Mobility Management in Ultra-Dense Networks

Abstract

User equipment (UE) mobility in ultra-dense networks (UDN) is based on a communication signal layer, which may include, for example, an orthogonal frequency division multiplexing (OFDM) domain, a code domain using a corresponding codebook, and / or corresponding data streams in a spatial domain. The UE uses candidate layer decoding parameters in layer-based decoding of communication signals received from network nodes. As the UE moves between different network service areas, layers can be assigned to the UE and transferred between network nodes. Layers can alternatively be assigned to network nodes. Providing layer-based decoding for UE mobility enables no significant handover processing to be required each time the UE moves between different service areas.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims priority to U.S. Patent Application No. 15 / 073,788, filed on Mar. 18, 2016, entitled "Mobility Handling in Ultra - Dense Networks", which claims priority to U.S. Provisional Patent Application No. 62 / 270,734, filed on Dec. 22, 2015, entitled "Mobility Handling in Ultra - Dense Networks", the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure generally relates to Ultra - Dense Networks (UDN), and more particularly, to handling mobility in UDN. Background Art

[0004] In a UDN, network nodes that provide wireless communication services to user equipment (UE) are closer to each other than in a less - dense "macro" network. Thus, when a UE moves a distance that is smaller compared to the distance between service areas in a less - dense network, it may transition between service areas of different network nodes. Service area transitions of the UE may also occur more frequently in a UDN.

[0005] Current Long - Term Evolution (LTE) systems rely on handovers between network nodes to support UE mobility between service areas. It may be desirable to avoid handover processing each time a UE transitions between service areas, especially in a network such as a UDN where frequent service area transitions may be expected. Summary of the Invention

[0006] According to one aspect of the present disclosure, a method performed by a UE includes receiving, when the UE is located in a first service area of a communication network, a first plurality of communication signals from a first subset of network nodes, each communication signal of the first plurality of communication signals being associated with a respective one of a plurality of communication signal layers in the communication network; determining, from a set of communication signal layer decoding parameters available to the UE, first candidate communication signal layer decoding parameters for layer decoding the first plurality of communication signals; performing layer-based decoding of the first plurality of communication signals using the first candidate communication signal layer decoding parameters; after the UE moves to a second service area, receiving a second plurality of communication signals from a second subset of the network nodes, each communication signal of the second plurality of communication signals being associated with a respective one of the plurality of communication signal layers, the second subset of the network nodes including at least one network node not in the first subset of the network nodes; determining, from the set of communication signal layer decoding parameters available to the UE, second candidate communication signal layer decoding parameters for layer decoding the second plurality of communication signals; and performing layer-based decoding of the received second plurality of communication signals using the second candidate communication signal layer decoding parameters.

[0007] According to another aspect of the present disclosure, a UE includes: a receiver for receiving, when the UE is located in a first service area of a communication network, a first plurality of communication signals from a first subset of network nodes in the communication network, each communication signal of the first plurality of communication signals being associated with a respective one of a plurality of communication signal layers in the communication network; and a signal decoder coupled to the receiver for determining, from a set of communication signal layer decoding parameters available to the UE, first candidate communication signal layer decoding parameters for layer decoding the first plurality of communication signals and for performing layer-based decoding of the first plurality of communication signals using the first candidate communication signal layer decoding parameters. The receiver is further for receiving, after the UE moves to the second service area of the communication network, a second plurality of communication signals from a second subset of the network nodes, each communication signal of the second plurality of communication signals being associated with a respective one of the plurality of communication signal layers, the second subset of the network nodes including at least one network node not in the first subset of the network nodes. The signal decoder is further for determining, from the set of communication signal layer decoding parameters available to the UE, second candidate communication signal layer decoding parameters for layer decoding the second plurality of communication signals and for performing layer-based decoding of the received second plurality of communication signals using the second candidate communication signal layer decoding parameters.

[0008] In accordance with other aspects of the present disclosure, a method includes: configuring a first subset of network nodes in a communication network to transmit a first communication signal that can be decoded by a user equipment (UE) using decoding parameters for a communication signal associated with a communication signal layer in the communication network, each of the first communication signals being associated with a respective one of the plurality of communication signal layers; and configuring a second subset of the network nodes in the communication network to transmit a second communication signal that can be decoded by the UE using the decoding parameters, the second subset of the network nodes including at least one network node not in the first subset of the network nodes, each of the second communication signals being associated with a respective one of the plurality of communication signal layers.

[0009] Another aspect of the present invention relates to an apparatus including a coordination controller for: configuring a first subset of network nodes in the communication network to transmit a first communication signal that can be decoded by the UE using the decoding parameters, each of the first communication signals being associated with a respective one of the plurality of communication signal layers; and configuring a second subset of the network nodes in the communication network to transmit a second communication signal that can be decoded by the UE using the decoding parameters, the second subset of the network nodes including at least one network node not in the first subset of the network nodes, each of the second communication signals being associated with a respective one of the plurality of communication signal layers. The apparatus further includes a coordination interface coupled to the coordination controller to communicate with the network nodes.

[0010] Other aspects and features of embodiments of the present disclosure will become apparent to those skilled in the art after reading the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Embodiments of the present invention will be described in more detail with reference to the accompanying drawings.

[0012] Figure 1 is a schematic structural diagram of a communication network according to an embodiment.

[0013] Figure 2 is a schematic structural diagram depicting the allocation and mobility of UE communication signal layers.

[0014] Figure 3 is a schematic structural diagram depicting the allocation and mobility of network node communication signal layers.

[0015] Figure 4 is a flowchart of a method according to an embodiment.

[0016] Figure 5 is a schematic structural diagram of a UE according to an embodiment.

[0017] Figure 6It is a flowchart of a method according to another embodiment.

[0018] Figure 7 It is a schematic structural diagram of a central processing system according to an embodiment.

