Candidate beam selection for terminal devices

Abstract

A mechanism is provided for candidate beam updates triggered by rotational movement at a terminal device. One method is performed by the terminal device. The method includes: performing beamforming communication with transmitting and receiving points in a first beam having a first pointing direction. The method includes: detecting that the terminal device has undergone rotational movement. The rotational movement causes the first beam to change its pointing direction. The method includes: updating a candidate set of second beams to be used for beam training when the rotational movement of the terminal device is detected. The candidate set of second beams, after being updated, includes at least one second beam having a predefined pointing direction.

Description

Technical Field

[0001] The embodiments presented herein relate to a method, a terminal device, a computer program, and a computer program product for candidate beam updates triggered by rotational movement at a terminal device. Background Technology

[0002] For example, future generations of mobile communication networks may require frequency bands operating on many different carrier frequencies. Lower frequency bands may be needed to achieve adequate network coverage for wireless devices, while higher frequency bands (e.g., millimeter wave (mmW), i.e., around 30 GHz and above) may be required to achieve the necessary network capacity. Typically, the propagation characteristics of radio channels at higher frequencies are more challenging and may require beamforming at both network nodes and wireless devices to achieve sufficient link budget.

[0003] At such high frequencies, narrow-beam transmit and receive schemes may be required to compensate for the anticipated high propagation loss. For a given communication link, appropriate beams can be applied at both the network end (represented by the network node or its transmit and receive points TRP) and the terminal (represented by the terminal equipment), which are commonly referred to as beam-pair links (BPLs). One task of the beam management process is to discover and maintain beam-pair links. BPLs (i.e., the beams used by the network node and the beams used by the terminal equipment) are expected to be discovered and monitored by the network using measurements of downlink reference signals used for beam management (e.g., Channel State Information Reference Signal (CSI-RS) or Synchronization Block (SSB) signals).

[0004] CSI-RS used for beam management can be transmitted periodically, semi-persistently, or non-periodically (event-triggered), and they can be shared among multiple terminal devices or device-specific. SSB is transmitted periodically and shared by all terminal devices. To enable a terminal device to find a suitable network node beam, the network node transmits a reference signal in different transmit (TX) beams at which the terminal device performs measurements (e.g., Reference Signal Received Power (RSRP)) and reports M optimal TX beams (where M can be configured by the network). Furthermore, the transmission of the reference signal on a given TX beam can be repeated to allow the terminal device to evaluate a suitable receive (RX) beam. The reference signal shared among all terminal devices served by the TRP can be used to determine a first coarse direction for the terminal device. Using the SSB as a reference signal at the TRP for such periodic TX beam scanning may be appropriate. One reason for this is that the SSB is transmitted periodically anyway (for initial access / synchronization purposes), and the SSB is also expected to be beamformed at higher frequencies to overcome the aforementioned higher propagation loss.

[0005] The term Quasi-Co-located Space (QCL) typically refers to the relationship between the antenna ports of two different downlink reference signals (RS). If the TRP or network node configures two transmitted downlink RSs to spatial QCL at the terminal device receiver, the terminal device can assume that the first RS and the second RS are transmitted using approximately the same transmitter spatial filter configuration. Therefore, the terminal device can receive the second reference signal using approximately the same receiver spatial filter configuration used to receive the first reference signal. In this way, spatial QCL is a term that facilitates the use of analog beamforming and formalizes the concept of the same terminal device receiving beams at different time instances.

[0006] While spatial QCL refers to the relationship between two distinct downlink RSs from the perspective of the end device, the term spatial relationship refers to the relationship between one uplink RS and another RS ​​(which can be either a downlink RS or an uplink RS). This is also defined from the perspective of the end device. If an uplink RS is spatially related to a downlink RS, it means that the end device should transmit the uplink RS in the opposite direction to where it received the previous downlink RS. More precisely, the end device should apply the same transmitter spatial filtering configuration for the transmission of the second RS as the receiver spatial filtering configuration it previously used to receive the previous downlink RS. Alternatively, if the end device has already transmitted an uplink RS, then the end device should apply the same transmitter spatial filtering configuration for the transmission of the next uplink RS as the transmitter spatial filtering configuration it used to transmit the previous RS.

