阅读说明：本技术 实现波束参考信令的方法、无线设备和网络节点 (Method, wireless device and network node for realizing beam reference signaling ) 是由 赵堃 F·卢塞克 E·本特松 O·赞德 于 2020-03-26 设计创作，主要内容包括：公开了一种由网络节点执行的用于波束参考信令的方法。网络节点被配置为使用波束集与无线通信系统的无线设备进行通信。所述方法包括以下步骤：向无线设备发送一个或更多个第一下行链路DL波束参考信号；以及从无线设备接收指示需要改变下行链路波束参考信令的控制信令。(A method performed by a network node for beam reference signaling is disclosed. The network node is configured to communicate with a wireless device of the wireless communication system using a beam set. The method comprises the following steps: transmitting one or more first downlink, DL, beam-reference signals to a wireless device; and receiving control signaling from the wireless device indicating a need to change the downlink beam reference signaling.)

1. A method performed by a network node for beam reference signaling, wherein the network node is configured to communicate with a wireless device of a wireless communication system, the method comprising:

-transmitting (S202) one or more first downlink, DL, beam-reference signals to the wireless device; and

-receiving (S204) control signaling from the wireless device indicating a need to change downlink beam reference signaling.

2. The method according to claim 1, comprising the steps of: upon satisfying one or more criteria:

-transmitting (S206) one or more second DL beam-reference signals to the wireless device based on the received control signaling, wherein the one or more second DL beam-reference signals are different from the one or more first DL beam-reference signals.

3. The method according to claim 1 or 2, comprising the steps of: transmitting (S205) control signaling indicating the changed DL beam reference signaling.

4. The method according to any of claims 1 to 3, wherein the control signaling indicating that a change of downlink beam reference signaling is required comprises at least one of: control signaling indicating that additional downlink, DL, resources for beam-reference signaling are needed, control signaling indicating that modified power of the one or more DL beam-reference signals is needed, and control signaling indicating that modified transmission periods of the one or more DL beam-reference signals are needed.

5. The method according to any of claims 1 to 4, wherein the control signaling indicating that a change of downlink beam reference signaling is required comprises control signaling indicating that an uplink beam scanning is required, the method comprising the steps of: requesting the wireless device to perform an uplink beam sweep.

6. The method according to any of claims 1-5, wherein the step of transmitting (S202) one or more first DL beam-reference signals to the wireless device comprises: transmitting (S202A) the one or more first DL beam-reference signals to the wireless device on one or more receive beams.

7. The method according to any of claims 1-6, wherein the step of transmitting (S202) one or more first DL beam-reference signals to the wireless device comprises: broadcasting (S202B) the one or more first DL beam-reference signals.

8. The method of any one of claims 2 to 7, wherein the one or more second DL beam-reference signals comprise one or more second DL beam-reference signals having one or more of: modified transmit power, allocated additional resources, and modified transmit period.

9. A method performed by a wireless device for beam reference signaling, wherein the wireless device is configured to communicate with a network node of a wireless communication system using a beam set, the method comprising:

-determining (S104) inability to establish beam correspondence; and

-in response to the determination (S104), transmitting (S108) control signaling to the network node indicating that DL beam reference signaling needs to be changed for the beam correspondence.

10. The method according to claim 9, comprising the steps of:

-receiving (S102) one or more downlink, DL, beam-reference signals from the network node; and is

Wherein the step of determining (S104) incapacity comprises:

-determining (S104A) one or more DL reception quality parameters associated with the capability of establishing beam correspondence based on the received one or more DL beam reference signals; and

-transmitting (S108) the control signaling upon determining that the one or more DL reception quality parameters do not satisfy a quality criterion.

11. The method according to claim 9 or 10, comprising the steps of: determining (S106) whether the one or more DL reception quality parameters meet the quality criterion.

12. The method according to any of claims 9 to 11, wherein the control signaling indicating that the DL beam reference signaling needs to be changed comprises at least one of: control signaling indicating that additional downlink, DL, resources for beam reference signaling are needed, control signaling indicating that modified power of the one or more DL beam reference signals is needed, and control signaling indicating that modified reception periods of the one or more DL beam reference signals are needed.

13. The method according to any of claims 9-12, wherein the DL beam reference signaling comprises a set of change levels.

14. The method of any of claims 9 to 13, wherein the one or more DL reception quality parameters associated with the capability of establishing beam correspondence comprise one or more of: a parameter indicative of a signal to noise ratio, a parameter indicative of a signal to interference and noise ratio, a parameter indicative of a received power, and a parameter indicative of a radiated power.

15. The method according to any one of claims 9 to 14, comprising the steps of:

-receiving (S110) one or more DL beam reference signals that are changed according to one or more of the following: increased transmit power, additional resources, and increased transmit periods; and

-establishing (S112) a beam correspondence.

Background

In a 5G New Radio (NR) wireless communication system, a wireless device (e.g., user equipment, UE) may both receive and transmit signals. In both cases, the wireless device may receive and/or transmit in a specified physical direction, and the wireless device may find the direction. To facilitate finding the receive direction, in NR, a network node (e.g., a base station or a gNB) sends a reference symbol or Reference Signal (RS) to the wireless device, which may allow the wireless device to test for different receive directions by measuring downlink reference signals and then select the best receive direction (e.g., the receive direction with the largest input power).

Due to the dynamic variation of wireless channels in real life and due to hardware issues, it may be difficult for a wireless device to always guarantee Beam Correspondence (BC) capability of the current wireless device based on BC capability signaling.

Relying on downlink measurements alone is not sufficient to properly select one or more uplink beams. Relying on uplink beam scanning is also typically sub-optimal due to the resulting delays and limited Sounding Reference Signal (SRS) resources that the network node can configure.

Disclosure of Invention

Accordingly, there is a need for methods, wireless devices and network nodes that mitigate, alleviate or address the existing disadvantages and provide improved beam reference signaling that allows for indicating to a wireless device that beam reference signaling needs to be changed (e.g., modified for adaptation or enhancement).

