Patent ID: 12231206

DESCRIPTION

Generally, all terms used herein are to be interpreted according to their ordinary meaning in the relevant technical field, unless a different meaning is clearly given and/or is implied from the context in which it is used. All references to a/an/the element, apparatus, component, means, step, etc. are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, step, etc., unless explicitly stated otherwise. The steps of any methods disclosed herein do not have to be performed in the exact order disclosed, unless a step is explicitly described as following or preceding another step and/or where it is implicit that a step must follow or precede another step. Any feature of any of the embodiments disclosed herein may be applied to any other embodiment, wherever appropriate. Likewise, any advantage of any of the embodiments may apply to any other embodiments, and vice versa. Other objectives, features and advantages of the enclosed embodiments will be apparent from the following description.

The following sets forth specific details, such as particular embodiments or examples for purposes of explanation and not limitation. It will be appreciated by one skilled in the art that other examples may be employed apart from these specific details. In some instances, detailed descriptions of well-known methods, nodes, interfaces, circuits, and devices are omitted so as not obscure the description with unnecessary detail. Those skilled in the art will appreciate that the functions described may be implemented in one or more nodes using hardware circuitry (e.g., analog and/or discrete logic gates interconnected to perform a specialized function, ASICs, PLAs, etc.) and/or using software programs and data in conjunction with one or more digital microprocessors or general-purpose computers. Nodes that communicate using the air interface also have suitable radio communications circuitry. Moreover, where appropriate the technology can additionally be considered to be embodied entirely within any form of computer-readable memory, such as solid-state memory, magnetic disk, or optical disk containing an appropriate set of computer instructions that would cause a processor to carry out the techniques described herein.

Hardware implementation may include or encompass, without limitation, digital signal processor (DSP) hardware, a reduced instruction set processor, hardware (e.g., digital or analogue) circuitry including but not limited to application specific integrated circuit(s) (ASIC) and/or field programmable gate array(s) (FPGA(s)), and (where appropriate) state machines capable of performing such functions.

As described above, in order to determine which beam on which to transmit data to a wireless device, a network node may determine a set of candidate beams for the wireless device to perform measurements on. However, each candidate beam adds an overhead load to the system.

Therefore, which beams to add to the candidate set of beams may become a trade-off between overhead and performance degradation due to suboptimal beam choice caused by user and/or environment mobility.

Thus, on one hand it may be acceptable to accept a large overhead and test a lot of beam candidates such that a wireless device (for example, a wireless device with fast-moving channel properties) is always covered by their best beam. However, in other circumstances, a large overhead may not be acceptable, and the number of candidate beams may be limited risking choosing a bad beam for communication, possibly leading to a beam failure.

FIG.2illustrates a method for adjusting a set of candidate beams that a wireless device is to perform measurements on. The wireless device may be configured to receive signals from a base station on one or more beams. In some examples, the method is performed by a network node. In some examples, the network node comprises the base station in communication with the wireless device.

In step201the network node obtains an estimated gain value Gestassociated with a first narrow beam in the set of candidate beams, wherein the estimated gain value is determined is based on a value indicative of first received energy of a first reference signal received by the wireless device on a first wide beam and a value indicative of a second received energy of a second reference signal received by the wireless device on the first narrow beam.

For example, for a candidate set of beams, a wireless device may perform measurements of the energy of reference signals received on each of the candidate beams.

The wireless device may also perform measurements of the energy of reference signals received on one or more wide beams in a similar way. The one or more wide beams may be parent beams of one or more of the candidate wide beams.

For example, the wireless device may measure the Reference Signal Received Power (RSRP) of a received Channel State Information Reference Signal (CSI-RS) on narrow beams (e.g. data beams). For example, the wireless device may measure the RSRP of a received Synchronization Signal Block (SSB) on wide beams.

In some examples, the wireless device may then transmit a report to the network node comprising an indication of the measured values indicative of the received energy on a predetermined top number of best beams. For example, the wireless device may indicate the measured RSRP values for the top one to four beams.

To determine the estimated gain value Gestassociated with the first narrow beam, the network node may calculate the estimated gain value Gestby subtracting the value indicative of second received energy from the value indicative of first received energy. In some examples, the values indicative of second received energy and/or the first received energy may be adjusted to compensate for a difference in transmission energies of the first wide beam and the first narrow beam. The energies may be expressed in dB. In some examples a ratio may be calculated if the energies are expressed in other units.