[0007] Due to the rotation of the terminal device (relative to roll, pitch, and / or yaw), the beams generated by the terminal device for transmitting and receiving signals may quickly become obsolete. If the beams generated by the terminal device for uplink transmission are based on spatial relationships from earlier uplink beam scans, the terminal device is not allowed to change the spatial filter weights of the analog antenna array to compensate for rotation.

[0008] Therefore, improved beam management and / or beam training processes are needed. Summary of the Invention

[0009] The purpose of the embodiments described herein is to achieve effective beam management and / or beam training for terminal devices subjected to rotational movement.

[0010] According to a first aspect, a method for candidate beam updating triggered by rotational movement at a terminal device is proposed. The method is performed by the terminal device. The method includes: performing beamforming communication with transmitting and receiving points in a first beam having a first pointing direction. The method includes: detecting that the terminal device has undergone rotational movement. The rotational movement causes the first beam to change its pointing direction. The method includes: updating a candidate set of second beams to be used for beam training when the rotational movement of the terminal device is detected. The candidate set of second beams, after being updated, includes at least one second beam having a predefined pointing direction.

[0011] According to a second aspect, a terminal device is proposed for candidate beam updating triggered by rotational movement at the terminal device. The terminal device includes processing circuitry. The processing circuitry is configured to cause the terminal device to perform beamforming communication with transmitting and receiving points in a first beam having a first pointing direction. The processing circuitry is configured to cause the terminal device to detect rotational movement. The rotational movement causes the first beam to change its pointing direction. The processing circuitry is configured to cause the terminal device to update a candidate set of second beams to be used for beam training when it detects rotational movement. The candidate set of second beams, after being updated, includes at least one second beam having a predefined pointing direction.

[0012] According to a third aspect, a terminal device is proposed for candidate beam updates triggered by rotational movement at the terminal device. The terminal device includes a communication module configured to perform beamforming communication with transmitting and receiving points in a first beam having a first pointing direction. The terminal device includes a detection module configured to detect rotational movement of the terminal device. The rotational movement causes the first beam to change its pointing direction. The terminal device includes an update module configured to update a candidate set of second beams to be used for beam training when rotational movement of the terminal device is detected. The candidate set of second beams, after being updated, includes at least one second beam having a predefined pointing direction.

[0013] According to the fourth aspect, a computer program for performing rotation-triggered candidate beam updates at a terminal device is proposed, the computer program including computer program code that, when run on the terminal device, causes the terminal device to perform the method according to the first aspect.

[0014] According to a fifth aspect, a computer program product is proposed, comprising the computer program as described in the fourth aspect and a computer-readable storage medium storing the computer program. The computer-readable storage medium may be a non-transitory computer-readable storage medium.

[0015] Advantageously, these aspects enable effective beam management and / or beam training of the terminal device when it is subjected to rotational movement.

[0016] Advantageously, instead of using a fixed set of candidate beams for beam training and / or beam management, the terminal device can adjust the candidate beam set based on prior knowledge, such as the horizontal plane, rotation amount, and / or previously suitable beams, which will improve path gain.

[0017] Other objects, features, and advantages of the appended embodiments will become apparent from the following detailed disclosure.

[0018] Generally, unless otherwise expressly stated herein, all terms used in this disclosure are to be interpreted according to their ordinary meaning in the art. Unless otherwise expressly stated, all references to “a / an / the said element, device, component, apparatus, module, step, etc.” are openly interpreted as referring to at least one instance of an element, device, component, apparatus, module, step, etc. Unless expressly stated otherwise, the steps of any method disclosed herein need not be performed in the exact order disclosed. Attached Figure Description

[0019] The inventive concept will now be described by way of example with reference to the accompanying drawings, in which:

[0020] Figure 1 This is a schematic diagram illustrating a communication network according to an embodiment;

[0021] Figure 2 A terminal device and its antenna system according to an embodiment are schematically illustrated;

[0022] Figure 3 This is a flowchart of the method according to an embodiment;

[0023] Figure 4 , Figure 5 and Figure 6 The illustration schematically depicts a scenario of candidate beam selection when the terminal device is rotated, according to an embodiment.

