Method and apparatus for beam management

Abstract

In particular, the present disclosure relates to a first apparatus comprising a processor and a transceiver configured to receive configuration information from a second apparatus, the configuration information indicating a first random access channel (RACH) time set (ROG) of a first set of synchronization signal block (SSB) beams and a second ROG of a second set of SSB beams; receiving a first SSB beam of the first ROG and / or a second SSB beam of the second ROG from the second device; and sending a random access request to the second device at the RACH occasion of the first SSB beam of the first ROG and / or at the RACH occasion of the second SSB beam of the second ROG.

Description

Technical Field

[0001] The present disclosure relates to, but is not limited to, communication networks. The present disclosure particularly relates to beam management (particularly intra-cell beam management), such as by means of a synchronization signal block (SSB) beam, for example when performing random access between a first device and a second device. Background Art

[0002] The conventional beam management process between a base station (such as a gNB) and a terminal device (such as a user equipment UE) is described in the 3rd Generation Partnership Project (3GPP) specifications. Here, UE beam management is defined in Phase #1, Phase #2, and Phase #3 as described in 3GPP. These phases are described in Figure 1 The signaling diagram 100 is shown and can be described as follows: Phase #1 (P1): When the gNB is performing SS bursting, the UE uses a wide Rx beam where the SSB is scanned and transmitted in different angular directions covering the cell. The UE measures all Reference Signal Received Power (RSRP) of all SSB beams on the UE panel and over the physical random access channel (RACH) at the random access channel (RACH) opportunity of the best SSB beam (PRACH) sends a random access preamble to connect to the network using the reciprocal transmit (Tx) beam of the best SSB beam. Phase #2 (P2): UE uses wide Rx beam to receive gNB in ​​connected SSB beam Fine downlink channel state information reference signal (DL CSI-RS) beam scanning. UE The RSRP of all CSI-RS beams is measured and the best beam ID is reported back to the gNB still using reciprocal wide Tx beams. Phase #3 (P3): The gNB sends repeated CSI-reference signals with the selected beam based on the UE report in Phase #2, and the UE scans the fine Rx beam settings to identify its best narrow Rx beam. At the end of Phase #3, the alignment between the gNB Tx beam and the UE Rx beam is obtained for maximized directional gain.

[0003] New radio Release 18 covering enhancements for PRACH such as the four-step RACH procedure is under consideration. Summary of the invention

[0004] However, there is a problem that the conventional beam management process between the gNB and the UE as described in 3GPP Technical Report 38.802 and Technical Specification 38.214 relies on SSB beams at Phase #1 and CSI-RS at Phase #2 and Phase #3. Phase #1, Phase #2 and Phase #3 are used for initial access (IA), but are also used for example for beam / link failure recovery, handover (HO), NR cell addition and general beam management (BM).

[0005] One of the significant differences between SSB and CSI-RS is that SSB is a common periodically transmitted reference signal (RS) known to the UE, whereas CSI-RS can be a UE-specific periodic or aperiodic RS assigned by the gNB whenever it is needed and is also used for other procedures besides BM. Therefore, it would be beneficial if the number of CSI-RS used in the BM procedure could be reduced as it would also reduce overhead, improve DL scheduling opportunities and ultimately enhance DL throughput. One way to achieve this is to assign the same CSI-RS to multiple UEs.

[0006] Another disadvantage of using the conventional beam alignment procedure described above is that throughout the RACH procedure (i.e., Msg1 to Msg4), both the gNB and the UE are using a wider beam (a beam with less gain than the supported antenna array), which may lead to failures due to low link budget. If the link budget between the gNB and the UE is insufficient, Msg3 (including the UE payload) will usually be the message that is lost.

[0007] In other words, the above method has the following disadvantages: The inherent minimum antenna gain configuration at both the gNB and UE side during the RACH procedure potentially leads to failures in high path loss environments. A higher number of required reference signals (resources) for beam alignment is needed, especially for busy / loaded networks, since CSI-RS is used for both Phase #2 and Phase #3 and is configured for each UE.

[0008] In view of the above, certain embodiments of the present disclosure may therefore have the effect of enabling the gNB to enhance the traditional 3GPP beam management process. Certain embodiments may have the effect of possibly requiring a smaller number of transmitted reference signals. Certain embodiments may have the effect of increased antenna gain, for example, to ensure successful transmission of critical Msg #3, and Thereby increasing coverage.

[0009] According to a first exemplary aspect, a first device is disclosed. The first device may include a processor and a transceiver, the transceiver being configured to: receive configuration information from a second device, the configuration information indicating a first random access channel (RACH) opportunity group (ROG) of a first set of synchronization signal block (SSB) beams and a second ROG of a second set of SSB beams. The first device may also be configured to receive a first SSB beam of the first ROG and / or a second SSB beam of the second ROG from the second device. The first device may also be configured to send a random access request to the second device on a RACH opportunity of a first SSB beam of the first ROG and / or on a RACH opportunity of a second SSB beam of the second ROG.

[0010] According to a second exemplary aspect, a second device is disclosed. The second device may include a processor and a transceiver, the transceiver being configured to: send configuration information to a first device, the configuration information indicating a first random access channel (RACH) opportunity group (ROG) of a first set of synchronization signal block (SSB) beams and a second ROG of a second set of SSB beams. The second device may also be configured to send a first set of SSB beams of the first ROG and a second set of SSB beams of the second ROG. The second device may also be configured to receive a random access request from the first device on a RACH opportunity of the SSB beam of the first ROG and / or on a RACH opportunity of the SSB beam of the second ROG.

[0011] According to each exemplary aspect, a corresponding method is also disclosed.

[0012] Therefore, according to a first exemplary aspect, a method performed by at least a first device is disclosed. The method may include receiving configuration information from a second device, the configuration information indicating a first random access channel RACH opportunity group ROG of a first set of synchronization signal block beams SSB and a second ROG of a second set of SSB beams. The method may also include receiving a first SSB beam of the first ROG and / or a second SSB beam of the second ROG from the second device. The method may further include transmitting a random access request to the second device on a RACH opportunity of a first SSB beam of the first ROG and / or a RACH opportunity of a second SSB beam of the second ROG.

[0013] According to a second exemplary aspect, a method performed by at least a second device is disclosed. The method may include: sending configuration information to the first device, the configuration information indicating a first random access channel RACH opportunity group ROG of a first set of synchronization signal block SSB beams and a second ROG of a second set of SSB beams; the method may also include: sending a first set of SSB beams of the first ROG and a second set of SSB beams of the second ROG. The method may further include receiving a random access request from the first device on a RACH opportunity of the SSB beam of the first ROG and / or a RACH opportunity of the SSB beam of the second ROG.

[0014] Any of the disclosed devices (first device, second device) may be a fixed device or a mobile device. The first device may in particular be a user equipment (UE), for example a mobile device such as a smart phone, a tablet, a wearable device, a smart watch, a low-power device, an IoT device, an IIoT device, a vehicle, a truck, a drone, an airplane, etc. The first device may in particular be capable of communicating with a second device (such as a second device of a communication network) (sending signals and / or data to the second device and / or receiving data and / or data from the second device). In general, the first device may also be any device capable of communicating with a communication network and / or another first device.

[0015] The second device may be understood as a wireless communication station installed at a fixed or mobile location, and may be in particular or include an entity of a radio access network of a communication system. For example, the second device may be, include or may be part of a second device (e.g., gNB, eNodeB, NodeB, BTS, etc.) of a communication network of any generation of the 3GPP standard. Typically, the second device may be or include a hardware or software component that implements a specific function. In the example, the second device may be an entity defined by a 3GPP 5G or NR standard (also referred to as a gNB). Therefore, although the second device may be understood as being implemented in a single device or module or being a single device or module, the second device may also be implemented across multiple devices or modules or include multiple devices or modules. In this way, the second device may be implemented in a fixed device or may be a fixed device. Multiple second devices of the exemplary aspect may in particular establish a communication system or network, which may in particular be a new radio (NR) or a 5G system (5GS) or any other mobile communication system defined by a past or future standard (in particular, a subsequent standard of this 3GPP standard). The second device of the exemplary aspect may be able to communicate directly and / or indirectly with the exemplary first device.

