Embodiments presented herein relate to a method for a network node, a network node, a method for a UE, a UE, a computer program, and a computer program product for adapting a beam sweep in a communications network.
The 5G NR (New Radio) is the latest in the series of 3GPP standards which supports very high data rate and with lower latency compare to its predecessor LTE (4G) and 3G/2G technology. In 5G NR, massive multiple input multiple output (MIMO) has become a key technology and therefore beam based cell sector coverage is used, which increases the link budget and overcomes the disadvantages of the mm-wave channel. In other words, all the data transmissions and control signalling transmissions are beam-formed. In an exemplary massive MIMO system there will be about 20 different beams transmitted to cover the 120 degrees cell sector.
Beam management procedures are used in 5G NR to acquire and maintain a set of transmission and reception points and/or UE beams which can be used for downlink (DL) and uplink (UL) transmission/reception. Beam management includes for example beam sweeping, beam measurements, beam determination and beam failure recovery but it is not limited thereto. The time during which a beam is the best choice to use depends on the time it takes to pass the beams coverage area. It is important to determine when another beam becomes a better choice, it is especially important to detect this before the currently used beam have deteriorated too much. Beam sweeping refers to covering a spatial area with a set of beams transmitted and received according to pre-specified intervals and directions. Beam measurement refers to evaluation of the quality of the received signal at the gNB or at the UE. Different metrics could be used such as Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ) and Signal to Interference & Noise Ratio (SINR) or Signal to Noise Ration (SNR) for this purpose.
Beam management is and will be an important topic for Advanced Antenna Systems (AAS) in 5G NR and LTE. Beam management needs to assure that that resources are used efficiently and to minimize the waste of resources such as air resources and transmission power. To ensure robust performance, for example, selecting the optimal beam, the communications system is designed to handle the ‘worst case scenario’. However, designing the communications system such that it can ensure robust performance also under ‘worst case scenario’ requires a lot of signaling and radio resources. The ‘worst case scenario’ is not that common and hence resources will be wasted for a large fraction of the time the system is used.
Hence, there is still a need for an improved beam sweeping.
According to a first aspect there is presented a method for a network node for adapting a beam sweep in a communications network, the communications network includes the network node, a transmission point, TP, and a user equipment, UE. The method includes determining at least one parameter related to the angular speed of the UE relative to the transmission point. The method further includes adapting at least one parameter associated with the beam sweep based on the parameter related to the angular speed.
According to a second aspect there is presented a network node including processing circuitry configured to adapt a beam sweep in a communications network, the communications network including the network node, a transmission point, TP, and a user equipment, UE. The processing circuitry is further configured to determine at least one parameter related to the angular speed of the UE relative to the transmission point. Furthermore, the processing circuitry is configured to adapt at least one parameter associated with the beam sweep based on the parameter related to the angular speed.
According to a third aspect there is presented a method for a user equipment, UE, for adapting a beam sweep in a communications network (100a), the communications network comprising a network node, a transmission point, TP, and the user equipment, UE. The method includes determining at least one parameter related to the angular speed of the UE relative to the transmission point. The method further includes adapting at least one parameter associated with the beam sweep based on the parameter related to the angular speed.
According to a fourth aspect there is presented a user equipment including processing circuitry configured to adapt a beam sweep in a communications network, the communications network including a network node, a transmission point, TP, and the user equipment, UE. The processing circuitry is further configured to determine at least one parameter related to the angular speed of the UE relative to the transmission point. Furthermore, the processing circuitry is configured to adapt at least one parameter associated with the beam sweep based on the parameter related to the angular speed.
According to a fifth aspect there is presented a computer program for adapting a beam sweep in a communications network, the computer program comprising computer program code which, when run on a network node, causes the radio transceiver device to perform a method according to the first aspect.
According to a sixth aspect there is presented a computer program for adapting a beam sweep in a communications network, the computer program comprising computer program code which, when run on a user equipment, causes the user equipment to perform a method according to the third aspect.