[0024] Figure 7 This is a schematic diagram illustrating the functional units of a terminal device according to an embodiment;

[0025] Figure 8 This is a schematic diagram illustrating the functional modules of a terminal device according to an embodiment; and

[0026] Figure 9 An example of a computer program product including a computer-readable storage medium according to an embodiment is shown. Detailed Implementation

[0027] The inventive concept will now be described more fully below with reference to the accompanying drawings, which illustrate certain embodiments of the inventive concept. However, the inventive concept can be embodied in many different forms and should not be construed as being limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art. Throughout the specification, similar reference numerals denote similar elements. Any step or feature indicated by dashed lines should be considered optional.

[0028] Figure 1 This is a schematic diagram illustrating a communication network 100 to which embodiments proposed herein may be applied. The communication network 100 may be a third-generation (3G) telecommunications network, a fourth-generation (4G) telecommunications network, or a fifth-generation (5G) telecommunications network, and supports any 3GPP telecommunications standard where applicable.

[0029] Communication network 100 includes network node 150 configured to provide network access to at least one terminal device 200 in radio access network 110. Radio access network 110 is operatively connected to core network 120. Core network 120 is then operatively connected to service network 130, such as the Internet. Terminal device 200 is thus able to access services of service network 130 via network node 150 and exchange data with service network 130.

[0030] Network node 150 includes a transmit and receive point (TRP) 140, and is co-located, integrated with, or operates and communicates with the TRP 140. Network node 150 (via its TRP 140) and terminal device 200 are configured to communicate with each other in a beam. Figure 1 In the illustrative example, beam 160 is the beam that TRP 140 currently uses to communicate with terminal device 200, and beam 170 is the beam that terminal device 200 currently uses to communicate with TRP 140. Beam 170 has a pointing direction 180.

[0031] Examples of network nodes 150 include radio access network nodes, radio base stations, base transceivers, Node Bs, evolved Node Bs, gNBs, access points, access nodes, and backhaul nodes. Examples of terminal devices 200 include wireless devices, mobile stations, mobile phones, cell phones, wireless local loop telephones, user equipment (UEs), smartphones, laptop computers, tablet computers, network-enabled sensors, network-enabled vehicles, and so-called Internet of Things (IoT) devices.

[0032] Figure 2This is a schematic diagram of a typical terminal device 200, and specifically illustrates an example of an antenna system in the form of two antenna panels 240a, 240b used by the terminal device 200 to generate one or more beams 170', 170'". In some embodiments, the beams are generated by at least one antenna array in the terminal device 200. The antenna array is one-dimensional or two-dimensional. Figure 2 As an illustrative example, the two panels have pointing directions orthogonal to each other to improve coverage and increase the order of spatial multiplexing. To handle this uplink beam management of the terminal device 200 efficiently (e.g., with minimal overhead), the TRP 140 can trigger the terminal device 200 to simultaneously transmit one uplink reference signal resource set for each panel. This means that the terminal device 200 can perform multiple simultaneous uplink beam management processes in parallel; one for each panel 240a, 240b.

[0033] As mentioned above, there is a need for improved beam management and / or beam training processes, and the purpose of the embodiments herein is to achieve effective beam management and / or beam training of the terminal device 200 subjected to rotational movement.

[0034] The embodiments disclosed herein relate to a mechanism for candidate beam updates triggered by rotational movement at a terminal device 200. To obtain such a mechanism, a terminal device 200, a method executed by the terminal device 200, and a computer program product including code, such as a computer program, are provided that causes the terminal device 200 to execute the method when run on the terminal device 200.

[0035] Figure 3 This is a flowchart illustrating an embodiment of a method for candidate beam updating triggered by rotational movement at a terminal device 200. The method is performed by the terminal device 200. The method is advantageously provided as a computer program 920.

[0036] Assume that terminal device 200 participates in beamforming communication with transmitting and receiving points 140. Specifically, terminal device 200 is configured to perform step S102:

[0037] S102: Terminal device 200 performs beamforming communication with transmitting and receiving points 140 in a first beam 170 having a first pointing direction 180.

[0038] Assume that terminal device 200 is rotated. That is, terminal device 200 is configured to execute step S104:

[0039] S104: Terminal device 200 detects that terminal device 200 has undergone rotational movement. The rotational movement causes the first beam 170 to change its pointing direction 180.

