a second UE to the particular TRP.

12. The method of claim 11, wherein a third TRP transmission sent is sent from the UE to a second TRP, wherein the third TRP transmission is sent using a second resource comprising a same SRS base sequence as the SRS resource, wherein a cyclic shift is applied to the SRS base sequence for the third TRP transmission such that the second resource and the SRS resource are orthogonal.

13. The method of claim 11, wherein a third TRP transmission sent is sent from the UE to a second TRP, wherein the third TRP transmission is sent using a second resource comprising a different SRS base sequence as the SRS resource.

14. The method of claim 11, wherein a third TRP transmission sent is sent from the UE to a second TRP, wherein the third TRP transmission is sent using the SRS resource, wherein a comb structure, frequency hopping, or resource block-level partial frequency sounding structure is used to provide orthogonality between the third TRP transmission and the first TRP transmission.

15. The method of claim 10, wherein the first TRP transmission is sent from the UE to a first TRP and the second TRP transmission is sent from the UE to a second TRP.

16. The method of claim 10, wherein the UE applies the OCC to the SRS in response to receiving an indication from the gNB.

17. A method comprising: determining, at a gNB that a plurality of TRP transmissions from one or more UEs are using a particular SRS resource; and in response to determining that the plurality of TRP transmissions from the one or more UEs are using a same resource, sending an indication to the one or more UEs which causes the one or more UEs to apply an orthogonal cover code (OCC) to the plurality of TRP transmissions.

18. The method of claim 17, wherein: the plurality of TRP transmissions comprise a first TRP transmission from a first UE of the one or more UEs to a first TRP and a second TRP transmission from a second UE of the one or more UEs to the first TRP.

19. The method of claim 18, wherein: a third TRP transmission from the first UE of the one or more UEs to a second TRP uses a second SRS resource comprising a same SRS base sequence as the particular SRS resource, wherein a cyclic shift is applied to the SRS base sequence for the third TRP transmission such that the second SRS resource and the particular SRS resource orthogonal.

20. The method of claim 18, wherein: a third TRP transmission from the first UE of the one or more UEs to a second TRP uses a second SRS resource comprising a different SRS base sequence as the particular SRS resource.

21. The method of claim 18, wherein: a third TRP transmission sent is sent from the first UE of the one or more UEs to a second TRP, wherein the third TRP transmission is sent using the particular SRS resource, wherein a comb structure, frequency hopping, or resource block-level partial frequency sounding structure is used to provide orthogonality between the third TRP transmission and the first TRP transmission.

22. The method of claim 17, wherein: the plurality of TRP transmissions comprise a first TRP transmission from a first UE of the one or more UEs to a first TRP and a second TRP transmission from the first UE of the one or more UEs to a second TRP.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0047] The above and other aspects, features, and advantages of certain embodiments of the present disclosure will be more apparent from the following detailed description taken in conjunction with the accompanying drawings, in which:

[0048] FIG. 1 illustrates an example of a CJT scheme 100;

[0049] FIG. 2 illustrates the indication of beams for each of two channels;

[0050] FIG. 3 illustrates the indication of beams for each of two channels, according to an embodiment;

[0051] FIG. 4 illustrates an example of an SRS bandwidth configuration;

[0052] FIG. 5 depicts an example of a multi-TRP scenario where each UE utilizes a plurality of resources to perform the multi-TRP transmissions;

[0053] FIG. 6 depicts an example application of OCC codes;

[0054] FIG. 7 depicts an example of a multi-TRP scenario where each UE utilizes a single SRS base sequence to perform the multi-TRP transmissions;

[0055] FIG. 8 depicts an example application of OCC codes (system 800 comprises two UEs, each with a comb size of two);

[0056] FIG. 9 depicts an example method for SRS transmissions;

[0057] FIG. 10 is a block diagram of an electronic device in a network environment, according to an embodiment; and

[0058] FIG. 11 shows a system including a UE and a gNB in communication with each other.

DETAILED DESCRIPTION

[0059] Embodiments of the disclosure will be described herein below with reference to the accompanying drawings. However, the embodiments of the disclosure are not limited to the specific embodiments and should be construed as including all modifications, changes, equivalent devices and methods, and/or alternative embodiments of the present disclosure. Descriptions of well-known functions and/or configurations will be omitted for the sake of clarity and conciseness.

[0060] The expressions “have,” “may have,” “include,” and “may include” as used herein indicate the presence of corresponding features, such as numerical values, functions, operations, or parts, and do not preclude the presence of additional features. The expressions “A or B,” “at least one of A or/and B,” or “one or more of A or/and B” as used herein include all possible combinations of items enumerated with them. For example, “A or B,” “at least one of A and B,” or “at least one of A or B” indicate (1) including at least one A, (2) including at least one B, or (3) including both at least one A and at least one B.

[0061] Terms such as “first” and “second” as used herein may modify various elements irrespective of an order and/or importance of the corresponding elements, and do not limit the corresponding elements. These terms may be used for the purpose of distinguishing one element from another element. For example, a first user device and a second user device may indicate different user devices irrespective of the order or importance. A first element may be referred to as a second element without departing from the scope the disclosure, and similarly, a second element may be referred to as a first element.

[0062] When a first element is “operatively or communicatively coupled with/to” or “connected to” another element, such as a second element, the first element may be directly coupled with/to the second element, and there may be an intervening element, such as a third element, between the first and second elements. To the contrary, when the first element is “directly coupled with/to” or “directly connected to” the second element, there is no intervening third element between the first and second elements.

[0063] All of the terms used herein including technical or scientific terms have the same meanings as those generally understood by an ordinary skilled person in the related art unless they are defined otherwise. The terms defined in a generally used dictionary should be interpreted as having the same or similar meanings as the contextual meanings of the relevant technology and should not be interpreted as having ideal or exaggerated meanings unless they are clearly defined herein. According to circumstances, even the terms defined in this disclosure should not be interpreted as excluding the embodiments of the disclosure.

[0064] The following discloses refinement of the codebook design framework targeting one PMI reporting in hypothesis 3 of the CJT multi-TRP transmission.

