CN113228530A

CN113228530A - Beam selective transmit power control scheme

Info

Publication number: CN113228530A
Application number: CN201980085860.0A
Authority: CN
Inventors: 理查德·斯特林-加拉赫; 马里奥·凯斯坦尼达; 栗忠峰
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2018-12-21
Filing date: 2019-04-26
Publication date: 2021-08-06
Anticipated expiration: 2039-04-26
Also published as: CN113228530B; WO2020126042A1; EP3895335A1; WO2020126114A1

Abstract

The present invention relates to transmit power control at a wireless communication device (UE). In particular, the present invention provides a UE for performing beam selective transmit power control, and an apparatus, e.g., a network apparatus, for supporting beam selective transmit power control. The UE is configured to receive a first parameter of a downlink beamforming resource from the apparatus to the UE and a second parameter of a lateral link beamforming resource from a second UE to the UE. Further, the UE is configured to measure a first path loss based on the first parameter and a second path loss based on the second parameter, and determine a transmit power for the lateral link beamforming resource to the second UE based on the first path loss and the second path loss and according to a pre-configured determination scheme. Accordingly, the apparatus is configured to transmit a first parameter of a downlink beamforming resource from the apparatus to the UE and a second parameter of a lateral link beamforming resource from a second UE to the UE.

Description

Beam selective transmit power control scheme

Technical Field

The present invention relates to transmit power control performed at a wireless communication device or User Equipment (UE). In particular, the present invention provides a UE for performing beam selective Transmit power control, and provides means for configuring beam selective Transmit power control at the UE, such as network means like Transmit Receive Point (TRP). The invention also provides a corresponding transmission power control method.

Background

For example, for the 5G NR side link (i.e., UE-to-UE link), transmit power control is required. However, there is currently no power control scheme and conventional UE power control schemes (e.g. 5G NR uplink and LTE sidelink) are not suitable.

In particular, there is a need for a power control scheme that optimizes lateral link performance in a desired direction while minimizing interference to co-channel and/or adjacent channel users (e.g., Uu uplink or other adjacent channel lateral links). Conventional power control schemes are not suitable for this in their existing form.

Conventional 5G NR lateral link power control schemes may be open loop based, meaning that power control is based only on open loop measurements made at the UE. Alternatively, the 5G NR lateral link power control may be a closed loop based power control, meaning that it uses a combination of open loop measurements made at the UE and closed control signals from, for example, the serving TRP/gNB or other communication entities (e.g., UEs).

Conventional UE power control schemes include:

LTE V2x/D2D lateral link power control

LTE uplink power control

5G NR UE uplink Power control

For different reasons, none of the above conventional schemes is suitable for 5G NR side link transmit power control. A brief overview of conventional schemes and reasons for their inadequacies are given below.

The LTE V2x/D2D lateral link power control (releases 12, 13, and 14 of LTE V2 x) scheme is an open loop scheme that initially aims to minimize lateral link transmit power so that the lateral link does not cause interference to uplink users allocated in adjacent frequency bands.

The UE makes downlink measurements on signals received from the base station and calculates downlink Path Loss (PL). The following equation shows in a very general way how the transmit power (P) of the UE is set according to the scheme:

P＝min{P_MAX，10log₁₀(M)+P₀+α·PL}

in the above formula, the parameters can be interpreted as follows:

P₀: assuming a path loss of 0dB, the eNodeB received power per Resource Block (RB).

P_MAX: maximum power that the UE can transmit.

M: number of allocated resource blocks

10log₁₀(M): the bandwidth of the channel in terms of the number of resource blocks.

PL: estimated downlink path loss

α: enabling or disabling factors for partial Power Control (Fractional Power Control)

(for varying the effect of path loss measurements).

Since any potential interference to the base station as measured by the downlink is low, the higher the PL, the higher the power the UE is allowed to transmit.

Most importantly, this lateral link power control scheme depends only on the received path loss of the base station. This means that the transmit power for the sidelink increases as the UE moves away from the base station, but may not necessarily be the optimal power level for the sidelink itself. This does not apply to the 5G NR side link, since all that is needed is:

power control adapted to the lateral link itself.

Beam-based power control.

In addition to path loss measurements for the base station, path loss measurements are also made for other sidelink users (desired users, and users in adjacent bands-undesired users).

Closed and open loop options.

With respect to the LTE uplink power control scheme, LTE defines an open-loop power control scheme and a closed-loop power control scheme for uplink power control. The closed loop scheme can be summarized by the following equation:

UE transmit power P₀+α·PL+Δ_TF+fΔ_TPC+10log₁₀M

Other quantities not mentioned in the preceding equations are:

△_TF: offsets for different modulation and coding schemes.

f(△_TPC): the closed loop component of power control.

To set the basic operating point, the UE performs open loop path loss measurements for the base station and receives power control commands from the base station (dynamic offset part of the equation).

