Patent ID: 12212453

In the various figures, identical reference signs will be used for identical or at least functionally equivalent features.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

In the following description, reference is made to the accompanying drawings, which form part of the disclosure, and in which are shown, by way of illustration, specific aspects in which the present invention may be placed. It will be appreciated that other aspects may be utilized and structural or logical changes may be made without departing from the scope of the present invention. The following detailed description, therefore, is not to be taken in a limiting sense, as the scope of the present invention is defined by the appended claims.

For instance, it will be appreciated that a disclosure in connection with a described method may also hold true for a corresponding device or system configured to perform the method and vice versa. For example, if a specific method step is described, a corresponding device may include a unit to perform the described method step, even if such unit is not explicitly described or illustrated in the figures.

Moreover, in the following detailed description as well as in the claims embodiments with different functional blocks or processing units are described, which are connected with each other or exchange signals. It will be appreciated that the present invention covers embodiments as well, which include additional functional blocks or processing units that are arranged between the functional blocks or processing units of the embodiments described below.

Finally, it is understood that the features of the various exemplary aspects described herein may be combined with each other, unless specifically noted otherwise.

As will be described in more detail in the following, embodiments of the invention focus on a novel beam failure recovery procedure and a related signaling scheme for communication devices or user equipments (UEs) by utilizing a control or data connection that the communication device has with another communication device, but not with the failed serving communication device. Examples of such scenarios are shown inFIGS.2and3below.

FIG.2shows a schematic diagram of an exemplary wireless communication network200according to an embodiment, wherein the wireless communication network200comprises

a first communication device201c, a second communication device201a, and a third communication device201bfor a scenario which has vehicle-to-vehicle (V2V) communications links. In the exemplary embodiment shown inFIG.2, the communication devices201a-care implemented as vehicles or as a respective component thereof, such as an onboard unit. The person skilled in the art, however, will appreciate that embodiments of the invention can be applied to other types of communication devices as well.

In the exemplary embodiment shown inFIG.2, at a time T1, the second communication device201a, the third communication device201band the first communication device201care connected to each other.

At a later time T2, the communication link between the second communication device201aand the first communication device201cis blocked, because the third communication device201bblocks the signal path.

At a further later time T3, the third communication device201bmoves further such that the first communication device201ccan receive reference or synchronization signals from the second communication device201aagain. However, since the second communication device201aand the first communication device201care no longer connected in both directions (forward and reverse direction), the first communication device201cdoes not have a control connection with the second communication device201aand therefore the second communication device201acannot receive beam failure recovery requests (BFRQ) from the first communication device201cusing the conventional PUCCH procedure as described above.

Furthermore, as explained above, using the conventional non-contention RACH scheme would need an overhead which would be too high for this application. The embodiments of the invention provide a scheme whereby the beam failure recovery request (BFRQ) uses a control or data connection to another communication device (in this case the third communication device201b) which then forwards the request to the second communication device201a.

More specifically, embodiments of the invention provide the first communication device201cto be configured to communicate with the second communication device201aand the third communication device201bin the wireless communication network200using beamforming. The first communication device201cis configured to: determine a new beam from a plurality of available beams of the second communication device201a, in response to a beam failure event with the second communication device201a; and transmit a beam failure recovery request, BFRQ, message to the third communication device201busing a first beam, wherein the BFRQ message contains information about the new beam of the second communication device201adetermined by the first communication device201c.

The third communication device201bis configured to: receive a beam failure recovery request, BFRQ, message from the first communication device201cusing a fourth beam; determine that the beam failure recovery request, BFRQ, message is intended for the second communication device201a; and forward the BFRQ message to the second communication device201a. There can be a fixed, configurable and or preconfigured spatial relationship between the second beam and the new beam.

The second communication device201ais configured to receive a beam failure recovery request, BFRQ, message from the third communication device201band transmit to the first communication device201ca BFRQ response message using the new beam, wherein the BFRQ response message contains a confirmation of the new beam. There can be a fixed, configurable or preconfigured time offset between the reception of the BRFQ message and the transmission of the BFRQ response. Later, the first communication device201cthen receives a BFRQ response message from the second communication device201ausing a second beam.