[0065] In this scheme, CSI reporting can follow the same approach as introduced for NCJT multi-TRP transmission in Rel. 17. That is, one CSI reporting triggering state would trigger X+1 CSIs, where X=0, 1, 2 CSIs are associated with the single-TRP measurement hypotheses and one CSI is associated with the CJT measurement hypothesis. If X=1, one CSI may be associated with the best single-TRP measurement, and if X=2, two CSIs may be associated with two different single-TRP measurements. A UE can be alternatively configured to report one CSI associated with the best one among CJT and single-TRP measurement hypotheses. In such a case, CSI can implicitly identify whether a reported CSI corresponds to a single-TRP CSI hypothesis or a CJT CSI hypothesis. The bitwidth associated to X+1 CSI reports may be given as Ceil(log.sub.2N) for X=0, Ceil(log.sub.2N)+Ceil(log.sub.2K.sub.s) for X=1, and Ceil(log.sub.2N)+Ceil(log.sub.2K.sub.1)+Ceil(log.sub.2K.sub.2) for X=2.

[0066] Further disclosed herein is dynamic updating of TCI states of port groups in CMRs and/or CMR resources of the CJT measurement hypothesis through a MAC-CE or DCI indication.

[0067] RAN 1 has agreed to support CJT multi TRP transmission with up to four TRPs/TRP groups with equal priority. The CJT measurement hypothesis would, however, be based on N cooperating TRPs/TRP groups where the value of N can be selected and reported by the UE. This requires the introduction of a new UE capability that indicates how many CSIs can be calculated by a UE corresponding to different CJT transmission hypotheses with a different number of cooperating TRPs/TRP groups assumptions. In such a case, to provide the best channel quality, a UE would calculate multiple CSIs for all/some different possible CJT measurement hypothesis and select the value of N based on the best CJT hypothesis and report the corresponding CSI to a gNB. Such a UE capability may be based on n CSIs, where n∈[1, 2, . . . , n.sub.max]. The maximum value for n can be derived with assumption of a maximum total of M TRPs in CJT, as

[00003]$\max \left(n\right)=n_{\max }=\left(\begin{array}{c}M\\ 2\end{array}\right)+.Math.+\left(\begin{array}{c}M\\ M\end{array}\right),$

if not including a single TRP hypothesis, and as

[00004]$\max \left(n\right)=n_{\max }=\left(\begin{array}{c}M\\ 1\end{array}\right)+.Math.+\left(\begin{array}{c}M\\ M\end{array}\right),$

if including the single TRP hypothesis. With a total of M=4 TRPs in CJT, as agreed upon in RAN1, the maximum value for n is

[00005]$n_{\max }=\left(\begin{array}{c}4\\ 2\end{array}\right)+\left(\begin{array}{c}4\\ 3\end{array}\right)+\left(\begin{array}{c}4\\ 4\end{array}\right)=11,$

if not including the single TRP hypothesis, and as

[00006]$\begin{array}{cc}{n}_{\max }=\left(\begin{array}{c}4\\ 1\end{array}\right)+\left(\begin{array}{c}4\\ 2\end{array}\right)+\left(\begin{array}{c}4\\ 3\end{array}\right)+\left(\begin{array}{c}4\\ 4\end{array}\right)=15,& \end{array}$

if including the single TRP hypothesis.
Codebook Design Refinement for CJT mTRP Targeting FDD

[0068] The Type I codebook design is founded based on a long term evolution (LTE) codebook design to support a single user MIMO for both high and low order transmissions. The Type II codebook is, however, designed based on a specific mathematic approach to provide more accurate information on channel characteristics using more sophisticated precoding matrices to support a multi-user MIMO with up to two layers of transmission. Both Type I and Type II codebooks are constructed based on 2-dimensional (2D) discrete Fourier transform (DFT) based beams and PMI reporting of information on beam selection and co-phase combining between two polarizations. The Type II codebook additionally reports the information on wide-band and sub-band amplitude coefficients of the selected beams.

[0069] Specifically, all radiating antenna elements are associated with an electric and magnetic field in each location around the antenna. The electric field at any point can be represented as a vector represented in two dimensions by projecting it along the spherical unit vectors {circumflex over (ϕ)} and {circumflex over (θ)}. The electric field of an antenna in a given direction (ϕ, θ) in far-field should be fully represented as the two dimensional vector, F(ϕ, θ)=[F.sub.ϕ(ϕ, θ) F.sub.θ(ϕ, θ)].sup.T which is referred to as the polarization vector. F.sub.ϕ and F.sub.θ are field components in the direction {circumflex over (ϕ)} and {circumflex over (θ)}. The real-valued instantaneous field in RF frequency can thus be simply written as

[0070] {right arrow over (E)}(t, ϕ, θ)={circumflex over (ϕ)}|F.sub.ϕ(ϕ, θ)|cos(ωt+kr+∠F.sub.ϕ(ϕ, θ))+{circumflex over (θ)}|F.sub.θ(ϕ, θ)|cos(ωt+kr+∠F.sub.θ(ϕ, θ)) where ω represents the transmission frequency in hertz (Hz) and kr contributes as a constant phase offset as a function of distance.

[0071] In the Type I codebook, PMI reporting occurs in 2 stages. In stage 1, wideband information including beam selection, or beam group selection is reported, and in stage 2, sub-band information including beam selection from within a group and phase shift selection for co-phasing between polarizations, layers and antenna panels is reported. The Type I codebook design provides two solutions of single panel and multi panel designs where each supports a Mode 1 and Mode 2 of reporting operation. The Type II codebook design, however, is based on reporting the information of a beam selection set and then a set of amplitude and phase shift coefficients to generate a linearly weighted combination of those selected beams. The Type II codebook design provides two solutions of single panel and port selection designs. The Type II single panel solution relies on a hypothetical beam position using oversampling factors while the Type II port selection solution is based on a set of actual, beamformed CSI-RS transmissions.

Type I Multi-Panel Codebook Refinement for CJT mTRP Targeting FDD

[0072] In the Type I codebook, PMI reporting has dual stages of wideband and sub-band CSI reporting. In stage 1, long term channel characteristics such as beam selection or beam group selection is reported. In stage 2, short-term and frequency selective channel characteristics such as beam selection from within a group and phase shift selection for co-phasing between polarizations, layers and antenna panels is reported.

[0073] Currently, precoding matrices are defined based on a specific antenna configuration assumption at a gNB. These antenna configurations are specified by defining the number of cross polar antenna elements in each panel where N.sub.1 is the number of cross polar antenna element columns and N.sub.2 is the number of cross polar antenna element rows. The number of CSI-RS ports is derived by 2N.sub.1N.sub.2. With a definition of DFT oversampling for higher granularity for beam sweeping where O1 and O2 are oversampling factors in columns and rows, the number of candidate beams in the horizontal direction is defined as N.sub.1O.sub.1 and number of candidate beams in the vertical direction is defined as N.sub.2O.sub.2. Note that O.sub.2 is set to one when N.sub.2=1 (i.e., no beamforming in the vertical direction).