This does not apply to the 5G NR side link, since all that is needed is:

power control for the sidelink rather than the uplink

Beam-based power control

Path loss measurements are made for other sidelink users (desired users, and users in adjacent bands-undesired users) in addition to path loss measurements for the base station

Regarding the 5G NR UE Uplink power control scheme, the 5G NR specifies different Uplink schemes for beam-based power control for different signal types that the UE can transmit, i.e., Physical Uplink Shared Channel (PUSCH), Physical Uplink Control Channel (PUCCH), Sounding Reference Signal (SRS), or Physical random access Channel (P-RACH). These schemes allow for beamforming-based power control by signaling to the UE the beam-based resources transmitted by the base station that the UE should make measurements on, and the corresponding receiver beam at the UE is then the power-controlled transmit beam at the UE.

However, these beam-based reference signals are only from the base station and not from other lateral link resources. Therefore, this scheme is also not suitable for 5G NR side links, since all that is needed is:

lateral link power control for the lateral link instead of for the uplink.

Disclosure of Invention

In view of the above disadvantages, embodiments of the present invention aim to improve the conventional power control scheme. In particular, it is an object to provide a wireless communication device for beam selective transmit power control, and another device for supporting beam selective transmit power control, in particular a network device. Therefore, transmission power control suitable for the side link is required. Transmit power control at the UE should be beam-based. In addition to path loss measurements for e.g. network devices, the proposed device should also be able to make and use path loss measurements for other lateral links (desired and undesired transmission directions). Also, options for implementing closed loop power control and open loop power control are needed.

Furthermore, for 5G NR side link power control, the flexibility to combine different spatial directions in different ways and the possibility to weight the signal and power levels in different ways is also needed.

The above objects are achieved by embodiments of the present invention as described in the appended independent claims. Advantageous implementations of the invention are further defined in the dependent claims.

In particular, embodiments of the present invention illustratively propose a detailed, 5G NR compatible, beam-based lateral link transmit power control scheme for three different signal types:

physical Sidelink Shared Channel (PS-SCH)

Physical Sidelink Control Channel (PS-CCH)

Physical Sidelink Sounding Reference (PS-SRS)

Furthermore, embodiments of the present invention allow for consideration of beamformed reference signals from, for example, network devices and from at least one other lateral link (desired or undesired direction of transmission). In this way, the transmit power for the desired lateral link direction can be optimized and the signal power radiated in other undesired transmission directions can also be controlled.

Five different specific ways of combining these downlink and sidelink beamforming measurements in a transmit power control equation are presented in embodiments of the present invention.

A first aspect of the present invention provides a wireless communication apparatus (UE) for performing beam-selective transmit power control, the UE configured to: receiving, in particular, from a Power Control Configuration Device (PCCD) (i.e., a network entity, TRP, gNB, etc.), first parameters of downlink beamforming resources from the PCCD to the UE and second parameters of lateral link beamforming resources from a second UE to the UE; measuring a first path loss based on the first parameter and a second path loss based on the second parameter; and determining a transmit power for the lateral link beamforming resource to the second UE based on the first path loss and the second path loss and according to a pre-configured determination scheme.

The PCCD may be a 5G NR Transmit Receive Point (TRP), a 5G next generation Node B (gNB), an evolved Node B (eNB), a secondary Node B (SeNB), a base station or Remote Radio Head (RRH), or another UE. The UE may be a mobile device, e.g. a phone, but may in particular be mounted on or in a vehicle such as a car. That is, the lateral link beamforming resources may be related to the V2V link. The beamforming resources may be transmit beams or beam pairs (a beam pair — a transmit beam at a transmitting apparatus together with a corresponding receive beam at a receiving apparatus), etc. The preconfigured scheme may be a formula or algorithm implemented at the UE that derives an optimal transmit power for the lateral link beamforming resource to the second UE (desired lateral link transmission direction) based on the path loss.

The beamforming at the UE may be formed by any one of the beamforming methods (i.e., digital beamforming, RF beamforming, hybrid beamforming), and the different beamforming directions at the UE may be different beamforming directions from a single beamforming array, panel, or antenna element or from one or more beamforming arrays, panels, or antenna elements. Furthermore, in some implementations, each beamforming array, panel, or antenna element may also form a single fixed beam direction. A panel may be defined as a set of co-located antenna elements.

The UE of the first aspect is capable of performing transmit power control that is suitable for side links, e.g. 5G NR side links, and is beam-based, i.e. per beam.

In an implementation form of the first aspect, the wireless communication device is further configured to determine a transmit power for the uplink beamforming resource to the PCCD based on the first path loss and the second path loss.

Accordingly, transmit power control at the UE is also enabled (and optimized) for uplink beamforming resources to PCCD (undesired transmission direction) or any other supporting apparatus. That is, interference to the uplink channel may be avoided when transmitting to the second UE via the sidelink channel.

In an implementation form of the first aspect, the spatial direction at the UE associated with the downlink receive beamforming resources from the PCCD to the UE corresponds to the spatial direction associated with the uplink beamforming resources to the PCCD.