[0019] Figure 8 It is a schematic structural diagram of a network node according to an embodiment. Detailed implementation manners

[0020] For illustrative purposes, specific exemplary embodiments will now be explained in more detail below with reference to the accompanying drawings.

[0021] The embodiments described herein fully disclose the information for implementing the claimed subject matter and describe the best mode for implementing such subject matter. After reading the following description with reference to the drawings, those skilled in the art will understand the concepts of the claimed subject matter and will recognize the applications of these concepts that are not specifically mentioned herein. It should be understood that these concepts and applications fall within the scope of the present disclosure and the appended claims.

[0022] Moreover, it will be understood that any module, component, or device for executing instructions disclosed herein may include or access a non-transitory computer / processor-readable storage medium for storing information, such as computer / processor-readable instructions, data structures, program modules, and / or other data. Non-exhaustive examples of non-transitory computer / processor-readable storage media include magnetic tape cartridges, tapes, disk memories, or other magnetic storage devices, optical discs such as compact disc read-only memory (CD-ROM), digital video discs or digital versatile discs (i.e., DVDs), Blu-ray discs or other optical memories, volatile and non-volatile, removable and non-removable media implemented by any method or technology, random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory, or other memory technologies. Any such non-transitory computer / processor storage medium may be part of the device or accessible / connectable to a part of the device. The computer / processor-readable or executable instructions for implementing the applications or modules described herein may be stored or otherwise held by such non-transitory computer / processor-readable storage media.

[0023] Now, with reference to the accompanying drawings, some specific exemplary embodiments will be described.

[0024] Figure 1 It is a schematic structural diagram of a communication network according to an embodiment. The communication network 100 includes a core network 102 and an access network 106.

[0025] The core network 102 can provide any one of various services to other networks, such as call control / switching and gateways. The core network 102 includes network components such as routers, switches, and servers.

[0026] The access network 106 is a UDN and is connected or coupled to the core network 102. Network nodes 108a, 108b, 108c, 108d, 108e, which may also be referred to as transmission points or TPs in UDN terminology, provide wireless communication services within their respective wireless coverage areas 110a, 110b, 110c, 110d, 110e. Each network node 108a - e can be implemented using a radio transceiver, one or more antennas, and associated processing circuits such as antenna radio frequency (RF) circuits, analog - to - digital / digital - to - analog converters, etc.

[0027] UEs 104a, 104b, 104c, 104d wirelessly access the communication network 100 using the access network 106. Each UE 104a - d includes a radio transceiver, one or more antennas, and associated processing circuits such as antenna RF circuits, analog - to - digital / digital - to - analog converters, etc. The network nodes 108 - e and UEs 104a - d can include similar types of components to support communication with each other in the communication network 100, but the actual implementation may be different. For example, UEs 104a - d are portable between multiple locations, while the network nodes 108a - e are typically intended to be installed in fixed positions.

[0028] The network nodes 108a - e are connected to a central processing system 120 in the access network 106 via respective communication links 112a, 112b, 112c, 112d, 112e. In one embodiment, each communication link 112a - e is an optical fiber communication link. Each network node 108a - e includes circuits for sending data to the central processing system 120 and for receiving data from the central processing system via its respective communication link 112a - e. Although shown as a single central processing system in Figure 1 the central processing system 120 can be implemented by a network of one or more processing and control servers. Optionally, the central processing system 120 can be implemented as a single server.

[0029] The network nodes 108a-e can be used as gateways between the wired and wireless parts of the access network 106, but this is not necessarily the case in embodiments where the communication links 112a-e are wireless links. The network nodes can be placed by the network provider in fixed positions, for example to provide continuous wireless coverage areas in a strategic manner. This is shown in Figure 1 where the wireless coverage areas 110a-e overlap with each other such that the UEs 104a-d can move throughout the wireless coverage area while still being served by the access network 106. At different locations in the access network 106, different subsets of the network nodes 108a-e provide wireless communication services.

[0030] Some service areas in the access network 106 are served by a single network node, as is the case with the current positions of the UEs 104a-d. However, the wireless coverage areas 110a-e also overlap with each other. When a UE is located in a service area with overlapping coverage from multiple network nodes, the UE is exposed to communication signals from these network nodes. Therefore, the subset of network nodes providing communication services in a service area can include one or more network nodes.

[0031] In a UDN such as the access network 106, different from other types of communication networks, the network nodes 108a-e are closer to each other in terms of their positions. Therefore, compared to a communication network with a larger wireless coverage area, fewer network nodes, and network nodes that are farther apart from each other, a UE can change service areas by moving a shorter distance. For example, when moving Figure 1 from left to right in, the UE 104a can transition through different service areas in the following manner:

[0032] From the service area served by the network node 108a to the service area served by the network nodes 108a, 108d (at a position within the overlapping area of the wireless coverage areas 110a, 110d);

[0033] From the service area served by the network nodes 108a, 108d to the service area served by the network nodes 108a, 108d, 108b (at a position within the overlapping area of the wireless coverage areas 108a, 108d, 108b);

[0034] From the service area served by the network nodes 108a, 108d, 108b to the service area served by the network node 108b;

[0035] and so on, through different service areas, where different subsets in the different service areas include one or more of the network nodes 108a-e providing communication services.

[0036] For example, in a UDN, these service area transitions may all occur when the UE has only moved a few hundred meters. When service area transitions occur over such short distances and are expected to occur frequently, the handover processes used in current LTE systems and other communication networks to support UE mobility can impose a significant burden on communication and processing resources.

[0037] The present disclosure proposes a method of "layers" of communication signals for mobility in a UDN. Joint detection and decoding methods such as Successive Interference Cancellation (SIC), Message Passing Algorithm (MPA), or Maximum Likelihood Detection (MLD) allow the UE to jointly receive and decode communication signals that can be received from multiple network nodes and are associated with multiple layers.