[0074] The Type I codebook design provides two solutions of single panel and multi panel designs, where each supports Mode 1 and Mode 2 of reporting operation. The operation mode is configured by radio resource control (RRC) parameter codebookMode to instruct a UE to apply a specific mode. In the Mode 1 operation for the Type I single panel codebook, the UE reports a specific beam selected from all candidate beams at stage 1 and a specific phase shift for cross polarized port groups at stage 2. The available values for phase shift of cross polarized port groups to select at stage 2 are [0, 90, 180, 270] for a single layer and [0, 90] for two layers with the same conceptual operation as a MIMO precoding for a two-port transmission scenario. In the Mode 2 operation for the Type I single panel codebook, the UE reports beam group selection at stage 1 and selection of a specific beam within the chosen beam group and a specific phase shift for cross polarized port groups at stage 2.

[0075] The i parameters are used by the UE to report channel state information to the gNB, where i.sub.1,1 indicates beam selection in the horizontal direction, i.sub.1,2 indicates beam selection in the vertical direction, i.sub.1,3 indicates a beam offset of multiple layers and i.sub.2 indicates sub-band properties at stage 2 reporting. The beam offset uses values of multiple oversampling factors in either the horizontal and/or vertical direction to create spatial separation and relies on reflection and scattering.

[0076] The Type I multi panel codebook design supports configuration of either 2 or 4 antenna panels where the antenna elements configuration per panel is similarly defined as in the Type I single panel codebook. That is, the number of cross polar antenna element columns per panel is N.sub.1, the number of cross polar antenna element rows per panel is N.sub.2, and O1 and O2 are oversampling factors in columns and rows per panel. With N.sub.g antenna panels, the number of CSI ports is derived as 2N.sub.gN.sub.1N.sub.2, but the number of candidate beams are N.sub.1O.sub.1N.sub.2O.sub.2, meaning that the same beam is used for other polarizations and the other panels.

[0077] In the Mode 1 operation for the Type I multi panel codebook, the UE reports beam selection and wideband phase shift(s) for inter-panel co-phasing at stage 1 and one phase shift for sub-band inter-polarization co-phasing at stage 2. Mode 1 operation for the Type I multi panel codebook supports configuration of N.sub.g=2 or N.sub.g=4 antenna panels where for N.sub.g=2 panels, one phase shift for inter-panel co-phasing is reported and for N.sub.g=4 panels, three phase shifts are reported.

[0078] In the Mode 2 operation for the Type I multi panel codebook, the UE reports beam selection and two phase shifts for a combination of inter-panel and inter-polarization co-phasing at stage 1 and three phase shifts per sub-band combination of inter-panel and inter-polarization co-phasing at stage 2. Mode 2 operation for the Type I multi panel codebook supports the configuration of N.sub.g=2 antenna panels.

[0079] The Type I multi panel codebook design, i.sub.1,1 indicates beam selection in the horizontal direction, i.sub.1,2 indicates beam selection in the vertical direction, i.sub.1,3 indicates beam offset of multiple layers, i.sub.1,4 is inter-panel co-phasing for Mode 1 while wideband combined inter-panel and inter-polarization co-phasing for Mode 2, and i.sub.2 is sub-band combined inter-panel and inter-polarization co-phasing at stage 2 reporting.

[0080] The generation of precoding matrix for the Type I codebook is based on composition of beamforming (wideband precoder) and MIMO precoding (sub-band precoder) matrices where cross polarized port groups and multiple panels are assumed to share the same beam and beamforming virtualization coefficients. The inter-panel and inter-polarization co-phasing are included in MIMO precoding that reflects the short-term frequency selective channel information. In the current specification, the precoding matrix is defined in Equation (1) as follows.

W=W.sub.1W.sub.2  (1)

where W.sub.1 is the wideband beamforming precoder matrix and W.sub.2 is the sub-band precoder matrix that are derived as follows. In the Type I single panel codebook design, the wideband beamforming precoder W.sub.1 is defined in Equation (2) as follows.

[00007]$\begin{array}{cc}{W}_1=\left[\begin{array}{cc}{v}_{l,m}& 0\\ 0& v_{l,m}\end{array}\right]& \left(2\right)\end{array}$

where v.sub.l,m are 2D DFT virtualization coefficients derived as v.sub.l,m=x.sub.l.Math.u.sub.m in Equations (3) and (4) as follows.

[00008]$\begin{array}{cc}{x}_i=\left[\begin{array}{cccc}1& e^{\frac{j2\pi l}{N_1{O}_1}}& .Math.& e^{\frac{j2\pi \left(N_1-1\right)l}{N_1{O}_1}}\end{array}\right]& \left(3\right)\end{array}$$\begin{array}{cc}{u}_m=\left[\begin{array}{cccc}1& e^{\frac{j2\pi l}{N_2{O}_2}}& .Math.& e^{\frac{j2\pi \left(N_2-1\right)m}{N_2{O}_2}}\end{array}\right]& \left(4\right)\end{array}$

and sub-band precoder matrix W.sub.2 is defined in Equation (5) as follows.

[00009]$$\begin{gathered} \begin{array}{cc}{W}_2=\frac{1}{\sqrt{P}}\left[\begin{array}{c}1\\ {\phi }_n\end{array}\right]\mathrm{or} \\ \frac{1}{\sqrt{2P}}\left[\begin{array}{cc}1& 1\\ {\phi }_n& -{\phi }_n\end{array}\right]& \left(5\right)\end{array} \end{gathered}$$

for a rank-1 or a rank-2 transmission where φ.sub.n is the inter-polarization co-phasing.

[0081] In the Type I multi-panel codebook design, the wideband beamforming precoder matrix W.sub.1 (for a two-panel scenario) is defined in Equation (6) as follows.

[00010]$\begin{array}{cc}{W}_1=\left[\begin{array}{cc}\left[\begin{array}{cc}{v}_{l,m}& 0\\ 0& v_{l,m}\end{array}\right]& 0\\ 0& \left[\begin{array}{cc}{v}_{l,m}& 0\\ 0& v_{l,m}\end{array}\right]\end{array}\right]& \left(6\right)\end{array}$

[0082] Sub-band precoder matrix W.sub.2 design considers inter-panel co-phasing (i.e., φ.sub.p) in addition to inter-polarization co-phasing (i.e. φ.sub.n) as defined below in Equation (7) for a rank-1 or a rank-2 transmission.