Therefore, by measuring the path loss for the parameter related to the downlink reception beamforming resource, the transmission power control for the uplink beamforming resource to the PCCD can be accurately performed.

In an implementation form of the first aspect, a spatial direction at the UE associated with a lateral link receive beamforming resource from the second UE to the UE corresponds to a spatial direction associated with a lateral link beamforming resource to the second UE.

Thus, by measuring the path loss for the parameter relating to the lateral link receive beamforming resource, transmit power control for the lateral link beamforming resource to the second UE may be performed accurately.

In an implementation form of the first aspect, the wireless communication device is further configured to determine the transmit power based on one or more predetermined weighting factors applied to the first path loss and/or the second path loss, respectively.

Thus, the flexibility is obtained that different spatial directions can be combined in different ways.

In an implementation form of the first aspect, the wireless communication device is further configured to determine the transmit power based on a minimum of the weighted first path loss and the weighted second path loss.

In an implementation form of the first aspect, the wireless communication apparatus is further configured to determine the transmit power based on predetermined target transmit powers predefined for zero path loss of the downlink beamforming resource from the PCCD to the UE and the lateral link beamforming resource from the second UE to the UE, respectively.

Thus, the flexibility of combining different spatial directions in different ways and the possibility of weighting the signals and power levels in different ways is fully achievable.

In an implementation form of the first aspect, the wireless communication apparatus is further configured to: receiving a third parameter of a lateral link beamforming resource from a third UE to the UE; measuring a third path loss based on the third parameter; and determining a transmit power for the lateral link beamforming resource to the second UE and/or for the lateral link beamforming resource to the third UE based on one, some or all of the measured path losses.

Thus, in addition to path loss measurements for PCCD, the UE of the first aspect is also able to make and use path loss measurements for other lateral links (desired and/or undesired transmission directions).

In an implementation form of the first aspect, the wireless communication device is further configured to determine a transmit power for the uplink beamforming resource to the PCCD based on one, some or all of the measured path losses.

In an implementation form of the first aspect, the lateral link beamforming resource to the second UE is associated with a spatial direction for transmission and the lateral link beamforming resource to the third UE is associated with another spatial direction for transmission.

In an implementation form of the first aspect, the lateral link beamforming resource to the second UE is associated with a spatial direction for transmission, and the lateral link beamforming resource to the third UE associated with another spatial direction for transmission is reduced, in particular such that the lateral link beamforming resource has a lower transmit power than the lateral link beamforming resource to the second UE.

In an implementation form of the first aspect, the wireless communication device is further configured to determine the transmit power based on predetermined weighting factors applied to the second path loss and the third path loss, respectively.

Thus, the transmit power control scheme enables different weighting of different lateral links, thereby increasing flexibility.

In an implementation form of the first aspect, the wireless communication device is further configured to determine the transmit power based on a predetermined set function applied to the second path loss and the third path loss.

This is particularly advantageous when simultaneously forming beams to multiple receiving UEs in multicast or multicast scenarios.

In an implementation form of the first aspect, the predetermined set function comprises a mean, a median, a minimum, a maximum, and/or a weighted sum of the second and third path losses.

In an implementation form of the first aspect, the wireless communication device is further configured to determine a transmit power for transmission on a physical lateral link shared channel, PS-SCH, a physical lateral link control channel, PS-CCH, and/or a lateral link sounding reference, PS-SRS.

In an implementation form of the first aspect, the pre-configured determination scheme is an open-loop scheme based on path loss measurements only, or the pre-configured determination scheme is a closed-loop scheme based on path loss measurements and one or more power control commands received by the UE, in particular from the PCCD.

A second aspect of the present invention provides an apparatus for supporting beam selective transmit power control performed by a wireless communication apparatus (UE), the apparatus configured to: in particular, a first parameter of a downlink beamforming resource from the apparatus to the UE and a second parameter of a lateral link beamforming resource from a second UE to the UE are transmitted to the UE.

In an implementation form of the second aspect, the apparatus is further configured to: in particular, the UE is sent a third parameter of a lateral link beamforming resource from a third UE to the UE and/or in particular one or more power control commands.

The apparatus of the second aspect supports the transmit power control scheme at the UE of the first aspect and thus supports all of the above effects and advantages.

A third aspect of the present invention provides a method for performing beam-selective transmit power control at a wireless communication device (UE), the method comprising: receiving, in particular from a Power Control Configuration Device (PCCD), a first parameter of a downlink beamforming resource from the PCCD to the UE and a second parameter of a lateral link beamforming resource from a second UE to the UE; measuring a first path loss based on the first parameter and a second path loss based on the second parameter; determining a transmit power for a lateral link beamforming resource from the UE to a second UE based on the first path loss and the second path loss and according to a pre-configured determination scheme.

In an implementation form of the third aspect, the method includes determining a transmit power for an uplink beamforming resource to the PCCD based on the first path loss and the second path loss.