[0038] As disclosed herein, network node-to-UE association can be performed dynamically. In one embodiment, multiple layers that may originate from multiple network nodes are associated with the UE. As the UE moves, different subsets of network nodes are responsible for serving the UE. Since the UE has layers that are transparent with respect to network node association, and / or has a transparent subset of "active" network nodes, service area transitions can be transparent to the UE.

[0039] A communication signal layer, also referred to herein simply as a "layer", can include, for example, an Orthogonal Frequency Division Multiplexing (OFDM) domain, a code domain using a corresponding codebook, and / or corresponding data streams in the spatial domain. In the code domain, different codebooks are used to encode communication signals associated with different layers. In one embodiment, input bits are mapped to sparse multi-dimensional complex codewords that are selected from a predefined set of codebooks in a method that can also be referred to as Sparse Code Multiple Access (SCMA). For example, a spatial domain layer can be a layer in a Multiple Input Multiple Output (MIMO) system.

[0040] Layers can be assigned to the UE or network nodes. These two options will be described in detail below. Although the following detailed description relates to code domain layers, other types of layers are also possible.

[0041] In the UE layer allocation method, one or more layers are provided for the UE and the one or more layers are allocated to the UE. This method may be more suitable for a lightly loaded network. For example, in the lightly loaded network, there are a sufficient number of layers available for allocating at least one layer to each UE. Figure 2 It is a schematic structural diagram for describing UE layer allocation and mobility.

[0042] To avoid overcrowding in the figure, Figure 2 only network nodes 208a, 208b, 208c, 208d, 208e, 208f of the UDN 200 are shown, and there is no central processing system or core network as Figure 1 shown. Different positions of the UE are shown at 204A, 204B, 204C, and the A, B, C labels are intended to represent different positions of the same UE rather than different UEs. The mobility of the UE is shown at 220, 222. Three layers are represented at 230A, 230B, 230C, 232A, 232B, 232C, 234A, 234B, 234C, where the numbers 230, 232, 234 respectively represent three different layers and the A, B, C markings respectively represent the signals received when the UE is at each of the positions shown at 204A, 204B, 204C. Network node 208f is not involved in Figure 2 the mobility example in, and it is shown to illustrate that the communication network 200 may include additional network nodes, where when the UE moves between service areas within the communication network, the additional network nodes do not belong to any subset of network nodes that provide services to the UE.

[0043] The UE at each position 204A, 204B, 204C is exposed to multiple communication signals. For example, at position 204A, the UE receives communication signals associated with layers 230A, 232A, 234A respectively. In this example, the UE receives signals carried by three layers 230A, 232A, 234A from three different network nodes 208a, 208b, 208c, but in other embodiments, multiple layers may originate from a single network node.

[0044] Interference caused by network nodes serving other UEs is not a limiting factor in the communication system 200. For example, the UE at position 204A receives communication signals associated with layers 230A, 232A, 234A and performs layer-based decoding on them. For the code domain layer, the UE receives a codebook set with corresponding pilot patterns. For example, codebooks for different layers can be allocated by the central processing system shown at 120 in Figure 1 and distributed to the UE. In some embodiments, multiple layers may share the same pilot set and originate from the same physical / logical antenna port.

[0045] The UE estimates the channel or communication signal associated with each of the different layers and attempts to jointly decode the data associated with the UE. For the code domain layer, when the UE is at 204A, the UE decodes the received communication signal using the layer codebook and may discard the communication signal associated with any layer that has not been assigned to the UE.

[0046] As the UE moves, the subset of "potential" network nodes, including the network nodes that can serve the UE, may change. The subset of potential network nodes can be updated using one or more of uplink (UL) reciprocity, tracking channels, user feedback, location services, etc. For example, as shown by 220, the movement of the UE from location 204A to location 204B can be detected by the central processing system shown by 120 in Figure 1 . The subset of potential network nodes now includes network nodes 208b, 208c, 208d that provide communication services in the serving area where the UE is currently located. This subset of potential network nodes is determined based on the current location of the UE at 204B. Similarly, this can be processed by the central processing system, and the central processing system can also notify network node 208d that network node 208d is part of the subset of potential network nodes for the UE. Similarly, the central processing system or other components in the communication network 200 can notify network node 208a that network node 208a is no longer part of the subset serving the UE.

[0047] When the UE is at location 204B, network node 208d is responsible for layer 230. Figure 2 230A and 230B in represent the same layer. Thus, this layer can be considered to follow the UE, i.e., this layer is transferred from network node 208a to network node 208d as the UE moves. The UE may not know the current network node - layer association. From the perspective of the UE, communication signals associated with the same layer are received at locations 204A and 204B, and the UE does not have to know that one of the layers has moved from network node 208a to network node 208d. As far as the UE is concerned, whether the UE is at location 204A or location 204B, the same codebook, for example in the code domain layer implementation, is used to decode the communication signals of the same layer. In other embodiments, this type of layer transition between different network nodes can be transparent to the UE, although this type of layer transition may be confirmed by the UE and / or the network nodes.

[0048] The same consistency of communication and layer also applies to the movement of the UE from location 204B to location 204C shown at 222. In this case, as shown at 234C, layer 234 moves from network node 208b to network node 208e.

[0049] Such allocation and transition of UE layers between different network nodes can support mobility each time the potential subset of network nodes changes as the UE moves between service areas, without the need for an explicit handover procedure.

[0050] Even in the case of UE layer allocation, the codebook can be updated. The UE codebook can be updated and distributed periodically by, for example, a central processing system as shown in 120 of Figure 1 . The codebook and codebook assignment are thus considered to be dynamic or semi-static, depending on the update frequency of the codebook. However, such codebook updates are not necessarily performed as part of the layer transition process outlined herein. If the UE moves between service areas before the codebook update occurs and the layers remain the same after the UE moves into a different service area, the UE can use the same codebook for the layers assigned to it regardless of the specific network nodes in the currently active or potential subset of network nodes.