[0040] During rotation, terminal device 200 updates its candidate beam set for beam management based on the estimated rotation of terminal device 200. Therefore, terminal device 200 is configured to execute step S108:

[0041] S108: When the terminal device 200 detects that the terminal device 200 has undergone rotational movement, it updates the candidate set 190a, 190b, and 190c of the second beam to be used for beam training. The candidate set 190a, 190b, and 190c of the second beam, after being updated, includes at least one second beam with a predetermined pointing direction.

[0042] Embodiments relating to further details of candidate beam updates triggered by rotational movement at terminal device 200, as performed by terminal device 200, will now be disclosed.

[0043] In some respects, the candidate sets 190a, 190b, and 190c for the second beam are updated by adjusting their antenna weights in terms of gain and / or phase.

[0044] In some aspects, in order for the terminal device 200 to correctly determine a predefined pointing direction, the terminal device 200 determines its spatial orientation, at least relative to the horizontal plane. That is, according to an embodiment, the terminal device 200 is configured to perform (optional) step S106:

[0045] S106: Terminal device 200 estimates the spatial orientation of terminal device 200 at least relative to the horizontal plane.

[0046] In some aspects, in order for terminal device 200 to correctly determine a predefined pointing direction, terminal device 200 determines its spatial orientation relative to roll, pitch, and / or yaw. Terminal device 200 may estimate its spatial orientation, for example, by using accelerometers, sensors, cameras, etc.

[0047] In some aspects, terminal device 200 performs a beam training process, during which an updated candidate set of second beams 190a, 190b, and 190c is used. That is, according to an embodiment, terminal device 200 is configured to perform (optional) step S110:

[0048] S110: After updating the candidate sets 190a, 190b, and 190c of the second beam, the terminal device 200 performs a beamforming process. The beamforming process involves the terminal device 200 performing beamforming communication with the transmitting and receiving points 140 within the candidate sets 190a, 190b, and 190c of the second beam.

[0049] In S110, terminal device 200 can perform different types of beam training. In some embodiments, the beam training process involves terminal device 200 transmitting and / or receiving reference signals from a candidate set of second beams 190a, 190b, 190c. In other embodiments, the beam training process involves terminal device 200 selecting one of the candidate sets of second beams 190a, 190b, 190c to continue communication with the transmitting and receiving point 140.

[0050] As will be revealed next, there may be different examples pointing in a predefined direction.

[0051] In some aspects, the terminal device 200 is configured to determine its angle relative to the horizontal line, and is also configured to always have at least one beam pointing along the horizontal plane in the candidate set of second beams 190a, 190b, 190c. Therefore, in some embodiments, the predefined pointing direction is horizontal as much as possible.

[0052] This is an intermediate reference. Figure 4 . Figure 4 Examples of the antenna weights of the candidate sets 190a, 190b of the second beam being fixed when the terminal device 200 undergoes rotational movement are shown in (a), (b) and (c) in its left column. Figure 4 Examples of terminal devices 200 having a single beam 190b pointing along the horizontal plane are shown in (a), (b) and (c) in the right column, by adjusting the antenna weights of candidate beams 190a, 190b in terms of gain and / or phase when the terminal device 200 undergoes rotational movement.

[0053] Furthermore, since it can be assumed in some aspects that the transmitting and receiving points 140 are located vertically above the terminal device, the terminal device 200 can be configured to always have at least one beam with a vertically tilted pointing direction in the candidate set of second beams 190a, 190b, 190c. In some embodiments, therefore, the tilt angle of the predefined pointing direction relative to the horizontal plane is in the range of 30 degrees to 60 degrees, preferably in the range of 40 degrees to 50 degrees, and more preferably 45 degrees.

[0054] In some aspects, the terminal device 200 has previously determined that a first beam 170 with a first pointing direction 180 is the optimal beam for communicating with the transmitting and receiving point 140, and is also configured to always have at least one beam in the candidate set of second beams 190a, 190b, 190c pointing in the same direction as the previously optimal beam. Therefore, in some embodiments, the predefined pointing direction is as similar as possible to the first pointing direction 180.