In an implementation form of the third aspect, the spatial direction at the UE associated with the downlink receive beamforming resources from the PCCD to the UE corresponds to the spatial direction associated with the uplink beamforming resources to the PCCD.

In an implementation form of the third aspect, a spatial direction at the UE associated with a lateral link receive beamforming resource from the second UE to the UE corresponds to a spatial direction associated with a lateral link beamforming resource to the second UE.

In an implementation form of the third aspect, the method comprises determining the transmit power based on one or more predetermined weighting factors applied to the first path loss and/or the second path loss, respectively.

In an implementation form of the third aspect, the method comprises determining the transmit power based on a minimum of the weighted first path loss and the weighted second path loss.

In an implementation form of the third aspect, the method comprises determining the transmit power based on predetermined target transmit powers predefined for zero path loss for downlink beamforming resources from the PCCD to the UE and lateral link beamforming resources from the second UE to the UE, respectively.

In an implementation form of the third aspect, the method comprises: receiving a third parameter of a lateral link beamforming resource from a third UE to the UE; measuring a third path loss based on the third parameter; and determining a transmit power for the lateral link beamforming resource to the second UE and/or for the lateral link beamforming resource to the third UE based on one, some or all of the measured path losses.

In an implementation form of the third aspect, the method further comprises determining a transmit power for the uplink beamforming resource to the PCCD based on one, some or all of the measured path losses.

In an implementation form of the third aspect, the lateral link beamforming resource to the second UE is associated with a spatial direction for transmission and the lateral link beamforming resource to the third UE is associated with another spatial direction for transmission.

In an implementation form of the third aspect, the lateral link beamforming resource to the second UE is associated with a spatial direction for transmission and the lateral link beamforming resource to the third UE associated with another spatial direction for transmission is reduced, in particular such that the lateral link beamforming resource has a lower transmit power than the lateral link beamforming resource to the second UE.

In an implementation form of the third aspect, the method further comprises determining the transmit power based on predetermined weighting factors applied to the second path loss and the third path loss, respectively.

In an implementation form of the third aspect, the method further comprises determining the transmit power based on a predetermined set function applied to the second path loss and the third path loss.

In an implementation form of the third aspect, the predetermined set function comprises a mean, a median, a minimum, a maximum, and/or a weighted sum of the second and third path losses.

In an implementation form of the third aspect, the method further comprises determining a transmit power for transmission on a physical lateral link shared channel PS-SCH, a physical lateral link control channel PS-CCH, and/or a physical lateral link sounding reference PS-SRS.

In an implementation form of the third aspect, the pre-configured determination scheme is an open-loop scheme based on path loss measurements only, or the pre-configured determination scheme is a closed-loop scheme based on path loss measurements and one or more power control commands received by the UE, in particular from the PCCD.

The method of the third aspect and its implementation forms achieve the same advantages and effects as the apparatus of the first aspect and its corresponding implementation forms described above.

It has to be noted that all means, elements, units and means described in the present application can be implemented in software or hardware elements or any combination thereof. All steps described in this application as being performed by various entities and functions described as being performed by various entities are intended to mean that the respective entity is adapted or configured to perform the respective steps and functions. Although in the following description of certain embodiments, certain functions or steps to be performed by an external entity are not reflected in the description of certain detailed elements of the entity performing the certain steps or functions, it should be clear to a skilled person that these methods and functions may be implemented in corresponding software or hardware elements or any type of combination thereof.

Drawings

The above aspects and implementations of the invention will be explained in the following description of specific embodiments with reference to the drawings, in which:

fig. 1A illustrates a wireless communication device and a (e.g., network) device according to an embodiment of the present invention.

Fig. 1B shows a schematic view of an apparatus according to another embodiment of the invention.

Fig. 2 shows a wireless communication apparatus and a network apparatus according to an embodiment of the present invention.

Fig. 3 illustrates a wireless communication device and a network device according to an embodiment of the present invention.

Fig. 4 shows a wireless communication apparatus and a network apparatus according to an embodiment of the present invention.

Fig. 5 illustrates a transmission power control method according to an embodiment of the present invention.

Detailed Description

Fig. 1A illustrates a wireless communication apparatus (UE)100 configured to perform beam selective transmit power control according to an embodiment of the present invention. Further, fig. 1A shows an apparatus 101 for supporting beam selective transmit power control performed by a UE100 according to another embodiment of the present invention. As exemplarily assumed in the following description of the embodiments, the device 101 may be a PCCD capable of being a network device (i.e., TRP, etc.). However, the apparatus 101 may also be another UE or any other entity supporting power control according to the features described below.

The UE100 is configured to receive, in particular from the device/PCCD 101, a first parameter 102 of downlink beamforming resources from the PCCD101 to the UE100 and a second parameter 103 of lateral link beamforming resources from a second UE 104 to the UE 100. Accordingly, the device 101 is configured to transmit to the UE100, inter alia, a first parameter 102 of a downlink beamforming resource from the device 101 to the UE100 and a second parameter 103 of a lateral link beamforming resource from the second UE 104 to the UE 100. The UE100 may communicate with the second UE 104 via a lateral link as indicated by the dashed line. The UE100 may communicate with the device/PCCD 101 via a downlink/uplink (or another sidelink if the apparatus 101 is another UE) as indicated by the dashed line.