[00011]$\begin{array}{cc}{W}_2=\frac{1}{\sqrt{P_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{c}1\\ {\phi }_n\\ {\phi }_p\\ {\phi }_n{\phi }_p\end{array}\right]\mathrm{or}\frac{1}{\sqrt{2P_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{cc}1& 1\\ {\phi }_n& -{\phi }_n\\ {\phi }_p& {\phi }_p\\ {\phi }_n{\phi }_p& -{\phi }_n{\phi }_p\end{array}\right]& \left(7\right)\end{array}$

[0083] In the above codebook design, the priority of the precoder matrix design is to first consider cross polarization transmission and to then consider multi-beam transmission.

[0084] Further, there is a special design case in the current Type I single panel codebook design for rank-3 and rank-4 transmissions when antenna configuration can support more than 16 CSI-RS signals. In this case, antenna elements in the panel are divided into groups and a single beam is selected to be reused for transmission by each group of antenna elements with a different phase shift (i.e. θ.sub.p) to provide differentiation. For a rank-3 transmission, the precoder matrix is defined in Equation (8) as follows.

[00012]$\begin{array}{cc}W=\frac{1}{\sqrt{3P_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{ccc}{v}_{l,m}& v_{l,m}& v_{l,m}\\ {\theta }_p{v}_{l,m}& -{\theta }_p{v}_{l,m}& {\theta }_p{v}_{l,m}\\ {\phi }_n{v}_{l,m}& {\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}\\ {\phi }_n{\theta }_p{v}_{l,m}& -{\phi }_n{\theta }_p{v}_{l,m}& -{\phi }_n{\theta }_p{v}_{l,m}\end{array}\right]& \left(8\right)\end{array}$

[0085] For rank-4 transmission, the precoder matrix is defined in Equation (9) as follows.

[00013]$\begin{array}{cc}W=\frac{1}{\sqrt{3P_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{cccc}{v}_{l,m}& v_{l,m}& v_{l,m}& v_{l,m}\\ {\theta }_p{v}_{l,m}& -{\theta }_p{v}_{l,m}& {\theta }_p{v}_{l,m}& -{\theta }_p{v}_{l,m}\\ {\phi }_n{v}_{l,m}& {\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}\\ {\phi }_n{\theta }_p{v}_{l,m}& -{\phi }_n{\theta }_p{v}_{l,m}& -{\phi }_n{\theta }_p{v}_{l,m}& {\phi }_n{\theta }_p{v}_{l,m}\end{array}\right]& \left(9\right)\end{array}$

[0086] For the Type I codebook to address the CJT scenario, the current Type I multi-panel codebook design is based on an assumption that different panels are quasi co-located and experience similar long term channel characteristics that mainly involve wideband PMI information such as beam or beam group selection. As previously discussed, when there are N.sub.g multiple panels (each with N.sub.1N.sub.2 ports), the number of beams available for selection is given by N.sub.1O.sub.1N.sub.2O.sub.2 and not by N.sub.gN.sub.1O.sub.1N.sub.2O.sub.2, indicating that the same selected beam is reused for transmission from N.sub.g panels. This assumption is inapplicable to, and thus, unrealistic for a distributed MIMO scenario in which multiple TRPs are not quasi co-located and each TRP may experience different long term channel characteristics requiring different beam/beam group selections per panel. That is, a different beam/beam group can be selected for each group of N.sub.1N.sub.2 antenna elements (i.e., each panel).

[0087] In this case, the present disclosure enables multiple beam selections at a first stage of PMI reporting for different panels. This can be performed by a separate indication of beams per panel using separate i parameters. As an example of such a scheme for a two-layer transmission over a two-panel multi-TRP scenario, the first stage of PMI reporting involves additionally introducing i.sub.1,k1, i.sub.1,k2 values for identification of the second panel beams or group of beams in the horizontal and vertical directions, respectively. These i.sub.1,k1, i.sub.1,k2 parameters can be any suitable values as long as their corresponding beams are spatially separated to rely on reflection and scattering.

[0088] Alternatively, and to reduce signaling overhead, the first stage of PMI reporting involves additionally introducing sets of i.sub.1,k parameters for identification of the beams of other panels or group of beams in a similar approach as in the current specification. That is, the first layer beam in a panel is identified by its location in the horizontal and vertical directions while beams selected for other layers in that panel are identified by defining their offsets with respect to the first layer beam in that panel. For a two-layer transmission over the two panel multi-TRP scenario, i.sub.1,1 and i.sub.1,2 identify the first layer beam in the horizontal and vertical directions, i.sub.1,3 identifies an offset between the beams selected for each layer in the first panel as in the current specification, and then additionally introduced parameters i.sub.1,4, i.sub.1,5 specify the second panel's first layer beam in the horizontal and vertical directions, and i.sub.1,6 specifies a beam selected for other layer in the second panel with same approach as in the current specification by defining offset between the beams selected for each layer in the second panel. As previously discussed, beam offset only takes values of multiple oversampling factors in either the horizontal and/or vertical direction to create spatial separation to rely on reflection and scattering. This decreases the PMI signaling overhead by limiting the available position of selected beams or group of beams.

[0089] Alternatively, the first beam/beam group is indicated for the first layer of the first panel and beams of other panels are indicated using offset values from that first selected beam/beam group. The offset can be a multiple of oversampling factors in the horizontal or/and vertical directions. Since beam offset only takes values of multiple oversampling factors in either horizontal and/or vertical direction to create spatial separation and relies on reflection and scattering, the available positions of panels of the other beams are restricted with respect to the position of the first layer beam at the first panel. This significantly reduces signaling overhead but may degrade the overall performance depending on the environment. The offset may be zero, demoting this design to the current Type I multi-panel codebook design that all panels use the same beams/group of beams.

[0090] FIG. 2 illustrates the indication of beams for each of two channels, according to the prior art. In FIG. 2, relating to the current specification, one reported beam can support up to rank two per panel (i.e. one cross polar beam per panel), and identical beam configurations 203, 204 are included per panel 201, 202, respectively.

[0091] FIG. 3 illustrates the indication of beams for each of two channels, according to an embodiment. In FIG. 3, different beam configurations 303, 304 are included in the panels 301, 302. The embodiment shown in FIG. 3 is more practical for frequency range 2 (FR2) applications.