[0051] When the UE moves between different service areas, the layers do not necessarily remain the same. For example, when the UE moves to a different service area, the layer may not be migrated to a different network node, and thus the layer will disappear from the set of active layers for some time. The layer can be completely removed or reassigned to a different UE, and as the UE moves between service areas, the layer does not move to a different network node. For example, in embodiments where different layers are assigned to the UE, or after a layer is removed and multiple layers are assigned to the UE and one or more layers remain assigned to the UE, the layer can be removed or reassigned.

[0052] Similarly, other communication characteristics can be dynamic or semi-static. For example, characteristics such as the Forward Error Correction (FEC) coding rate and / or the actual number of layers assigned to the UE can be updated frequently, such as at each downlink (DL) grant.

[0053] The UE can perform blind detection to determine the layers active at its current location. Blind detection involves determining resources based on the attributes of the received signal without prior knowledge such as signaling from the transmitter indicating which resources are being used. In a blind detection implementation, the UE blindly detects the set of active layers by determining the layers for which the UE can decode the communication signal. One or more network nodes can notify the UE of the active layers, for example, as part of a radio resource grant. Any of these methods can provide distributed scheduling where each network node decides whether to serve the UE.

[0054] Other options for UE layer allocation include vertical or horizontal coding. For example, in a synchronous network, vertical coding can use the same FEC block for all layers and involves some data sharing.

[0055] Some embodiments may support layer "lending". For example, a central processing system may decide to use the codebooks of UEs from one or more network nodes to serve other UEs. In this case, the UE can jointly decode the communication signals associated with all layers from all network nodes, but the UE only retains its own data and discards the data intended for other UEs.

[0056] Figure 2 The above description relates to UE layer allocation. Network node layer allocation is also possible. For example, network node layer allocation solutions may be more suitable for scenarios with high network load and / or a number of UEs greater than the number of available layers. Figure 3 is a schematic structural diagram describing network node layer allocation and mobility.

[0057] As shown in Figure 2 in, Figure 3 only network nodes 308a, 308b, 308c, 308d, 308e, 308f of the UDN 300 are shown, different positions of the UEs are shown at 304A, 304B, 304C, and the mobility of the UEs is shown at 320, 322. However, Figure 3 in, layers 330, 332A, 332B, 332C, 334A, 334B, 336A, 336B, 338 are assigned to network nodes 308a, 308b, 308c, 308d, 308e, rather than to the UEs.

[0058] In Figure 3 each network node 308a, 308b, 308c, 308d, 308e is assigned one or more layers. One or more layers may also be assigned to network node 308f, but this is not shown in Figure 3 because in this example, network node 308f is not involved in serving the UEs.

[0059] In the code domain layer system, a list of possible codebooks and pilots for the layers assigned to network nodes near the UE is distributed to the UE. Such a list of possible codebooks and pilots is an example of candidate decoding parameters used by the UE in layer-based decoding of received communication signals. The list of candidate decoding parameters may include information for determining the decoding parameters, which is for not only the layers active in the serving area where the UE is currently located, but also for layers that may be active in different serving areas, such as serving areas adjacent to the current serving area. In this example, if the UE moves from one serving area to an adjacent serving area, the UE may attempt to decode the received communication signals using the same candidate decoding parameters.

[0060] Layers of the same network node may share the same pilot pattern. The FEC code rate and possibly other relevant information may also be transmitted to the UE. This information may be known to the UE explicitly through broadcast or unicast signaling or through being standardized within the network 300, and thus is priori known to the UE.

[0061] At each of positions 304A, 304B, 304C, the UE is exposed to multiple communication signals. Each communication signal is associated with a different layer and is received from Figure 3 different network nodes. For example, at position 304A, the UE receives communication signals associated with layers 330, 332A, 334A from network nodes 308a, 308b, 308c respectively.

[0062] The UE performs layer-based decoding of the received communication signals using the candidate codebook. The UE may report to the central processing system shown at 120 in Figure 1 , for example, that the codebook list has successfully decoded the received communication signals. This may involve direct or indirect measurement of the channel. For example, the UE may use previous transmission time interval (TTI) information to determine the layers of the decodable communication signals, and use the measurement channel to send the list of decodable layers to the central processing system. Since when the UE is at position 304A, the decodable communication signals are associated with the layers assigned to network nodes 308a, 308b, 308c, the information about the layers of the communication signals that are decodable, or an indication of other types of candidate layer decoding parameters used to decode the received communication signals, can be used to determine the current location of the UE. More generally, the location of the UE can be determined based on the layer decoding parameters (such as codebooks) that it can use to successfully decode communication signals, and the network nodes to which the layers associated with the decodable signals are assigned. The UE is able to use different codebooks, for example, depending on its location, to successfully decode communication signals.

[0063] After the UE moves to location 304B as indicated at 320, the UE receives communication signals from network nodes 308b, 308c, 308d and performs layer-based decoding on the received signals. The UE can now successfully decode the communication signals using the codebooks of the layers assigned to these network nodes. The codebooks and layers active at location 304B include layers 332B, 334B, 336A. Two of these layers, 332B and 334B, are associated with the signals received at location 304A, but in this example there is a different layer 336A. Figure 2 There is no layer transition between different network nodes in Figure 2 . The UE may not know the current network node layer associations at the current location of the UE. When at location 304B, the UE can still attempt to decode the received communication signals using the same set of candidate codebooks it used when at location 304A. At location 304B, the candidate codebooks that could not be used to successfully decode any communication signals received at location 304A now correspond to the received signals and can decode the received communication signals.