[0016] Any disclosed device or second device component or function can be implemented in hardware and / or software. They may include one or more modules or units that provide the corresponding functions. For example, they may include at least one processor of a computer program code for performing the desired function, at least one memory for storing the program code, or both. Alternatively, they may include, for example, a circuit designed to implement the desired function, such as a function implemented in a chipset or chip (such as an integrated circuit). In general, the component may include, for example, one or more processing components or processors.

[0017] Therefore, according to the corresponding exemplary aspects of the present disclosure, in each case, a corresponding device (i.e., a first device and a second device) is also disclosed, which device includes at least one processor and at least one memory including computer program code, and the at least one memory and the computer program code are configured to, together with the at least one processor, enable the device to at least perform the method according to the corresponding aspect of the present disclosure.

[0018] However, any of the exemplary aspects disclosed above may generally be performed by an apparatus, which may be a module or component for a device (e.g., a chip). The disclosed apparatus may include the disclosed components, such as a part, a processor, a memory, or may further include one or more additional components.

[0019] According to exemplary aspects of the present disclosure, there is also disclosed in each case a computer program which, when executed by a processor of an apparatus, causes the apparatus to perform a method according to the respective aspect.

[0020] In various cases, the computer program may be stored on a computer-readable storage medium, in particular a tangible and / or non-transitory medium. The computer-readable storage medium may be, for example, a disk or a memory or the like. The computer program may be stored in a computer-readable storage medium in the form of instructions encoding the computer-readable storage medium. The computer-readable storage medium may be intended to participate in the operation of a device, such as an internal or external memory, such as a read-only memory (ROM) or a hard disk of a computer, or intended for distribution of the program, such as an optical disk.

[0021] The beams may be generated by the first device or the second device with the aid of multiple antennas, multiple antenna ports and / or multiple panels. The beams may be generated with the aid of analog, hybrid and / or digital beam scanning architectures.

[0022] The SSB may span multiple subcarriers and multiple OFDM symbols. The SSB may carry the primary synchronization signal (PSS), the secondary synchronization signal (SSS), and the physical broadcast channel (PBCH).

[0023] An SSB beam can generally be understood as a beam that includes or transmits a certain SSB signal in a specific spatial or angular direction, and is therefore identified or associated with an SSB. However, as will be explained in more detail below, in some cases, different SSB beams can also be associated with or include the same SSB.

[0024] The SSB of a certain SSB beam may be associated with or indicate a certain RACH opportunity of the first device (e.g., a certain frequency and / or time instance, such as certain OFDM symbols in a certain time slot). In the case where the first device uses the corresponding RACH opportunity to communicate with the second device, the second device will know which SSB beam the first device receives. In the present disclosure, it is now proposed to group the RACH opportunities for the first set of SSB beams into a first ROG and to group the RACH opportunities for the second set of SSB beams into a second ROI, and the following disclosure may assume that there are two ROGs with two SSB beam sets, and the present disclosure is also applicable to embodiments with more than two SSB beam sets and more than two ROGs may be defined.

[0025] Although the described exemplary aspects assume the use of SSB beams, the exemplary embodiments described herein may also be implemented with reference signals other than SSB beams.

[0026] The first device may now receive configuration information sent by the second device. The configuration information may indicate a first ROG for a first set of SSB beams and a second ROG for a second set of SSB beams in different ways. For example, the configuration information may indicate the first and second ROGs explicitly or implicitly. In one example, the configuration information may define different RACH opportunities (ROs) and indicate which of the RACH opportunities belong to the first ROG and the second ROG. In one example, the configuration information may indicate which part of the defined set of RACH opportunities belongs to the first ROG and the second ROG. For example, the configuration information may indicate the first ROG and the second ROG by indicating a split or split between an SSB beam of a first set or RACH opportunity belonging to the first ROG and an SSB beam of a second set or RACH opportunity belonging to the second ROG. For example, the configuration information may be an indication that the first n RACH opportunities of a total number of N RACH opportunities belong to the first ROG, and the remaining Nn RACH opportunities belong to the second ROG.

[0027] The second device may then transmit a first set of SSB beams of the first ROG and a second set of SSB beams of the second ROG. Wherein, each SSB beam of the first set of SSB beams of the first ROG may be transmitted by the second device in a different spatial or angular direction. Similarly, each SSB beam of the second set of SSB beams of the second ROG may be transmitted by the second device in a different spatial or angular direction. Thus, the first device will then receive (at least) one of the SSB beams of the first ROG (also referred to as the first SSB beam) and / or (at least) one of the SSB beams of the second ROG (also referred to as the second SSB beam), which are transmitted in the direction of the first device. The other SSB beams of the set of SSB beams of the corresponding ROG may not be received or may be received at the first device with lower quality or power.

[0028] Depending on whether the first device is familiar with the approach described herein, the first device may react differently to the received SSB beam. According to the present disclosure, it is expected that the first device sends a random access request (RAR) for each ROG to the second device, i.e., a (first) random access request on a RACH opportunity indicated by or associated with a first SSB beam received in a first set of SSB beams of the first ROG and a (second) random access request on a RACH opportunity indicated by or associated with a second SSB beam received in a second set of SSB beams of the second ROG.

[0029] However, as will be explained in more detail below, a conventional first device will only send a single random access request for the RACH opportunity indicated by or associated with the strongest received SSB beam.

[0030] Therefore, depending on the behavior of the first device, the second device will then receive one or two random access requests from the first device, namely a random access request on the RACH opportunity of the SSB beam of the first ROG and / or a random access request on the RACH opportunity of the SSB beam of the second ROG.

[0031] Since the method described herein relies only on SSB beams (and does not require, for example, CSI-RS), overhead is reduced. In addition, since the second device can obtain a random access request in response to two different SSB beams received by the first device, the second device is able to derive beam information from the received random access request, which can allow fine beams to be used for further steps of the RACH process. In other words, the SSB beams, in particular the spatial coverage or angular direction of their two ROGs, can be selected so that the second device will be able to select a precise beam for communicating with the first device. Specifically, the management of SSB beams in different ROGs and their signaling by the second device to the first device will allow a beam management process with a smaller number of transmitted reference signals and increased antenna gain and therefore increased coverage. These and further advantages will become apparent and will be explained in more detail below.

[0032] In the case where the first device receives multiple SSB beams of the same ROG, the first device may send a random access request on the corresponding RACH opportunity of the SSB beam received, for example, with the highest received power (such as the highest reference signal received power (RSRP), the highest signal-to-noise ratio (SNR), the highest signal to interference plus noise ratio (SINR), and / or the highest estimated channel quality). Alternatively, the random access request may be sent on the RACH opportunity of the SSB beam that is above the corresponding configuration (e.g., power, RSRP, SNR, SINR, or estimated channel quality) threshold. From the perspective of the first device, the corresponding beam may be considered to be the best or optimal beam. Therefore, the first device will respond to the second device on those RACH opportunities that, for each ROG, are associated with the SSB beam received with the highest corresponding rating. Therefore, by receiving the corresponding random access request, the second device will know which beam of the respective ROG is best directed to the first device.

[0033] Depending on the RACH procedure, the random access request may include different information. For example, the first random access request and the second random access request may each include a random access preamble. For example, the first random access request and the second random access request may include the same random access preamble. For example, the first and second random access requests may each be Msg1 of a four-step or two-step RACH procedure.

[0034] For example, the coverage or width of beams in different beam sets may be different. For example, the beams in the first set of beams may have a first width, and the beams in the second set of beams may have a second (different) width. In the example, the SSB beams in the first set are beams that are wider than those in the second set, and the SSB beams in the second set are beams that are narrower than those in the first set. Therefore, the SSB beams of the first set may be referred to as wide beams or wider beams. The SSB beams of the second group may be referred to as narrow beams, narrower beams, or fine beams. The narrow beams of the second set may be used to refine the SSB beams of the first set. However, the configuration described may also be other ways (i.e., the SSB beams in the first set may also be narrower beams, and the SSB beams in the second set may also be wider beams). For example, the term wider may be understood to mean that the half-power beamwidth of the antenna radiation pattern shows a wider angle. For example, this can be achieved by activating fewer elements of the antenna array. All beams within a set of SSB beams may have the same or substantially the same width or coverage. However, each beam in the set of beams may be oriented in a different spatial or angular direction.Essentially, the second set of SSB beams may be considered as replacing the CSI-RS beams of the conventional beam refinement process of stage #2 as described above.