[0092] Specifically, in a scheme for a two-layer transmission over a two panel multi-TRP scenario, the first stage of PMI reporting involves additionally introducing is, for identification of the second panel beams or group of beams. That is, the first stage of PMI reporting provides values for i.sub.1,1 and i.sub.1,2 that identify the first layer beam or group of beams in the horizontal and vertical directions, a value for i.sub.1,3 that identifies an offset between the beams selected for each layer in the first panel, values for i.sub.1,4 and i.sub.1,5 that specify offsets between the beams selected for the first layer in the first panel and the beam of the first layer and the beam of the second layer in the second panel.

[0093] The current Type I multi-panel codebook design as illustrated in FIG. 2 considers reporting inter-panel co-phasing values (i.e., φ.sub.p) in addition to inter-polarization co-phasing (i.e. φ.sub.n) while inter-panel co-phasing is only used for coherent transmission of the same data from different panels. Similar to cross polarized transmission, the present disclosure introduces the use of MIMO precoding on different panels to provide short term frequency selective information of channel characteristics over different panels. To illustrate, in the current Type I multi panel codebook design, inter-panel co-phasing information is only used to achieve coherent combining of the same transmitted data from different panels at the UE.

[0094] With the introduction of MIMO precoding on panels, the number of required beams can be decreased for transmission of a specific rank compared to the current Type I multi-panel codebook illustrated in FIG. 2. That is, each beam can now be used to provide up to a rank-2K transmission with K panels. In contrast to the NCJT scenario, embodiments of the disclosure achieve jointly precoded transmission with decreased CSI reporting overhead, particularly for high mobility scenarios where UE velocity combined with panels incoherency generates faster channel variations. In the high mobility NCJT scenario, the channel would rapidly change and more frequent NCJT CSI acquisition would be required, resulting in a rapid change of precoding matrices at each TRP. Thus, for a rank-R transmission with Mode 1, Equation (10) is derived as follows.

[00014]$\begin{array}{cc}\text{?}=\{\begin{array}{c}\frac{1}{\sqrt{{\mathrm{RP}}_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{ccc}\left[\begin{array}{cc}\left[\begin{array}{cc}{v}_{l,m}& 0\\ 0& v_{l,m}\end{array}\right]& 0\\ 0& \left[\begin{array}{cc}{v}_{l,m}& 0\\ 0& v_{l,m}\end{array}\right]\end{array}\right]& & 0\\ & \ddots & \\ 0& & \left[\begin{array}{cc}\left[\begin{array}{cc}\text{?}& 0\\ 0& \text{?}\end{array}\right]& 0\\ 0& \left[\begin{array}{cc}\text{?}& 0\\ 0& \text{?}\end{array}\right]\end{array}\right]\end{array}\right]C_{\mathrm{MIMO}}\mathrm{if}\mathrm{mod}\left(R,4\right)=0\\ \frac{1}{\sqrt{{\mathrm{RP}}_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{ccc}\left[\begin{array}{cc}\left[\begin{array}{cc}{v}_{l,m}& 0\\ 0& v_{l,m}\end{array}\right]& 0\\ 0& \left[\begin{array}{cc}{v}_{l,m}& 0\\ 0& v_{l,m}\end{array}\right]\end{array}\right]& & 0\\ & \ddots & \\ 0& & \left[\begin{array}{cc}\left[\begin{array}{cc}\text{?}& 0\\ 0& \text{?}\end{array}\right]& 0\\ 0& \text{?}\end{array}\right]\end{array}\right]C_{\mathrm{MIMO}}\mathrm{if}\mathrm{mod}\left(R,4\right)=3\\ \frac{1}{\sqrt{{\mathrm{RP}}_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{ccc}\left[\begin{array}{cc}\left[\begin{array}{cc}{v}_{l,m}& 0\\ 0& v_{l,m}\end{array}\right]& 0\\ 0& \left[\begin{array}{cc}{v}_{l,m}& 0\\ 0& v_{l,m}\end{array}\right]\end{array}\right]& & 0\\ & \ddots & \\ 0& & \left[\begin{array}{cc}\text{?}& 0\\ 0& \text{?}\end{array}\right]\end{array}\right]C_{\mathrm{MIMO}}\mathrm{if}\mathrm{mod}\left(R,4\right)=2\\ \frac{1}{\sqrt{{\mathrm{RP}}_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{ccc}\left[\begin{array}{cc}\left[\begin{array}{cc}{v}_{l,m}& 0\\ 0& v_{l,m}\end{array}\right]& 0\\ 0& \left[\begin{array}{cc}{v}_{l,m}& 0\\ 0& v_{l,m}\end{array}\right]\end{array}\right]& & 0\\ & \ddots & \\ 0& & \left[\text{?}\right]\end{array}\right]C_{\mathrm{MIMO}}\mathrm{if}\mathrm{mod}\left(R,4\right)=1\end{array}\text{?}\text{indicates text missing or illegible when filed}& \left(10\right)\end{array}$

[0095] In Equation (10), v.sub.l,m is 2D DFT virtualization coefficient of selected beam and C.sub.MIMO is a MIMO precoding matrix over both panel and polarization that is defined in Equation (11) as follows.

C.sub.MIMO=C.sub.polarization.Math.C.sub.panel  (11)

[0096] Depending on the value of R, C.sub.polarization and C.sub.panel are defined in Equations (12) and (13), respectively, as follows.