A method for beam reference signaling is disclosed. The method is performed by a network node. The network node is configured to communicate with a wireless device of a wireless communication system. The method comprises the following steps: one or more first downlink DL beam-reference signals are transmitted to the wireless device. The method comprises the following steps: control signaling is received from the wireless device indicating that a change in downlink beam reference signaling (such as for a beam) is required.

In addition, a network node is provided. The network node includes a memory, a processor, and an interface. The network node is configured to perform any of the methods disclosed herein.

Thus, the network node may change the downlink beam reference signaling in response to receiving the disclosed signaling indicating that the downlink beam reference signaling needs to be changed, which may obtain a beam correspondence.

A method for beam reference signaling is disclosed. The method is performed by a wireless device. The wireless device is configured to communicate with a network node of the wireless communication system using the beam set. The method comprises the following steps: determining inability to establish beam correspondence. The method comprises the following steps: in response to the determination, transmitting control signaling indicating that the DL beam reference signaling needs to be changed for the beam correspondence.

Additionally, a wireless device is provided. The wireless device includes a memory, a processor, and a wireless interface. The wireless device is configured to perform any of the methods disclosed herein.

Thus, when the wireless device determines that a beam correspondence cannot be established for the current uplink beam, the wireless device may indicate a need to change downlink beam reference signaling. Thus, the wireless device may obtain beam correspondence by receiving appropriate or adjusted DL beam reference signaling, e.g., from a network node.

The present disclosure provides, in one or more embodiments, improvements in wireless device selection of beams (such as uplink UL beams) and ultimately improves performance of uplink communications established using beam correspondence when: due to conditions associated with the communication channel and/or wireless device hardware, it may be difficult for the wireless device to determine the appropriate transmission beam.

Drawings

The above and other features and advantages of the present disclosure will become apparent to those skilled in the art from the following detailed description of exemplary embodiments thereof, which proceeds with reference to the accompanying drawings, wherein:

figure 1A is a diagram illustrating an example wireless communication system including an example network node and an example wireless device according to the present disclosure,

fig. 1B illustrates two example graphs illustrating RSRP accuracy and signal-to-noise ratio (SNR) and RSRP accuracy and DL RS configuration, respectively,

fig. 1C illustrates two example graphs illustrating uplink beam spherical coverage with different downlink RSRP measurement accuracy (error) for autonomously selected uplink beams, and illustrating uplink spherical coverage with different Sounding Reference Signal (SRS) resources for uplink beam scanning, respectively.

Figure 2 is a flow chart illustrating an example method performed by a network node for beam reference signaling according to the present disclosure,

figure 3 is a flow chart illustrating an example method performed by a wireless device for beam reference signaling in accordance with the present disclosure,

FIG. 4 is a block diagram illustrating an example wireless device, an

Fig. 5 is a block diagram illustrating an example network node in accordance with the present disclosure.

Detailed Description

Various exemplary embodiments and details are described below with reference to the accompanying drawings when relevant. It should be noted that the figures may or may not be drawn to scale and that elements of similar structure or function are represented by like reference numerals throughout the figures. It should also be noted that the drawings are only intended to facilitate the description of the embodiments. The drawings are not intended as an exhaustive description of the disclosure or as a limitation on the scope of the disclosure. Moreover, the illustrated embodiments need not have all of the aspects or advantages shown. Aspects or advantages described in connection with a particular embodiment are not necessarily limited to that embodiment and may be practiced in any other embodiment, even if not so illustrated or even if not so explicitly described.

Third generation partnership project (3GPP) defined Beam Correspondence (BC) holds when a wireless device can autonomously select an uplink beam for transmission to a network node based on a downlink reference signal (DL RS) from the network node.

The third generation partnership project (3GPP) system will operate with Tx/Rx beam correspondence at the network node (e.g. the gNB and/or the transmission reception point TRP) and the wireless device (so-called UE) according to the following rules.

The Tx/Rx beam correspondence at the TRP holds if at least one of the following is satisfied:

the TRP can determine the TRP Rx beam for uplink reception based on UE downlink measurements of one or more Tx beams of the TRP.

The TRP can determine a TRP Tx beam for downlink transmission based on TRP uplink measurements on one or more Rx beams of the TRP.

The Tx/Rx beam correspondence at the UE is true if at least one of the following is satisfied:

the UE can determine a UE Tx beam for uplink transmission based on UE downlink measurements of one or more Rx beams of the UE.

The UE can determine a UE Rx beam for downlink reception based on TRP indications from uplink measurements on one or more Tx beams of the UE.

The third generation partnership project 3GPP system specifies that beam correspondence is mandatory with the following capability signaling definitions. For example, a UE that satisfies the beam correspondence requirement without uplink beam scanning sets the BC capability bit to 1. For example, a UE or wireless device that meets the beam correspondence requirement with uplink beam scanning sets the BC capability bit to 0.

At the wireless device, the DL beam corresponds to an Rx beam and the UL beam corresponds to a Tx beam.

Beam correspondence may be viewed as the ability of the UE to select a suitable beam for UL transmission based on DL measurements, with or without relying on UL beam scanning. In other words, beam correspondence may be viewed as the ability of the UE to autonomously select an uplink beam based on DL measurements.

Measurement errors may affect the actual ability and performance of determining the best beam. To overcome measurement errors, a BC capability parameter is set to indicate that UL beam scanning is always required (e.g., BC capability set to 0) to satisfy BC. This results in increased overhead that can be avoided by the disclosed techniques.

The BC capability bit may be interpreted to provide good BC performance with poor BC performance. There are a number of factors that can cause measurement errors to affect communication performance and thus the ability to establish BC.

For example, the likelihood of the wireless device selecting the highest performing uplink beam is limited by the DL RS measurement accuracy (or more precisely, by the accuracy of the L1 reference signal received power (L1-RSRP) in release 16 (Rel-16)). For example, the accuracy of the L1-RSRP measurement may be affected by multipath propagation in the channel, interference from neighboring cells, measurement periodicity of the wireless device, DL RS configuration, and the like. Thus, in many cases, the wireless device may not be able to autonomously select an appropriate uplink beam.

