Shared preamble set for coherent joint transmission random access channel

Abstract

Systems, methods, apparatuses, and computer program products for a shared preamble set for a coherent joint transmission (CJT) random access channel (RACH). A method may include receiving, from a network element and at least one other network element, at least one preamble index for coherent joint transmissions associated with the network element and the at least one other network element. The method may also include determining a set of coherent joint transmission indexes for the network element and at least one other network element based on the at least one preamble index. The method may further include determining a set of coherent joint transmission services based on metric information associated with the set of coherent joint transmission indexes. The method may also include synchronizing with the network element and one or more other network elements of the at least one other network element.

Description

Technical Field

[0001] Some example embodiments may generally relate to mobile or wireless telecommunications systems, such as Long Term Evolution (LTE) or 5th Generation (5G) New Radio (NR) access technologies, or 5G Beyond, or 6th Generation (6G) access technologies, or other communication systems. For example, some example embodiments may relate to a shared set of preambles for a Coherent Joint Transport (CJT) Random Access Channel (RACH). Background Technology

[0002] Examples of mobile or wireless telecommunications systems can include Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (UTRAN), Evolved UTRAN (E-UTRAN) for Long Term Evolution (LTE), LTE-Advanced (LTE-A), MulteFire, LTE-APro, 5G or New Radio (NR) access technologies, and / or 6G radio access technologies. 5G and 6G radio systems refer to Next Generation (NG) radio systems and network architectures. While 5G and 6G network technologies are largely based on New Radio (NR) technology, 5G / 6G (or NG) networks can also be built on E-UTRAN radio. It is estimated that NR can provide bit rates of approximately 10-20 GBit / s or higher and can at least support Enhanced Mobile Broadband (eMBB) and Ultra-Reliable Low Latency Communication (URLLC) as well as Massive Machine-Type Communication (mMTC). NR is expected to provide ultra-wideband and ultra-robust, low-latency connectivity and massive networks to support the Internet of Things (IoT). Summary of the Invention

[0003] Some example embodiments may relate to a method. The method may include receiving from a network element and at least one other network element at a time for coherent joint transmissions associated with the network element and at least one other network element. The method may further include determining a set of coherent joint transmission indices for the network element and at least one other network element based on the at least one preamble index. The method may further include determining a set of coherent joint transmission services based on metric information associated with the set of coherent joint transmission indices. According to some example embodiments, the set of coherent joint transmission services may include one or more other network elements among the network element and at least one other network element with which a connection will be established, all of which have the capability for coherent joint transmission. The method may also include synchronizing with one or more of the network elements among the network element and at least one other network element.

[0004] Other example embodiments may relate to an apparatus. The apparatus may include at least one processor and at least one memory storing instructions that, when executed by the processor, cause the apparatus to determine a set of coherent joint transport indexes for the network element and at least one other network element, based at least one preamble index. The apparatus may also determine a set of coherent joint transport services based on metric information associated with the set of coherent joint transport indexes. According to some example embodiments, the set of coherent joint transport services may include one or more other network elements with coherent joint transport capabilities that will establish a connection with the network element and at least one other network element. The apparatus may also be able to synchronize with the network element and at least one or more of the other network elements.

[0005] Other example embodiments may relate to an apparatus. The apparatus may include components for receiving from a network element and at least one other network element at a time for coherent joint transmissions associated with the network element and at least one other network element. The apparatus may also include components for determining a set of coherent joint transmission indexes for the network element and at least one other network element based on the at least one preamble index. The apparatus may further include components for determining a set of coherent joint transmission services based on metric information associated with the set of coherent joint transmission indexes. According to some example embodiments, the set of coherent joint transmission services may include one or more other network elements among the network element and at least one other network element that will establish a connection with it and have the capability for coherent joint transmissions. The apparatus may also include components for synchronizing with the network element and at least one or more of the other network elements.

[0006] According to other example embodiments, a non-transitory computer-readable medium may be encoded with instructions that, when executed in hardware, perform a method. The method may include receiving from a network element and at least one other network element at a time for coherent joint transmissions associated with the network element and at least one other network element. The method may further include determining a set of coherent joint transmission indices for the network element and at least one other network element based on the at least one preamble index. The method may further include determining a set of coherent joint transmission services based on metric information associated with the set of coherent joint transmission indices. According to some example embodiments, the set of coherent joint transmission services may include one or more other network elements among the network element and at least one other network element with which a connection will be established, all possessing the capability for coherent joint transmission. The method may also include synchronizing with one or more of the network element and at least one other network element.

[0007] Other example embodiments may relate to a computer program product that performs a method. The method may include receiving from a network element and at least one other network element at a time for coherent joint transmissions associated with the network element and at least one other network element. The method may further include determining a set of coherent joint transmission indices for the network element and at least one other network element based on the at least one preamble index. The method may further include determining a set of coherent joint transmission services based on metric information associated with the set of coherent joint transmission indices. According to some example embodiments, the set of coherent joint transmission services may include one or more other network elements among the network element and at least one other network element with which a connection will be established, all of which have the capability for coherent joint transmission. The method may also include synchronizing with one or more of the network element and at least one other network element.

[0008] Other example embodiments may relate to an apparatus that may include circuitry configured to receive from a network element and at least one other network element at a time for coherent joint transmissions associated with the network element and at least one other network element. The apparatus may also include circuitry configured to determine a set of coherent joint transmission indexes for the network element and at least one other network element based on the at least one preamble index. The apparatus may further include circuitry configured to determine a set of coherent joint transmission services based on metric information associated with the set of coherent joint transmission indexes. According to some example embodiments, the set of coherent joint transmission services may include one or more other network elements among the network element and at least one other network element that will establish a connection with it and have the capability for coherent joint transmissions. The apparatus may also include circuitry configured to synchronize with the network element and at least one or more of the other network elements.