[00015]$\begin{array}{cc}{C}_{\mathrm{polarization}}=\left[\begin{array}{c}1\\ {\phi }_n\end{array}\right]\mathrm{or}\left[\begin{array}{cc}1& 1\\ {\phi }_n& -{\phi }_n\end{array}\right]& \left(12\right)\end{array}$$\begin{array}{cc}{C}_{panel}=\left[\begin{array}{c}\left[\begin{array}{c}1\\ {\phi }_{p_1}\end{array}\right]\\ .Math.\\ \left[\begin{array}{c}1\\ {\phi }_{p_{K-1}}\end{array}\right]\end{array}\right]\mathrm{or}\left[\begin{array}{c}\left[\begin{array}{cc}1& 1\\ {\phi }_{p_1}& -{\phi }_{p_1}\end{array}\right]\\ .Math.\\ \left[\begin{array}{cc}1& 1\\ {\phi }_{p_{K-1}}& {\phi }_{p_{K-1}}\end{array}\right]\end{array}\right]& \left(13\right)\end{array}$

[0097] where φ.sub.n is the inter-polarization co-phasing and φ.sub.p.sub.k, k=1, . . . , K−1 is the inter-panel co-phasing for K panels with respect to the first panel where in the current specification, max(K)=4 for Mode 1. The above-disclosed scheme follows the same design foundation as in the special design case in the Type I single panel codebook for rank 3 and 4 with CSI-RS ports larger than 16. In this special design case, only one panel was included and the precoder matrix design priority was to first perform transmission over different groups of antenna elements and then perform cross polarization where the co-phasing among antenna element groups (i.e., θ.sub.p) were used as one of the codebook design factors. The disclosed scheme targets multi-panel transmission with extension of the same design foundation over multiple panels, instead of multiple antenna groups of one panel, where inter-panel co-phasing (i.e. φ.sub.p) is used as one of the precoder matrix design multiplexing factors. A simple codebook design of such a scheme for a one-to-eight layer transmission under Mode 1 with two panels is defined in Equations (13)-(20) as shown below. In Equations (14)-(21), each beam can be used to provide up to rank-4 transmission.

[00016]$\begin{array}{cc}{W}_{l,m,p,n}^{\left(1\right)}=\frac{1}{\sqrt{P_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{c}{v}_{l,m}\\ {\phi }_p{v}_{l,m}\\ {\phi }_n{v}_{l,m}\\ {\phi }_n{\phi }_p{v}_{l,m}\end{array}\right]& \left(14\right)\end{array}$$\begin{array}{cc}{W}_{l,m,p,n}^{\left(2\right)}=\frac{1}{\sqrt{2P_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{cc}{v}_{l,m}& v_{l,m}\\ {\phi }_p{v}_{l,m}& -{\phi }_p{v}_{l,m}\\ {\phi }_n{v}_{l,m}& {\phi }_n{v}_{l,m}\\ {\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}\end{array}\right]& \left(15\right)\end{array}$$\begin{array}{cc}{W}_{l,m,p,n}^{\left(3\right)}=\frac{1}{\sqrt{3P_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{ccc}{v}_{l,m}& v_{l,m}& v_{l,m}\\ {\phi }_p{v}_{l,m}& -{\phi }_p{v}_{l,m}& {\phi }_p{v}_{l,m}\\ {\phi }_n{v}_{l,m}& {\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}\\ {\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}\end{array}\right]& \left(16\right)\end{array}$$\begin{array}{cc}{W}_{l,m,p,n}^{\left(4\right)}=\frac{1}{\sqrt{4P_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{cccc}{v}_{l,m}& v_{l,m}& v_{l,m}& v_{l,m}\\ {\phi }_p{v}_{l,m}& -{\phi }_p{v}_{l,m}& {\phi }_p{v}_{l,m}& -{\phi }_p{v}_{l,m}\\ {\phi }_n{v}_{l,m}& {\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}\\ {\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l,m}\end{array}\right]& \left(17\right)\end{array}$$\begin{array}{cc}{W}_{l,l^{\prime },m,m^{\prime },p,n}^{\left(5\right)}=\frac{1}{\sqrt{5P_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{ccccc}{v}_{l,m}& v_{l,m}& v_{l,m}& v_{l,m}& v_{l^{\prime },m^{\prime }}\\ {\phi }_p{v}_{l,m}& -{\phi }_p{v}_{l,m}& {\phi }_p{v}_{l,m}& -{\phi }_p{v}_{l,m}& {\phi }_p{v}_{l^{\prime },m^{\prime }}\\ {\phi }_n{v}_{l,m}& {\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}& {\phi }_n{v}_{l^{\prime },m^{\prime }}\\ {\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}\end{array}\right]& \left(18\right)\end{array}$$\begin{array}{cc}{W}_{l,l^{\prime },m,m^{\prime },p,n}^{\left(6\right)}=\frac{1}{\sqrt{6P_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{cccccc}{v}_{l,m}& v_{l,m}& v_{l,m}& v_{l,m}& v_{l^{\prime },m^{\prime }}& v_{l^{\prime },m^{\prime }}\\ {\phi }_p{v}_{l,m}& -{\phi }_p{v}_{l,m}& {\phi }_p{v}_{l,m}& -{\phi }_p{v}_{l,m}& {\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_p{v}_{l^{\prime },m^{\prime }}\\ {\phi }_n{v}_{l,m}& {\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}& {\phi }_n{v}_{l^{\prime },m^{\prime }}& {\phi }_n{v}_{l^{\prime },m^{\prime }}\\ {\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}\end{array}\right]& \left(19\right)\end{array}$$\begin{array}{cc}{W}_{l,l^{\prime },m,m^{\prime },p,n}^{\left(7\right)}=\frac{1}{\sqrt{7P_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{ccccccc}{v}_{l,m}& v_{l,m}& v_{l,m}& v_{l,m}& v_{l^{\prime },m^{\prime }}& v_{l^{\prime },m^{\prime }}& v_{l^{\prime },m^{\prime }}\\ {\phi }_p{v}_{l,m}& -{\phi }_p{v}_{l,m}& {\phi }_p{v}_{l,m}& -{\phi }_p{v}_{l,m}& {\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_p{v}_{l^{\prime },m^{\prime }}& {\phi }_p{v}_{l^{\prime },m^{\prime }}\\ {\phi }_n{v}_{l,m}& {\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}& {\phi }_n{v}_{l^{\prime },m^{\prime }}& {\phi }_n{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{v}_{l^{\prime },m^{\prime }}\\ {\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}\end{array}\right]& \left(20\right)\end{array}$$\begin{array}{cc}{W}_{l,l^{\prime },m,m^{\prime },p,n}^{\left(8\right)}=\frac{1}{\sqrt{8P_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{cccccccc}{v}_{l,m}& v_{l,m}& v_{l,m}& v_{l,m}& v_{l^{\prime },m^{\prime }}& v_{l^{\prime },m^{\prime }}& v_{l^{\prime },m^{\prime }}& v_{l^{\prime },m^{\prime }}\\ {\phi }_p{v}_{l,m}& -{\phi }_p{v}_{l,m}& {\phi }_p{v}_{l,m}& -{\phi }_p{v}_{l,m}& {\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_p{v}_{l^{\prime },m^{\prime }}& {\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_p{v}_{l^{\prime },m^{\prime }}\\ {\phi }_n{v}_{l,m}& {\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}& {\phi }_n{v}_{l^{\prime },m^{\prime }}& {\phi }_n{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{v}_{l^{\prime },m^{\prime }}\\ {\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}& {\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}\end{array}\right]& \left(21\right)\end{array}$

[0098] In the scheme defined in Equations (14)-(21), the precoder matrix design priority is transmission over multi-panel, cross polarization and multi-beam. This design may be inefficient for cross polar antenna panels where cross polarization transmission is prioritized over multi-panel transmission. Hence, another design approach for the disclosed scheme is to change the precoder matrix design priority rule to cross polarization, multi-panel and multi-beam transmissions. For example, the codebook design for a one-to-eight layer transmission under Mode 1 with two panels is defined in Equations (22)-(29) as shown below. Similar to Equations (14)-(21), each beam in Equations (22)-(29) can be used to provide up to rank-4 transmission.