In some examples, if a narrow beam has multiple parent beams, a parent beam with highest reported quality value (e.g. RSRP) may be utilized to calculate the estimated gain. In other words, the first wide beam may be the parent beam of the first narrow beam having the highest reported value indicative of the received energy.

In some alternative examples, the wireless device may determine the estimated gain value Gestinstead of the network node.

In some examples therefore, the wireless device may perform the method illustrated inFIG.3.

In step301, the method comprises measuring a value indicative of a first received energy of a first reference signal received by the wireless device on a first wide beam.

In step302, the method comprises measuring a value indicative of a second received energy of a second reference signal received by the wireless device on a first narrow beam.

In step303, the method comprises calculating an estimated gain value associated with a first narrow beam based on the value indicative of the first received energy and the value indicative of the second received energy. Similarly to as described above, the wireless device may calculate the estimated gain value Gestby subtracting the second received energy from the first received energy. Again, in some examples, the second received energy and/or the first received energy may be adjusted to compensate for a difference in transmission energies of the first wide beam and the first narrow beam.

In step304, the method comprises transmitting an indication of the estimated gain value to a network node.

In some examples, the network node may indicate to the wireless device which wide beam to utilise as the first wide beam when calculating the estimated gain value for the first narrow beam. For example, the network node may transmit an indication of which beam is the first wide beam for use in calculating the estimated gain value for the first narrow beam.

Returning toFIG.2, in step202, the network node compares the obtained estimated gain value Gest(either calculated by the network node or by the wireless device) to an expected gain value Gexpectedassociated with the first narrow beam. For example, the network node may subtract the estimated gain value Gestfrom the expected gain value Gexpected. Alternatively, the network node may calculate a ratio between the estimated gain value and the expected gain value.

The expected gain value Gexpectedmay comprise a gain value representative of the energy that is expected to be measured by the wireless device on the first narrow beam. This expected gain value Gexpectedmay for example be based on the shape of the beams that are produced by the base station. For example, the expected gain value may comprise a maximum known energy of the first narrow beam minus the energy of the first wide beam in the direction of the first narrow beam.

In step203, the network node, based on the comparison, determines whether to adjust which beams belonging to the candidate set of beams.

In some examples, step203comprises determining whether the magnitude of the difference between the estimated gain value Gestand the expected gain value Gexpectedis greater than a threshold value. In particular, in some examples, responsive to the difference between the estimated gain value Gestand the expected gain value Gexpectedbeing greater than a threshold value T0, the network node adjusts which beams belonging to the candidate set of beams.

In some examples, step203comprises determining whether the ratio between the estimated gain value and the expected gain value crosses a second threshold value.

For example, if Gexpected−Gest>T0, the network node may adjust the set of candidate beams. For example, the network node may add a second narrow beam to the set of candidate beams. For example, the second narrow beam may be a child beam of the first wide beam.

In other words, if the value indicative of the received energy of a candidate beam (e.g. the first narrow beam) is too low compared to the value indicative of the received energy of the corresponding wide beam (e.g. the first wide beam) at the wireless device's position, this indicates that a better path than the one currently used by the candidate beam is available within the wide beam. Hence, it is likely that the candidate beam in question is sub-optimal, and therefore the network node may add other data beams within the same wide beam to the set of candidate beams so that they can be tested.

In some examples, as the candidate beam that is the first narrow beam may be considered sub-optimal, the step of adjusting may comprise removing the first narrow beam from the set of candidate beams.

However, in some examples, whilst the candidate beam that is the first narrow beam may be considered sub-optimal, the wireless device may have made measurements on other candidate beams which were not reported to the network node. The network node may therefore assume that the non-reported beams comprise worse candidate beams than the reported first narrow beam. In some examples therefore, the step of adjusting may comprise removing a non-reported narrow beam from the set of candidate beams.

FIG.4illustrates an example of how the method ofFIG.2may be implemented.

In this example, a base station provides a wide beam401, and three narrow beams402a,402band402cwhich are all child beams of the wide beam401.

Two wireless devices403aand403bare illustrated.

At first, the narrow beam402bis a candidate beam for both the wireless device403aand403b. The arrow404represents the estimated gain Gestof the narrow beam402bfor the wireless device403a. An expected gain Gexpectedof the narrow beam302bmay be similar to this gain, and therefore the beam402bmay be a suitable candidate for the wireless device403a.