When the wireless device is unable to autonomously select an uplink beam, there are two possible scenarios:

the network node may select an uplink beam from the wireless device by requesting the wireless device to perform an uplink beam scan.

The wireless device attempts to autonomously select its uplink beam again.

In either case, it is unclear whether any of these two possible scenarios will yield any improvement. It may be difficult for a wireless device to determine when and how to set the wireless device to a particular mode in which an UL beam may be selected autonomously (e.g., a DL-based estimation mode) or another mode with UL beam scanning (e.g., an UL beam scanning mode). Additionally, a wireless device may have its preferences and capabilities limited in certain choices; for example, the uplink beam scanning procedure (or UL beam scanning mode) typically results in severe delays in communication. For example, a wireless device may prefer to operate its uplink beam autonomously rather than entering an uplink beam scanning mode due to delay effects.

When the wireless device sets the BC capability bit to 1, the network node may know that the wireless device may find the most favorable transmit direction from the downlink beam-reference signals transmitted by the network node.

When the wireless device sets the bit to 0, the network node may know that it is difficult for the wireless device to find the most favorable transmission direction from the downlink beam-reference signals transmitted by the network node. Thus, the wireless device may perform its own uplink beam scan, and then the network node performs measurements and reports the best direction (e.g., best beam) to the wireless device.

A wireless device may test its EIRP for spherical coverage in a mode where the wireless device autonomously selects an uplink beam (beam corresponding to Effective Isotropic Radiated Power (EIRP)1) and in a mode with uplink beam scanning (EIRP 2). The Cumulative Distribution Function (CDF) of the difference between the two sets of EIRP values at X% (EIRP 2-EIRP 1) should be in the range of Y dB, where X and Y can be obtained from Table 6.6.4.2-1 at Chapter 6.6.4.2 of 3GPP TS 38.101. This may give a measure of how well the UE autonomously selects a beam. This can be seen as a tolerance requirement for wireless devices that require UL beam scanning to meet spherical coverage requirements and that need to be tested with autonomous uplink beam selection. The tolerance of EIRP may be below a certain level. For example, in some scenarios, X may be in the range of 85% and Y may be in the range of 2dB to 7 dB.

The present disclosure provides in one or more embodiments that when a wireless device determines that a beam correspondence cannot be established for current conditions, the wireless device indicates a need to change downlink beam reference signaling. This may in turn cause the wireless device to obtain beam correspondence by, for example, receiving appropriate DL beam reference signaling (e.g., with adjusted resources, adjusted power, and/or adjusted transmission parameters) from the network node.

The beam reference signaling may be considered as signaling indicating a configuration of beam reference signals (e.g., reference signals for beam measurement). For example, resource allocation (time and/or frequency), repetition rate of UL and/or DL beams may be shared via beam reference signaling. For example, beam-reference signaling may be used to indicate that DL reference signals are to be transmitted with a shorter periodicity, and/or that DL reference signals are to be transmitted with a higher number of OFDM symbols, and/or that DL reference signals are to be transmitted in different frequency band portions.

For the sake of clarity, the drawings are schematic and simplified and show only details that are helpful for understanding the disclosure, while other details are omitted. The same reference numerals are used throughout the same or corresponding parts.

Fig. 1A is a diagram illustrating an example wireless communication system including an example network node and an example wireless device according to the present disclosure.

As discussed in detail herein, the present disclosure relates to a wireless communication system 1, e.g., a 3GPP wireless communication system, including a cellular system, e.g., including millimeter wave communication. The wireless communication system 1 comprises a wireless device 300 and/or a network node 400. The wireless device 300 is configured to communicate with a network node 400.

The network Node 400 disclosed herein refers to a radio network Node, such as a radio access network Node, such as a base station, an evolved Node B (eNB) and/or a gNB, operating in a radio access network.

The wireless communication system 1 described herein may comprise one or more wireless devices 300, 300A and/or one or more network nodes 400, such as one or more of the following: a base station, an eNB, a gNB, and/or an access point.

A network node may refer to an entity of a wireless network of a wireless communication system that is used to establish and control an air interface for communication with one or more wireless devices.

A wireless device may refer to one or more of the following: mobile devices, mobile or stationary computers, tablets, smart wearable devices, and smart phone devices. In the specifications under 3GPP, a wireless device is generally referred to as a User Equipment (UE).

The wireless device 300, 300A may be configured to communicate with the network node 400 via a wireless link (or radio access link) 10, 10A. For example, the wireless device 300 is configured to determine Tx beams for uplink transmissions based on downlink measurements of one or more Rx beams of the wireless device.

The wireless device 300 includes a wireless interface that includes an antenna panel and optionally additional antenna panels. The antenna panel may include one or more antenna elements (e.g., one or more antenna arrays).

Fig. 1B illustrates two example graphs, a first graph 50 illustrating RSRP accuracy and signal-to-noise ratio (SNR), and a second graph 60 illustrating RSRP accuracy and DL RS configuration, respectively.

As discussed herein, a wireless device may use capability signaling as an indication of whether the wireless device needs Uplink (UL) beam scanning. In a real-world scenario, the accuracy of the measurement for DL reference signals (e.g., synchronization signal reference signal received power (SS-RSRP) or channel state information RSRP (CSI-RSRP)) depends on a number of factors, such as HW implementation of the measurement receiver of the wireless device, SNR of the DL synchronization signals, interference conditions seen by the wireless device, and multipath propagation environment.

The first graph 50 illustrates CDF as a function of RSRP delta (e.g., RSRP error indicating RSRP accuracy) measured in dB at four different SNR values. In the first curve 51, the SNR value is 6 dB. In the second curve 52, the SNR value is 3 dB. In the third curve 53, the SNR value is 0 dB. In the fourth curve 54, the SNR value is-3 dB.