[00017]$\begin{array}{cc}{W}_{l,m,p,n}^{\left(1\right)}=\frac{1}{\sqrt{P_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{c}{v}_{l,m}\\ {\phi }_n{v}_{l,m}\\ {\phi }_p{v}_{l,m}\\ {\phi }_n{\phi }_p{v}_{l,m}\end{array}\right]& \left(22\right)\end{array}$$\begin{array}{cc}{W}_{l,m,p,n}^{\left(2\right)}=\frac{1}{\sqrt{2P_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{cc}{v}_{l,m}& v_{l,m}\\ {\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}\\ {\phi }_p{v}_{l,m}& {\phi }_p{v}_{l,m}\\ {\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}\end{array}\right]& \left(23\right)\end{array}$$\begin{array}{cc}{W}_{l,m,p,n}^{\left(3\right)}=\frac{1}{\sqrt{3P_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{ccc}{v}_{l,m}& v_{l,m}& v_{l,m}\\ {\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}& {\phi }_n{v}_{l,m}\\ {\phi }_p{v}_{l,m}& {\phi }_p{v}_{l,m}& -{\phi }_p{v}_{l,m}\\ {\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}\end{array}\right]& \left(24\right)\end{array}$$\begin{array}{cc}{W}_{l,m,p,n}^{\left(4\right)}=\frac{1}{\sqrt{4P_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{cccc}{v}_{l,m}& v_{l,m}& v_{l,m}& v_{l,m}\\ {\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}& {\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}\\ {\phi }_p{v}_{l,m}& {\phi }_p{v}_{l,m}& -{\phi }_p{v}_{l,m}& -{\phi }_p{v}_{l,m}\\ {\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l,m}\end{array}\right]& \left(25\right)\end{array}$$\begin{array}{cc}{W}_{l,l^{\prime },m,m^{\prime },p,n}^{\left(5\right)}=\frac{1}{\sqrt{5P_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{ccccc}{v}_{l,m}& v_{l,m}& v_{l,m}& v_{l,m}& v_{l^{\prime },m^{\prime }}\\ {\phi }_n{v}_{l,m}& {\phi }_n{v}_{l,m}& {\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}& {\phi }_n{v}_{l^{\prime },m^{\prime }}\\ {\phi }_p{v}_{l,m}& {\phi }_p{v}_{l,m}& -{\phi }_p{v}_{l,m}& -{\phi }_p{v}_{l,m}& {\phi }_p{v}_{l^{\prime },m^{\prime }}\\ {\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}\end{array}\right]& \left(26\right)\end{array}$$\begin{array}{cc}{W}_{l,l^{\prime },m,m^{\prime },p,n}^{\left(6\right)}=\frac{1}{\sqrt{6P_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{cccccc}{v}_{l,m}& v_{l,m}& v_{l,m}& v_{l,m}& v_{l^{\prime },m^{\prime }}& v_{l^{\prime },m^{\prime }}\\ {\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}& {\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}& {\phi }_n{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{v}_{l^{\prime },m^{\prime }}\\ {\phi }_p{v}_{l,m}& {\phi }_p{v}_{l,m}& -{\phi }_p{v}_{l,m}& -{\phi }_p{v}_{l,m}& {\phi }_p{v}_{l^{\prime },m^{\prime }}& {\phi }_p{v}_{l^{\prime },m^{\prime }}\\ {\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}\end{array}\right]& \left(27\right)\end{array}$$\begin{array}{cc}{W}_{l,l^{\prime },m,m^{\prime },p,n}^{\left(7\right)}=\frac{1}{\sqrt{7P_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{ccccccc}{v}_{l,m}& v_{l,m}& v_{l,m}& v_{l,m}& v_{l^{\prime },m^{\prime }}& v_{l^{\prime },m^{\prime }}& v_{l^{\prime },m^{\prime }}\\ {\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}& {\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}& {\phi }_n{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{v}_{l^{\prime },m^{\prime }}& {\phi }_n{v}_{l^{\prime },m^{\prime }}\\ {\phi }_p{v}_{l,m}& {\phi }_p{v}_{l,m}& -{\phi }_p{v}_{l,m}& -{\phi }_p{v}_{l,m}& {\phi }_p{v}_{l^{\prime },m^{\prime }}& {\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_p{v}_{l^{\prime },m^{\prime }}\\ {\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}\end{array}\right]& \left(28\right)\end{array}$$\begin{array}{cc}{W}_{l,l^{\prime },m,m^{\prime },p,n}^{\left(8\right)}=\frac{1}{\sqrt{8P_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{cccccccc}{v}_{l,m}& v_{l,m}& v_{l,m}& v_{l,m}& v_{l^{\prime },m^{\prime }}& v_{l^{\prime },m^{\prime }}& v_{l^{\prime },m^{\prime }}& v_{l^{\prime },m^{\prime }}\\ {\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}& {\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}& {\phi }_n{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{v}_{l^{\prime },m^{\prime }}& {\phi }_n{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{v}_{l^{\prime },m^{\prime }}\\ {\phi }_p{v}_{l,m}& {\phi }_p{v}_{l,m}& -{\phi }_p{v}_{l,m}& {\phi }_p{v}_{l,m}& {\phi }_p{v}_{l^{\prime },m^{\prime }}& {\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_p{v}_{l^{\prime },m^{\prime }}\\ {\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}& {\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}\end{array}\right]& \left(29\right)\end{array}$

[0099] In the scheme defined in Equations (22)-(29), the precoder matrix design priority is cross polarization, multi-panel and multi-beam transmissions. However, for consistency with the current specification, the prioritization rule of this codebook design scheme is further modified to first perform cross polarization followed by multi-beam transmission with up to two beams as in the current specification for the Type I multi-panel codebook, and then multi-panel transmissions. Thus, the codebook design for a one-to-eight layer transmission under Mode 1 for a two panel scenario is defined below in Equations (30)-(37) where the codebook for one to four layer transmission is identical to the current specification.