[0035] However, in general, other beam configurations may be used and it is conceivable to, for example, provide a ROG associated with an SSB beam set comprising beams with different widths or spatial coverage, i.e. a mix of wider and narrower SSB beams with one beam set.

[0036] For example, the configuration information may be received in an RRC configuration or other higher layer signaling. For example, the configuration information may be received in a broadcast message. All first devices in a cell or sector or generally served by a second device may receive configuration information about a specified ROG in this manner without any terminal-specific signaling. Therefore, the configuration information may be received by the first device as a common configuration or information. In one example, the configuration information may be received in a system information block (SIB) message, such as a system information block type 2 (SIB2) message. As an example, an information element (IE) field carrying the configuration information may be present in a SIB2 message. For example, specifically, in the case where the configuration information only indicates a split or partition between a RACH opportunity belonging to a first ROG and a RACH opportunity belonging to a second ROG, the configuration information may only need to be a bit string of x bits, for example, x is between 1 and 6 bits, so as to indicate the number of RACH opportunities belonging to the corresponding ROG.

[0037] The first set of SSB beams may be sequentially transmitted by the second device in different angular directions. Each SSB beam in the first set may have a different SSB or be associated with a different SSB. Thus, each SSB beam in the first set may be associated with a different RACH opportunity of the first ROG. Thus, when the first device transmits a random access request on a RACH opportunity of the first ROG, the second device may unambiguously identify the corresponding SSB beam of the first ROG received by the first device and used for the random access request.

[0038] In an example, certain SSB beams in the first and / or second sets of SSB beams (i.e., SSB beams of the first and / or second ROGs) may be transmitted simultaneously in a group manner. In other words, the first set and / or the second set of SSB beams may be transmitted in a corresponding multiple common SSB beam configuration. For example, the second set of SSB beams may be transmitted simultaneously in a corresponding SSB group (or a corresponding simultaneous common SSB beam configuration), wherein each SSB beam of the simultaneously transmitted SSB group may have the same SSB identifier. In one interpretation, such an SSB group of simultaneously transmitted SSB beams may also be considered as a single SSB beam having multiple lobes radiating in different directions.

[0039] In an example, each SSB group of simultaneously transmitted SSB beams in the second set includes (or consists of) a beam for each beam in the first set of SSB beams. More specifically, in an example, each SSB group of simultaneously transmitted SSB beams in the second set includes (or consists of) a beam for each beam in the first set of SSB beams and having an angular direction within the angular range of the corresponding beam of the first set of SSB beams. Even if multiple SSB beams in the second set are transmitted with the same SSB identifier (as described above), additional information from a random access request via a RACH opportunity based on a received SSB beam in the first set of the first ROG can also clearly identify the SSB beam of the second set (and its angle or spatial direction) that has been received by the first device (e.g., with the highest RSRP), even if multiple SSB beams can be transmitted in the second set in an SSB group with the same SSB identifier or in a simultaneous common SSB beam configuration.

[0040] In an example, each SSB group of simultaneously transmitted SSB beams in the second set includes (or is composed of) multiple beams in different angular directions. In other words, each simultaneously transmitted SSB beam of the SSB group has a different angular direction. For example, each SSB beam in the second set of the second ROG may generally have a different angular direction.

[0041] In an example, each SSB group of simultaneously transmitted SSB beams in the second set includes (or consists of) beams that are shifted (e.g., with respect to an angular direction) compared to beams of corresponding other SSB groups. For example, each beam is shifted from one SSB group to another SSB group by a certain degree (e.g., 5°). Typically, the shift should be such that all SSB beams of the second group together cover substantially the same angular range as the SSB beams of the first group of SSB beams. For example, the sum of all narrow beam half-power beamwidths can be equal to the corresponding wide beamwidth. For example, the corresponding half-power beamwidth (HPBW) can be determined based on a 2D cut of a 3D beam radiation pattern. For example, this cut can be aligned with the orientation of the antenna (e.g., a horizontal or vertical plane).

[0042] In one example, each SSB group of simultaneously transmitted SSB beams in the second set includes (or consists of) beams transmitted using the same physical resource block (PRB), but it should be noted that, in general, even if the beams can be transmitted simultaneously on the same PRB with different spatial filters, they can still indicate different resources (e.g., PRBs) reserved for the first device to send subsequent messages (such as Msg3).

[0043] In an example, each SSB group of simultaneously transmitted SSB beams in the second set includes (or consists of) beams associated with the same RACH opportunity. Since the beams of the SSB group can be transmitted with the same SSB, these SSBs will be associated with the same RACH opportunity accordingly.

[0044] To provide a non-limiting example, a first set of SSB beams may include four (or any other number) wide SSB beams, each having a different SSB (e.g., SSB #1, SSB #2, SSB #3, SSB #4, etc.) and therefore having the same number of RACH opportunities in the first ROG (e.g., one for each SSB). In the second set of SSB beams, there may now be four (or any other number depending on the desired beam refinement) SSB groups. Each SSB group (or concurrent common SSB beam configuration) has four SSB beams (e.g., one SSB beam for each SSB beam of the first set) that have the same SSB (and therefore are associated with the same RACH opportunities). That is, in this example, the first SSB group has four narrow SSB beams sent simultaneously with SSB#5 in different angular directions; the second SSB group has four narrow SSB beams sent simultaneously with SSB#6 in different angular directions; the third SSB group has four narrow SSB beams sent simultaneously with SSB#7 in different angular directions; the fourth SSB group has four narrow SSB beams sent simultaneously with SSB#8 in different angular directions, and so on.

[0045] The SSB beams in the second set of SSB beams may cover substantially the same angular range as the SSB beams in the first set of SSB beams. For example, the SSB beams of the second set may be considered as refinements of the SSB beams of the first set. However, since multiple beams of the second set of the second ROG may have the same SSB identity, as described above, the number of required reference signals (SSBs) may be kept low.

[0046] More specifically, the number of SSBs used for the first set and the second set may be particularly independent of the number of connected first devices. Since multiple SSB beams from the second set may be transmitted simultaneously in different directions with the same SSB identification, the number of used SSBs does not increase with the number of SSB beams in the SSB group of simultaneously transmitted SSB beams. Furthermore, since the second set of (fine) SSB beams may cover essentially the same angular range as the (wider) SSB beam of the first set, the number of (fine) SSB beams also does not increase with the number of connected devices from different directions (i.e., different SSB beams from the first set).

[0047] In an example, the number of SSBs for the first ROG may be 4, 8, 16, or 32. Likewise, the number of SSBs for the second ROG may be 4, 8, 16, or 32. For example, the total number of SSBs for the first and second ROGs may be 8 (e.g., in the case of 4 SSBs for the first ROG and 4 SSBs for the second ROG), 12 (e.g., in the case of 8 SSBs for the first ROG and 4 SSBs for the second ROG), 20 (e.g., in the case of 16 SSBs for the first ROG and 4 SSBs for the second ROG), or 36 (e.g., in the case of 32 SSBs for the first ROG and 4 SSBs for the second ROG).

[0048] Now consider the case where the second device receives a random access request on the RACH opportunity of the SSB beam of the first ROG and receives a random access request on the RACH opportunity of the SSB beam of the second ROG, the second device can determine the aligned second device Tx and / or Rx beam for the first device based on the received random access request. The (first) received random access request sent by the first device based on the first received (e.g., wide) SSB beam of the first ROG can be compared with the Msg1 sent in stage #1 of the above-mentioned conventional beam management process. The (second) received random access request sent by the first device based on the second received (e.g., narrow) SSB beam of the second ROG can be compared with the CSI-RS refinement of stage #2 of the above-mentioned conventional beam management process. The combination of the two random access requests (and therefore the knowledge at the second device about the two SSB beams (one SSB beam for each ROG) received and used on the terminal side) can allow the second device to unambiguously identify the (narrower) beam in the second set of SSB beams for the first device, even if multiple SSB beams have the same SSB identifier in the second set. Therefore, the method according to the present disclosure allows refinement with fewer reference signals based only on SSB beams with two random access requests.