The first graph 50 illustrates that the estimation error of RSRP increases (increases) as the SNR decreases (decreases). In some cases, this may illustrate that the wireless device may estimate the transmission direction from a reference signal of the network node, but in other cases the wireless device cannot do so. Therefore, reporting the capabilities of the wireless device at the time of initial access and keeping the capabilities fixed is considered suboptimal.

To further illustrate this finding, the second graph 60 illustrates CDF as a function of RSRP delta measured in dB with three different OFDM symbol configurations in the DL Reference Signal (RS). In the first curve 61, there are a large number of subcarriers having a large number of OFDM symbols (e.g., larger than the second curve 62 and the third curve 63). In the second curve 62, there are a small number of subcarriers with a large number of OFDM symbols. In the third curve 63, there are a small number of subcarriers with a small number of OFDM symbols.

In a second graph 60, RSRP accuracy is compared to different OFDM symbol configurations in the DL RS. As can be seen from graph 60, increasing the resources on the DL RS may improve RSRP measurement accuracy, which in turn may improve the UE's selection of beams based on RSRP measurements.

Fig. 1C illustrates two example graphs, a third graph 70 illustrating uplink beam spherical coverage with different downlink RSRP measurement accuracy (error) for autonomously selected uplink beams, and a fourth graph 80 illustrating uplink spherical coverage with different Sounding Reference Signal (SRS) resources for uplink beam scanning, respectively.

When the wireless device determines the uplink beam from measurements of downlink beam reference signals from the network node, the EIRP of the uplink beam from the wireless device in the desired direction is directly related to the measurement accuracy of the downlink beam reference signals.

In the third graph 70, the measurement error of the RSRP of the downlink beam-reference signal is modeled as a gaussian distribution with a standard deviation σ. The third graph 70 illustrates CDF as a function of array gain measured in dB at four different standard deviations (σ) and without error. In the first curve 71, σ is 8. In the second curve 72, σ is 6. In the third curve 73, σ is 4. In the fourth curve 74, σ is 2. The fifth curve 75 has no error.

It can be observed that the antenna gain in the desired direction (or EIRP in a real network) decreases with increasing measurement error. Thus, the wireless device's ability to estimate the transmit direction or transmit beam or UL beam may change over time.

The fourth graph 80 illustrates uplink spherical coverage (CDF is illustrated as a function of array gain measured in dB) with different Sounding Reference Signal (SRS) resources for uplink beam scanning at three different values indicating the number of allocated SRS resources and without performing uplink beam scanning. The RSRP error σ is 5 for all four curves. In the first curve 81, no uplink beam scanning is performed. In the second curve 82, the SRS value is 2. In the third curve 83, the SRS value is 4. In the fourth curve 84, the SRS value is 8.

When the wireless device reports that the BC capability bit is set to 0, this means that uplink beam scanning is necessary, and the inventors have found that performance is limited by the number of SRS resources that can be configured to the wireless device. For example, as shown in the fourth graph 80, the spherical coverage of a wireless device with uplink beam scanning may be improved by allocating a greater number of SRS resources to the wireless device.

For example, uplink performance of the wireless device may be improved by improving measurement accuracy of the downlink beam-reference signals (e.g., increasing measurement samples or measurement symbols) or configuring more SRS resources. In either way, however, the time and overhead of communication may be increased, and an unnecessarily large amount of SRS or excessive DL measurement time may be required. Thus, the network node may need additional information to decide on an optimization solution to improve the uplink performance of the wireless device.

The present disclosure enables a network node to obtain additional information to decide to change or modify DL beam reference signaling, thereby enabling a wireless device to achieve or obtain or maintain beam correspondence.

Fig. 2 is a flow diagram illustrating an example method 200 for beam reference signaling performed by a network node (e.g., a network node disclosed herein, such as network node 400 of fig. 1A and 5) in accordance with the present disclosure.

The network node is configured to communicate (optionally using a beam set or an omni-directional antenna) with wireless devices of the wireless communication system.

The beams disclosed herein may be considered spatial filters. In one or more example embodiments, an antenna circuit of a network node may be configured to radiate a set of beams associated with a set of directions. The antenna circuitry of the wireless device may be configured to radiate a set of beams associated with the set of directions.

For example, the method is performed when the wireless device is unable to select a UL beam based on DL measurements (due to interference, noise, hardware problems, etc.), and before the wireless device decides to fall back to performing uplink beam scanning (which is time consuming and power consuming). In the present disclosure, a wireless device indicates to a network node that a change of beam reference signaling is required. As illustrated herein, a network node may change resource allocation, periodicity, power in beam-reference signals to enable a wireless device to autonomously select an UL beam based on DL measurements.

The method 200 comprises the following steps: one or more first downlink DL beam-reference signals are transmitted S202 to the wireless device. A beam reference signal is, for example, a reference signal received on a beam used by a wireless device for DL measurements to select one or more suitable UL and/or DL beams, such as a Tx beam and/or an Rx beam.

For example, the step of transmitting S202 one or more first DL beam-reference signals may comprise: one or more first DL beam-reference signals are broadcast (e.g., using one or more Synchronization Signal Block (SSB) signals). In one or more example methods, the step of transmitting S202 one or more first DL beam-reference signals to the wireless device comprises: one or more first DL beam reference signals are transmitted S202A to the wireless device on one or more receive beams (Rx). In one or more example methods, the step of transmitting S202 one or more first DL beam-reference signals to the wireless device comprises: broadcasting S202B one or more first DL beam-reference signals.

The method 200 comprises the following steps: control signaling is received S204 from the wireless device indicating a need to change the DL beam reference signaling (e.g., for beam correspondence, enabling the wireless device to autonomously select an UL beam based on DL measurements). For example, the control signaling may indicate that the wireless device needs to modify DL beam reference signaling to autonomously obtain beam correspondence. For example, the control signaling may indicate a request to modify DL beam reference signaling. For example, control signaling may be transmitted from the wireless device to the network node by one or more control signals. Changing the DL beam reference signaling may include enhancing the beam reference signaling and/or adjusting the beam reference signaling.