[0064] In another embodiment, when a network node or a central processing system determines that the UE has moved between serving areas, information on a different set of candidate decoding parameters (codebooks in this example) is sent to the UE. However, as in the UE layer assignment mobility example in Figure 2 when the active subset of network nodes changes from 308a, 308b, 308c at location 304A to 308b, 308c, 308d at location 304B, no obvious handover process is required in Figure 3 When the UE moves between serving areas, the UE can receive information to determine new candidate decoding parameters, but the UE still does not need to know that the new candidate decoding parameters are for layers from a different subset of network nodes in a different serving area (which includes at least one different network node).

[0065] Another movement of the UE from location 304B to location 304C is indicated at 322. Similarly, the active subset of network nodes is changed to 308c, 308d, 308e. Two of these layers, 332C and 336B, are the same as those at location 304B, but the codebook for layer 338 can now decode the communication signals received by the UE at location 304C.

[0066] The layer-to-network node assignment in the network node layer assignment implementation, for example, depending on the number of network nodes and the number of codebooks available for assignment, can be semi-static or static. Layers can also or alternatively be initially assigned to network nodes or moved from one network node to another, for example, for load balancing or energy saving. In one embodiment, as in Figure 1As shown at 120 in, new or updated codebook allocations are distributed to network nodes by a central processing system. The new or updated codebook and pilot signal lists can be similarly distributed to UEs.

[0067] The scheduling of UEs in the network node layer allocation system can be handled by each network node (distributed scheduling) or by a central processing system as shown at 120 in a centralized manner. The decisions of the scheduler can be sent as part of the radio resource grant, or detected blindly by the UE based on the layer at which it can decode the communication signal. Figure 1 As shown at 120 in. The decisions of the scheduler can be sent as part of the radio resource grant, or detected blindly by the UE based on the layer at which it can decode the communication signal.

[0068] Layer coordination can be optimized dynamically by network nodes coordinating with each other or under the control or guidance of a central processing system. However, such dynamically optimized layer coordination may pose higher requirements for backhaul and synchronization. Other options for layer coordination include semi-static optimized layer coordination and long-term coordination and setup, which can be achieved with more relaxed backhaul and synchronization requirements. Hybrid coordination, to accommodate different levels of cooperation between network nodes, is another option.

[0069] Figure 4 is a flowchart of a method according to an embodiment. Method 400 is an illustration of a method performed by a UE.

[0070] At 402, the UE receives communication signals from a subset of network nodes, as described above with reference to Figure 2 and Figure 3 . Each received communication signal is associated with a corresponding one of a plurality of layers.

[0071] Candidate layer decoding parameters are determined at 404. Such determination of candidate decoding parameters can involve, for example, accessing a list of candidate codebooks in a memory. Such a list, or more generally, the information for determining candidate decoding parameters, can be generated by a network node or a central processing system based on the current location of the UE and distributed to the UE. The candidate decoding parameters can include all decoding parameters available to the UE or a subset of these decoding parameters. The information for determining the candidate decoding parameters used by the UE in layer-based decoding of the received communication signal does not need to include the decoding parameters. The decoding parameters can be distributed to the UE individually and then the decoding parameters are available to the UE for use in layer-based decoding.

[0072] The candidate decoding parameters can include a set of codebooks for all layers in the network, or at least include the codebooks for the layers that can be active in one or more service areas of the network. The layers that may be active in a service area can include the layers that are already active in the case of network node layer allocation, or, in the case of UE layer allocation and layer transition between network nodes, the layers that have not been active so far but may subsequently become active after the UE moves to a different service area.

[0073] At 406, layer - based decoding of the received communication signal is performed. The layer - based decoding uses the candidate layer decoding parameters determined at 404. The UE attempts to decode the received communication signal using the candidate decoding parameters.

[0074] In the context of the code - domain layer, consider Figure 2 the example shown. At position 204A, the UE performs layer - based decoding using the codebooks it received for the three layers 230A, 232A, 234A. Using the layer conversion between network nodes as shown in Figure 2 , at position 204B, the same codebooks are also used to perform layer - based decoding of the additional communication signal received by the UE at that position. Thus, regardless of which specific network node the layer originated from, the codebook is an example of the layer decoding parameters for the layer associated with the currently received communication signal at position 204A.

[0075] Similarly, in the example of network node layer allocation shown in Figure 3 , the UE performs layer - based decoding using the codebooks for the three layers 330, 332A, 334A associated with the communication signal it received at position 304A. As described above, not all layers may be decodable at this position of the UE. However, the UE can still attempt to decode (i.e., perform layer - based decoding) using all the codebooks in its current candidate codebook list and determine the layers for which the communication signal is decodable. Some candidate codebooks may work while others may not. When the UE is at position 304A, the codebook for layer 336A cannot be used to successfully decode the communication signal, but when the UE moves to position 304B, the codebook for layer 336A can be used to successfully decode the communication signal. Thus, the candidate codebooks in this example represent a form of the decoding parameters for the layers associated with the currently received communication signal at position 304A, and after the UE moves to position 304B, the candidate codebooks are also used for the layers outside the current serving area.

[0076] Method 400 can be repeated when a new communication signal is received. The UE can receive a new communication signal while remaining in the same serving area and attempt to decode these signals as described above. As shown at 408, the UE can alternatively switch to a different serving area and, at 402, receive communication signals from a different subset of network nodes. At 404, the UE can determine some or all of the same candidate layer decoding parameters as in the previous serving area, and at 406, use those candidate decoding parameters to attempt to decode the newly received communication signal. For example, the determination of the candidate layer decoding parameters can be based on the UE receiving from, for example Figure 1Information received by the central processing system shown at 120 in []. The received information may include information for determining first candidate communication signal layer decoding parameters to be used by the UE in a service area and information for determining second candidate communication signal layer decoding parameters to be used by the UE after it moves to a different service area.