However, the estimated gain Gestof the narrow beam402bfor the wireless device403bis represented by the arrow405. This arrow405is smaller than the arrow404, and would be smaller than the expected gain Gexpectedfor the narrow beam402b. In particular, the magnitude of the difference between the expected gain Gexpectedfor the narrow beam402band the estimated gain Gestrepresented by the arrow405may be greater than a threshold value T0. In this example therefore, the wireless device403bmay benefit from testing one of the other narrow beams.

In this example therefore, in step203of the method illustrated inFIG.2, the network node may add another child beam, for example beam402ato the set of candidate beams for the wireless device403b. In some examples, the network node may remove the narrow beam402bfrom the set of candidate beams for the wireless device403b.

FIG.5illustrates another example of how the method ofFIG.2may be implemented.

In this example a base station provides a wide beam501and three narrow beams502ato502c. In this example the narrow beams502ato502care all child beams of the wide beam501. A wireless device503starts at position504and moves to position505.

In position504, the narrow beam502amay provide the best candidate beam for communication with the wireless device503, as the received energy in the direction of the wireless device in position504in the narrow beam502ais high. However, as the wireless device503moves behind an object506into position505behind an object506, the energy received by the wireless device from the narrow beam502amay drop substantially as the line of sight between the beam502aand the wireless device503is obstructed by the object506.

However, the energy received by the wide beam501may still be high, as the signal received on the wide beam501may be reflected off another object507, and received by the wireless device503.

In this circumstance therefore, as the wireless device503moves into position505, the network node may receive measurements from the wireless device indicating that the energy received on the narrow beam502ahas dropped. In particular, the magnitude of the difference between the estimated gain and the expected gain may be greater than a threshold value.

The network node may then add one or more other narrow beams to the set of candidate beams. For example, the network node may add the beam502band/or502cto the set of candidate beams. In doing this, the network node may discover that the narrow beam502cmay provide a better alternative for communication with the wireless device, as the signal transmitted by the narrow beam502cmay be reflected off the object507to reach the wireless device503.

FIG.6illustrates another example of how the method ofFIG.2may be implemented.

In this example a base station provides a first wide beam601and a second narrow beam602. Three narrow beams603ato603care provided. In this example the narrow beams603aand603bare child beams of the first wide beam601. The narrow beam603cis a child beam of the second wide beam602. A wireless device604starts at position605and moves to position606. Initially the set of candidate beams comprises the narrow beam603aand the narrow beam603c.

In position605, the narrow beam603cmay provide a suitable beam for communication with the wireless device604. However, as the wireless device604moves to position606, the magnitude of the difference between the estimated gain and the expected gain for the beam603cincreases, and the narrow beam603cmay become unsuitable.

However, the other candidate beam603amay also be sub-optimal due to a difference between the estimated gain and the expected gain of603a. In other words, the signal received from the candidate beam603athat is reflected off the object607may not be of high enough energy. The network node may therefore adjust the set of candidate beams to include the beam603b. The beam603bmay be considered suitable for communication with the wireless device in position606.

Consider an example in which a wireless device provides a report containing information relating to the received energy on only one candidate beam, B. In this example, if the received energy on the parent beam SBof B is higher than the received energy on other wide beams, the best reported beam B may still be considered as the best beam for communication with the wireless device. However, if B does not have a reasonable directivity gain compared to SB, e.g. if Gexpected−Gest>T0, then the network node may adjust the set of candidate beams. In particular, a next beam sweep may include one or several siblings to B. For example, either a full sweep of the child beams of the parent beam SBmay be initiated, or sibling beams B may be tested in a round robin scheme (possibly including the old best beam B) over multiple beam sweeps until a better beam is found.

For example, the step of adjusting in step203ofFIG.2may comprise performing a beam sweep of a set of narrow beams and requesting that the wireless device provides a measurement report on said set of narrow beams; and adding a best reported narrow beam from the beam sweep to the set of candidate beams. In some examples, the set of narrow beams comprises child beams of the first wide beam. However, in some examples, the set of narrow beams in the beam sweep comprises narrow beams which are not sibling beams of the first narrow beam.