For example, when the DL SNR (or signal to interference plus noise ratio (SINR)) is below a first threshold, the wireless device may send control signaling to the network node indicating to the network node that the wireless device needs changed DL beam reference signaling (e.g., more DL RS resources) to autonomously select an uplink beam (to obtain beam correspondence). The network node may consider RSRP, SNR (or SINR) and UE measurement periods reported by the wireless device and configure enhanced DL RS, or alternatively degraded DL RS. There may be scenarios where beam reference signaling is adjusted to become degraded (e.g., reduce resource allocation, reduce transmit power), e.g., due to traffic in the cell observed by the network node.

For example, in a real-world scenario, the accuracy of measurements for DL beam reference signals (e.g., synchronization signal reference signal received power (SS-RSRP) or CSI-RSRP) depends on a number of factors, such as the hardware implementation of the measurement receiver of the wireless device, the SNR of the DL synchronization signal, the interference situation seen by the wireless device, and the multipath propagation environment.

In one or more example methods, the method 200 may include the steps of: after one or more criteria are met, one or more second DL beam-reference signals are transmitted S206 to the wireless device based on the received control signaling. In one or more example methods, the one or more second DL beam-reference signals may be different from the one or more first DL beam-reference signals. For example, the one or more criteria may be based on a maximum power level of a cell controlled by the network node or based on a resource allocation of the network node (e.g., all resources have been used). For example, the one or more second DL beam-reference signals may include SSB signals. For example, the network node may configure the number of SRSs based on the wireless device's capability on the maximum number of SRS resources supported and the RSRP, SNR and/or SINR reported by the wireless device.

In one or more example methods, the one or more second DL beam-reference signals may be partially identical to the one or more first DL beam-reference signals.

In one or more example methods, the method 200 may include the steps of: transmitting S205 control signaling indicating the changed DL beam reference signaling. In other words, the network node may indicate the changed DL beam reference signaling to the wireless device.

In one or more example methods, the control signaling indicating a need to change downlink beam-reference signaling includes control signaling indicating a need for additional downlink DL resources for beam-reference signaling.

In one or more example methods, the control signaling indicating a need to change downlink beam-reference signaling includes control signaling indicating a need for modified power of one or more DL beam-reference signals.

In one or more example methods, the control signaling indicating a need to change downlink beam-reference signaling includes control signaling indicating a need for a modified transmission period of one or more DL beam-reference signals. For example, the modified transmission period of the one or more DL beam-reference signals may include CSI-RSs that are transmitted more frequently.

In one or more example methods, the control signaling indicating a need to change downlink beam reference signaling includes control signaling indicating a need for uplink beam scanning. In one or more example methods, the method 200 may include the steps of: requesting S208 the wireless device to perform an uplink beam sweep.

In one or more example methods, the one or more second DL beam-reference signals may include one or more second DL beam-reference signals having one or more of: modified transmit power, allocated additional resources, and modified transmit period. For example, the one or more second DL beam-reference signals may include enhanced or degraded DL RSs. For example, the one or more second DL beam-reference signals may include CSI-RSs transmitted more frequently. For example, the one or more second DL beam-reference signals may include a greater number of OFDM symbols for the DL beam-reference signals in the subcarriers.

Fig. 3 is a flow diagram illustrating an example method 100 performed by a wireless device for beam reference signaling in accordance with the present disclosure. For example, the beam reference signaling may be considered as signaling indicating control of beam reference signals (e.g., reference signals for beam measurement).

The method is performed by a wireless device, such as the wireless device disclosed herein, such as the wireless device 300 of fig. 1A and 4.

The wireless device is configured to communicate with a network node of the wireless communication system using the beam set. The beam may be considered a spatial filter. The antenna circuitry of the network node may be configured to radiate a set of beams associated with the set of directions. The antenna circuitry of the wireless device may be configured to radiate a set of beams associated with the set of directions.

The method 100 comprises the steps of: it is determined S104 that there is no ability to establish beam correspondence. In other words, the wireless device determines that beam correspondence cannot be established. For example, the wireless device may measure noise when the wireless device is turned on. For example, the inability to establish beam correspondence may be viewed as, for example, the wireless device being unable to autonomously select an appropriate UL beam based on DL measurements for DL beams (see TS38.306, ts38,101v 15.5.0).

For example, the wireless device cannot implement beam correspondence because the wireless device cannot select an appropriate UL beam based on DL measurements for the DL beam, or cannot select an appropriate DL beam based on UL measurements for the UL beam due to channel conditions and/or hardware configuration of the wireless device.

The method 100 comprises the steps of: in response to the determination S104, control signaling is sent S108 indicating that DL beam reference signaling needs to be changed for the beam correspondence. For example, the need to change DL beam reference signaling for beam correspondence may be considered as an indicator that beam reference signaling needs to be changed at the wireless device so that the wireless device can autonomously select a suitable UL beam. The need may include requested changes, such as requested modifications. In other words, the control signaling may indicate a request to change DL beam reference signaling to enable the wireless device to autonomously obtain beam correspondence. For example, changing the DL beam reference signaling may include DL beam reference signaling enhancements. For example, changing the DL beam reference signaling may include degrading the DL beam reference signaling. The network node that changes DL beam reference signaling may assist the wireless device in selecting an UL beam based on DL measurements.

For example, in response to determining that there is no capability to establish beam correspondence, when the DL SNR or SINR is below a first threshold, the wireless device may send control signaling to the network node indicating (which may indicate) that the wireless device requires changed DL beam reference signaling (such as more DL RS resources) to autonomously select an uplink beam (to obtain beam correspondence).

In one or more example methods, the method 100 may include the steps of: information about the current reference signaling is obtained from the network node (e.g., by receiving information about the current reference signaling in a System Information Block (SIB), or by retrieving a default preconfigured value for the current reference signaling). In one or more example methods, the method may include the steps of: noise and interference levels are measured. In one or more example methods, the method may include the steps of: it is optionally determined whether to establish beam correspondence based on the obtained information and the measurements.