[0077] When the UE moves between service areas, the candidate decoding parameters may or may not change. In the UE layer allocation mode, for example, the communication signal layer assigned to the UE may be the same in different service areas, and thus the UE, at 404, may determine the same candidate decoding parameters and use the candidate decoding parameters in different service areas. In the network node layer allocation mode, the UE may be provided with information for determining the decoding parameters of the layers that can be active in its current service area and the layers that can be active in adjacent service areas. In this scenario, when the UE is located in the current service area and after it moves to an adjacent service area, the UE may use the same candidate decoding parameters.

[0078] In the case of UE layer allocation, the layer decoding parameters are used to decode the communication signals associated with the layer assigned to the UE. These parameters are independent of which particular one of the network nodes transmits the communication signal. For the case of network node layer allocation, the decoding parameters are used to decode the communication signals associated with the layer assigned to the network node.

[0079] Example method 400 is an illustration of one embodiment. Other embodiments may include different operations or additional operations. Examples of additional operations that may be performed, and / or various ways of performing the illustrated operations, may or may become apparent.

[0080] For example, at 404, any variation or combination of various decoding methods such as SIC, MPA, joint detection, MLD, and MIMO (linear or non - linear) decoders may be used to decode different layers from the same network node or different network nodes.

[0081] In some embodiments, the UE location is tracked at least in part based on the layer(s) on which the communication signal is successfully decoded. An example of an additional operation that may be performed in such embodiments is to send an indication of the candidate decoding parameters used to successfully decode the communication signal to the network node. For example, this operation may be performed after Figure 4 406 in []. In a mobile scenario, the UE may send an indication of the decoding parameters in the first candidate decoding parameters that are used to decode the first plurality of received communication signals to the network nodes in the first subset of network nodes, and / or, send an indication of the decoding parameters in the second candidate layer decoding parameters that are used to decode the second plurality of communication signals received after the service area transition to the network nodes in the second subset of the plurality of network nodes.

[0082] For example, the UE may detect a change in a set of layer decoding parameters for successfully decoding a received communication signal, and in response to detecting the change, send an indication of the decoding parameters among the layer decoding parameters that are used to decode the communication signal. The transmission of such an indication may also or alternatively be request-based, where the UE sends the indication in response to a request from a central processing system or a network node. Other options, including periodic or scheduled transmission times, are also possible.

[0083] The above description generally relates to layers and communication signals associated with such layers. There may be multiple levels of layers. The decoding method may separate different data layers, and the UE first successfully decodes the communication signal associated with one layer before proceeding to the next step. The hierarchical structure may alternatively involve a multi-layer setup such that the communication signal associated with a layer at a certain level will be decoded before attempting to decode at a higher level. For example, the first layer may have a relatively low modulation and coding scheme (MCS), and the second layer may have a relatively high MCS, such that the first layer can be decoded without knowledge of the second layer, and it is advantageous to decode the first layer before decoding the second layer. In both cases, there may be multiple levels of layers, and before performing layer-based decoding on the communication signal of the second level, layer-based decoding is first performed on one or more communication signals associated with the layer of the first level. A special case of the hierarchical structure is that each level includes only one layer.

[0084] Figure 5 FIG. 500 is a schematic structural diagram of a UE 500 that can perform the above method according to an embodiment. The exemplary UE 500 includes an antenna 502, a receiver 504 operably coupled to the antenna, and a decoder 506 operably coupled to the receiver. Although the embodiments disclosed herein mainly relate to receiving and decoding communication signals, the UE may include components such as a transmitter 508 and an encoder 510 operably coupled to the transmitter. In the illustrated example, the transmitter 508 is also operably coupled to the antenna 502 and the decoder 506.

[0085] Although a single antenna 502 is shown in Figure 5 , the UE may include multiple antennas. Separate receive and transmit antennas or a set of multiple antennas may be provided at 502, or the same antenna or the same set of multiple antennas may be used to receive and transmit communication signals. The antenna 502 may include one or more antennas of any of different types. The type of antenna provided at 502 may be implementation-specific.

[0086] In general, hardware, firmware, components that execute software, and some combination thereof can be used to implement the receiver 504, decoder 506, transmitter 508, and encoder 510. Electronic devices that may be suitable for implementing any or all of these components include microprocessors, microcontrollers, programmable logic devices (PLDs), field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), and other types of "intelligent" integrated circuits, among others.

[0087] Software and / or information, such as a codebook, that can be used in the operation of the UE 500 can be stored in one or more physical memory devices. Solid state memory devices and / or memory devices with removable or even removable storage media can be implemented. Examples of memory devices were provided above. The memory device can be within one or more of the components shown in Figure 5 and thus is not shown separately in the figures. An external memory device operably coupled to the described components or operably coupled to one or more processors that implement these components is also possible.

[0088] The receiver 504 can perform operations such as downconversion and demodulation of frequencies, and the transmitter 508 can perform inverse operations including upconversion and modulation of frequencies. Depending on the particular implementation, the communication functions to be supported, and the type of protocol to be supported, the receiver 504 and transmitter 508 can perform other operations in lieu of these example operations, or can perform other operations in addition to these example operations. As described herein, the decoder 506 performs layer-based decoding of received communication signals, and the encoder 510 encodes according to layers, or a plurality of layers on which the UE transmits to network nodes.

[0089] The receiver 504 is operable to receive communication signals from one or more network nodes that provide communication services within the service area of a communication network. Each communication signal is associated with a corresponding layer. For example, as referenced above Figure 4As described, decoder 506 is operable to perform layer-based decoding of a received communication signal using candidate layer decoding parameters. Receiver 504 and decoder 506 may be configurable, for example, by executing software in a processor-based embodiment, to perform these and other operations. Examples of other operations that receiver 504 and / or decoder 506 may be used to perform are described above. For example, decoder 506 may be further used to send an indication of the decoding parameters used to decode the received communication signal to transmitter 508, which enables UE 500 to send signals to a network node. A network node and / or a central processing system may use such an indication to track the location of UE 500.