[0049] In addition, since the beam refinement or alignment on the second device side may have been implemented after the random access request (Msg1), the second device can use the aligned second device Tx beam to send Msg2 of the four-step RACH process to the first device. In addition, this can also allow the second device to receive Msg3 of the four-step RACH process from the first device using the aligned second device Rx beam. In addition, this can further allow the second device to use the aligned second device Tx beam to send Msg4 of the four-step RACH process to the first device.

[0050] Now consider the case where the second device receives a random access request on a RACH opportunity of only the (e.g., narrower) SSB beam of the second ROG (e.g., because the first device is a legacy device and only sends a single random access request, not a random access request for each ROG), the second device may send a random access response on each SSB beam of the second ROG that has the same SSB as the SSB beam on which the RACH opportunity on which the random access request was received. These random access responses may be sent sequentially. Since multiple SSB beams in the second set of the second ROG may have the same SSB identifier, the second device may not be able to clearly identify which specific SSB beams (and their angular directions) transmitted simultaneously in the SSB group are actually received by the first device and considered to be optimal (e.g., with the highest power, SNR, SINR, quality, etc.). This problem can be solved by the second device by sending multiple random access responses on related ambiguous SSB beams. The random access response can enable the second device to determine which random access response (and which SSB beam) is received and considered to be optimal by the first device based on a subsequent message (e.g., Msg3) of the first device. This may be achieved by allocating different resources for subsequent messages from the first device in each random access response.

[0051] In one example, each random access response allocates a different bandwidth part BWP for the corresponding Msg3. However, each random access response may still allocate the same time instance (eg, frame, time slot or symbol) for the corresponding Msg3.

[0052] Since the Msg3 received at the second device allows the determination of the SSB considered optimal by the first device, the second device can determine the aligned second device Tx and / or Rx beam for the first device based on the received random access request and the received Msg3.

[0053] Note, however, that even if the aligned second device beam is identified only after Msg3 is received, the random access response (e.g., Msg2) may still have been transmitted by the second device on multiple narrow beams, such that in this case, the random access response (e.g., Msg2) can be transmitted by the second device with increased antenna gain compared to stage #2 of conventional beam management.

[0054] In addition, similar to the above situation, the second device may receive a random access request on a RACH opportunity for the (e.g., wider) SSB beam of only the first ROG (e.g., because the first device is a legacy device and only sends a single random access request, rather than a random access request for each ROG). In this case, the second device does not have or cannot derive any information about the optimal narrow SSB beam for the second set or ROG, but only knows the wide SSB beam of the first set or ROG and the associated RACH opportunities used by the first device. This situation is similar to the situation after a random access response (Msg2) has been received in stage #2 of the conventional beam management process described at the beginning. Therefore, in this case, the second device may decide to switch to the conventional beam management process, continue and complete stage #1 using the (wide) SSB beam, and then continue beam refinement in stage #2 via the CSI-RS beam.

[0055] It should be understood that the embodiments disclosed herein are presented by way of example only and not limitation.

[0056] In this article, the disclosure of a method step should also be regarded as the disclosure of a component for performing the corresponding method step. Similarly, the disclosure of a component for performing a method step should also be regarded as the disclosure of the method step itself.

[0057] Other features of the present disclosure will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It should be understood, however, that the drawings are designed for illustrative purposes only and not as a definition of the limits of the present disclosure, for which reference should be made to the appended claims. It should also be understood that the drawings are not drawn to scale and that they are intended only to conceptually illustrate the structures and procedures described herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 A signaling diagram showing three stages (stage #1, stage #2, stage #3) of conventional beam alignment for intra-cell beam management using SSB beam and CSI-RS beam;

[0059] Figure 2a shows an exemplary illustration of a wide SSB beam that may be used for a first set of SSB beams for a first ROG;

[0060] Figure 2b-2d An exemplary diagram showing a narrow CSI-RS beam used in stage #2 of conventional beam alignment for comparison;

[0061] Figure 2e-2h An exemplary illustration of different narrow SSB beams in a second set of SSB beams of a second ROG transmitting simultaneously in a group having the same SSB identifier is shown;

[0062] Figure 3 An exemplary signaling diagram illustrating an exemplary embodiment of a beam management process between a base station and a terminal device according to the present disclosure;

[0063] Figure 4 An exemplary random access configuration illustrating the concept of ROG is shown;

[0064] Figure 5a , Figure 5b shows an exemplary signaling diagram between a base station and a conventional terminal device prior to an exemplary embodiment of a beam management process according to the present disclosure;

[0065] Figure 6 An exemplary relationship between Msg2 and Msg3 of the signaling diagram of FIG5 is shown in more detail;

[0066] Figure 7 A schematic diagram illustrating an example radio environment in which example embodiments of the present disclosure may be performed;

[0067] Figure 8 A schematic diagram illustrating a block diagram of an exemplary embodiment of an apparatus according to the present disclosure is shown;

[0068] Fig. 9 A block diagram illustrating an exemplary embodiment of a base station; and

[0069] Fig.10 A schematic diagram illustrating an example of a tangible and non-transitory computer-readable storage medium is shown. DETAILED DESCRIPTION

[0070] The following description is intended to deepen the understanding of the present disclosure and should be understood as supplementing and reading together with the description of example embodiments of the present disclosure provided in the above Summary of the Disclosure.

[0071] In the following and with reference Figure 7 , describes an example communication system in which the present disclosure may be applied. Although the specific radio system in the following examples may be, for example, a 5G system, these are considered to be non-limiting examples only.

[0072] Figure 7A 5G communication network is shown as an example, which introduces new radio technology and the architecture of different sub-layers of the RAN can be split into two logical entities in a communication network control unit (such as a BS or gNB), which are called distributed units (DU) and central units (CU). For example, a CU is a logical node that controls the operation of one or more DUs on a fronthaul interface (called an F1 interface). A DU is a logical node that includes a subset of gNB functions, depending on the functional split option. The communication network control element can be a network node. gNB will be used interchangeably with network node in this disclosure.

[0073] like Figure 7 As shown, as an example of a first device of an exemplary aspect of the present disclosure, a user equipment (UE) 710 is connected to a network device (e.g., gNB 720) or a cell 1 of a base station (as an example of a second device of the present disclosure) via a communication beam of cell 1. Figure 7 In the example shown, the gNB 730 is provided with a CU 733 and two DUs 731 and 732 connected to the CU 733 via an F1 interface. Figure 7 As shown in the example of , there are multiple additional cells to which UE 710 can connect.

[0074] Naturally, in each cell, multiple UEs can exist and be connected to the corresponding cell. Similar to cell 1, cells 2 and 3 are controlled by gNBs 725 and 726, respectively, and each cell provides multiple beams 1 to 3, which can be used for beam diversity or beam hopping. Figure 7 As shown, each base station or gNB of the cell is connected to the core network, such as 5GC, via a corresponding interface indicated as NG interface. In addition, each gNB in ​​the cell is connected to each other through a specific interface, which is called Xn-C interface. Any of these network entities (such as gNB, gNB-DU, gNB-CU and / or 5GC) can be an example of a base station or a part thereof according to the present disclosure, either individually or together.

[0075] Turning now to FIG. 2, the conventional or conventional beam management process ( Figure 2a-2d ) compared to describing the beam management process according to the present disclosure ( Figure 2a and Figure 2e-2h ). The described example will use four wider beams for a first ROG, where each wider beam of the first ROG is refined by 4 narrower beams of a second ROG. However, the described example is not limited to a particular beam configuration (e.g., number of beams per ROG), but is equally applicable to other beam configurations, and specifically to different numbers of beams. Furthermore, it should be noted that the basic idea can be transferred to other combinations of wider and narrower beams.

[0076] The basic idea of ​​the present disclosure is to enable the gNB to map or associate a synchronization signal block (SSB) beam with two different RACH opportunity groups (ROGs). The beamforming behavior of the SSB beams according to the mapped groups can be described as follows. The SSB beam mapped to or associated with the first ROG is transmitted by the base station sequentially with the wider beam, such as Figure 2a As shown. So far, this is the same as in the conventional process. However, the SSB beams mapped to or associated with the second ROG (ROG#2) will be transmitted in a sequential narrow beam scanning manner with narrower beams (beam refinement), but with one narrower beam transmitted simultaneously for each wider beam used in the first ROG (ROG#1). This behavior is Figure 2e-2h exemplarily shown in FIG. 1 and will be described in more detail below.