[0009] Further example embodiments may relate to a method. This method may include determining at least one coherent joint transmission preamble index for coherent joint transmissions associated with a network element and at least one other network element. The method may also include sending at least one coherent joint transmission preamble index to a user equipment. The method may further include receiving a transmission from the user equipment based on a set of coherent joint transmission services determined by the at least one coherent joint transmission preamble index. According to some example embodiments, the transmission may be synchronized with one or more of the network element and at least one other network element. According to other example embodiments, the set of coherent joint transmission services may include one or more of the network element and at least one other network element.

[0010] Other example embodiments may relate to an apparatus. The apparatus may include at least one processor and at least one memory including computer program code. The at least one memory and the computer program code may be configured, together with the at least one processor, to cause the apparatus to at least determine at least one coherent joint transmission preamble index for coherent joint transmissions associated with a network unit and at least one other network unit. The apparatus may also be configured to send a set of coherent joint transmission preamble indices to a user equipment. The apparatus may further be configured to receive transmissions from a user equipment based on a set of coherent joint transmission services determined by the set of coherent joint transmission preamble indices. According to some example embodiments, the transmission may be synchronized with one or more of the network unit and at least one other network unit, and the set of coherent joint transmission services may include one or more of the network unit and at least one other network unit.

[0011] Other example embodiments may relate to an apparatus. The apparatus may include components for determining at least one coherent joint transmission preamble index for coherent joint transmissions associated with a network element and at least one other network element. The apparatus may also include components for transmitting at least one coherent joint transmission preamble index to a user equipment. The apparatus may further include components for receiving transmissions from the user equipment based on a set of coherent joint transmission services determined by the at least one coherent joint transmission preamble index. According to some example embodiments, the transmission may be synchronized with one or more of the network element and at least one other network element. According to other example embodiments, the set of coherent joint transmission services may include one or more of the network element and at least one other network element.

[0012] According to other example embodiments, a non-transitory computer-readable medium may be encoded with instructions that, when executed in hardware, perform a method. The method may include determining at least one coherent joint transmission preamble index for coherent joint transmissions associated with a network element and at least one other network element. The method may further include sending at least one coherent joint transmission preamble index to a user equipment. The method may further include receiving a transmission from the user equipment based on a set of coherent joint transmission services determined by the at least one coherent joint transmission preamble index. According to some example embodiments, the transmission may be synchronized with one or more of the network element and at least one other network element. According to other example embodiments, the set of coherent joint transmission services may include one or more of the network element and at least one other network element.

[0013] Other example embodiments may relate to a computer program product that performs a method. The method may include determining at least one coherent joint transmission preamble index for coherent joint transmissions associated with a network element and at least one other network element. The method may also include sending at least one coherent joint transmission preamble index to a user equipment. The method may further include receiving a transmission from the user equipment based on a set of coherent joint transmission services determined by the at least one coherent joint transmission preamble index. According to some example embodiments, the transmission may be synchronized with one or more of the network element and at least one other network element. According to other example embodiments, the set of coherent joint transmission services may include one or more of the network element and at least one other network element.

[0014] Other example embodiments may relate to an apparatus that may include circuitry configured to determine at least one coherent joint transmission preamble index for coherent joint transmissions associated with a network element and at least one other network element. The apparatus may also include circuitry configured to transmit a set of coherent joint transmission preamble indices to a user equipment. The apparatus may further include circuitry configured to receive transmissions from the user equipment based on a set of coherent joint transmission services determined by the set of coherent joint transmission preamble indices. According to some example embodiments, the transmission may be synchronized with one or more of the network element and at least one other network element. According to other example embodiments, the set of coherent joint transmission services may include one or more of the network element and at least one other network element. Attached Figure Description

[0015] To better understand the exemplary embodiments, reference will be made to the accompanying drawings, in which:

[0016] Figure 1 This illustrates an example set of gNB-wise preambles according to certain example embodiments.

[0017] Figure 2 Example signal diagrams are shown according to certain example embodiments.

[0018] Figure 3 An example flowchart is shown according to some example embodiments of a method.

[0019] Figure 4 An example flowchart is shown, illustrating another method according to certain example embodiments.

[0020] Figure 5 A set of apparatuses according to certain example embodiments are shown. Detailed Implementation

[0021] It will be readily understood that the components of some example embodiments generally described herein and shown in the accompanying drawings can be arranged and designed in a variety of different configurations. The following is a detailed description of some example embodiments of systems, methods, apparatuses, and computer program products for a shared preamble set for a Coherent Joint Transport (CJT) Random Access Channel (RACH).

[0022] Features, structures, or characteristics of the exemplary embodiments described in this specification can be combined in any suitable manner into one or more exemplary embodiments. For example, the use of phrases such as "certain embodiments," "exemplary embodiments," "some embodiments," or other similar language in this specification means that a particular feature, structure, or characteristic described in connection with an embodiment can be included in at least one embodiment. Therefore, the phrases "certain embodiments," "exemplary embodiments," "some embodiments," or other similar language appearing in this specification do not all refer to the same set of embodiments, and the features, structures, or characteristics can be combined in any suitable manner into one or more exemplary embodiments. Furthermore, the terms "base station," "cell," "node," "gNB," "network," or other similar language in this specification are used interchangeably. Additionally, the term "CJT-compliant network" can define a gNB / TRP capable of serving a UE together with other CJT-compliant networks in a CJT. Furthermore, the term "CJT service set" can define a subset of the set of CJT-compliant networks that a UE can receive with sufficient quality (RSSI / RSRP) and falls within a certain received power range (RSSI / RSRP). The CJT service set also defines a subset of the set of CJT-compliant networks that a UE selects to connect to simultaneously based on RSSI / RSRP.