[0055] This is an intermediate reference. Figure 5 . Figure 5 An embodiment is shown in which the terminal device 200 always has a beam 190b pointing in the same direction as the previously optimal beam. At (a), the terminal device 200 performs one or more beam scans among beams 170a, 170b, and 170c to determine the optimal beam. This process may have been performed over a period of time to allow the terminal device 200 to find the optimal beam. At (b), the terminal device 200 uses the optimal beam found in (a) (assumed to be beam 170b for illustrative purposes) for data communication with the transmitting and receiving points 140. The terminal device 200 then undergoes rotational movement. At (c), the terminal device 200 updates the candidate set of second beams 190a, 190b, and 190c such that at least one beam (assumed to be beam 190b for illustrative purposes) points in the same direction as the previously optimal beam 170b.

[0056] In some aspects, the terminal device 200 has previously determined that a first beam 170 with a first pointing direction 180 is the optimal beam for communicating with the transmitting and receiving point 140, and is also configured to have beams with a denser angular distribution around the previously optimal beam in the candidate set of second beams 190a, 190b, 190c. That is, the pointing directions of the candidate set of second beams 190a, 190b, 190c produce an angular distribution of pointing directions, and in some embodiments, the angular distribution is denser on or at least as close as possible to the first pointing direction 180 than in any other pointing direction.

[0057] This is an intermediate reference. Figure 6 . Figure 6 An embodiment is shown in which the terminal device 200 always has a denser distribution of beams pointing in the same direction as the previously optimal beam. At (a), the terminal device 200 performs one or more beam scans in beams 170a, 170b, 170c to determine the optimal beam. This process may have been performed over a period of time to allow the terminal device 200 to find the optimal beam. At (b), the terminal device 200 uses the optimal beam found in (a) (assumed to be beam 170b for illustrative purposes) for data communication with the transmitting and receiving points 140. The terminal device 200 then undergoes rotational movement. At (c), the terminal device 200 updates the candidate set 190a, 190b, 190c of the second beam such that the angular distribution of the candidate beams is denser in the same direction as, or at least as close as possible to, the same direction as the previously optimal beam 170b than in any other pointing direction.

[0058] In some aspects, the terminal device 200 is configured to prioritize an alternative that always has at least one beam pointing in the same direction as the previous best beam (i.e., where the predefined pointing direction is as similar as possible to the first pointing direction 180) and / or has a beam with a denser angular distribution around the previous best beam (i.e., where the angular distribution of the candidate set of second beams 190a, 190b, 190c is denser on or at least as close as possible to the first pointing direction 180 than in any other pointing direction). This is preferred over an alternative that always has at least one beam pointing along a horizontal plane (i.e., where the predefined pointing direction is as horizontal as possible) or always has at least one beam with a vertically tilted pointing direction (i.e., where the predefined pointing direction has an angle of inclination relative to the horizontal plane, as disclosed above).

[0059] However, prioritizing which alternative may depend on factors such as the amount of received power, whether rotation is still in progress, and the rotation speed. For example, if the amount of received power is relatively low, if rotation is still in progress, and / or if the rotation speed is relatively high, it may be preferable to always have at least one beam pointing along the horizontal plane (i.e., where the predefined pointing direction is as horizontal as possible) or always have at least one beam with the pointing direction tilted vertically (i.e., where the predefined pointing direction has an angle of inclination relative to the horizontal plane, as disclosed above). Furthermore, the higher the rotation speed, the wider the candidate set of second beams 190a, 190b, 190c may be. Additionally, the candidate set of second beams 190a, 190b, 190c can be selected such that the polarization state is maintained.

[0060] In some aspects, two or more alternatives are combined. Thus, in some embodiments, within the candidate sets 190a, 190b, 190c of the second beam, there are two or more second beams, each with its own predefined pointing direction. That is, as an example, a beam having at least one pointing in the same direction as the previously optimal beam (i.e., where the predefined pointing direction is as similar as possible to the first pointing direction 180) is combined with a beam having a denser angular distribution around the previously optimal beam (i.e., where the angular distribution of the candidate sets 190a, 190b, 190c of the second beams is denser on or at least as close as possible to the first pointing direction 180 than in any other pointing direction), and / or with at least one beam that always points along a horizontal plane (i.e., where the predefined pointing direction is as horizontal as possible), and / or with at least one beam that always has a vertically tilted pointing direction (i.e., where the predefined pointing direction has an angle of inclination relative to the horizontal plane, as disclosed above). Other combinations of alternatives are also possible.