In an embodiment, the third communication device201bis further configured to transmit a BFRQ acknowledgement message to the first communication device201cusing a fifth beam. In an embodiment, there is a fixed, configurable or preconfigured time offset between the reception of the BRFQ message at the third communication device and the transmission of the BFRQ acknowledgment from the third communication device or a fixed, configurable or preconfigured spatial relationship between the fourth beam and the fifth beam as well as between the first beam and the third beam.

Then, the first communication device201cis configured to receive from the third communication device201busing a third beam a BFRQ acknowledgement message that the BFRQ message is or has been forwarded by the third communication device201bto the second communication device201a. In an embodiment, there is a fixed or configurable time offset between the reception of the BFRQ acknowledgment message and the reception of the BFRQ response message.

It is worth noting that the first communication device201ccan select the third communication device201bfrom a plurality of communication devices, for example, known communication devices or communication devices to which it is already connected to, wherein the third communication device201bcan selected on the basis of information received by the first communication device201c, in particular one or more of the following information: information about neighbouring communication devices, position information of at least one of the known or connected communication devices, an identifier of a serving base station serving at least one of the known or connected communication devices, information about one or more beams of at least one of the known or connected communication devices, an identifier of a group of at least one of the known or connected communication devices.

In an embodiment, the first communication device201cis configured to receive information about the spatial relationship between the first beam and the third beam from the second communication device201aor another network entity. In an embodiment, the first communication device201cis configured to receive configuration information, in particular a candidate beam RS list, from a fourth communication device including information about a plurality of available beams of the second communication device201afor beam recovery reporting. The first communication device201ccan be configured to determine selection of the new beam on the basis of this information and the signals received from the second communication device201c.

FIG.3shows a schematic diagram of a further embodiment of the wireless communication network200, where the first communication device201cand the third communication device201bare vehicular user equipments and the second communication device is a serving base station201a, such as a gNB, TRP or RSU. In the exemplary embodiment shown inFIG.3, the connection between the serving base station201aand the first communication device201cis blocked by another vehicle303. In this case, according to embodiments of the invention the first communication device201cuses its existing connection with the third communication device201bto relay the beam failure recovery request (BFRQ).

To enable this scheme, the embodiments of the invention can provide five key changes to the conventional schemes. These features and the corresponding signaling examples will be shown further below under reference toFIGS.4,5and6.

First, as already mentioned above, embodiments of the invention can include a “candidate beam RS-List” for each communication device, which is configured by the serving gNB201aand sent to each communication device and contains a complete set of sidelink and Uu (Sync block and CSI-RS) resources transmitted by other neigbouring communication devices to the communication device. This is very different to the state-of-the-art schemes because since conventionally this list only contains downlink SSB and CSI-RS resources from the serving gNB.

The first communication device201ccan choose from this list, to select new beams.

Secondly, when the first communication device201c(as shown, for instance, inFIG.2) detects a beam failure in both the forward (downlink) and reverse (uplink) directions with the present connected entity (e.g., the second communication device201aas shown inFIG.2), the first communication device201cfirst determines which new received beam from the second communication device201ais the new best received beam from the set of beams in the “candidate beam RS-list” and then transmits the beam failure recovery request (BFRQ) to at least one other connected entity (e.g., the third communication device201b), from a set of candidate entities to relay the request to the second communication device201a. This enables the system not to use the resource intensive non-contention RACH scheme.

Thirdly, as already described above, the choice of the third communication device201bfrom the set of candidates for transmitting the BFRQ request may be based on additional signals or information: a list of connected neighboring devices to the candidate entity; position information of candidate entities; ID or indicator indicating which base station, gNB or TRP is serving the candidate entity; and assigned beam resources or group ID of the candidate entity or alternatively it may just multicast the request to all other connected entities or communication devices.

Fourthly, as already described above, if the chosen entity (i.e., the third communication device201b) can or cannot forward the BFRQ request to the second communication device201a, it transmits an acknowledgment or non-acknowledgment to the first communication device201c. This could be in the form of a “BFRQ relay ACK/NACK” signal.