[0090] Figure 6 is a flowchart of a method according to another embodiment. Method 600 is an illustration of a method performed by a network device. Method 600 may be centralized and, for example, performed in a central processing system as shown in 120 in Figure 1 in a communication network. Method 600 may alternatively be performed in a distributed manner at multiple network nodes, where the multiple network nodes communicate with each other to determine layer assignments and their own configurations.

[0091] At 602, layer assignment is coordinated, for example, by a central processing system as shown in 120 in Figure 1 or by a network node. The coordination at 602 involves determining how to assign layers. As described above, layers may be assigned to UEs or network nodes. Any one or more of the following factors may be considered in layer assignment: the number of layers available for assignment, the number of UEs, the number of network nodes in the network, load balancing, and energy saving. After determining the layer assignment, at 604, the layers are assigned to UEs or network nodes.

[0092] At 606, the decoding parameters for decoding communication signals associated with different layers are distributed to UEs. At 608, a first subset of network nodes (such as network nodes 208a, 208b, 208c in Figure 2 or 308a, 308b, 308c in Figure 3 ) is configured to send a first communication signal that can be decoded by UEs using the decoding parameters. A second subset of network nodes (such as network nodes 208b, 208c, 208d in Figure 2 or 308b, 308c, 308d in Figure 3 ) is also configured to send a second communication signal that can be decoded by UEs using the decoding parameters. Network nodes may be used to send communication signals associated with multiple layers.

[0093] In the layer allocation implementation for network nodes, for example, a layer is allocated to a network node. At 604, the configuration of the network nodes in the first subset and the second subset can be performed simultaneously.

[0094] However, the network nodes in the first and second subsets do not necessarily need to be configured simultaneously. In an embodiment where a layer is allocated to a UE, the location of the UE can be tracked and at least one network node in the second subset that takes over the responsibility of a specific layer from the network nodes in the first subset (after the UE enters the second service area) may not be configured until the UE has moved into or at least nearly entered the second service area. Refer to Figure 2 , for example, when the UE is at location 204A, the network node 208a can be used to send a communication signal associated with layer 230A. In response to detecting the movement of the UE from the first service area at location 204A to the second service area at location 204B, when the UE moves to location 204B, the network node 208d that takes over the responsibility of this layer from the network node 208a can be used to send a communication signal associated with layer 230B.

[0095] Figure 6 represents an illustrative embodiment. Other embodiments may include additional or different operations, which are performed in a similar order or a different order as Figure 6 shown.

[0096] For example, a method that may involve scheduling the transmission of communication signals by network nodes. Such scheduling can be performed at a central processing system in a communication network or in a distributed manner at each network node.

[0097] A method that may also or alternatively include tracking the location of a UE in a communication network, determining candidate decoding parameters used by the UE in the decoded communication signals received by the UE based on the current location of the UE, and sending information about the determined candidate decoding parameters to the UE. Location tracking may involve receiving an indication from the UE about the decoding parameters used to decode the communication signals received by the UE, and tracking the location of the UE in the communication network based on this indication. In some embodiments, other information is also or alternatively considered for location tracking.

[0098] Figure 7It is a schematic structural diagram depicting a central processing system according to an embodiment. The exemplary central processing system 700 includes a decoding parameter distributor 702, a coordination controller 704, and a scheduler 708, all of which are operably coupled to a coordination interface 706. The decoding parameter distributor 702, the coordination controller 704, and the scheduler 708 can be implemented using at least hardware, firmware, components executing software, or some combination thereof. The coordination interface 706 includes one or more physical ports or connectors connected to a communication medium through which the central processing system 700 communicates with network nodes. The coordination interface 706 also includes communication circuitry, which can be hardware-based, software-based, and / or firmware-based to support communication with a base station. The form of the coordination interface 706 depends on the communication medium / media and / or protocol supported between the central processing system 700 and the network nodes.

[0099] As referred to above Figure 6 The decoding parameter distributor 702 is operable to distribute decoding parameters to the UEs through the coordination interface 706 and one or more network nodes. Thus, the distribution from the central processing system 700 to the UEs can be indirect, i.e., through the coordination interface 706 and the network nodes that communicate with the central processing system and the UEs.

[0100] The coordination controller 704, in a manner described by 604 in Figure 6 is operably configured to configure a first subset of network nodes and a second subset of network nodes. In the UE layer allocation model, the coordination controller 704 can also be used to allocate layers to the UEs and configure the network nodes in the first subset to transmit communication signals associated with the layer. The coordination controller 704 can also be used to detect the movement of the UE from a first service area to a second service area and configure the network nodes in the second subset to transmit communication signals associated with the layer, thereby providing layer handover between network nodes for the movement of the UE.

[0101] To implement network node layer allocation, the coordination controller 704 can be used to allocate layers to the network nodes and configure the network nodes in the first subset and the second subset to transmit communication signals associated with the layers allocated to the network nodes, respectively.

[0102] As described above, the scheduling can be centralized, and the scheduler 708 is used to schedule the transmission of communication signals through the network nodes. In an embodiment of distributed scheduling, a scheduler may not be provided at the central processing system.

[0103] Some aspects of coordination and / or scheduling between network nodes can be implemented at the network nodes. Figure 8Is a schematic structural diagram depicting a network node according to an embodiment. The exemplary network node includes, as shown, a coordination controller 804, an encoder 806, a transmitter 808, one or more antennas at 810, a coordination interface 812, a scheduler 813, a decoder 814, and a receiver 816 that are operatively coupled together.