[0077] It should be noted that the SSB in the present disclosure may also be another reference signal or a different periodic synchronization signal, such as a channel state information reference signal (CSI-RS).

[0078] To make the UE aware of the different ROGs, the gNB shall first indicate to the UE configuration information indicating a first ROG for a first set of SSB beams and a second ROG for a second set of SSB beams, for example by indicating a split in the SSB and RACH occasion configurations. This allows the gNB to simultaneously send multiple narrow SSB beams to the UE, such as Figure 2e-2h exemplarily shown in each group shown. As will become apparent from the following examples, this will speed up beam alignment and enhance coverage.

[0079] From the perspective of a terminal device, a method is provided, and the method includes: receiving configuration information from a base station, the configuration information indicating a first random access channel RACH of a first group of synchronization signal blocks, a timing group ROG, an SSB of a second group of SSB beams, a beam, and a second ROG; and

[0080] A first set of SSB beams of a first ROG and / or a second set of SSB beams of a second ROG are received from a base station; and a random access request is sent to the base station on a RACH timing of the first set of SSB beams of the first ROG and / or a RACH timing of the second set of SSB beams of the second ROG.

[0081] The SSB beams of the first set may be, for example, wider beams than the SSB beams of the second set, and wherein the SSB beams of the second set are narrower beams than the SSB beams of the first set.

[0082] The SSB beams of the second set may be transmitted simultaneously in an SSB group, and each SSB beam of the simultaneously transmitted SSB group has the same SSB identifier.

[0083] It should be understood that the SSB beams of the first set may be narrower beams than those of the second set, and the SSB beams of the second set may be wider beams than those of the first set.

[0084] Consider first conventional beam management and now refer to Figure 2a and Figure 2b , showing the case where only one UE is connected or connected to the gNB. The conventional or original process would use a total of 8 reference signals (RS) for phase #1 and phase #2, namely 4 SSB beams for phase #1 (each SSB covers 20° in this example) and 4 CSI-RS beams for phase #2 (each CSI-RS beam covers 5° in this example), for Figure 2a However, when the number of connected or connected UEs increases, the number of required RSs will increase significantly.

[0085] For example, if there are connected or connected UEs in the beams identified by SSB#1 and SSB#3, 8 CSI-RS beams are already required for beam refinement of the two UEs, such as Figure 2c As shown in FIG, the conventional CSI-RS refinement for two SSB beams is shown. Figure 2a If there is a UE in the area of ​​each wider SSB beam in the UE, 16 CSI-RS are required, and the total number of reference signals has reached 20 RS, that is, 4 SSBs and 16 CSI-RS, as shown in Figure 2a and Figure 2d As shown, conventional CSI-RS refinement for four SSB beams is shown. This number can theoretically be further increased for more connected / connected UEs if the CSI-RS of UEs in the same SSB beam cannot be shared.

[0086] Turning now to the example of the present disclosure, for which the proposed RACH procedure will always use 8 reference signals for beam alignment in both Phase #1 and Phase #2, regardless of the number of connected / connected UEs.

[0087] First, use Figure 2a A wide panel beam for the first ROG is shown, which matches the conventional SSB scan pattern. Figure 2b-2d CSI-RS, Figure 2e-2h The SSB beam is now used as the second ROG. Figure 2e-2f A second set of SSB beams transmitted simultaneously in four SSB groups is shown (each SSB group includes four SSB beams transmitted simultaneously). That is, Figure 2eA first simultaneous common SSB beam configuration for a second ROG is shown; Figure 2f A second simultaneous common SSB beam configuration for a second ROG is shown; Figure 2g A third simultaneous common SSB beam configuration for a second ROG is shown; and Figure 2h A fourth simultaneous common SSB beam configuration for a second ROG is shown. It can be noted that all SSB beams shown in the common configuration are shifted by 5° from configuration to configuration, ie, SSB group to SSB group in this example.

[0088] To generate the above beams, the gNB can be a multi-panel gNB or a gNB with a hybrid / digital beam scanning architecture.

[0089] Count the reference signals used, in Figure 2a There are four wider SSB beams in Figure 2e to Figure 2h Four simultaneous common SSB beam configurations are shown in FIG. , each of which uses only a single SSB for each set of simultaneously transmitted narrow beams.

[0090] Using the above process, the gNB uses the same physical resource block (PRB) to send multiple SSBs in different angular directions in the second ROG at the same time, so that these SSBs will be allocated the same RACH opportunity (RO). In response, the UE sends the same preamble of the best RO for each allocated ROG. A high-level overview of the beam alignment steps can be summarized as follows: the gNB uses 2 ROGs, and the first ROG (ROG#1) is configured with wide beams (SSB#1-4) and the second ROG (ROG#2) is configured with narrow beams (SSB#5-11).

[0091] The gNB sequentially transmits SSB beams of SSB#1-4 in different angular directions as part of ROG1 ( Figure 2a The gNB then transmits an SSB beam with the same SSB#5 from all panels of a multi-panel gNB simultaneously, or transmits an SSB beam from the same panel of a hybrid / digital gNB in ​​multiple angular directions as part of ROG2 ( Figure 2e ). This is repeated for SSB#6 and SSB#7 with the beam in a shifted angular direction each time until the gNB transmits SSB beams with SSB#8 simultaneously from all panels of a multi-panel gNB, or transmits SSB beams from the same panel of a hybrid / digital gNB in ​​multiple angular directions as part of ROG2 ( Figure 2h ).

[0092] In turn, the UE sends a first random access request or RACH preamble (Msg1) from ROG1 on the best SSB (e.g., associated with the beam with the highest received power). The UE also sends a second random access request or RACH preamble (Msg1) on the SSB from ROG2 (e.g., associated with the beam with the highest received power). To this end, the gNB can derive which narrow beam the UE is detecting and connecting to.

[0093] Note that a legacy UE is expected to send only one preamble for the received SSB, which is considered the best, and will most likely report the SSB sent with a narrow beam (since it will have higher antenna gain and thus potentially higher EIRP), i.e. Figure 2e-2f The gNB will not know the exact angular direction of the UE because the RO is monitored simultaneously with the narrower beam at different angular directions. The process by which the gNB overcomes this problem is described in further detail below.

[0094] As shown in the above process, when the UE sends one preamble for each of the two RACH opportunity groups, the first received preamble will inform the gNB of the best wider beam, and the second preamble will inform the gNB of the best narrower beam. This will enable the gNB to perform narrow beam alignment (corresponding to phase #1 and phase #2), but based on only a few SSB signals.

[0095] The advantage of using SSBs of stage #2 (compared to CSI-RS in the regular beam alignment process) is that they are common to all UEs in the coverage area of ​​that gNB sector, so the gNB uses only eight SSBs regardless of the number of UEs in the coverage area of ​​that sector. In addition, the coverage area of ​​the gNB will also increase because Msg2, Msg3, and Msg4 of the four-step RACH procedure will be received and transmitted by the gNB with higher antenna gain. The gain improvement will depend on how many beams are used to refine the wider traditional SSB beams. For example, a 3dB gain improvement is possible for a refinement of 2 to 4 beams, while a 6dB gain improvement is possible for a refinement of 8 to 16 beams.

[0096] An example of reference signal reduction obtained by the proposed method for refining 4 beams compared to the conventional beam management process is shown in the following Table 1. It is assumed that at least one UE is connected to each SSB via a RACH process (so that each SSB beam needs to be refined). Table 1: Number of RSs required for the conventional BM process compared with the proposed BM process

[0097] For the proposed procedure, a significant reduction in the number of required RSs for beam management is observed (i.e., between a factor of 20 / 8 = 2.5 to 160 / 36 = 4.4 in these examples). The optimal balance or split between the number of wider SSBs in the first ROG and the number on narrower SSBs in the second ROG depends on the total number of required RSs and the hardware capabilities of the gNB.

[0098] For the above process, an additional information element (IE) may be used, which may be referred to as "ROGroup-Split", to inform the UE of the utilization of multiple ROGs. This IE may be broadcasted and implemented, for example, as an optional part of a SIB2 message.