[0023] As used herein, expressions such as “at least one of the following: ” and “at least one of ”, wherein a list of two or more elements connected by “and” or “or” means at least any one element, or at least any two or more elements, or at least all elements.

[0024] The 3GPP (3rd Generation Partnership Project) specifications already provide Time-Domain Duplex (TDD) systems, in which the radio frequency spectrum is divided into alternating time slots for uplink (UL) and downlink (DL) communication. In such systems, Synchronization Signal Blocks (SSBs) can play a crucial role in 5G NR. For example, an SSB can act as a master reference signal for synchronization and cell search procedures, enabling a User Equipment (UE) to identify and utilize subsequent Physical Random Access Channel (PRACH) transmissions to connect to a nearby base station (gNB). SSBs can be periodically transmitted during specific DL time slots and frequency slots, providing synchronization information to the UE. Using SSBs, a UE can synchronize with its gNB by detecting and decoding the SSB received during the DL time slot corresponding to its target gNB.

[0025] In 3GPP, the Physical Random Access Channel (PRACH) can be implemented by the UE to initiate communication with the gNB. In TDD systems (where the UL-DL configuration can change periodically), it can be beneficial for the UE to know when and where its PRACH preamble is sent. The PRACH preamble can correspond to a pseudo-random symbol sequence (selected from 64 different possible sequences), which the UE can send to the gNB during the initial access process to notify the gNB that the UE is attempting to connect to the network. Furthermore, the preamble index refers to a number between 1 and 64 corresponding to one of the preamble sequences. In some cases, the pseudo-random sequence can be the same on all gNBs, so that the preamble index selected by the UE can be derived separately from the preamble sequences sent / received at each gNB. Additionally, each network (e.g., the gNB) can have 64 preamble indices corresponding to the 64 different preambles, completely different from those of neighboring networks.

[0026] To avoid conflicts when multiple UEs transmit the same PRACH preamble, preambles can have a certain degree of availability and a mechanism for the UE to select an individual preamble. This availability can be achieved through code field orthogonality between different PRACH preambles associated with different preamble indices. For example, in the 5G NR standard, the random access procedure has 64 different PRACH preambles (e.g., indices) per SSB for selection. The mechanism for the UE to select different preambles can generally be obtained through random selection.

[0027] To help improve network data rates and reliability, CJT (Concurrently Jointed Beamformer) can be utilized. For example, CJT can be used to improve signal quality in weak coverage areas (e.g., cell edges) by coherently combining received signal payloads from multiple sources (e.g., Transmitting Receiver Points (TRPs) and gNBs). Implementing CJT can involve a high level of synchronization between the UE and any signal sources to be combined. For example, the UE may need to synchronize to multiple TRPs and / or gNBs simultaneously. Since synchronization can be fine-tuned via various reference signals during connected mode, providing the possibility of early (coarse) synchronization to multiple signal sources can be beneficial. For example, synchronization can already be achieved during the initial access procedure via SSB and PRACH responses. Coarse synchronization can indicate that time and frequency synchronization is accurate enough for successful communication. In this context, the UE can coarsely synchronize its receive / transmit beamformer to maximize energy transfer toward the set of CJT services it is connected to, and find a more accurate beamformer once the UE receives additional reference signals (and thus obtains a better estimate of the RF channel) during connected mode (fine-tuning). Fine-tuning can also include mitigating hardware impairments, such as, for example, phase drift, by using a phase-tracking reference signal.

[0028] While CJT can be beneficial in improving network data rates and reliability, 5G NR defines initial access as the process between the UE and a single gNB / TRP (e.g., single gNB synchronization) rather than multiple gNB / TRPs. Under CJT, the UE can synchronize to multiple signal sources (e.g., gNB / TRPs). However, current standards require multiple separate synchronization processes to achieve multi-gNB (or single gNB multiple TRP) synchronization. Therefore, as previously mentioned, providing the ability to synchronize to multiple signal sources early and providing solutions on how to improve PRACH preamble detection performance under cell edge conditions could be beneficial. Further improvements in PRACH preamble detection performance under cell edge conditions may also be needed.

[0029] In 5G NR, initial access can be defined as the process between the UE and a single TRP / gNB. To achieve CJT (Continuous Handover) between the UE and two or more individual TRPs / gNBs, the UE can synchronize with each TRP / gNB separately through a single initial access (or soft handover) procedure. Given the various shortcomings in current 5G NR, certain example embodiments can provide solutions to improve PRACH preamble detection performance under cell edge conditions. Certain example embodiments can also provide more efficient CJT initialization, enabling the UE to coarsely synchronize with multiple different CJT-compliant TRPs / gNBs during a single initial access procedure (after which synchronization can be fine-tuned in connected mode).

[0030] According to certain example embodiments, multi-gNB synchronization during initial access can be achieved by classifying some PRACH preambles (or indices) into CJT commons (e.g., CJT indices) within a CJT service set. The CJT service set may include a set of CJT-compliant networks (e.g., gNBs may follow CJT operating modes) from which the UE can receive SSBs with sufficient quality. The common preamble index set may not be explicitly available through current 5G NR standards. However, implicitly, all gNBs in the CJT service set can associate some preamble indices as CJT commons, but this will be invisible to the UE. In some example embodiments, each CJT-compliant network can indicate the CJT common set to the UE via System Information Block 1 (SIB1), after which the UE has the option to select all CJT service set gNBs to interpret as preamble indices for multi-synchronization PRACH transmission.

[0031] As described herein, certain example embodiments can distinguish a CJT-compliant network from a legacy operating mode, for example, by enabling the network to design its PRACH preamble sequence so that its preamble root sequence provides code that is completely separate from legacy operating modes. Therefore, a CJT-compliant network may not assume that a legacy user is attempting to perform multi-gNB synchronization.