[0061] The embodiments disclosed herein apply to both uplink and downlink communication between terminal device 200 and transmitting and receiving point 140. Therefore, the embodiments disclosed herein are applicable to both beam training and beam management in the uplink and in the downlink. That is, when terminal device 200 should receive downlink reference signals (e.g., Channel State Information Reference Signal (CSI-RS) or Synchronization Signal Block (SSB) signals) in different candidate beams, or when the UE should transmit uplink reference signals (e.g., Sounding Reference Signal (SRS)) in different candidate beams.

[0062] In the case where the terminal device 200 has a two-dimensional antenna array, the embodiments disclosed herein are applied in the same manner to both dimensions.

[0063] Figure 7 The components of a terminal device 200 according to an embodiment are schematically shown in a manner that represents multiple functional units. A product 910 capable of executing computer programs (such as...) is used. Figure 9 The processing circuit 210 may be provided as one or more of any combination of a suitable central processing unit (CPU), multiprocessor, microcontroller, digital signal processor (DSP), etc., storing software instructions in a medium (e.g., in the form of storage medium 230). The processing circuit 210 may also be provided as at least one application-specific integrated circuit (ASIC) or field-programmable gate array (FPGA).

[0064] Specifically, the processing circuit 210 is configured to cause the terminal device 200 to perform the set of operations or steps disclosed above. For example, the storage medium 230 may store the set of operations, and the processing circuit 210 may be configured to retrieve the set of operations from the storage medium 230 so that the terminal device 200 executes the set of operations. The set of operations may be provided as a set of executable instructions.

[0065] Therefore, the processing circuitry 210 is thus arranged to perform the methods disclosed herein. The storage medium 230 may also include a persistent storage device, for example, it may be any single memory or any combination of magnetic storage, optical storage, solid-state storage, or even remotely mounted memory. The terminal device 200 may also include a communication interface 220, which is at least configured to communicate with the transmitting and receiving point 140. Therefore, the communication interface 220 may include one or more transmitters and receivers, which include analog and digital components. The communication interface 220 may include antenna panels 240a, 240b.

[0066] Processing circuitry 210 controls the overall operation of terminal device 200, for example, by sending data and control signals to communication interface 220 and storage medium 230, by receiving data and reports from communication interface 220, and by retrieving data and instructions from storage medium 230. Other components and related functions of terminal device 200 are omitted to avoid obscuring the concepts presented herein.

[0067] Figure 8 The components of the terminal device 200 according to the embodiment are schematically shown in the manner of multiple functional modules. Figure 8 The terminal device 200 includes multiple functional modules: a communication module 210a configured to perform step S102, a detection module 210b configured to perform step S104, and an update module 210d configured to perform step S108. Figure 8 The terminal device 200 may also include multiple optional functional modules, such as any one of the estimation module 210c configured to perform step S106 and the training module 210e configured to perform step S110. Generally, each functional module 210a-210e may be implemented solely in hardware in one embodiment and in software in another embodiment; that is, the latter embodiment has computer program instructions stored on the storage medium 230 that, when executed on the processing circuitry, cause the terminal device 200 to perform the above-described combination. Figure 8 The corresponding steps mentioned. It should also be mentioned that even modules corresponding to parts of a computer program need not be separate modules; rather, their software implementation depends on the programming language used. Preferably, one or more or all functional modules 210a-210e can be implemented by processing circuitry 210 (possibly cooperating with communication interface 220 and / or storage medium 230). Therefore, processing circuitry 210 can be configured to retrieve instructions provided by functional modules 210a-210e from storage medium 230 and execute these instructions, thereby performing any steps disclosed herein.

[0068] The above has been referenced Figure 1 The description provides an example of terminal device 200.

[0069] Figure 9An example of a computer program product 910 including a computer-readable storage medium 930 is shown. On this computer-readable storage medium 930, a computer program 920 may be stored that causes processing circuitry 210 and entities and devices operatively coupled to the processing circuitry 210 (e.g., communication interface 220 and storage medium 230) to perform the methods according to the embodiments described herein. The computer program 920 and / or the computer program product 910 may therefore provide means for performing any of the steps disclosed herein.