According to a seventh aspect there is presented a computer program product comprising a computer program according to the fifth or the sixth aspect and a computer readable storage medium on which the computer program is stored. The computer readable storage medium could be a non-transitory computer readable storage medium.
Advantageously these methods, this user equipment, this network node, this computer program, and this computer program product enables adapting a beam sweep in a communications network.
Advantageously the adapting the beam sweep based on determined at least one parameter related to the angular speed of the UE relative to the transmission point.
Advantageously these methods, this user equipment, this network node, this computer program, and this computer program product adapts the beam sweep such that only the amount of resources, for example data associated with the beam management such as RSRP, RSRQ, SINR, SNR, CSI-RS, CSI reports and SRS that are necessary to maintain a robust system performance is transmitted between the user equipment and the network node. The avoidance of unnecessary transmission of beam management related data will also save energy, increase the amount of data resources available for user data, and reduce the amount of interference to neighboring cells.
Other objectives, features and advantages of the enclosed embodiments will be apparent from the following detailed disclosure, from the attached dependent claims as well as from the drawings.
Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to “a/an/the element, apparatus, component, means, module, step, etc.” are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, module, step, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.
The inventive concept is now described, by way of example, with reference to the accompanying drawings, in which:
The inventive concept will now be described more fully hereinafter with reference to the accompanying drawings, in which certain embodiments of the inventive concept are shown. This inventive concept may, however, be embodied in many different forms and should not be construed as 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. Like numbers refer to like elements throughout the description. Any step or feature illustrated by dashed lines should be regarded as optional.
The communications network 100a comprises a transmission point, TP, 140 including an antenna device 500 which may be a Multiple-Input Multiple-Output (MIMO) antenna including two or more antennas. The antenna device 500 is connected to a radio device 400. The communications network 100a further includes the network node 200 may include one or more TPs. The network node is configured to, in a radio access network 110, provide network access to an user equipment, UE, 300. The radio access network 110 is operatively connected to a core network 120. The core network 120 is in turn operatively connected to a service network 130, such as the Internet. The UE 300 is thereby, via network node and the transmission point 140, enabled to access services of, and exchange data with, the service network 130. Examples of network nodes are radio access network nodes, radio base stations, base transceiver stations, Node Bs, evolved Node Bs, g Node Bs, access points, access nodes, antenna integrated radios (AIRs), and transmission and reception points (TRPs). Examples of UEs are, terminal devices, wireless devices, mobile stations, mobile phones, handsets, wireless local loop phones, smartphones, laptop computers, tablet computers, network equipped sensors, network equipped vehicles, and so-called Internet of Things devices.
The network node 200 provides network access in the radio access network 110 by transmitting signals to, and receiving signals from, the UE 300 using beams. The signals could be transmitted from, and received by, a network node 200, using a transmission and reception points.