[0032] Figure 1 A set of gNB-related preambles is shown according to certain example embodiments. For example, Figure 1 This shows the current standard preamble index range, divided into different groups based on the initial access type being used. For example... Figure 1 As further shown, the current standard does not have CJT capabilities, while gNB#1 to gNB#N have multiple CJT index groups / sets. Figure 1 The set of gNB-related preambles designated as public by CJT is also shown, as defined in SIB1 of their respective gNBs. Figure 1 The example shown represents a case where the synchronization signal (SS) / physical broadcast channel (PBCH) beam per PRACH timing is less than or equal to 1.

[0033] like Figure 1 As shown, the downward-pointing arrows from each gNB#1, gNB#2 to gNB#N indicate the UE's desired connection to a specific gNB. For example, in Figure 1 In the first arrow on the far left, the UE may expect to connect to gNB#1 and gNB#N, and this arrow indicates one of the common indices between gNB{1, N}, and so on for the other arrows. Furthermore, gNB#2 is not included in the first arrow, meaning it is inactive.

[0034] Figure 2 Example signal diagrams according to certain example embodiments are shown. For example, Figure 2 The diagram illustrates the signal transmission on the UE side based on the CJT common PRACH preamble within a limited set of CJT services (e.g., a set of CJT-compliant networks within predetermined signal quality and network constraint parameters).

[0035] like Figure 2 As shown, UE 215 has the capability to simultaneously initiate access to multiple gNBs / TRPs 200, 205, and 210 in a CJT manner. At 220, 225, and 230, gNB#1 200, gNB#2 205, and gNB#N 210 can each define their preamble index set as CJT common, or otherwise referred to as CJT index. At 235, 240, and 245, each corresponding gNB sends its corresponding CJT common preamble index to UE 215 in the corresponding SIB1 during initial access. In addition to receiving the CJT common preamble index from gNBs 200, 205, and 210 in the corresponding SIB1, the UE also receives SSBs from gNBs 220, 205, and 210.

[0036] At 250, UE 215 looks up the CJT common preamble index set for each CJT-compliant network (e.g., gNBs 200, 205, and 210), along with its corresponding signal quality metric (e.g., Received Signal Strength Indicator (RSSI) / Reference Received Power (RSRP)). In some example embodiments, the CJT common set may correspond to the preamble index set identified by the gNB (and UE) for multi-TRP / gNB synchronization. In some example embodiments, the CJT common preamble index set may be different on each gNB / TRP, and UE 215 may be able to determine the indices (e.g., CJT common preamble indexes) belonging to all gNB / TRPs that UE 215 expects to connect to simultaneously, while also avoiding indices belonging to gNB / TRPs that UE 215 should avoid. According to some example embodiments, any legacy gNB / TRP may have a "void" designation instead of the CJT common index set, and thus, legacy gNB / TRPs can be distinguished from CJT-compliant networks. If the traditional gNB / TRP is selected, UE 215 can use the traditional PRACH preamble index selection and the traditional preamble root sequence (which provides orthogonality to the preamble sequence of CJT-compliant networks).

[0037] At 255, UE 215 defines a CJT service set when it detects a set of CJT common preambles. In some example embodiments, the network may specify several sets of CJT common preambles, and these index sets may differ between networks (e.g., gNBs). In some example embodiments, UE 215 may define the CJT service set based on specific signal metrics / constraints. For example, if UE 215 detects SSBs from multiple gNBs / TRPs, UE 215 may define the CJT service set based on SSB-wise signal strength and other relevant metrics. In some example embodiments, metrics may include, for example, the RSRI / RSRP levels of the best received SSB from each gNB / TRP. UE 215 may use these measurements to determine whether a gNB / TRP is active within each gNB / TRP set. Another metric may include the range of RSSI / RSRP levels within which the CJT service set falls (to avoid noise enhancement from weak SSBs).

[0038] Another metric that UE 215 can use to define the CJT service set can include timing / delay differences between different gNB / TRP SSBs to avoid large differences in timing advance (TA). In other example embodiments, the metric may also include a gNB transmission preference parameter that limits the maximum number of CJT-compliant networks (e.g., CJT gNB / TRP) in the service set if the gNB is selected in the service set.

[0039] At position 260, UE 215 can begin synchronizing to multiple gNBs 200, 205, and 210. For example, UE 215 can select the PRACH preamble index of the CJT preamble index set belonging to all gNBs / TRPs that UE 215 wishes to synchronize to within the selected CJT service set (within the RSSI / RSRP range), e.g., possibly a subset of gNBs / TRPs within the RSSI / RSRP range. In some example embodiments, the preamble index can be found in the intersection of the (gNB / TRP-wise) CJT common preamble sets associated with the respective gNBs / TRPs that UE 215 wishes to connect to. In other example embodiments, UE 215 can avoid using an index in the CJT common set of gNBs / TRPs that it does not wish to include in the CJT service set.

[0040] According to some example embodiments, once a CJT common preamble index has been selected, UE 215 transmits the PRACH along with the selected preamble index. For example, at 265, UE 215 may determine the beamformer and timing advance for the CJT service set. At 270 and 275, UE 215 utilizes the respective beamforming and timing advance to transmit PRACH to each gNB 200, 205, and 210 on orthogonal resources, respectively. According to some example embodiments, orthogonal resources may correspond to resources transmitted by the UE, such as, for example, using different timing instances and / or different frequencies and / or using spatially separated beamforming PRACH. Orthogonality can indicate that signals toward different gNBs are separated in a way that allows them to be detected without interference from other signals. Alternatively, in other example embodiments, PRACH may utilize the average timing advance between a combined beamformer (such as one based on singular value decomposition (SVD)) and a set of gNB / TRPs (e.g., gNBs 200, 205, and 210) while simultaneously transmitting to that set of gNB / TRPs. This set of gNB / TRPs may include all gNB / TRPs in the CJT service set, or a subset of gNB / TRPs in the CJT service set.