If the received energy on the parent beam SBis less than the received energy on another wide beam SX, then it may be possible that the best beam for communication with the wireless device is not a sibling beam of B. In this example, one or more child beams of Sxmay be added to the set of candidate beams. In other words, in some examples, responsive to an indication of a value indicative of a third received energy of a third reference signal received by the wireless device on a second wide beam being greater than the value indicative of the first received energy, the network node may add one or more child beams of the second wide beam to the set of candidate beams.

It will be appreciated that the network node may perform the method as described with reference toFIG.2for each beam reported by the wireless device. For example, the network node may determine a plurality of estimated gain values associated with a plurality of narrow beams in the set of candidate beams. In some examples the plurality of narrow beams are all child beams of the first wide beam. However, in some examples, the plurality of narrow beams comprises at least one child beam of the first wide beam and at least one child beam of a second wide beam. In other words, in some examples the set of candidate beams may not all be child beams of the same wide beam.

In some examples therefore, responsive to a magnitude of a difference between any of the respective estimated gain values and an expected gain value for the respective narrow beam being greater than a respective threshold value, the network node may add a third narrow beam to the set of candidate beams, wherein the third narrow beam is a sibling beam of the respective narrow beam. For example, if any of the narrow beams reported by the wireless device meet the condition Gexpected−Gest>T0, then the network node may add a sibling beam of that narrow beam to the set of candidate beams.

Similarly, responsive to the magnitude of the difference between any of the respective estimated gain values and the expected gain value for the respective narrow beam being greater than the respective threshold value (e.g Gexpected−Gest>T0), the network node may remove the respective narrow beam from the set of candidate beams.

However, in some examples, as described above, whilst a candidate beam that meets the condition Gexpected−Gest>T0may be considered sub-optimal, the wireless device may have made measurements on other candidate beams which were not reported to the network node. In some examples therefore, responsive to the magnitude of the difference between any of the respective estimated gain values and the expected gain value for the respective narrow beam being greater than the respective threshold value, the network node may remove a non-reported narrow beam form the set of candidate beams.

Consider an example in which a wireless device provides a report containing information relating to the received energy on a plurality of candidate beams which are all child beams of the same wide beam.

In this example, if any of the reported candidate beams fulfill the Gexpected−Gest>T0requirement, they may be exchanged for another sibling beam not currently included in the set of candidate beams. It should be noted that any non-reported sibling beams currently in the candidate set will have lower received energy measured by the wireless device, (for example, the wireless device may be able to report a maximum of four beams from the candidate set) and therefore would evaluate even worse against the set threshold. In some examples therefore, responsive to the difference between any of the respective estimated gain values and the expected gain value for the respective narrow beam being greater than the respective threshold value, the network node may remove a non-reported narrow beam from the set of candidate beams.

Consider an example in which a wireless device provides a report containing information relating to the received energy on a plurality of candidate beams, wherein at least one of the candidate beams is a child beam of a first wide beam and at least one of the candidate beams is a child beam of a second wide beam.

This example may be described as an adaptive sparse sweep of narrow beams that are child beams of wide beams providing SSBs to the wireless device that have received energies that are considered interesting (e.g. based on reported RSRP being high enough or close enough to current best SSB).

The reported candidate beams may be evaluated by the network node as to whether or not they meet the condition Gexpected−Gest>T0. When the condition is not fulfilled, a sibling beam of the corresponding narrow beam may be added to the set of candidate beams. In some examples, the corresponding narrow beam may be removed from the set of candidate beams. In some examples, responsive to the difference between any of the respective estimated gain values and the expected gain value for the respective narrow beam being greater than the respective threshold value, the network node may remove a non-reported sibling of the corresponding narrow beam from the set of candidate beams.

Consider an example in which a set of candidate beams is shared by one or more wireless device.

In this example, if for a particular wireless device the condition Gexpected−Gest>T0is fulfilled for a reported beam B, the step of adjusting may comprise initiating a beam sweep of child beams of the first wide beam and request a measurement report from the wireless device; and adding the best reported beam from the beam sweep to the set of candidate beams.

If the magnitude of the gain difference between Gexpectedand Gestincreases, or if the reported beam B is not reported among a number of best beams for any of the wireless devices sharing the set of candidate beams for a certain time interval, the reported beam B may be removed from the set of candidate beams

For example, the method ofFIG.2may comprise, responsive to the first narrow beam not being reported among a predetermined number of best beams for any of the plurality of wireless devices for a predetermined time interval, removing the first narrow beam from the set of candidate beams.