In a further embodiment, as already described above, there can be a fixed or configurable time offset between transmission of this acknowledgement signal (BFRQ relay ACK/NACK) by the third communication device201band its previous reception of the BFRQ request from the first communication device201c, so the first communication device201cknows when to receive the BFRQ relay ACK/NACK message (this is shown as “time A” inFIGS.4,5and6below).

Additionally, as already described above, there can be a “spatial correspondence”, which is sometimes referred to as QCL (quasi-co-located) between the beams which are used for transmission and reception. This may mean a same or fixed beam offset, between the reception of the BFRQ request and the transmission of the BFRQ relay ACK/NACK signal, so the first communication device201cknows which beam direction to receive the BFRQ relay ACK/NACK signal. This is shown with the label “same beam” inFIGS.4,5and6below.

Finally, when the second communication device201acan respond to the BFRQ request, it will send a BFRQ response message to the first communication device201c. According to an embodiment, there can be a fixed, preconfigured or configurable time offset between the BFRQ response and the BFRQ relay ACK/NACK signal. This is to ensure that the first communication device201cknows when to receive the BFRQ response. This is shown as “time B” inFIGS.4,5and6below.

Additionally, the beam direction(s) which is used by the first communication device201cfor the reception of the BFRQ response can have a spatial correspondence, sometimes called QCL (quasi co-located), with the identified new beams used for transmission from the second communication device201a. This is shown as “spatially QCL'ed with indicated beam resources” inFIGS.4,5and6below.

FIG.4shows a schematic diagram summarizing a signaling procedure400according to an embodiment, wherein the third communication device201backnowledges that it can forward the BFRQ request from the first communication device201cto the second communication device201a. The procedure400shown inFIG.4comprises the following steps:

Step401: if the second communication device201ais a serving gNB, the second communication device201asends a beam recovery configuration message to the first communication device201c. This message may contain the candidate beam-RS-List.

Step403: the third communication device201bsends a neighbour connectivity information to the first communication device201c.

Step405: the second communication device201asends a neighbour connectivity information to the first communication device201c.

Step407: the first communication device201cdetermines downlink (DL), uplink (UL) or sidelink (SL) beam failures with the second communication device201a.

Step409: the first communication device201cdetermines newbeams from the second communication device201a.

Step411: the first communication device201cdetermines that the third communication device201bcould assist for the beam recovery on the basis of some information (i.e. neighbour connectivity information).

Step413: the first communication device201csends a beam failure recovery request (BFRQ) message to the third communication device201bvia a control channel (i.e. PUCCH) or a data (i.e. PUSCH) channel.

Step415: the third communication device201btransmits a BFRQ acknowledgement message to the first communication device201c.

Step417: the third communication device201bforwards a BFRQ message to the second communication device201a.

Step419: the second communication device201atransmits a BFRQ response message to the first communication device201c.

FIG.5shows a schematic diagram summarizing a further signaling procedure500according to an embodiment, wherein the further signaling procedure is similar to that shown inFIG.4, but for the case that the third communication device201bconfirms via a negative acknowledgement (NACK) message that it cannot forward the BFRQ request to the second communication device201a. This may happen due to a variety of reasons, including lack of available resources, or the fact that the third communication device201bis not presently connected to the second communication device201a. The procedure500shown inFIG.5comprises the following steps:

Step501: if the second communication device201ais a serving gNB, the second communication device201asends a beam recovery configuration message to the first communication device201c. This message may contain the candidate beam-RS-List.

Step503: the third communication device201bsends a neighbour connectivity information to the first communication device201c.

Step505: the second communication device201asends a neighbour connectivity information to the first communication device201c.

Step507: the first communication device201cdetermines downlink (DL), uplink (UL) or sidelink (SL) beam failures with the second communication device201a.

Step509: the first communication device201cdetermines new beams from the second communication device201a.

Step511: the first communication device201cdetermines that the third communication device201bcould assist for the beam recovery.

Step513: the first communication device201csends a beam failure recovery request (BFRQ) message to the third communication device201bvia a control channel (i.e. PUCCH) or a data channel (i.e. PUSCH).