The UE100 is further configured to measure a first path loss 105 based on the received first parameter 102 and a second path loss 106 based on the received second parameter 103. The path loss measurements 105, 106 may be performed by the UE100 in a conventional manner, i.e. as known in the art.

The UE100 is then configured to: transmit power 108 for the lateral link beamforming resource to the second UE 104 is determined based on the first path loss 105 and the second path loss 106 and according to a pre-configured determination scheme 107. The pre-configured determination scheme 107 may be at least one algorithm or formula pre-installed at the UE 100. The UE100 can select an algorithm or formula from a plurality of algorithms or formulas preconfigured at the UE100, e.g., according to the type of link for which loss has been measured, or according to different embodiments of the present invention as described below.

In an exemplary embodiment of the invention, the transmit power control of the 5G NR beam-based lateral link is considered for three different signal types, namely physical lateral link shared channel (PS-SCH), physical lateral link control channel (PS-CCH), physical lateral link sounding reference (PS-SRS). For each of these signal types, an exemplary beam-based lateral link power control equation (i.e., as a preconfigured determination scheme 107) is presented below (a modified version of the beam-based equation for the 5G NR uplink). In particular, these equations 107 determine how to combine and weight the measured path losses 105, 106 from different beamforming resources, i.e., from the apparatus 101 and from one or different lateral link resources, in different ways to achieve beam-based lateral link transmit power control to the second UE 104.

Fig. 1B shows a schematic diagram of a user device according to another embodiment of the present invention. As can be seen from the figure, different beamforming at the device may correspond to different beam directions. Different beamforming may be achieved by a single beamforming array, panel or antenna element on the device. Alternatively, beamforming may be implemented using one or more beamforming arrays, panels, or antenna elements at different locations of the apparatus. Furthermore, in some implementations, each beamforming array, panel, or antenna element on the device may also form a single fixed beam (direction). A panel may be defined as a set of co-located antenna elements.

Fig. 1B shows an example of three possible scenarios in which the UE is a vehicle. In 201, different beam directions are formed using a single beamforming array, panel or antenna element located at a single location. In 202, different beam directions are formed using multiple beamforming arrays, panels, or antenna elements at different locations on the vehicle. In 203, a situation is shown where a fixed beam is formed using multiple beamforming arrays, panels or antenna elements at different locations of the vehicle.

Although fig. 1B shows different scenarios with reference to cars, it is clear that this is only one possible example of a UE and that the spatial filter described above may also be embodied in different types of UEs, such as mobile phones or any vehicles.

FIG. 2 illustrates the UE100 and the device 101 built on the UE100 and the device 101 shown in FIG. 1A according to an embodiment of the present invention. Like elements in fig. 1A and 2 are labeled with like reference numerals and have like functions. That is, also in fig. 2, the device 101 provides the UE100 with the parameter 102/103 and the UE100 determines the transmit power 108 for the lateral link beamforming resource to the second UE 104. Device 101 may also be a PCCD, such as a TRP.

Fig. 2 specifically illustrates a basic concept of a beam-based transmission power control scheme performed by the UE 100. Informing UE100 of parameters 102 (q) of downlink beamforming resources from device 101_d) And parameters 103 (q) of the lateral link beamforming resources from the second UE 104_s) Wherein the transmit power 108 of the UE100 is power controlled at least for the lateral link beamforming resource to the second UE (104), but optionally also for the uplink beamforming resource to the apparatus 101. At least these parameters 102 and 103 are considered for path loss measurements 105 and 106. The parameter 102 may refer to a resource from a Channel State Information-Reference Signal (CSI-RS) Signal or a Synchronization Signal Block (SSB) Signal transmitted through a base station (Uu link). The parameter 103 may be a lateral link CSI-RS or a lateral link SSB resource. The downlink beamforming resources from device 101 (here, the Uu downlink from the base station) correspond to undesired spatial transmission directions, while the lateral link beamforming resources to the second UE 104 correspond to desired spatial transmission directions. As shown in fig. 1A, the UE100 and the second UE 104 may be installed at vehicles, here, a car a and a car B.

Five embodiments of the present invention are exemplarily described below using an exemplary equation for PS-SCH (pre-configured determination scheme 107), but all of these five embodiments may also be applied to PS-CCH or PS-SRS (as well as to other signal types not explicitly defined herein). Further, closed loop power control implementations and open loop power control implementations are described.

a)PS-SCH closed-loop power control

The standard Power Control equation for the 5G NR physical Uplink shared channel (PU-SCH) is modified for PS-SCH, in particular for the lateral link with additional parameters and resources required for the 5G NR PS-SCH — see "3 GPP TS 38.213V15.1.0(2018-03), Section 7, Uplink Power Control". This modification is shown in equation (1) below, with equation (1) showing the baseline modification. Relevant modifications and changes are shown in equation (1) in grey shading. Other modifications not highlighted include changing the subscript to pssch.