[0070] exist Figure 9 In the example, computer program product 910 is shown as an optical disc, such as a CD (Compact Disc), DVD (Digital Versatile Disc), or Blu-ray Disc. Computer program product 910 can also be embodied as memory, such as random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM), or electrically erasable programmable read-only memory (EEPROM), and more specifically as a non-volatile storage medium of a device in external memory, such as a USB (Universal Serial Bus) memory or flash memory (e.g., compact flash memory). Therefore, although computer program 920 is schematically shown herein as a track on the depicted optical disc, computer program 920 can be stored in any manner suitable for computer program product 910.

[0071] The inventive concept has been primarily described above with reference to some embodiments. However, as will be readily apparent to those skilled in the art, other embodiments besides those disclosed above are also within the scope of the inventive concept as defined by the appended claims.

Claims

1. A method for performing rotation-triggered candidate beam update at a terminal device (200), the method being performed by the terminal device (200), the method comprising: (S102) Beamforming communication with the transmitting and receiving points (140) is performed in a first beam (170) having a first pointing direction (180), the first beam (170) being the optimal beam for communicating with the transmitting and receiving points (140); The terminal device (200) is subjected to rotational movement (S104), which causes the first beam (170) to change its pointing direction (180). as well as When the terminal device (200) is detected to have undergone the rotational movement, the candidate set (190a, 190b, 190c) of the second beam to be used for beam training is updated (S108), wherein the candidate set (190a, 190b, 190c) of the second beam, after being updated, includes at least one second beam with a predefined pointing direction, and wherein the predefined pointing direction is horizontal. The pointing directions of the candidate set (190a, 190b, 190c) of the second beam produce an angular distribution of pointing directions, wherein the angular distribution is denser on or at least near the first pointing direction (180) than in any other pointing direction.

2. The method according to claim 1, wherein, The tilt angle of the predefined pointing direction is in the range of 30 to 60 degrees relative to the horizontal plane.

3. The method according to claim 1, wherein, The predefined pointing direction is similar to the first pointing direction (180).

4. The method according to claim 1, further comprising: Estimate (S106) the spatial orientation of the terminal device (200) relative to the horizontal plane.

5. The method according to claim 1, further comprising: After the candidate set (190a, 190b, 190c) of the second beam has been updated, a beam training process (S110) is performed, wherein the beam training process involves the terminal device (200) performing beamforming communication with the transmitting and receiving points (140) in the candidate set (190a, 190b, 190c) of the second beam.

6. The method according to claim 5, wherein, The beam training process involves the terminal device (200) transmitting and / or receiving reference signals in the candidate set (190a, 190b, 190c) of the second beam.

7. The method according to claim 5, wherein, The beam training process involves the terminal device (200) selecting a second beam from a candidate set (190a, 190b, 190c) of the second beam to continue communication with the transmitting and receiving point (140).

8. The method according to claim 5, wherein, The beam is generated by at least one antenna array in the terminal device (200), wherein the antenna array is one-dimensional or two-dimensional.

9. A terminal device (200) for performing rotation-triggered candidate beam updates at the terminal device (200), the terminal device (200) including a processing circuit (210) configured to cause the terminal device (200) to: Beamforming communication with the transmitting and receiving points (140) is performed in a first beam (170) having a first pointing direction (180), the first beam (170) being the optimal beam for communicating with the transmitting and receiving points (140); The detection terminal device (200) undergoes rotational movement, which causes the first beam (170) to change its pointing direction (180); and When the terminal device (200) is detected to have undergone the rotational movement, the candidate set (190a, 190b, 190c) of the second beam to be used for beam training is updated, wherein, The candidate set of the second beam (190a, 190b, 190c), after being updated, includes at least one second beam with a predefined pointing direction, wherein the predefined pointing direction is horizontal. The pointing directions of the candidate set (190a, 190b, 190c) of the second beam produce an angular distribution of pointing directions, wherein the angular distribution is denser on or at least near the first pointing direction (180) than in any other pointing direction.

10. The terminal device (200) according to claim 9, wherein, The tilt angle of the predefined pointing direction is in the range of 30 to 60 degrees relative to the horizontal plane.

11. The terminal device (200) according to claim 9, wherein, The predefined pointing direction is similar to the first pointing direction (180).

12. The terminal device (200) according to claim 9, wherein the processing circuit is further configured to cause the terminal device (200): Estimate the spatial orientation of the terminal device (200) relative to the horizontal plane.