In one or more example methods, the method 100 may include the steps of: one or more downlink DL beam-reference signals are received S102 from a network node. In one or more example methods, the step of receiving S102 one or more downlink DL beam-reference signals from a network node may comprise: receiving S102A one or more downlink DL beam-reference signals from a network node through one or more beams. For example, one or more downlink beam-reference signals may include one or more spatial filters.

In one or more example methods, the step of determining S104 incapacity comprises: determining S104A one or more DL reception quality parameters associated with the capability of establishing beam correspondence based on the received one or more DL beam reference signals. The one or more DL reception quality parameters may be indicative of radio or channel conditions and/or indicative of hardware noise. The one or more DL reception quality parameters may include SNR signal to noise ratio and/or SINR signal to interference plus noise ratio. The DL reception quality parameters may include a noise parameter (e.g., SNR), an interference parameter (e.g., SINR), an RSRP parameter, and/or a received signal strength parameter.

In one or more example methods, the method 100 includes the steps of: it is determined S106 whether one or more DL reception quality parameters meet a quality criterion.

In one or more example methods, the method 100 includes the steps of: after determining that the one or more DL reception quality parameters do not meet the quality criterion, control signaling is sent S108.

In one or more example methods, the method 100 includes the steps of: after determining that the one or more DL reception quality parameters meet the quality criterion, the transmission of the control signaling is abandoned S107.

In one or more example methods, the quality criterion may be based on a set of thresholds. For example, the wireless device may send control signaling upon determining that one or more DL reception quality parameters do not meet a quality criterion, which may be based on the first threshold. Further, the wireless device may send control signaling to the network node to perform uplink beam scanning when the DL SNR or SINR is below a second threshold, which may be lower than the first threshold.

For example, the transmission of the control signaling may also be triggered after the network node changes the DL beam reference signaling.

For example, the wireless device may selectively send control signaling based on channel conditions. For noise limited channels, a wireless device may request an enhanced DL RS.

In one or more example methods, the control signaling indicating that the DL beam reference signaling needs to be changed includes control signaling indicating that additional downlink DL resources for the beam reference signaling are needed. For example, additional DL resources may refer to additional resources in time and/or resources in frequency. For example, the additional DL resources may refer to a greater number of OFDM symbols in a subcarrier and/or more SRS resources.

In one or more example methods, the control signaling indicating that the DL beam reference signaling needs to be changed comprises control signaling indicating that a modified power of one or more DL beam reference signals is needed.

In one or more example methods, the control signaling indicating a need to change DL beam reference signaling comprises control signaling indicating a modified reception period requiring one or more DL beam reference signals.

For example, the modified periodicity may include CSI-RSs that are transmitted more frequently. In one or more example methods, the control signaling indicating a need to change DL beam reference signaling comprises control signaling indicating a modified signal strength.

In one or more example methods, the control signaling indicating a need to change DL beam reference signaling comprises a request for an increase and/or decrease amount of allocated resources.

In one or more example methods, control signaling indicating a need to change DL beam reference signaling includes one or more DL reception quality parameters associated with the ability to establish beam correspondence. For example, the capabilities may be considered current capabilities of the wireless device, e.g., to implement beam correspondence.

In one or more example methods, the control signaling indicating that the DL beam reference signaling needs to be changed may include control signaling indicating that uplink beam scanning is needed.

In one or more example methods, the DL beam reference signaling may include a set of change levels. For example, the control signaling indicating that DL beam reference signaling needs to be changed may include control signaling indicating a level of change, such as a level of change required by the wireless device. The change level corresponds to a change technique such as one or more of: modification of transmission power of the DL beam reference signal, modification of resource allocation of the DL beam reference signal, modification of a period of the DL beam reference signal, and the like.

In one or more example methods, the techniques described with respect to DL beam reference signals may be applied to UL beam reference signals, as DL beams may be selected based on an indication of uplink measurements of one or more UL/Tx for a UE by a network node.

In one or more example methods, the set of change levels may include one or more change levels ordered according to an order. For example, the change levels may be ordered based on changing power consumption and/or changing interference levels (e.g., not causing interference to neighboring cells).

In one or more example methods, the one or more DL reception quality parameters associated with the capability of establishing beam correspondence may include one or more of: a parameter indicative of signal-to-noise ratio, a parameter indicative of received power, and a parameter indicative of radiated power.

In one or more example methods, the method 100 includes the steps of: receiving S109 control signaling indicating the changed DL beam reference signaling.

In one or more example methods, the method 100 includes the steps of: receiving S110 one or more DL beam-reference signals that are changed in accordance with one or more of: increased transmit power, additional resources, and increased transmit periods.

In one or more example methods, the method 100 includes the steps of: a beam correspondence is obtained S112. The step of obtaining S112 beam correspondences may include: autonomously selecting an UL beam based on DL measurements for DL beams and/or autonomously selecting a DL beam based on network node indications of uplink measurements for one or more Tx beams of the UE. The step of obtaining S112 BC may include: the BC is obtained and/or maintained.

Fig. 4 is a block diagram illustrating an example wireless device 300 according to the present disclosure.

The wireless device 300 includes a memory circuit 301, a processor circuit 302, and a wireless interface 303. The wireless device 300 is configured to perform any of the methods disclosed in fig. 3.

Wireless device 300 is configured to communicate with a network node, such as network node 400 disclosed herein, using a wireless communication system (as shown in fig. 1A).

The wireless interface 303 is configured for wireless communication via a wireless communication system, such as a 3GPP system supporting beam reference signaling. The wireless interface 303 may include an antenna array 303A comprising a plurality of antenna array elements.

The wireless device 300 is configured to communicate with a network node of the wireless communication system using a set of beams (via a wireless interface 303).

The wireless device 300 is configured to determine (e.g., using the processor circuit 302) an inability to establish a beam correspondence.

The wireless device 300 is configured to, in response to the determination, transmit control signaling (e.g., using the wireless interface 303) to the network node indicating that the DL beam reference signaling needs to be changed for the beam correspondence.