[0041] In some example implementations, once UE 215 uses one of the public indices, the gNB / TRP can recognize that UE 215 is attempting to connect to multiple gNB / TRPs simultaneously. If there is overlap between public sets / gNBs, UE 215 can select overlapping indices among two or three TRPs. For example, the UE can attempt to connect to overlapping TRPs.

[0042] Figure 3 An example flowchart of a method according to certain example embodiments is shown. In the example embodiments, Figure 3 The method can be performed by a network entity or a group of multiple network elements (such as LTE or 5G-NR) in a 3GPP system. For example, in one example embodiment, Figure 3 The method can be similar to Figure 5 The UE executes one of the devices 10 or 20 shown.

[0043] like Figure 3As shown, the method may include, at 300, receiving from a network element and at least one other network element at a time, at least one preamble index for coherent joint transmission associated with the network element and at least one other network element. The method may also include, at 305, determining a set of coherent joint transmission indexes for the network element and at least one other network element based on the at least one preamble index. The method may further include, at 310, determining a set of coherent joint transmission services based on metric information associated with the set of coherent joint transmission indexes. According to some example embodiments, the set of coherent joint transmission services may include one or more other network elements among the network element and at least one other network element with which a connection will be established, that have the capability for coherent joint transmission. The method may also include, at 315, synchronizing with one or more of the network elements among the network element and at least one other network element.

[0044] According to some example embodiments, the method may further include selecting a preamble index belonging to the coherent joint transport service set from the coherent joint transport index set. According to some example embodiments, the method may further include sending a preamble corresponding to the selected preamble index from the coherent joint transport index set belonging to the coherent joint transport service set to one or more other network elements among the synchronized network element and at least one other network element. According to other example embodiments, the coherent joint transport index for the network element is different from the coherent joint transport index for at least one other network element.

[0045] In some example embodiments, at least one preamble index may be received from a network unit or at least one other network unit via a system information block. In some example embodiments, measurement information may be associated with a network unit or at least one other network unit and includes at least one of the following: a reference signal received power transmitted from the network unit or at least one other network unit, a reference signal strength indication transmitted from the network unit or at least one other network unit, or a timing difference between the network unit and at least one other network unit transmitted from the network unit or at least one other network unit. In other example embodiments, the measurement information may further include at least one of the following: a range of reference signal received power transmitted from the network unit or at least one other network unit, or a range of reference signal strength indications transmitted from the network unit or at least one other network unit.

[0046] According to some example embodiments, at least one preamble index may be associated with a network element and at least one other network element. According to some example embodiments, synchronization may include selecting a physical random access channel (PRAM) preamble index belonging to one or more other network elements with which the network element and at least one other network element will establish synchronization. According to other example embodiments, synchronization may include transmitting a physical random access channel (PRAM) to one or more other network elements based on the PRAM preamble index. According to further example embodiments, the PRAM may be transmitted on orthogonal resources to one or more other network elements, or the PRAM may be transmitted on the same physical resources to one or more other network elements.

[0047] Figure 4 An example flowchart of another method according to certain example embodiments is shown. In the example embodiments, Figure 4 The method can be performed by a network entity or a group of multiple network elements (such as LTE or 5G-NR) in a 3GPP system. For example, in one example embodiment, Figure 4 The method can be similar to Figure 5 The NW or gNB of one of the devices 10 or 20 shown is executed.

[0048] like Figure 4 As shown, the method may include, at 400, determining at least one coherent joint transmission preamble index for coherent joint transmissions associated with the network unit and at least one other network unit. The method may also include, at 405, sending at least one coherent joint transmission preamble index to the user equipment. The method may further include, at 410, receiving a transmission from the user equipment based on a coherent joint transmission service set determined by the at least one coherent joint transmission preamble index. In some example embodiments, the transmission may be synchronized with one or more of the network unit and at least one other network unit, and the coherent joint transmission service set may include one or more of the network unit and at least one other network unit.

[0049] According to some example embodiments, at least one coherent joint transport preamble index is sent to the user equipment via a system information block. According to some example embodiments, the system information block may include measurement information of network elements and at least one other network element. According to other example embodiments, the transport may also be received from the user equipment based on the measurement information of the network elements and at least one other network element.

[0050] In some example embodiments, the measurement information may include at least one of the following: reference signal received power of a transmission from a network unit or at least one other network unit, reference signal strength indication of a transmission from a network unit or at least one other network unit, or timing difference between a network unit and at least one other network unit. In some example embodiments, the measurement information may further include at least one of the following: a range of reference signal received power of a transmission from a network unit or at least one other network unit, or a range of reference signal strength indications of a transmission from a network unit or at least one other network unit. In other example embodiments, the transmission includes a physical random access channel having a selected preamble index belonging to one or more of the network unit and at least one other network unit. In further example embodiments, the physical random access channel may be received from the user equipment on orthogonal resources for one or more of the network unit and at least one other network unit, respectively, or the physical random access channel may be received simultaneously on the same physical resources for one or more of the network unit and at least one other network unit.

[0051] Figure 5 A set of devices 10 and 20 according to certain example embodiments are shown. In some example embodiments, devices 10 and 20 may be elements in or associated with a communication network. For example, device 10 may be a UE or other similar radio communication computer equipment, and device 20 may be a BS, gNB, LMF, network, or other similar computing device.

[0052] In some example embodiments, devices 10 and 20 may include one or more processors, one or more computer-readable storage media (e.g., memory, storage device, etc.), one or more radio access components (e.g., modem, transceiver, etc.), and / or a user interface. In some example embodiments, devices 10 and 20 may be configured to operate using one or more radio access technologies, such as GSM, LTE, LTE-A, NR, 5G, WLAN, WiFi, NB-IoT, Bluetooth, NFC, MulteFire, and / or any other radio access technology. It should be noted that those skilled in the art will understand that devices 10 and 20 may include... Figure 5 Components or features not shown in the diagram.