13. The terminal device (200) according to claim 9, wherein the processing circuit is configured to cause the terminal device (200): After the candidate set (190a, 190b, 190c) of the second beam has been updated, the beam training process is performed, wherein, The beam training process involves the terminal device (200) performing beamforming communication with the transmitting and receiving points (140) in the candidate set (190a, 190b, 190c) of the second beam.

14. The terminal device (200) according to claim 13, wherein, The beam training process involves the terminal device (200) transmitting and / or receiving reference signals in the candidate set (190a, 190b, 190c) of the second beam.

15. The terminal device (200) according to claim 13, wherein, The beam training process involves the terminal device (200) selecting a second beam from a candidate set (190a, 190b, 190c) of the second beam to continue communication with the transmitting and receiving point (140).

16. The terminal device (200) according to any one of claims 9 to 15, wherein, The beam is generated by at least one antenna array in the terminal device (200), wherein the antenna array is one-dimensional or two-dimensional.

17. A terminal device (200) for performing rotation-triggered candidate beam updates at the terminal device (200), the terminal device (200) comprising: The communication module (210a) is configured to perform beamforming communication with the transmitting and receiving points (140) in a first beam (170) having a first pointing direction (180), the first beam (170) being the optimal beam for communicating with the transmitting and receiving points (140); The detection module (210b) is configured to detect that the terminal device (200) undergoes rotational movement, which causes the first beam (170) to change its pointing direction (180). as well as The update module (210d) is configured to update the candidate set (190a, 190b, 190c) of the second beam to be used for beam training when the terminal device (200) is detected to undergo the rotational movement, wherein the candidate set (190a, 190b, 190c) of the second beam, after being updated, includes at least one second beam with a predefined pointing direction, and wherein the predefined pointing direction is horizontal. The pointing directions of the candidate set (190a, 190b, 190c) of the second beam produce an angular distribution of pointing directions, wherein the angular distribution is denser on or at least near the first pointing direction (180) than in any other pointing direction.

18. The terminal device (200) according to claim 17 is further configured to perform the method according to any one of claims 2 to 8.

19. A computer program product (910) comprising a computer program (920) for performing rotation-triggered candidate beam updates at a terminal device (200), the computer program including computer code that, when executed on a processing circuitry (210) of the terminal device (200), causes the terminal device (200) to: (S102) Beamforming communication with the transmitting and receiving points (140) is performed in a first beam (170) having a first pointing direction (180), the first beam (170) being the optimal beam for communicating with the transmitting and receiving points (140); Detection (S104) shows that the terminal device (200) undergoes rotational movement, which causes the first beam (170) to change its pointing direction (180); and When the terminal device (200) is detected to have undergone the rotational movement, the candidate set (190a, 190b, 190c) of the second beam to be used for beam training is updated (S108), wherein, The candidate set of the second beam (190a, 190b, 190c), after being updated, includes at least one second beam with a predefined pointing direction, wherein the predefined pointing direction is horizontal. The pointing directions of the candidate set (190a, 190b, 190c) of the second beam produce an angular distribution of pointing directions, wherein the angular distribution is denser on or at least near the first pointing direction (180) than in any other pointing direction.

20. A computer-readable storage medium (930) storing a computer program (920) for performing rotation-triggered candidate beam updates at a terminal device (200), the computer program including computer code that, when executed on a processing circuitry (210) of the terminal device (200), causes the terminal device (200) to: (S102) Beamforming communication with the transmitting and receiving points (140) is performed in a first beam (170) having a first pointing direction (180), the first beam (170) being the optimal beam for communicating with the transmitting and receiving points (140); Detection (S104) shows that the terminal device (200) undergoes rotational movement, which causes the first beam (170) to change its pointing direction (180); and When the terminal device (200) is detected to have undergone the rotational movement, the candidate set (190a, 190b, 190c) of the second beam to be used for beam training is updated (S108), wherein, The candidate set of the second beam (190a, 190b, 190c), after being updated, includes at least one second beam with a predefined pointing direction, wherein the predefined pointing direction is horizontal. The pointing directions of the candidate set (190a, 190b, 190c) of the second beam produce an angular distribution of pointing directions, wherein the angular distribution is denser on or at least near the first pointing direction (180) than in any other pointing direction.

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