The processor circuit 302 is optionally configured to perform any of the operations disclosed in fig. 3 (e.g., S102A, S104A, S106, S107, S108, S109, S110, S112). The operations of the wireless device 300 may be embodied in the form of executable logic routines (e.g., lines of code, software programs, etc.) stored on a non-transitory computer readable medium (e.g., memory circuit 301) and executed by the processor circuit 302.

Further, the operations of the wireless device 300 may be considered a method that the wireless circuitry is configured to perform. Further, while the functions and operations described may be implemented in software, such functions may also be performed via dedicated hardware or firmware, or some combination of hardware, firmware, and/or software.

The memory circuit 301 may be one or more of a buffer, a flash memory, a hard drive, a removable media, a volatile memory, a non-volatile memory, a Random Access Memory (RAM), or other suitable device. In a typical arrangement, the memory circuit 301 may include non-volatile memory for long-term data storage and volatile memory for use as system memory for the processor circuit 302. The memory circuit 301 may exchange data with the processor circuit 302 via a data bus. There may also be control lines and an address bus (not shown in fig. 4) between the memory circuit 301 and the processor circuit 302. The memory circuit 301 is considered to be a non-transitory computer-readable medium.

The memory circuit 301 may be configured as a set of change levels in a portion of the memory circuit 301.

Fig. 5 is a block diagram illustrating an example network node 400 according to the present disclosure.

The network node comprises a memory circuit 401, a processor circuit 402 and a wireless interface 403. The network node 400 is configured to perform any of the methods disclosed in fig. 2.

Network node 400 is configured to communicate with wireless devices and networks, such as wireless device 300 disclosed herein, using a wireless communication system (as shown in fig. 1A).

The wireless interface 403 is configured for wireless communication via a wireless communication system, such as a 3GPP system supporting beam-reference signaling.

The wireless interface 403 may include an antenna array 403A comprising a plurality of antenna array elements. The network node 400 is optionally configured to communicate with the wireless device (via the wireless interface 403) using a set of beams (e.g. radiated by 403A). Network node 400 is optionally configured to communicate with wireless devices using an omni-directional antenna (via wireless interface 403).

The network node 400 is configured to transmit (e.g. via the wireless interface 403) one or more first downlink DL beam-reference signals to the wireless device. The network node 400 is configured to receive (e.g. using the wireless interface 403) control signaling from the wireless device indicating that the downlink beam reference signaling needs to be changed (e.g. to autonomously obtain beam correspondence).

The processor circuit 402 may optionally be configured to perform any of the operations disclosed in fig. 2 (e.g., S202A, S202B, S204, S205, S206, S208). The operations of the network node 400 may be embodied in the form of executable logic routines (e.g., lines of code, software programs, etc.) stored on a non-transitory computer readable medium (e.g., memory circuit 401) and executed by the processor circuit 402.

Further, the operation of the network node 400 may be considered as a method that the radio circuitry is configured to perform. Further, while the functions and operations described may be implemented in software, such functions may also be performed via dedicated hardware or firmware, or some combination of hardware, firmware, and/or software.

The memory circuit 401 may be one or more of a buffer, a flash memory, a hard drive, a removable media, a volatile memory, a non-volatile memory, a Random Access Memory (RAM), or other suitable device. In a typical arrangement, the memory circuit 401 may include non-volatile memory for long-term data storage and volatile memory for use as system memory for the processor circuit 402. The memory circuit 401 may exchange data with the processor circuit 402 via a data bus. There may also be control lines and an address bus (not shown in fig. 5) between the memory circuit 401 and the processor circuit 402. The memory circuit 401 is considered a non-transitory computer-readable medium.

The memory circuit 401 may be configured to store the set of change levels in a portion of memory.

The following clauses set forth embodiments of methods and products (network nodes and wireless devices) according to the present disclosure:

clause 1. a method for beam reference signaling performed by a network node, wherein the network node is configured to communicate with a wireless device of a wireless communication system, the method comprising the steps of:

-transmitting (S202) one or more first downlink, DL, beam-reference signals to the wireless device; and

-receiving (S204) control signaling from the wireless device indicating a need to change downlink beam reference signaling.

Clause 2. the method of clause 1, comprising the steps of: upon satisfying one or more criteria:

-transmitting (S206) one or more second DL beam-reference signals to the wireless device based on the received control signaling, wherein the one or more second DL beam-reference signals are different from the one or more first DL beam-reference signals.

Clause 3. the method of clause 1 or 2, comprising the steps of: transmitting (S205) control signaling indicating the changed DL beam reference signaling.

Clause 4. the method of any of clauses 1-3, wherein the control signaling indicating that the downlink beam-reference signaling needs to be changed comprises control signaling indicating that additional downlink DL resources for beam-reference signaling are needed.

Clause 5. the method of any of clauses 1-4, wherein the control signaling indicating that the downlink beam-reference signaling needs to be changed comprises control signaling indicating that the modified power of the one or more DL beam-reference signals is needed.

Clause 6. the method of any of clauses 1-5, wherein the control signaling indicating that the downlink beam-reference signaling needs to be changed comprises control signaling indicating that a modified transmission period of the one or more DL beam-reference signals is needed.

Clause 7. the method of any of clauses 1 to 6, wherein the control signaling indicating a need to change downlink beam reference signaling comprises control signaling indicating a need for uplink beam scanning, the method comprising the steps of: requesting the wireless device to perform an uplink beam sweep.

Clause 8. the method according to any one of clauses 1 to 7, wherein the step of transmitting (S202) one or more first DL beam reference signals to the wireless device comprises: transmitting (S202A) the one or more first DL beam-reference signals to the wireless device on one or more receive beams.

Clause 9. the method according to any one of clauses 1 to 8, wherein the step of transmitting (S202) one or more first DL beam reference signals to the wireless device comprises: broadcasting (S202B) the one or more first DL beam-reference signals.

Clause 10. the method of any of clauses 2 to 9, wherein the one or more second DL beam reference signals include one or more second DL beam reference signals having one or more of: modified transmit power, allocated additional resources, and modified transmit period.