[0053] like Figure 5As shown in the example, devices 10 and 20 may include or be coupled to processors 12 and 22 for processing information and executing instructions or operations. Processors 12 and 22 may be any type of general-purpose or special-purpose processor. In practice, processors 12 and 22 may include one or more of, for example, a general-purpose computer, a special-purpose computer, a microprocessor, a DSP, a field-programmable gate array (FPGA), an application-specific integrated circuit (ASIC), or a processor based on a multi-core processor architecture. Although Figure 5 Single processors 12 and 22 are shown, but multiple processors may be used according to other example embodiments. For example, it should be understood that in some example embodiments, devices 10 and 20 may include two or more processors forming a multiprocessor system capable of supporting multiprocessing (e.g., in this case, processor 12 may represent multiple processors). According to some example embodiments, the multiprocessor system may be tightly coupled or loosely coupled (e.g., to form a computer cluster).

[0054] Processors 12 and 22 can perform functions associated with the operation of devices 10 and 20, including, for example, precoding of antenna gain / phase parameters, encoding and decoding of individual bits forming a communication message, formatting of information, and overall control of devices 10 and 20, including... Figures 1 to 4 An example of the process shown.

[0055] Devices 10 and 20 may also include or be coupled to memories 14 and 24 (internal or external), which may be coupled to processors 12 and 24 respectively for storing information and instructions executable by processors 12 and 24. Memories 14 and 24 may be one or more memories and may be of any type suitable for the local application environment, implemented using any suitable volatile and non-volatile data storage technology, such as semiconductor-based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and / or removable memory. For example, memories 14 and 24 may include random access memory (RAM), read-only memory (ROM) (static storage devices such as disks or optical discs), hard disk drives (HDDs), or any other type of non-transitory machine or computer-readable medium, and any combination thereof. Instructions stored in memories 14 and 24 may include program instructions or computer program code that, when executed by processors 12 and 22, enable devices 10 and 20 to perform the tasks described herein.

[0056] In some example embodiments, devices 10 and 20 may also include or be coupled to (internal or external) drives or ports configured to accept and read external computer-readable storage media, such as optical discs, USB drives, flash drives, or any other storage media. For example, the external computer-readable storage media may store computer programs or software for execution by processors 12 and 22 and / or devices 10 and 20 to perform... Figures 1 to 4 Any methods and examples shown.

[0057] In some example embodiments, devices 10 and 20 may further include or be coupled to one or more antennas 15 and 25 for receiving downlink signals and transmitting from devices 10 and 20 via UL. Devices 10 and 20 may also include transceivers 18 and 28 configured to transmit and receive information. Transceivers 18 and 28 may also include radio interfaces (e.g., modems) coupled to antennas 15 and 25. The radio interface may correspond to a variety of radio access technologies, including one or more of GSM, LTE, LTE-A, 5G, NR, WLAN, NB-IoT, Bluetooth, BT-LE, NFC, RFID, UWB, etc. The radio interface may include other components such as filters, converters (e.g., digital-to-analog converters, etc.), symbol demappers, signal shaping components, inverse fast Fourier transform (IFFT) modules, etc., to process symbols carried by the downlink or UL, such as OFDMA symbols.

[0058] For example, transceivers 18 and 28 may be configured to modulate information onto a carrier waveform for transmission by antennas 15 and 25, and demodulate information received via antennas 15 and 25 for further processing by other elements of devices 10 and 20. In other example embodiments, transceivers 18 and 28 may be able to directly transmit and receive signals or data. Additionally or alternatively, in some example embodiments, device 10 may include input and / or output (I / O devices). In some example embodiments, devices 10 and 20 may also include a user interface, such as a graphical user interface or a touchscreen.

[0059] In some example embodiments, memories 14 and 34 store software and modules that provide functionality when executed by processors 12 and 22. These modules may include, for example, an operating system that provides operating system functionality to devices 10 and 20. The memories may also store one or more functional modules, such as applications or programs, to provide additional functionality to devices 10 and 20. Components of devices 10 and 20 may be implemented in hardware or as any suitable combination of hardware and software. According to some example embodiments, devices 10 and 20 may be optionally configured to communicate with each other (in any combination) via a wireless or wired communication link 70 according to any radio access technology (such as NR).

[0060] According to some example embodiments, processors 12 and 22, and memories 14 and 24, may be included in or formed part of processing or control circuitry. Furthermore, in some example embodiments, transceivers 18 and 28 may be included in or formed part of transceiver circuitry.

[0061] For example, in some example embodiments, device 10 may be controlled by memory 14 and processor 12 to receive at least one preamble index from a network unit and at least one other network unit for coherent joint transmissions associated with the network unit and at least one other network unit. Device 10 may also be controlled by memory 14 and processor 12 to determine a set of coherent joint transmission indexes for the network unit and at least one other network unit based on the at least one preamble index. Device 10 may further be controlled by memory 14 and processor 12 to determine a set of coherent joint transmission services based on metric information associated with the set of coherent joint transmission indexes. According to some example embodiments, the set of coherent joint transmission services may include one or more other network units among the network unit and at least one other network unit that will establish a connection with it and have the capability for coherent joint transmission. Device 10 may also be controlled by memory 14 and processor 12 to synchronize with one or more of the network unit and at least one other network unit.

[0062] In other example embodiments, device 20 may be controlled by memory 24 and processor 22 to determine at least one coherent joint transmission preamble index for coherent joint transmissions associated with the network unit and at least one other network unit. Device 20 may also be controlled by memory 24 and processor 22 to send a set of coherent joint transmission preamble indices to the user equipment. Device 20 may further be controlled by memory 24 and processor 22 to receive transmissions from the user equipment based on a set of coherent joint transmission services determined by the set of coherent joint transmission preamble indices. According to some example embodiments, the transmission may be synchronized with one or more of the network unit and at least one other network unit, and the set of coherent joint transmission services may include one or more of the network unit and at least one other network unit.