A UE moving from point D to point E in
Beam sweeping is performed to find a suitable beam for the UE within the set of beams and is directed to the operation of covering a spatial area, such as one of the sectors in
While the terminal device is moving from point D to point E in
However, as shown in
Step 401 in
Determining the at least one parameter related to the angular speed of the UE may include estimating the distance between the TP and the UE, step 403. The angular velocity of a UE relative to the transmission point is dependent on the distance between the UE and the TP. For example, a UE moving with the same speed between D and E will have a higher angular velocity compared to a UE moving between F and G, in
In step 404, determine the at least one parameter related to the angular speed of the UE includes estimating the velocity at which the UE is moving. A UE moving at higher velocity relative to the transmission point will also have a higher angular velocity relative to the transmission point compared to a UE moving at lower velocity. The velocity of the UE can be estimated using Doppler measurements or by obtaining changes in the timing advance value. Another way estimating the velocity of the UE is to measure the time a UE stays within a single beam. For example, referring to
In step 402 at least one parameter associated with the beam sweep is adapted based on the parameter related to the angular speed device. The at least one parameter associated with the beam sweep may include adapting the rate or the frequency of the beam sweep, e.g. adapting the rate or frequency may include adapting the rate of the frequency of the beam measurements during a sweep. Adapting at least one parameter associated with the beam sweep could may also include adapting rate or frequency at which the UE provides input to beam management. In step 405 the rate or the frequency of the beam sweep increases when the angular speed of the UE is increasing. In step 406 the rate or the frequency of the beam sweep decreases when the angular speed of the UE is decreasing. Increasing or decreasing the rate or the frequency of the beam sweep may include increasing or decreasing how often the UE provides input to beam management 160. Increasing or decreasing the rate or the frequency of the beam sweep may also include increasing or decreasing the rate of frequency of beam measurements 160 during the beam sweep. The parameter that is adapted may also include the frequency with which the reference signals such as CSI-RS is sent to the UE, the frequency with which measurements reports such as CSI reports are sent, the frequency with which the uplink SRS are sent from the UE to the network node, the frequency with which the UE measures the reference signals; and/or the frequency with which the UE reports measurements of reference signals. The frequency may some embodiment refer to how often these parameters are reported.
Particularly, the processing circuitry 210 is configured to cause network node 200 to perform a set of operations, or steps, 401-406, as disclosed above. For example, the storage medium or memory 230 may store the set of operations, and the processing circuitry 210 may be configured to retrieve the set of operations from the storage medium 230 to cause network node 200 to perform the set of operations. The set of operations may be provided as a set of executable instructions.
Thus the processing circuitry 210 is thereby arranged to execute methods as herein disclosed. The storage medium 230 may also comprise persistent storage, which, for example, can be any single one or combination of magnetic memory, optical memory, solid state memory or even remotely mounted memory. Network node 200 may further comprise a communications interface 220 at least configured for communications with other nodes, device, functions, and notes of the communications network 100a. As such the communications interface 220 may comprise one or more transmitters and receivers, comprising analogue and digital components. Signals could be transmitted from, and received by, a network node 200 using the communications interface 220.
The processing circuitry 210 controls the general operation of network 200 e.g. by sending data and control signals to the communications interface 220 and the storage medium 230, by receiving data and reports from the communications interface 220, and by retrieving data and instructions from the storage medium 230. Other components, as well as the related functionality, of network node 200 are omitted in order not to obscure the concepts presented herein.
Particularly, the processing circuitry 310 is configured to cause UE 300 to perform a set of operations, or steps, 401-406, as disclosed above. For example, the storage medium or memory 330 may store the set of operations, and the processing circuitry 310 may be configured to retrieve the set of operations from the storage medium 330 to cause UE 300 to perform the set of operations. The set of operations may be provided as a set of executable instructions.
Thus the processing circuitry 310 is thereby arranged to execute methods as herein disclosed. The storage medium 330 may also comprise persistent storage, which, for example, can be any single one or combination of magnetic memory, optical memory, solid state memory or even remotely mounted memory. UE 300 may further comprise a communications interface 320 at least configured for communications with other nodes, device, functions, and notes of the communications network 100a. As such the communications interface 320 may comprise one or more transmitters and receivers, comprising analogue and digital components. Signals could be transmitted from, and received by, a UE 300 using the communications interface 320.
The processing circuitry 310 controls the general operation of UE 300 e.g. by sending data and control signals to the communications interface 320 and the storage medium 330, by receiving data and reports from the communications interface 320, and by retrieving data and instructions from the storage medium 330. Optionally the UE may include a display 340 but the embodiments herein are not limited thereto. Other components, as well as the related functionality, of UE 300 are omitted in order not to obscure the concepts presented herein.
In the example of
The inventive concept has mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the inventive concept, as defined by the appended patent claims.
Filing Document | Filing Date | Country | Kind |
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PCT/SE2018/051373 | 12/28/2018 | WO | 00 |