Clause 11. a method performed by a wireless device for beam reference signaling, wherein the wireless device is configured to communicate with a network node of a wireless communication system using a beam set, the method comprising the steps of:

-determining (S104) inability to establish beam correspondence; and

-in response to the determination (S104), transmitting (S108) control signaling to the network node indicating that DL beam reference signaling needs to be changed for the beam correspondence.

Clause 12. the method of clause 11, comprising the steps of:

-receiving (S102) one or more downlink, DL, beam-reference signals from the network node; and is

Wherein the step of determining (S104) the incapacity comprises:

-determining (S104A) one or more DL reception quality parameters associated with the capability of establishing beam correspondence based on the received one or more DL beam reference signals; and

-transmitting (S108) the control signaling upon determining that the one or more DL reception quality parameters do not satisfy a quality criterion.

Clause 13. the method of clause 11 or 12, comprising the steps of: determining (S106) whether the one or more DL reception quality parameters meet the quality criterion.

Clause 14. the method of clause 12 or 13, wherein the quality criterion is based on a set of thresholds.

Clause 15. the method of any of clauses 11 to 14, wherein the control signaling indicating that the DL beam reference signaling needs to be changed comprises control signaling indicating that additional downlink DL resources for beam reference signaling are needed.

Clause 16. the method of any of clauses 11 to 15, wherein the control signaling indicating that the DL beam reference signaling needs to be changed comprises control signaling indicating that the modified power of the one or more DL beam reference signals is needed.

Clause 17. the method of any of clauses 11 to 16, wherein the control signaling indicating that the DL beam reference signaling needs to be changed comprises control signaling indicating that a modified reception period of the one or more DL beam reference signals is needed.

Clause 18. the method of any of clauses 11 to 17, wherein the control signaling indicating that DL beam reference signaling needs to be changed comprises one or more DL reception quality parameters associated with the capability to establish a beam.

Clause 19. the method of any one of clauses 11 to 18, wherein the control signaling indicating that the DL beam reference signaling needs to be changed comprises control signaling indicating that uplink beam scanning is needed.

Clause 20. the method of any one of clauses 11 to 19, wherein the DL beam reference signaling comprises a set of change levels.

Clause 21. the method of clause 20, wherein the set of change levels includes one or more change levels ordered according to an order.

Clause 22. the method of any of clauses 12-21, wherein the one or more DL reception quality parameters associated with the capability to establish beam correspondence include one or more of: a parameter indicative of a signal-to-noise ratio, a parameter indicative of a signal-to-noise-plus-interference ratio, a parameter indicative of a received power, and a parameter indicative of a radiated power.

Clause 23. the method of any one of clauses 11-22, comprising the steps of:

-receiving (S110) one or more DL beam reference signals that are changed according to one or more of the following: increased transmit power, additional resources, and increased transmit periods; and

-obtaining (S112) a beam correspondence.

Clause 24. the method of any one of clauses 11-23, comprising the steps of: receiving (S109) control signaling indicating the changed DL beam reference signaling.

Clause 25. a wireless device (300) comprising a memory circuit (301), a processor circuit (302), and a wireless interface (303), wherein the wireless device (300) is configured to perform any of the methods of clauses 11-24.

Clause 26. a network node (400) comprising a memory circuit (401), a processor circuit (402) and an interface (403), wherein the network node (400) is configured to perform any of the methods according to any of clauses 1 to 10.

The use of the terms "first," "second," "third," and "fourth," "primary," "secondary," "tertiary," etc. do not imply any particular order, but are included to identify individual elements. Moreover, the use of the terms "first," "second," "third," and "fourth," "primary," "secondary," "third," etc. do not denote any order or importance, but rather the terms "first," "second," "third," and "fourth," "primary," "secondary," "third," etc. are used to distinguish one element from another. Note that the words "first," "second," "third," and "fourth," "primary," "secondary," "third," etc., are used herein and elsewhere for purposes of notation only and are not intended to imply any particular spatial or temporal ordering. Further, the labeling of a first element does not imply the presence of a second element, and vice versa.

It will be understood that fig. 1A-5 include some circuits or operations illustrated with solid lines and some circuits or operations illustrated with dashed lines. The circuits or operations included in the solid lines are the circuits or operations included in the broadest example embodiments. The circuits or operations included in the dashed lines are exemplary embodiments, which may be included in or part of the circuits or operations of the solid line exemplary embodiments, or be additional circuits or operations that may be employed in addition to the circuits or operations of the solid line exemplary embodiments. It should be understood that these operations need not be performed in the order of presentation. Further, it should be understood that not all operations need be performed. The exemplary operations may be performed in any order and in any combination.

It should be noted that the word "comprising" does not necessarily exclude the presence of other elements or steps than those listed.

It should be noted that the word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements.

It should also be noted that any reference signs do not limit the scope of the claims, that the exemplary embodiments may be implemented at least partly by means of hardware and software, and that several "means", "units" or "devices" may be represented by the same item of hardware.

Various exemplary methods, devices, nodes and systems described herein are described in the general context of method steps or processes, which may be implemented in one aspect by a computer program product embodied in a computer-readable medium, including computer-executable instructions, such as program code, executed by a computer in a networked environment. The computer-readable medium may include removable and non-removable storage devices including, but not limited to, Read Only Memory (ROM), Random Access Memory (RAM), Compact Disks (CDs), Digital Versatile Disks (DVDs), and the like. Generally, program circuitry may include routines, programs, objects, components, data structures, etc. that perform particular tasks or implement particular abstract data types. Computer-executable instructions, associated data structures, and program circuitry represent examples of program code for executing steps of the methods disclosed herein. The particular sequence of such executable instructions or associated data structures represents examples of corresponding acts for implementing the functions described in such steps or processes.

While features have been shown and described, it will be understood that they are not intended to limit the claimed disclosure, and it will be apparent to those skilled in the art that various changes and modifications may be made without departing from the scope of the claimed disclosure. The specification and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense. The claimed disclosure is intended to cover all alternatives, modifications, and equivalents.