[0063] In some example embodiments, the apparatus (e.g., apparatus 10 and / or apparatus 20) may include components for performing the methods, processes, or any variations discussed herein. Examples of components may include one or more processors, memory, controllers, transmitters, receivers, and / or computer program code for causing the execution of operations.

[0064] Some example embodiments may relate to an apparatus including components for performing any of the methods described herein, such as components for receiving from a network element and at least one other network element at a time for coherent joint transmissions associated with the network element and at least one other network element. The apparatus may further include components for determining a set of coherent joint transmission indexes for the network element and at least one other network element based on the at least one preamble index. The apparatus may further include components for determining a set of coherent joint transmission services based on metric information associated with the set of coherent joint transmission indexes. According to some example embodiments, the set of coherent joint transmission services may include one or more other network elements among the network element and at least one other network element with which a connection will be established, all of which have the capability for coherent joint transmission. The apparatus may also include components for synchronizing with one or more of the network element and at least one other network element.

[0065] Other example embodiments may relate to an apparatus including components for performing any of the methods described herein, such as components for determining at least one coherent joint transmission preamble index for coherent joint transmissions associated with a network unit and at least one other network unit. The apparatus may also include components for transmitting at least one coherent joint transmission preamble index to a user equipment. The apparatus may further include components for receiving transmissions from the user equipment based on a set of coherent joint transmission services determined by the at least one coherent joint transmission preamble index. According to some example embodiments, the transmission may be synchronized with one or more of the network unit and at least one other network unit, and the set of coherent joint transmission services may include one or more of the network unit and at least one other network unit.

[0066] Certain example embodiments described herein provide several technical improvements, enhancements, and / or advantages. For example, in some example embodiments, more efficient CJT initialization can be provided, enabling the UE to synchronize earlier with multiple different CJT-compliant TRPs / gNBs, such as during a single initial access procedure via SSB and PRACH responses. In some example embodiments, synchronization can also be fine-tuned when the UE and TRP / gNB are in connected mode. In further example embodiments, the detection performance of the PRACH preamble under cell edge conditions can be improved. In other example embodiments, using CJT instead of a single network connection can provide enhanced signal quality, enhanced connection reliability, and enhanced robustness against dynamic congestion due to multiple signal sources at cell edges (or at the intersection of cells of two or more gNBs / TRPs).

[0067] A computer program product may include one or more computer-executable components that, when the program runs, are configured to perform some example embodiments. The one or more computer-executable components may be at least one piece of software code or a portion thereof. Modifications and configurations required to implement the functionality of certain example embodiments may be executed as routines, which may be implemented as added or updated software routines. The software routines may be downloaded to the device.

[0068] For example, software or computer program code, or portions thereof, may be in the form of source code, object code, or some intermediate form, and may be stored on some carrier, distribution medium, or computer-readable medium, which may be any entity or device capable of carrying the program. Such a carrier may include recording media, computer memory, read-only memory, optoelectronic and / or electrical carrier signals, telecommunication signals, and software distribution packages. Depending on the required processing power, the computer program may execute in a single electronic digital computer or may be distributed across multiple computers. Computer-readable media or computer-readable storage media may be non-transitory media.

[0069] In other example embodiments, the function may be performed by hardware or circuitry included in the device (e.g., device 10 or device 20), for example, by using an application-specific integrated circuit (ASIC), a programmable gate array (PGA), a field-programmable gate array (FPGA), or any other combination of hardware and software. In yet another example embodiment, the function may be implemented as a signal, an intangible component that can be carried by an electromagnetic signal downloaded from the Internet or other networks.

[0070] According to certain example embodiments, an apparatus such as a node, device, or corresponding component may be configured as a circuit, a computer, or a microprocessor, such as a single-chip computer element, or configured as a chipset, including at least a memory for providing storage capacity for arithmetic operations and an arithmetic processor for performing arithmetic operations.

[0071] It will be readily understood by those skilled in the art that the disclosure described above can be practiced using processes of different sequences and / or hardware components with different configurations than those disclosed. Therefore, although this disclosure has been described based on these exemplary embodiments, it will be understood by those skilled in the art that certain modifications, variations, and alternative constructions will be apparent while still remaining within the spirit and scope of the exemplary embodiments. While the foregoing embodiments refer to 5G NR and LTE technologies, the foregoing embodiments can also be applied to any other current or future 3GPP technologies, such as Advanced LTE and / or fourth-generation (4G) technologies.

[0072] Partial Glossary

[0073] 3GPP Third Generation Partnership Project

[0074] 5G fifth generation

[0075] 5GCN 5G Core Network

[0076] 5GS 5G system

[0077] BS base station

[0078] CJT coherent joint transmission

[0079] DL downlink

[0080] eNB Enhanced Node B

[0081] E-UTRAN Evolution UTRAN

[0082] gNB 5G or next-generation node B

[0083] LTE Long Term Evolution

[0084] NR New Radio

[0085] PBCH Physical Broadcast Channel

[0086] PL path loss

[0087] PRACH Physical Random Access Channel

[0088] RSRP reference signal received power

[0089] RSSI Received Signal Strength Indicator

[0090] SIB1 System Information Block 1

[0091] SS Synchronization Signal

[0092] SSB Synchronization Signal Block

[0093] Singular Value Decomposition (SVD)

[0094] TDD Time Domain Duplex

[0095] TRP Transmitter / Receiver Point

[0096] UE User Equipment

[0097] UL uplink

Claims

1. A method for communication, comprising: Receive at least one preamble index from the network unit and at least one other network unit for coherent joint transmission associated with the network unit and at least one other network unit; Based on the at least one preamble index, a coherent joint transmission index set for the network element and the at least one other network element is determined; Based on the metric information associated with the coherent joint transport index set, a coherent joint transport service set is determined, wherein the coherent joint transport service set includes the network element and one or more other network elements with coherent joint transport capabilities that will establish a connection with the at least one other network element. as well as Synchronize with the network unit and one or more other network units among the at least one other network unit.