Path loss measurements inside the min (.) expression include for the lateral link PL to the second UE 104_f,c(q_s) Of the path loss measurements 105, 106 and their own weighting factor (alpha) alpha_f,c,s(j) In that respect Equation (1) is a beam-based equation, which means that the indicated resource (q) is received for its UE100_dAnd q is_s) The transmission power in the spatial direction of (1) is a transmission power for power control according to equation (1). By including lateral link beamforming resources and downlink beamforming resources, transmissions in both directions may be controlled.

FIG. 3 illustrates the UE100 and the device 101 built on the UE100 and the device 101 shown in FIG. 1A and FIG. 2 according to an embodiment of the present invention. Like elements in fig. 1A, 2 and 3 are labeled with like reference numerals and have like functions. That is, also in fig. 3, the device 101 provides the UE100 with the parameter 102/103 and the UE100 determines the transmit power 108 for at least the lateral link beamforming resource to the second UE 104.

As shown in fig. 3, in particular, the UE100 may receive a third parameter 301 of a lateral link beamforming resource from at least a third UE 300 to the UE 100. The UE100 may measure a third path loss based on the third parameter 301 and may determine a transmit power 108 for the lateral link beamforming resource to the second UE 104 and/or the lateral link beamforming resource to the third UE 300 based on one, some, or all of the measured path losses. Thus, the beamforming resource to the third UE 300 is associated with another spatial direction for transmission. In fig. 3, the lateral link beamforming resource from the third UE 300 is related to the desired transmission direction.

This situation can be reflected by a first modification of equation (1) above, i.e. including n lateral link beamforming resources (q)_s1To q_sn) A possibility to be served. This may advantageously be used for sidelink multicast or for managing desired or undesired transmissions in different sidelink directions. The modification for this first modification is shown in equation (2) below:

the UE100 may also determine the transmit power 108 based on predetermined target transmit powers predefined for zero path loss of at least the downlink beamforming resource from the device 101 to the UE100 and the lateral link beamforming resource from the second UE 104 to the UE100, respectively.

This may be reflected by a second modification of equation (1). That is, the lateral link beamforming resource and the downlink beamforming resource in the min (.) portion of the equation may have different target transmit powers P₀(for zero path loss), as in P in the following equations_{od，Psssch，f，c}And P_{os，Psssch，f，c}As shown in detail. In this way, the target power transmitted in each of these spatial directions may be controlled. This is particularly useful in the case where one of the spatial directions is an undesired direction, as shown in fig. 3 with respect to another UE 300. This is shown in equation (3) below:

the UE100 may also be configured to determine the transmit power 108 based on one or more predetermined weighting factors applied to the first path loss 105 and/or the second path loss 106, respectively.

This may be reflected by a third modification of equation (1), where different target received powers P are considered for multiple lateral chain beamforming resources_{osl，psssch，f，c}，……P_{osn，psssch，fc}And different weighting factors (alpha) alpha_f，c，s1(j)……α_f，c，sn(j) In that respect This is shown in equation (4) below, where only the modified min (.) portion of the previous power control equation (3) is shown in equation (4). This modification is particularly useful for side link multicast or side link multicast when there are certain spatial directions for which transmit power in the desired direction and the undesired direction is to be controlled.

…min(P_{od，pssch，f，c}+α_f，c，u(j)·PL_f，c(qd)，

P_{osn1，pssch，f，c}+α_f，c，s1(j)·PL_f，c(q_s1)，..

P_{osn，pssch，f，c}+α_f，c，sn(j)·PL_f，c(q_sn)) (4)

Fig. 4 shows an example of such a situation. FIG. 4 illustrates the UE100 and the device 101 built on the UE100 and the device 101 illustrated in FIGS. 1A, 2 and 3 according to an embodiment of the present invention. Like elements in fig. 1A to 4 are labeled with like reference numerals and have like functions. That is, also in fig. 4, the device 101 provides the UE100 with the parameter 102/103, and the UE100 determines the transmit power 108 for the lateral link beamforming resource to the second UE 104.

Similar to in fig. 3, the UE100 shown in fig. 4 may receive third parameters 301 of lateral link beamforming resources from at least one third UE 300 to the UE 100. The lateral link beamforming resource to the third UE 300 is associated with another spatial direction for transmission. In contrast to fig. 3, however, in fig. 4 the lateral link beamforming resource from the third UE 300 is related to an undesired transmission direction.

The UE100 may also determine the transmit power 108 based on a predetermined set function applied to the second path loss 106 and the third path loss. This may be reflected by a fourth modification of equation (1), where the set of lateral link beamforming resources may be bundled together in a set function f in the mmin (.) -portion of equation (1). This may be useful for multicast or multicasting where beams to multiple receiving UEs may have to be formed simultaneously and the performance of the best or worse set of those multiple receiving UEs in the group should be optimized.