[00018]$\begin{array}{cc}{W}_{l,m,p,n}^{\left(1\right)}=\frac{1}{\sqrt{P_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{c}{v}_{l,m}\\ {\phi }_n{v}_{l,m}\\ {\phi }_p{v}_{l,m}\\ {\phi }_n{\phi }_p{v}_{l,m}\end{array}\right]& \left(30\right)\end{array}$$\begin{array}{cc}{W}_{l,l^{\prime },m,m^{\prime },p,n}^{\left(2\right)}=\frac{1}{\sqrt{2P_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{cc}{v}_{l,m}& v_{l^{\prime },m^{\prime }}\\ {\phi }_n{v}_{l,m}& {\phi }_n{v}_{l^{\prime },m^{\prime }}\\ {\phi }_p{v}_{l,m}& {\phi }_p{v}_{l^{\prime },m^{\prime }}\\ {\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}\end{array}\right]& \left(31\right)\end{array}$$\begin{array}{cc}{W}_{l,l^{\prime },m,m^{\prime },p,n}^{\left(3\right)}=\frac{1}{\sqrt{3P_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{ccc}{v}_{l,m}& v_{l^{\prime },m^{\prime }}& v_{l,m}\\ {\phi }_n{v}_{l,m}& {\phi }_n{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{v}_{l,m}\\ {\phi }_p{v}_{l,m}& {\phi }_p{v}_{l^{\prime },m^{\prime }}& {\phi }_p{v}_{l,m}\\ {\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{\phi }_p{v}_{l,m}\end{array}\right]& \left(32\right)\end{array}$$\begin{array}{cc}{W}_{l,l^{\prime },m,m^{\prime },p,n}^{\left(4\right)}=\frac{1}{\sqrt{4P_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{cccc}{v}_{l,m}& v_{l,m}& v_{l^{\prime },m^{\prime }}& v_{l^{\prime },m^{\prime }}\\ {\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}& {\phi }_n{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{v}_{l^{\prime },m^{\prime }}\\ {\phi }_p{v}_{l,m}& {\phi }_p{v}_{l,m}& {\phi }_p{v}_{l^{\prime },m^{\prime }}& {\phi }_p{v}_{l^{\prime },m^{\prime }}\\ {\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}\end{array}\right]& \left(33\right)\end{array}$$\begin{array}{cc}{W}_{l,l^{\prime },m,m^{\prime },p,n}^{\left(5\right)}=\frac{1}{\sqrt{5P_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{ccccc}{v}_{l,m}& v_{l,m}& v_{l^{\prime },m^{\prime }}& v_{l^{\prime },m^{\prime }}& v_{l,m}\\ {\phi }_n{v}_{l,m}& {\phi }_n{v}_{l,m}& {\phi }_n{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{v}_{l^{\prime },m^{\prime }}& {\phi }_n{v}_{l,m}\\ {\phi }_p{v}_{l,m}& {\phi }_p{v}_{l,m}& {\phi }_p{v}_{l^{\prime },m^{\prime }}& {\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_p{v}_{l,m}\\ {\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{\phi }_p{v}_{l,m}\end{array}\right]& \left(34\right)\end{array}$$\begin{array}{cc}{W}_{l,l^{\prime },m,m^{\prime },p,n}^{\left(6\right)}=\frac{1}{\sqrt{6P_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{cccccc}{v}_{l,m}& v_{l,m}& v_{l^{\prime },m^{\prime }}& v_{l^{\prime },m^{\prime }}& v_{l,m}& v_{l,m}\\ {\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}& {\phi }_n{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}\\ {\phi }_p{v}_{l,m}& {\phi }_p{v}_{l,m}& {\phi }_p{v}_{l^{\prime },m^{\prime }}& {\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_p{v}_{l,m}& -{\phi }_p{v}_{l,m}\\ {\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l,m}\end{array}\right]& \left(35\right)\end{array}$$\begin{array}{cc}{W}_{l,l^{\prime },m,m^{\prime },p,n}^{\left(7\right)}=\frac{1}{\sqrt{7P_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{ccccccc}{v}_{l,m}& v_{l,m}& v_{l^{\prime },m^{\prime }}& v_{l^{\prime },m^{\prime }}& v_{l,m}& v_{l,m}& v_{l,m}\\ {\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}& {\phi }_n{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{v}_{l^{\prime },m^{\prime }}& {\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}& {\phi }_n{v}_{l,m}\\ {\phi }_p{v}_{l,m}& {\phi }_p{v}_{l,m}& {\phi }_p{v}_{l^{\prime },m^{\prime }}& {\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_p{v}_{l,m}& -{\phi }_p{v}_{l,m}& -{\phi }_p{v}_{l,m}\\ {\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}\end{array}\right]& \left(36\right)\end{array}$$\begin{array}{cc}{W}_{l,l^{\prime },m,m^{\prime },p,n}^{\left(8\right)}=\frac{1}{\sqrt{8P_{\mathrm{CSI}-\mathrm{RS}}}}\left[\begin{array}{cccccccc}{v}_{l,m}& v_{l,m}& v_{l^{\prime },m^{\prime }}& v_{l^{\prime },m^{\prime }}& v_{l,m}& v_{l,m}& v_{l,m}& v_{l,m}\\ {\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}& {\phi }_n{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{v}_{l^{\prime },m^{\prime }}& {\phi }_n{v}_{l,m}& -{\phi }_n{v}_{l,m}& {\phi }_n{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{v}_{l,m}\\ {\phi }_p{v}_{l,m}& {\phi }_p{v}_{l,m}& {\phi }_p{v}_{l^{\prime },m^{\prime }}& {\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_p{v}_{l,m}& -{\phi }_p{v}_{l,m}& -{\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_p{v}_{l,m}\\ {\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{\phi }_p{v}_{l^{\prime },m^{\prime }}& -{\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l,m}& -{\phi }_n{\phi }_p{v}_{l,m}& {\phi }_n{\phi }_p{v}_{l,m}\end{array}\right]& \left(37\right)\end{array}$