Step515: the third communication device201btransmits a negative acknowledgement (NACK) message to the first communication device201cinforming that it cannot forward the BFRQ request to the second communication device201a.

Step517: the first communication device201cselects another communication device or entity to assist it beam recovery or selects another method, e.g. using a non-contention RACH scheme.

As shown inFIG.5, if the third communication device201bdoes not respond at all to the second communication device201ain a specified period of time (Time A), the first communication device201cmay interrupt this in the same way as receiving a negative acknowledgement (NACK) message. In this example, once the first communication device201cknows that the third communication device201bcannot forward the BFRQ request, it may choose to select another communication device or entity to assist its beam recovery or may (if it is configured to do so) select another method, e.g. using a non-contention RACH scheme.

FIG.6shows a schematic diagram summarizing a further signaling procedure600according to an embodiment, wherein the first communication device201cmay successively request further connected communication devices or entities, such as the further communication device201dillustrated inFIG.6, to assist in relaying its beam recovery request (BFRQ) to the second communication device201a, in a beam sweeping multicast manner. In the embodiment shown inFIG.6, the communication device201d, which has been requested, confirms via a NACK message that it is not possible to forward the BFRQ request to the second communication device201a. Subsequently, the first communication device201cthen requests another entity, namely the third communication device201b, for relay assistance and the third communication device201bconfirms it can relay the request to the second communication device201a. The procedure600shown inFIG.6comprises the following steps:

Step601: if the second communication device201ais a serving gNB, the second communication device20asends a beam recovery configuration message to the first communication device201c. This message may contain the candidate beam-RS-List.

Step603: the first communication device201cdetermines downlink (DL), uplink (UL) or sidelink (SL) beam failures with the second communication device201a.

Step605: the first communication device201cdetermines new beams from the second communication device201a.

Step607: the first communication device201cdetermines that the third communication device201bor the further communication device201dcould assist for the beam recovery.

Step609: the first communication device201csends a beam failure recovery request (BFRQ) message to the further communication device201dvia a control channel (i.e. PUCCH) or a data (PUSCH) channel.

Step611: the further communication device201dtransmits a negative acknowledgement (NACK) message to the first communication device201cinforming that it cannot forward the BFRQ request to the second communication device201a.

Step613: the first communication device201csends a beam failure recovery request (BFRQ) message to the third communication device201bvia a control channel (i.e. PUCCH) or a data (i.e. PUSCH) channel.

Step615: the third communication device201btransmits a BFRQ acknowledgement message to the first communication device201c.

Step617: the third communication device201bforwards a BFRQ message to the second communication device201a.

Step619: the second communication device201atransmits a BFRQ response message to the first communication device201c.

While a particular feature or aspect of the disclosure may have been disclosed with respect to only one of several implementations or embodiments, such feature or aspect may be combined with one or more other features or aspects of the other implementations or embodiments as may be desired and advantageous for any given or particular application. Furthermore, to the extent that the terms “include”, “have”, “with”, or other variants thereof are used in either the detailed description or the claims, such terms are intended to be inclusive in a manner similar to the term “comprise”. Also, the terms “exemplary”, “for example” and “e.g.” are merely meant as an example, rather than the best or optimal. The terms “coupled” and “connected”, along with derivatives may have been used. It should be understood that these terms may have been used to indicate that two elements cooperate or interact with each other regardless whether they are in direct physical or electrical contact, or they are not in direct contact with each other.

Although specific aspects have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate or equivalent implementations may be substituted for the specific aspects shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations or variations of the specific aspects discussed herein.

Although the elements in the following claims are recited in a particular sequence with corresponding labeling, unless the claim recitations otherwise imply a particular sequence for implementing some or all of those elements, those elements are not necessarily intended to be limited to being implemented in that particular sequence.

Many alternatives, modifications, and variations will be apparent to those skilled in the art in light of the above teachings. Of course, those skilled in the art readily recognize that there are numerous applications of the invention beyond those described herein. While the present invention has been described with reference to one or more particular embodiments, those skilled in the art recognize that many changes may be made thereto without departing from the scope of the present invention. It is therefore to be understood that within the scope of the appended claims and their equivalents, the invention may be practiced otherwise than as specifically described herein.