…min(P_{od，pssch，f，c}+α_f，c，u(j)·PL_f，c(q_d)，

f(P_{os1，pssch，f，c}+α_f，c，s1(j)·PL_f，c(q_s1)，..P_{osn，pssch，f，c}+Δ_f，c，sn(j)·PL_f，c(q_sn)))

(5)

The set function f () may be many different types of expressions that may include: mean (), Minimum (), Max (), Sum (), Median (), Weighted Sum (), etc.

b)PS-SCH open Loop

Above under a), a proposal for closed loop power control for PS-SCH is described. For an open loop version of power control, a reference modification to 5G NR beam-based power control for Physical Uplink Shared Channel (PUSCH) is proposed. This baseline modification is shown in equation (6) below (the relevant modifications are again shown in grey shading):

this is in contrast to the closed loop of power control above for the PS-SCHThe changes proposed by the versions are very similar. The main difference between the closed loop and open loop versions of power control is: does not include dynamic offset Δ that varies with link adaptation for different Modulation and Coding Schemes (MCS)_TF，f，cAnd power control feedback command f_f，c(i，j)。

Thus, the pre-configured determination scheme 107 may be a closed-loop scheme based on path loss measurements and one or more power control commands received by the UE100, in particular from the PCCD 101.

All of the first to fourth modifications described for the PS-SCH closed loop equation may be applied in addition to the reference modification described above for the open-loop power equation (6).

c)PS-CCH closed and open loops

For PS-CCH, it is also proposed to use a modified version of the 5G NR physical uplink control channel (PU-CCH). The key baseline modifications for closed and open loops are shown in equations (7) and (8) below, respectively.

Equation (7) for closed-loop reference modification:

equation (8) for open-loop reference modification:

in addition to these reference modifications, all of the first to fourth modifications proposed above can also be applied thereto.

d)PS-SRS closed and open loops

For PS-SRS, it is also proposed to use a modified version of the 5G NR SRS (SRS) power control equation. Key reference modifications for closed and open loops are shown in equations (9) and (10) below.

Equation for reference modification of closed loop:

equation for open-loop reference modification:

The key modifications for all these signal types are changes to include Downlink (DL) and Sidelink (SL) measurements and how they are weighted in the power control equations. In particular, five different variants of how to use Downlink (DL) and lateral link (SL) measurements for each of the modifications proposed above are presented:

i) minimum in (one downlink, one sidelink) -reference modification.

Ii) different target powers for the downlink and sidelink — first modification.

Iii) minimum in (one DL and multiple sidelinks) -second modification.

Iv) different α for different lateral links — third modification.

V) a set of lateral link path losses and an associated parameter set function f () -a fourth modification.

Throughout the above description of embodiments, the current 3GPP 5G NR uplink power control equation is used as a basis and is modified for different signal types to illustrate the key point. Traditionally, these equations are for systems where the Control Channel (CCH) and the Shared Channel (SCH) (data part) are Time Domain Multiplexed (TDM). Thus, power control and bandwidth can be easily separated for these separate parts. However, the control portion and the data portion may be multiplexed in the frequency domain.

In all of the above equations, the bandwidth portion of the equation may also include portions from both the control portion and the data portion. For example, if physical sidelink control channel is taken as an example, in equation (1), the bandwidth portion may be selected from

Become into

However, this is merely an example.

Fig. 5 illustrates a method 500 according to an embodiment of the invention. The method 500 is for performing beam-selective transmit power control at the UE 100. The method 500 may be specifically performed by the UE100 in fig. 1A-4.

The method comprises the following steps: step 501, receiving, in particular from the TRP 101, a first parameter 102 of a downlink beamforming resource from the TRP 101 to the UE100 and a second parameter 103 of a lateral link beamforming resource from the second UE 104 to the UE 100; step 502, measuring a first path loss 105 based on the first parameter 102 and a second path loss 106 based on the second parameter 103; and step 503, determining the transmit power 108 of the lateral link beamforming resource from the UE100 to the second UE 104 based on the first path loss 105 and the second path loss 106 and according to the pre-configured determination scheme 107.

The invention has been described in connection with various embodiments and implementations as examples. However, other variations will be understood and effected by those skilled in the art and practicing the claimed invention, from a study of the drawings, the disclosure, and the independent claims. In the claims as well as in the description, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality. A single element or other unit may fulfill the functions of several entities or items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Claims

1. A wireless communication device, UE, (100) for performing beam selective transmit power control, the UE (100) being configured to:

receiving in particular from a power control configuration device, PCCD, a first parameter (102) of a downlink beamforming resource from the PCCD (101) to the UE (100) and a second parameter (103) of a lateral link beamforming resource from a second UE (104) to the UE (100),

measuring a first path loss (105) based on the first parameter (102) and a second path loss (106) based on the second parameter (103), and

determining a transmit power (108) for lateral link beamforming resources to the second UE (104) based on the first path loss (105) and the second path loss (106) and according to a pre-configured determination scheme (107).