2. A method for communication, comprising: Determine at least one coherent joint transmission preamble index for coherent joint transmission associated with a network element and at least one other network element; Send the at least one coherent joint transmission preamble index to the user equipment; as well as Based on the coherent joint transmission service set determined by the at least one coherent joint transmission preamble index, transmissions from the user equipment are received. The transmission is synchronized with the network unit and one or more other network units among the at least one other network unit, and The coherent joint transport service set includes the network element and one or more other network elements among the at least one other network element.

3. A device for communication, comprising: At least one processor; as well as At least one memory storing instructions, wherein, when executed by the at least one processor, the means causes the device to at least: Receive at least one preamble index from the network unit and at least one other network unit for coherent joint transmission associated with the network unit and at least one other network unit; Based on the at least one preamble index, a coherent joint transmission index set for the network element and the at least one other network element is determined; Based on metric information associated with the coherent joint transport index set, a coherent joint transport service set is determined, wherein the coherent joint transport service set includes the network element and one or more other network elements with coherent joint transport capabilities with which a connection will be established from the at least one other network element; and Synchronize with the network unit and one or more other network units among the at least one other network unit.

4. The apparatus according to claim 3, wherein, When the computer program code is executed by the at least one processor, the device further causes at least: Based on the coherent joint transport index set and the coherent joint transport service set, select the preamble index belonging to the coherent joint transport service set from the coherent joint transport index set; as well as The preamble corresponding to the selected preamble index is sent from the coherent joint transport index set belonging to the coherent joint transport service set to one or more other network elements among the synchronized network elements and at least one other network element.

5. The apparatus according to claim 3 or 4, wherein, The coherent joint transport index used for the network element is different from the coherent joint transport index used for the at least one other network element.

6. The apparatus according to claim 3 or 4, wherein, The at least one preamble index is received from the network unit or the at least one other network unit via a system information block.

7. The apparatus according to claim 3 or 4, wherein, The metric information is associated with the network unit or the at least one other network unit, and includes at least one of the following: The received power of the reference signal transmitted from the network unit or the at least one other network unit. A reference signal strength indication transmitted from the network unit or the at least one other network unit, or The timing difference between the network unit and the at least one other network unit in the transmission from the network unit or the at least one other network unit.

8. The apparatus according to claim 7, wherein, The measurement information further includes at least one of the following: The range of received power of the reference signal transmitted from the network unit or the at least one other network unit, or The range of reference signal strength transmitted from the network unit or the at least one other network unit.

9. The apparatus according to claim 3 or 4, wherein, The at least one preamble index is associated with the network unit and the at least one other network unit.

10. The apparatus according to claim 3 or 4, wherein, The synchronization includes: selecting a physical random access channel preamble index belonging to the network element and one or more other network elements with which synchronization will be established.

11. The apparatus according to claim 10, wherein, The synchronization includes: sending the physical random access channel to the network element and one or more other network elements among the at least one other network element, based on the physical random access channel preamble index.

12. The apparatus according to claim 11, wherein, The physical random access channel is transmitted on orthogonal resources to the network element and one or more other network elements among the at least one other network element, or The physical random access channel is sent on the same physical resources to the network element and one or more other network elements among the at least one other network element.

13. An apparatus for communication, comprising: At least one processor; as well as At least one memory storing instructions, wherein, when executed by the at least one processor, the means at least: Determine at least one coherent joint transmission preamble index for coherent joint transmission associated with a network element and at least one other network element; Send a set of coherent joint transmission preamble indexes to the user equipment; and Based on the coherent joint transmission service set determined by the coherent joint transmission preamble index set, transmissions from the user equipment are received. The transmission is synchronized with the network unit and one or more other network units among the at least one other network unit, and The coherent joint transport service set includes the network element and one or more other network elements among the at least one other network element.

14. The apparatus according to claim 13, wherein, The at least one coherent joint transmission preamble index is sent to the user equipment via a system information block.

15. The apparatus according to claim 14, wherein, The system information block includes the measurement information of the network unit and the at least one other network unit.

16. The apparatus according to any one of claims 13 to 15, wherein, The transmission is also received from the user equipment based on the measurement information of the network unit and the at least one other network unit.

17. The apparatus according to claim 16, wherein, The measurement information includes at least one of the following: The received power of the reference signal transmitted from the network unit or the at least one other network unit. A reference signal strength indication transmitted from the network unit or the at least one other network unit, or The timing difference between the network unit and the at least one other network unit.

18. The apparatus according to claim 16, wherein, The measurement information further includes at least one of the following: The range of received power of the reference signal transmitted from the network unit or the at least one other network unit, or The range of reference signal strength transmitted from the network unit or the at least one other network unit.

19. The apparatus according to any one of claims 13 to 15, wherein, The transmission includes a physical random access channel having a selected preamble index belonging to the network element and one or more of the other network elements.

20. The apparatus according to claim 19, wherein, The physical random access channel is received from the user equipment on orthogonal resources for the network element and one or more other network elements among the at least one other network element, or The physical random access channel is received from the user equipment on the same physical resources simultaneously for the network element and one or more other network elements among the at least one other network element.

21. A non-transitory computer-readable medium comprising program instructions stored thereon for performing the method according to claim 1 or 2.

22. An apparatus for communication, comprising circuitry configured to cause the apparatus to perform the method according to claim 1 or 2.

Images