FIG.7illustrates a network node700comprising processing circuitry (or logic)701. The processing circuitry701controls the operation of the network node700and can implement the method described herein in relation to a network node700(e.g. a base station or network node). The processing circuitry701can comprise one or more processors, processing units, multi-core processors or modules that are configured or programmed to control the network node700in the manner described herein. In particular implementations, the processing circuitry701can comprise a plurality of software and/or hardware modules that are each configured to perform, or are for performing, individual or multiple steps of the method described herein in relation to the network node700.

Briefly, the network node700is configured to: obtain an estimated gain value associated with a first narrow beam in the set of candidate beams, wherein the estimated gain value is determined based on a value indicative of first received energy of a first reference signal received by the wireless device on a first wide beam and a value indicative of a second received energy of a second reference signal received by the wireless device on the first narrow beam; compare the estimated gain value to an expected gain value associated with the first narrow beam; and based on the comparison, determine whether to adjust which beams belonging to the candidate set of beams.

In some embodiments, the network node700may optionally comprise a communications interface702. The communications interface702of the network node700can be for use in communicating with other nodes, such as other virtual nodes. For example, the communications interface702of the network node700can be configured to transmit to and/or receive from other nodes requests, resources, information, data, signals, or similar. The processing circuitry701of network node700may be configured to control the communications interface702of the network node700to transmit to and/or receive from other nodes requests, resources, information, data, signals, or similar.

Optionally, the network node700may comprise a memory703. In some embodiments, the memory703of the network node700can be configured to store program code that can be executed by the processing circuitry701of the network node700to perform the method described herein in relation to the network node700. Alternatively or in addition, the memory703of the network node700, can be configured to store any requests, resources, information, data, signals, or similar that are described herein. The processing circuitry701of the network node700may be configured to control the memory703of the network node700to store any requests, resources, information, data, signals, or similar that are described herein.

FIG.8illustrates a wireless device800comprising processing circuitry (or logic)801. The processing circuitry801controls the operation of the wireless device800and can implement the method described herein in relation to a wireless device800. The processing circuitry801can comprise one or more processors, processing units, multi-core processors or modules that are configured or programmed to control the wireless device800in the manner described herein. In particular implementations, the processing circuitry801can comprise a plurality of software and/or hardware modules that are each configured to perform, or are for performing, individual or multiple steps of the method described herein in relation to the wireless device800.

Briefly, the wireless device800is configured to measure a value indicative of a first received energy of a first reference signal received by the wireless device on a first wide beam; measuring a value indicative of a second received energy of a second reference signal received by the wireless device on a first narrow beam; calculate an estimated gain value associated with a first narrow beam based on the value indicative of the first received energy and the value indicative of the second received energy; and transmit an indication of the estimated gain value to a network node.

In some embodiments, the wireless device800may optionally comprise a communications interface802. The communications interface802of the wireless device800can be for use in communicating with other nodes, such as other virtual nodes. For example, the communications interface802of the wireless device800can be configured to transmit to and/or receive from other nodes requests, resources, information, data, signals, or similar. The processing circuitry801of wireless device800may be configured to control the communications interface802of the wireless device800to transmit to and/or receive from other nodes requests, resources, information, data, signals, or similar.

Optionally, the wireless device800may comprise a memory803. In some embodiments, the memory803of the wireless device800can be configured to store program code that can be executed by the processing circuitry801of the wireless device800to perform the method described herein in relation to the wireless device800. Alternatively or in addition, the memory803of the wireless device800, can be configured to store any requests, resources, information, data, signals, or similar that are described herein. The processing circuitry801of the wireless device800may be configured to control the memory803of the wireless device800to store any requests, resources, information, data, signals, or similar that are described herein.

Advantages of the embodiments described herein include providing a response as to whether or not a good beam candidate has been selected from the children beams of a wide beam, without actually transmitting any more data beams grouped under said wide beam (parent beam). The result is less signaling overhead for beam management resources, and less resources being required to determine if a current beam is suitable. Embodiments described herein may also have an energy saving effect (less signaling and more resources left for data) and cause less interference in neighboring cells from beam sweeps.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. The word “comprising” does not exclude the presence of elements or steps other than those listed in a claim, “a” or “an” does not exclude a plurality, and a single processor or other unit may fulfil the functions of several units recited in the claims. Any reference signs in the claims shall not be construed so as to limit their scope.