2. The wireless communication device (100) of claim 1, further configured to: determining a transmit power for uplink beamforming resources to the PCCD (101) based on the first path loss (105) and the second path loss (106).

3. The wireless communication device (100) of claim 2, wherein:

the spatial direction at the UE (100) associated with downlink receive beamforming resources from the PCCD (101) to the UE (100) corresponds to the spatial direction associated with uplink beamforming resources to the PCCD (101).

4. The wireless communication device (100) according to one of claims 1 to 3, wherein:

the spatial direction at the UE (100) associated with the lateral link receive beamforming resource from the second UE (104) to the UE (100) corresponds to the spatial direction associated with the lateral link beamforming resource to the second UE (104).

5. The wireless communication device (100) according to one of claims 1 to 4, configured to:

determining the transmit power (108) based on one or more predetermined weighting factors applied to the first path loss (105) and/or the second path loss (106), respectively.

6. The wireless communication device (100) of claim 5, configured to:

determining the transmit power (108) based on a minimum of the weighted first path loss (105) and the weighted second path loss (106).

7. The wireless communication device (100) according to one of claims 1 to 6, configured to:

determining the transmit power (108) based on predetermined target transmit powers predefined for zero path loss of downlink beamforming resources from the PCCD (101) to the UE (100) and lateral link beamforming resources from the second UE (104) to the UE (100), respectively.

8. The wireless communication device (100) according to one of claims 1 to 7, further configured to:

receiving a third parameter (301) of a lateral link beamforming resource from a third UE (300) to the UE (100),

measuring a third path loss based on the third parameter (301), an

Determining a transmit power (108) for the lateral link beamforming resource to the second UE (104) and/or the lateral link beamforming resource to the third UE (300) based on one, some or all of the measured path losses.

9. The wireless communication device (100) of claim 8, further configured to:

determining a transmit power of an uplink beamforming resource to the PCCD (101) based on the one, some or all measured path losses.

10. The wireless communication device (100) of claim 8 or 9, wherein:

a lateral link beamforming resource to the second UE (104) is associated with a spatial direction for transmission, and

a lateral link beamforming resource to the third UE (300) is associated with another spatial direction for transmission.

11. The wireless communication device (100) of claim 8 or 9, wherein:

lateral link beamforming resources to the third UE (300) associated with another spatial direction for transmission are reduced, in particular such that the lateral link beamforming resources have a lower transmit power than lateral link beamforming resources to the second UE (104).

12. The wireless communication device (100) according to one of claims 8 to 11, configured to:

determining the transmit power (108) based on predetermined weighting factors applied to the second path loss (105) and the third path loss, respectively.

13. The wireless communication device of one of claims 8 to 12, configured to:

determining the transmit power (108) based on a predetermined set function applied to the second path loss (106) and the third path loss.

14. The wireless communication device (100) of claim 13, wherein:

the predetermined set function comprises a mean, median, minimum, maximum, sum or weighted sum of the second path loss (106) and the third path loss.

15. The wireless communication device (100) according to one of claims 1 to 14, configured to:

transmit power for transmissions on a physical sidelink shared channel (PS-SCH), a physical sidelink control channel (PS-CCH), and/or a physical sidelink sounding reference (PS-SRS) is determined (108).

16. The wireless communication device (100) according to one of claims 1 to 15, wherein:

the pre-configured determination scheme (107) is an open-loop scheme based on path loss measurements only, or

The pre-configured determination scheme (107) is a closed-loop scheme based on path loss measurements and one or more power control commands received by the UE (100), in particular from the PCCD (101).

17. An apparatus (101) for supporting beam selective transmit power control performed by a wireless communication apparatus, UE, (100), the apparatus (101) being configured to:

-transmitting in particular to the UE (100) a first parameter (102) of a downlink beamforming resource from the device (101) to the UE (100) and a second parameter (103) of a lateral link beamforming resource from a second UE (104) to the UE (100).

18. The apparatus (101) of claim 17, further configured to:

transmitting, in particular to the UE (100), a third parameter of a lateral link beamforming resource from a third UE (300) to the UE (100), and/or

-in particular to transmit one or more power control commands to the UE (100).

19. A method (500) for performing beam selective transmit power control at a wireless communication device, UE, (100), the method (500) comprising:

receiving (501), in particular from a power control configuration device, PCCD, first parameters (102) of downlink beamforming resources from the PCCD (101) to the UE (100) and second parameters (103) of lateral link beamforming resources from a second UE (104) to the UE (100),

measuring (502) a first path loss (105) based on the first parameter (102) and measuring (502) a second path loss (106) based on the second parameter (103),

determining (503) a transmit power (108) for lateral link beamforming resources from the UE (100) to the second UE (104) based on the first path loss (105) and the second path loss (106) and according to a pre-configured determination scheme (107).