[0099] Now go to Figure 3 , shows a signaling diagram 300 between a gNB and a UE, which is configured to handle the configuration of such signaling regarding ROI-Group-Split.

[0100] Using the first ROG, the gNB sequentially sends x wider SSB beams with different SSBs each time (a total of x SSBs) in different angular directions (each beam is shifted by 20° in this example), which can be considered to correspond to the traditional SSB procedure (action 301).

[0101] Using the second ROG, the gNB sequentially transmits y groups of simultaneously transmitted narrow SSB beams with the same SSB identity, where one narrow SSB beam in each angular direction is covered by a wider SSB beam belonging to the first ROG (y SSBs in total). In this example, the narrow beams are shifted by 5° from SSB group to SSB group. This operation is repeated sequentially for all narrow beams used to refine the wider SSB beam (action 302).

[0102] The gNB then listens to the RACH preamble in the first ROG and will receive the first Msg1 with the preamble and associated with the SSB of the best SSB beam from the UE in the RACH opportunity of the first ROG, action 303. Based on this, the gNB can determine the best wider SSB beam.

[0103] The gNB will also listen to the RACH preamble in the second ROG, where the associated beam is configured in action 302 for each allocated RO, and will receive a second Msg1 with preamble and associated with the SSB of the best SSB beam from the UE in a RACH opportunity of the second ROG, action 304. Based on this, the gNB can determine the best (set of) narrow beams.

[0104] Based on the two received preambles, the gNB can unambiguously identify the best narrow Tx / Rx SSB beam.

[0105] Hence, further messages may be exchanged on the gNB side with the increased antenna gain, i.e. the gNB sends Msg2 with the increased antenna gain (action 305), the gNB receives Msg3 with the increased antenna gain (action 306), and the gNB sends Msg4 with the increased antenna gain (action 307).

[0106] Compared with the conventional beam management process, the proposed method specifically introduces a new IE ("RO-Group-Split"), allowing the gNB to indicate to the UE the SSB / RO spatial filter switching of Tx ROG1 and Tx ROG2, and the switching of RxMsg1 in ROG1 and Rx Msg1 in ROG2, thereby providing two consecutive preambles received by two different spatial filters (gNB beams) for the RACH process.

[0107] The described example thus allows for phase #2 beam alignment using only common SSBs. Since only a few SSBs are used, the overhead can be reduced by a factor between 2.5 and 44. Furthermore, the alignment time to reach the gNB narrow beam is reduced. Furthermore, independent of the number of UEs in the coverage area of ​​the gNB, only a low and fixed number of SSBs is required to perform phase #1 and phase #2. Since Msg2 to Msg4 can be sent and received at the gNB with increased antenna gain, this increases the coverage range of the gNB. As will be explained in more detail below, the proposed method is also backward compatible for legacy UEs.

[0108] As already mentioned above, the UE can be informed of the actual SSB scanning method currently used by the gNB. In the following, an example is described how the signaling can be implemented into a SIB2 message.

[0109] This can be achieved by adding 1 to 6 bits to an optional new field in the SIB2 message, as shown below, where the red bold text highlights how a new field called "RO-Group-Split" can be added to the SIB2 message of 3GPP TS 38.331 V15.10.0 (July 2020). It should be noted that even if only a few bits are reserved in the field, the selective indication is another state because it will indicate the legacy behavior.

[0110] The interpretation of this optional IE field and the associated bits may be as follows: In the absence of the field, the legacy behavior of the gNB is assumed. In the presence of the IE field, the bit value shall represent the number of SSBs in the first RO group (ROG).

[0111] In the following and with reference Figure 4, provides an example of an exemplary random access configuration. In this example, the random access configuration, index=45 (see Table 2 below), is used to further illustrate the division or segmentation of RACH opportunities into ROGs as proposed in the present disclosure. Table 2: Random access configuration for FR2 and unpaired spectrum for assumed PRACH configuration.

[0112] Index = 45 [see Table 6.3.3.2-4; 3GPP 38.211].

[0113] For a subcarrier spacing (SCS) of 120 kHz, the random access configuration (index = 45) is Figure 4 , which indicates that the first 4 RACH opportunities belong to the first ROG, that is, RO-Group-Split=4. The UE will interpret it in the following way: SSB#1 to SSB#4 are part of ROG#1 and the UE shall send one preamble at the RO associated with the SSB (any one of SSB#1 to SSB#4) received at the highest RSRP level (or based on another suitable assessment of beam quality). SSB#5 to SSB#12 are part of ROG#2 and the UE will A preamble is sent at the RO associated with the SSB (any one of SSB#5 to SSB#12) received at the RSRP level (or based on another suitable assessment of beam quality).

[0114] For example, considering the case where the gNB receives the same preamble at RO#2 and RO#8, it will interpret it as narrow beam configuration #4 associated with wide beam configuration #2 (SSB#8 is the fourth beam configuration in ROG#2), and now a narrow beam with increased antenna gain can be configured for the remaining IA messages (Msg#2 to Msg#4).

[0115] Figure 4 The example just shown in uses a wider SSB beam in the first ROG and a narrower SSB beam in the second ROG. However, in general, the gNB may reverse this and use the first ROG for the narrower SSB beams and the second ROG for the wider SSB beams. In this example, the gNB would only need to change the value of the RO group split from 4 to 8. This would be transparent to the UE as it only needs to know the splits the gNB utilizes in different ROGs and not which beam configurations.

[0116] Now go to Figure 5a and Figure 5b, where a signaling diagram 500 is shown for the case when only the gNB is utilizing the proposed signaling (i.e., IE “RO-Group-Split”) but the UE is not configured to use ROG.

[0117] More specifically, a legacy UE will not understand the proposed ROG signaling (i.e., IE “RO-Group-Split”) and will be able to send only a single preamble for the SSB received at the highest RSRP in either the first ROG or the second ROG. If the gNB receives only the preamble for the wider SSB beam in the ROG (i.e., the preamble of the first ROG in the above example), it will revert to Figure 1 However, in the case where the gNB will only receive a single Msg1 on the RO associated with a narrow beam (i.e., the beam of the second ROG in the above example), the gNB will not be able to unambiguously identify the exact angular direction of the beam and the UE, as the RO is provided simultaneously with the narrow beam in multiple angular directions. Therefore, the gNB will initiate a Figure 5a , Figure 5b The process shown is to ensure a successful RACH process for the UE.

[0118] The first part of the signaling corresponds to the Figure 3 The described signaling, ie actions 501 , 502 , 504 , corresponds to actions 301 , 302 , 304 .

[0119] Therefore, in the first ROG, the gNB sends SSB sequentially in different angular directions (which can be considered as a traditional SSB process), action 501.

[0120] In the second ROG, the gNB shall simultaneously transmit one SSB with a narrow beam in each angular direction covered by the wider SSB beam belonging to the first ROG, which is repeated sequentially for all narrow beams used for fine wider SSB beams, action 502.

[0121] However, when the gNB is listening to the preambles in the first ROG to determine the best wider SSB beam, the gNB will not receive any preambles for that ROG because the UE is not configured to interpret the signaled ROG split and therefore does not send preambles for that first ROG, thereby deleting action 503.

[0122] The gNB may monitor the preamble in the second ROG with the associated beam configuration used in action 502 and will receive the corresponding Msg1 based on the RACH opportunity associated with the narrow SSB beam received at the UE, action 504. Thus, the gNB may determine the best narrow beam. Although the gNB may now know the best narrow beam, it may still not know the corresponding best wide SSB beam.

[0123] Therefore, with Figure 3 Compared to the process shown in FIG. 5 , the gNB may change its behavior. The gNB may now sequentially (or alternatively simultaneously) send one Msg2 (action 505 ) where each narrow beam has been identified based on the received Msg1 in action 504 (i.e., the SSB beams of the SB group with the same SSB).

[0124] The corresponding Msg2 message will be configured so that the associated Msg3 message for the Msg2 message will be allocated in the same time instance (e.g., time slot), but with a different bandwidth part (BWP), so that the gNB only needs to configure multiple narrow SSB beams for one reception, regardless of which narrow SSB beam (angular direction) the UE responds to. This concept is in Figure 6 These Msg2 will advantageously still be transmitted with increased antenna gain.

[0125] The UE may receive only the Msg2 transmitted in the direction to the UE (the other Msg2 will not be received or only with lower power or quality), and transmit Msg3 according to the resource allocation in Msg2, action 506. The gNB may then receive Msg3 using the simultaneous multiple narrow beam configuration identified in action 504. The gNB may use the BWP position of the received Msg3 to identify the best narrow beam for the UE.

[0126] The gNB may then send Msg4 with a single narrow beam with increased antenna gain, action 507.

[0127] A legacy UE may transmit its preamble on the RO that corresponds to or is associated with the best received SSB beam, which will depend on the EIRP levels of the SSB beams in different ROGs. In some cases, the EIRP levels of both ROGs may be at the same level even though the narrow SSB beam has a higher antenna gain than the wider SSB beam. This is due to potential hardware limitations at the gNB where the available PA power level must be divided between the simultaneously transmitted narrow SSB beams. Therefore, the gain in antenna gain is reduced with the reduced Tx power level. Other gNB implementations may be able to transmit narrow SSB beams with an increased EIRP equal to the increased antenna gain.

[0128] Compared to conventional beam management and the case where the UE utilizes configuration information about the ROG, in the example just described, the gNB receives a single Msg1 on only one ROG. Therefore, the gNB allocates Msg3 resources at the same time instance but in different BWPs to be able to distinguish different narrow SSB beams. The gNB listens to Msg3 with narrow beams simultaneously on all panels and associates the received Msg3 in a specific BWP with a specific narrow beam.

[0129] Now go to Figure 8 , a block diagram of an exemplary embodiment of a first or second terminal device or UE 800 according to the present disclosure is shown. For example, UE 800 may be a smart phone, a tablet computer, a notebook computer, a smart watch, a smart band, an IoT device, or a vehicle or a part thereof.

[0130] UE 800 includes a processor 801. Processor 801 may represent, for example, a single processor or two or more processors at least partially coupled via a bus. When executed on processor 801, processor 801 may execute program codes stored in program memory 802, for example, causing a mobile device 800 connected to base station 800 to execute program codes of one or more embodiments of the method of the present disclosure or a portion thereof, and dock with main memory 803. Program memory 802 may also include an operating system for processor 801. Some or all of memories 802 and 803 may also be included in processor 801.

[0131] One or both of the main memory and the program memory of the processor (e.g., program memory 802 and main memory 803) may be fixedly connected to the processor (e.g., processor 801) or at least partially removable from the processor, for example in the form of a memory card or a memory stick.

[0132] The program memory (e.g., program memory 802) may be, for example, a non-volatile memory. For example, it may be any of a flash memory (or a portion thereof), a ROM, a PROM, an EPROM, an MRAM or a FeRAM (or a portion thereof), or a hard disk (or a portion thereof), to name a few examples. For example, the program memory may, for example, include a first memory portion that is fixedly mounted and a second memory portion that is removable, for example, in the form of a removable SD memory card.

[0133] The main memory (e.g., main memory 803) can be, for example, a volatile memory. For example, it can be a DRAM memory, to give a non-limiting example. For example, when executing an operating system, an application, a program, etc., it can be used as a working memory of the processor 801.

[0134] The processor 801 may also control a communication interface 804 (e.g., a radio interface) configured to receive and / or send data and / or information. For example, the communication interface 804 may be configured to send and / or receive radio signals from a radio node such as a base station, in particular as described herein. It should be understood that any computer program code-based processing required to receive and / or evaluate radio signals may be stored in the communication interface 804's own memory and executed by the communication interface 804's own processor and / or it may be, for example, stored in the memory 803 and, for example, executed by the processor 801.

[0135] The communication interface 804 may in particular be configured to communicate in accordance with a cellular communication system such as 2G / 3G / 4G / 5G or a future generation cellular communication system.The terminal device 800 may use the radio interface 804 to communicate with a base station.

[0136] For example, the communication interface 804 may include a BLE and / or Bluetooth radio interface, including a BLE transmitter, receiver, or transceiver. For example, the radio interface 804 may additionally or alternatively include a WLAN radio interface, which includes at least a WLAN transmitter, receiver, or transceiver.

[0137] The components 802 to 804 of the terminal device 800 may be connected to the processor 801 , for example, via one or more serial and / or parallel buses.

[0138] It should be understood that the terminal device 800 may include various other components. For example, the terminal device 800 may optionally include a user interface (eg, a touch-sensitive display, a keyboard, a touchpad, a display, etc.).

[0139] Fig. 9 9 is a block diagram of an exemplary embodiment of a network entity, such as a base station or gNB. For example, the network device 900 may be configured to schedule and / or send signals to a UE, as described above.

[0140] The network device 900 includes a processor 901. The processor 901 may represent, for example, a single processor or two or more processors at least partially coupled via a bus. The processor 901 executes program codes stored in a program memory 902 (e.g., program codes that cause the network device 900 to execute alone or together with the terminal device 800 embodiment or part thereof according to the present disclosure), and interfaces with a main memory 903.

[0141] Program memory 902 may also include an operating system for processor 901. Some or all of memories 902 and 903 may also be included in processor 901.

[0142] In addition, the processor 901 controls the communication interface 904, which is configured to communicate according to a cellular communication system such as a 2G / 3G / 4G / 5G cellular communication system. The communication interface 904 of the apparatus 900 can be implemented by, for example, a radio head, and can be provided for communication between a network device and a terminal device.

[0143] The components 902 to 904 of the apparatus 900 may be connected to the processor 901 , for example, via one or more serial and / or parallel buses.

[0144] It should be understood that the apparatus 800, 900 may include various other components.

[0145] Fig.10 is a schematic diagram of an example of a tangible and non-transitory computer-readable storage medium according to the present disclosure, which can be used, for example, to implement Figure 8 Memory 802 or Fig. 9 Memory 902. To this end, Fig.10 Shown is a flash memory 1000 which may be, for example, soldered or bonded to a printed circuit board, a solid-state drive 1001 comprising a plurality of memory chips (e.g., flash memory chips), a magnetic hard disk drive 1002, a secure digital (SD) card 1003, a universal serial bus (USB) memory stick 1004, an optical storage medium 1005 (e.g., a CD-ROM or DVD), and a magnetic storage medium 1006.

[0146] Any connections presented in the described embodiments will be understood in a manner that the components involved are operatively coupled. Therefore, the connection may be direct or indirect with any number or combination of intermediate elements, and there may only be a functional relationship between the components.

[0147] Furthermore, as used herein, the term "circuitry" refers to any of the following: (a) Pure hardware circuit implementation (such as implementation in analog and / or digital circuits only) (b) a combination of circuitry and software (and / or firmware), such as: (i) processor(s) or (ii) a combination of portions of processor(s) / software (including digital signal processor(s), software and memory(s) that work together to enable a device such as a mobile phone to perform various functions), and (c) Circuitry, such as a microprocessor or portion of a microprocessor, that retrieves software or firmware for operation even though the software or firmware is not physically present.

[0148] This definition of circuitry applies to all uses of the term in this document, including in any claims. As another example, as used herein, the term "circuitry" also covers an implementation of merely a processor (or multiple processors) or a segment of a processor and its (or its) accompanying software and / or firmware. The term "circuitry" also covers, for example, a baseband integrated circuit or an applications processor integrated circuit for a mobile phone.

[0149] Any processor mentioned in this document, in particular but not limited to Figure 8 and Fig. 9 The processors 801 and 901 may be any suitable type of processor. Any processor may include, but is not limited to, one or more microprocessors, one or more processors with an accompanying digital signal processor, one or more processors without an accompanying digital signal processor, one or more special-purpose computer chips, one or more field programmable gate arrays (FPGAs), one or more controllers, one or more application-specific integrated circuits (ASICs), or one or more computers. The relevant structure / hardware has been programmed in a manner to perform the described functions.

[0150] In addition, any actions or steps described or illustrated herein may be implemented using executable instructions in a general or special purpose processor and stored on a computer-readable storage medium (e.g., disk, memory, etc.) to be executed by such a processor. References to computer-readable storage media should be understood to encompass special purpose circuits such as FPGAs, ASICs, signal processing devices, and other devices.

[0151] In addition, any actions described or illustrated herein may be implemented using executable instructions in a general or special purpose processor and stored on a computer-readable storage medium (e.g., disk, memory, etc.) to be executed by such a processor. References to computer-readable storage media should be understood to encompass special purpose circuits such as FPGAs, ASICs, signal processing devices, and other devices.

[0152] The phrase "A, or B or C or a combination thereof" or "at least one of A, B and C" may be understood as being non-exhaustive and including at least the following: (i) A or (ii) B or (iii) C, or (iv) A and B, or (v) A and C, or (vi) B and C, or (vii) A, B and C.

[0153] It should be understood that the embodiments disclosed herein are exemplary only, and any feature presented for a specific exemplary embodiment may be used alone or in combination with any feature presented for the same or another specific exemplary embodiment and / or in combination with any other feature not mentioned with any aspect of the present disclosure. It will also be understood that any feature presented for an exemplary embodiment in a particular category may also be used in a corresponding manner in any other category of exemplary embodiments. abbreviation SSB Synchronous Signal Block CSI-RS channel state information reference signal RS reference signal BM beam management RSPR reference signal received power MIB Master Information Block SIB System Information Block UE User Equipment gNBNext Generation Node B RO RACH Timing ROG RACH timing group IE Information Unit EIRP is equivalent isotropic radiated power. BWP Bandwidth Section

Claims

1. A first device, comprising a transceiver, wherein the transceiver is configured to: - receiving configuration information from a second device, the configuration information indicating a first random access channel RACH opportunity group ROG of a first set of synchronization signal block SSB beams and a second ROG of a second set of SSB beams; - receiving a first SSB beam of the first ROG and / or a second SSB beam of the second ROG from the second device; as well as -Sending a random access request to the second device on a RACH timing of the first SSB beam of the first ROG and / or on a RACH timing of the second SSB beam of the second ROG.

2. The first apparatus of claim 1 , wherein the random access request is sent on a corresponding RACH opportunity of a SSB beam received using one or more of: - The highest received power or the received power above the configured threshold; - The highest signal-to-noise ratio SNR or SNR above a configured threshold; - Highest signal to interference plus noise ratio SINR or SINR above a configured threshold; and / or - The highest estimated channel quality or an estimated channel quality above a configured threshold.

3. The first apparatus according to claim 1 or 2, wherein the first random access request and the second random access request - each including a random access preamble; and / or - include the same random access preamble; and / or - Each Msg1 is a four-step or two-step RACH procedure; 4. The first device according to any one of claims 1 to 3, wherein the SSB beams of the first set are wider beams than those of the second set, and wherein the SSB beams of the second set are narrower beams than those of the first set.

5. The first device according to any one of claims 1 to 4, wherein the configuration information is received in at least one of the following: -RRC configuration; - Broadcast messages; - System Information Block SIB message; - System Information Block Type 2 SIB2 message; and / or - Information element field in SIB2 message.

6. The first device according to any one of claims 1 to 5, wherein the SSB beams of the second set are transmitted simultaneously in an SSB group, and each SSB beam of the SSB group transmitted simultaneously has the same SSB identifier.

7. The first apparatus of claim 6, wherein each SSB group of the second set of simultaneously transmitted SSB beams comprises at least one of: - a beam corresponding to each beam in said first set of SSB beams; - a beam corresponding to each beam of said first set of SSB beams and having an angular direction within the angular range of the corresponding said beam of said first set of SSB beams; -Multiple beams at different angles; - a beam displaced relative to said angular direction compared to the beams of the corresponding other SSB groups; - beams transmitted using the same physical resource blocks (PRBs); and / or -Beams associated with the same RACH opportunity.

8. The first apparatus according to any one of claims 1 to 7, wherein the SSB beams in the second set of SSB beams cover substantially the same angular range as the SSB beams in the first set of SSB beams.

9. A second device, comprising a transceiver, wherein the transceiver is configured to: - sending configuration information to the first device, wherein the configuration information indicates a first random access channel RACH opportunity group ROG of a first set of synchronization signal block SSB beams and a second ROG of a second set of SSB beams; - transmitting the first set of SSB beams of the first ROG and the second set of SSB beams of the second ROG; as well as - receiving a random access request from the first device on a RACH timing of the SSB beam of the first ROG and / or on a RACH timing of the SSB beam of the second ROG.

10. The second apparatus of claim 9, wherein the SSB beams of the first set are wider beams than those of the second set, and wherein the SSB beams of the second set are narrower beams than those of the first set.

11. The second apparatus according to claim 9 or 10, wherein the SSB beams of the first set are transmitted sequentially in different angular directions.

12. The second device according to any one of claims 9 to 11, wherein the SSB beams of the second set are transmitted simultaneously in an SSB group, and each SSB beam of the SSB group transmitted simultaneously has the same SSB identifier.

13. The second apparatus according to claim 12, wherein each SSB group of the simultaneously transmitted SSB beams of the second ROG comprises: - a beam corresponding to each beam in said first set of SSB beams; - a beam corresponding to each beam of said first set of SSB beams and having an angular direction within the angular range of the corresponding said beam of said first set of SSB beams; -Multiple beams at different angles; - a beam displaced relative to said angular direction compared to the beams of the corresponding other SSB groups; - beams transmitted using the same physical resource blocks (PRBs); and / or -Beams associated with the same RACH opportunity.

14. The second device according to any one of claims 9 to 13, wherein the number of SSBs used for the first set and the second set is independent of the number of connected first devices.

15. The second device according to any one of claims 9 to 14, wherein - the number of SSBs for the first ROG is 4, 8, 16 or 32; - the number of SSBs for the second ROG is 4, 8, 16 or 32; and / or - The total number of SSBs for the first ROG and the second ROG is 8, 12, 20, 36 or 64.

16. The second device according to any one of claims 9 to 15, comprising means for: -When a random access request is received on a RACH timing of an SSB beam of the first ROG and a random access request is received on a RACH timing of an SSB beam of the second ROG, an aligned second device Tx and / or Rx beam for the first device is determined based on the received random access requests.

17. The second device according to any one of claims 9 to 16, comprising means for: - using the aligned second device Tx beam to send Msg2 of a four-step RACH procedure to the first device; - receiving Msg3 of a four-step RACH procedure from the first device using the aligned second device Rx beam; and / or - Using the aligned second device Tx beam to send Msg4 of the four-step RACH procedure to the first device.

18. The second device according to any one of claims 9 to 17, comprising means for: -In the event that a random access request is received only on the RACH occasion of the SSB beam of the second ROG, a random access response is sent on each SSB beam of the second ROG having the following aspects, and each SSB beam on which the random access response is sent has the same SSB as the SSB beam on which the random access request is received on the RACH occasion. The second apparatus according to claim 18 , wherein the random access responses are transmitted sequentially.

20. The second apparatus according to any one of claims 9 to 19, wherein each random access response allocates the same time instance and / or different bandwidth parts BWP for the corresponding Msg3.

21. The second device according to claim 20, comprising means for: -Determine an aligned second device Tx and / or Rx beam for the first device based on the received random access request and the received Msg3.

22. A method performed by at least a first device, the method comprising: - receiving configuration information from a second device, the configuration information indicating a first random access channel RACH opportunity group ROG of a first set of synchronization signal block SSB beams and a second ROG of a second set of SSB beams; - receiving a first SSB beam of the first ROG and / or a second SSB beam of the second ROG from the second device; as well as -Sending a random access request to the second device on a RACH timing of the first SSB beam of the first ROG and / or on a RACH timing of the second SSB beam of the second ROG.

23. A method performed by at least a second device, the method comprising: - sending configuration information to the first device, wherein the configuration information indicates a first random access channel RACH opportunity group ROG of a first set of synchronization signal block SSB beams and a second ROG of a second set of SSB beams; - transmitting the first set of SSB beams of the first ROG and the second set of SSB beams of the second ROG; as well as - receiving a random access request from the first device on a RACH timing of the SSB beam of the first ROG and / or on a RACH timing of the SSB beam of the second ROG.

24. Computer program code which, when executed by a processor of an apparatus, causes the apparatus to perform the method according to claim 22 or 23.

25. A computer storage medium comprising computer program code according to claim 24.

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