[0104] The coordination controller 804, the encoder 806, the transmitter 808, the scheduler 813, the decoder 814, and the receiver 816 can be implemented using at least hardware, firmware, components executing software, or some combination thereof. The antennas shown at 810 can include separate receive and transmit antennas, or a collection of antennas; alternatively, the same antenna or the same collection of antennas can be used for receiving and transmitting communication signals. One or more antennas of any type can be provided at 810, and the antenna type can be specific to the implementation. The antennas at 810 are compatible with the UE antennas 502 ( Figure 5 ) to enable communication between the network node 800 and the UE. Similarly, the coordination interface 812 is compatible with the coordination interface 706, and it can be implemented in a similar manner in embodiments including a central processing system. The network nodes can also or alternatively communicate with each other through the compatible coordination interfaces 812 at each network node. The communication circuitry in the coordination interface 812 can be hardware-, software-, and / or firmware-based to support communication with the central processing system and / or other network nodes. The form of the coordination interface 812 depends on the communication medium / media and / or protocol to be supported.

[0105] The coordination controller 804 can cooperate with the coordination controller 704 ( Figure 7 ) at the central processing system to distribute decoding parameters to the UE and / or configure the network node 800. For example, the coordination controller 804 can receive decoding parameters from the coordination controller 704 through the coordination interfaces 706, 812, and control the transmitter 808 to send these parameters to the UE. The coordination controller 804 can also or alternatively receive layer information, such as the codebook used by the network node 800, from the coordination controller 704, and configure the encoder 806 and / or the transmitter 808 such that the network node 800 sends communication signals associated with one or more specific layers. Alternatively, the coordination between network nodes can be distributed, where the coordination controllers 804 at the network nodes are used to communicate with each other to coordinate the allocation and distribution of decoding parameters and / or network node configurations.

[0106] Although the network node 800 also includes a scheduler 813, the ultimate control of network node scheduling can be centralized. For example, the scheduler 813 can be controlled by the scheduler 708 ( Figure 7) Control. The network node is still responsible for scheduling the traffic at the network node, but the scheduling is centrally controlled. In a distributed scheduling system, the scheduler 813 at each network node can alternatively be responsible for its own scheduling.

[0107] What has been described is merely an application of the principles of the embodiments of the present disclosure. Those skilled in the art can implement other settings and methods.

[0108] The content of the drawings is for illustrative purposes only, and the present invention is in no way limited to the specific exemplary embodiments clearly shown in the drawings and the description herein. For example, Figures 1 to 3 is a schematic structural diagram of a communication network in which the embodiments can be implemented. Other embodiments can be implemented in a communication network including more network nodes than the shown network nodes, or in a communication network having a topology different from the shown example. Similarly, Figure 4 and 6 the exemplary methods in Figure 5 the exemplary UEs in Figure 7 the exemplary central processing systems in Figure 8 and the exemplary network nodes in

[0109] The details of other implementations can also vary between different embodiments. For example, the layer-based coordination in the UDN disclosed herein can coexist with other transmission schemes. The OFDM layer or code layer can be assigned not only to mobile UEs but also to "cell center" low-mobility UEs.

[0110] As disclosed herein, the layer-based coordination may involve the transmission of various types of information between the central processing system, network nodes, and / or UEs. Any of various signaling methods can be implemented.

[0111] Taking into account the UE layer assignment, signaling at higher layers in the protocol stack can be used for the allocation and / or update of the initial signature / codebook in a semi-static or dynamic system. Similarly, MCS signaling can support the allocation or assignment of dynamic or semi-static MCS. For example, in an embodiment where the scheduling is non-blind scheduling, permission signaling can use the Physical Downlink Control Channel (PDCCH) in an LTE-based system. On a per-link and / or Time Division Duplex (TDD) basis, feedback for reporting signal strength and / or Channel Quality Indicator (CQI) can be implemented. Acknowledgement (ACK) / negative acknowledgement (NAK) signaling can use collective ACK or individual ACK.

[0112] For network node codebook allocation, higher-level signaling can be used to distribute a list of possible codebooks and / or other layer-related information. The measurement channels for UE reporting can be direct, indirect, or hybrid. As pointed out above for UE layer allocation, the scheduling in the network node layer allocation system can be blindly detected or included in the permission signaling, for example, using the PDCCH for permission signaling. ACK / NAK signaling can be ACK for blind-based ACK or ACK / NAK for PDCCH-based authorization signaling. For example, the optional feedback signaling for the list of decodable layers for UE reporting can be TDD-based or hybrid. Although horizontal and vertical coding are options in the UE layer allocation system, vertical coding is preferred for the network node layer allocation system.

[0113] These descriptions of implementation details can be combined with layer-based multi-point transmission implementations as disclosed herein.

[0114] This disclosure is mainly directed to the reception and decoding of communication signals by the UE. However, it should be understood that the UE can also send communication signals to the network node. The communication signals sent by the UE are similarly associated with the layers assigned to the UE or one or more network nodes to which the UE is sending. For example, the receiver 816 ( Figure 8 ) at the network node can receive signals from the UE. The signals received from the UE can include an indication of the decoding parameters used to decode the communication signals received by the UE. The received indication can be provided to the coordination controller 804 at the network node, to the coordination controllers at one or more other network nodes, and / or to the coordination controller 704 at the central processing system through the coordination interfaces 812, 706 ( Figure 7)。Any number or all of these coordination controllers can track the location of a UE in a communication network based on the indication.

[0115] Different layers can involve different levels of cooperation between network nodes. For example, assume that in a UE layer allocation embodiment, there are three network nodes serving a UE, where only two network nodes are connected by a relatively fast backhaul connection, and the third network node is connected by a slower backhaul connection. The network nodes with the fast backhaul connection can use a joint scheduler to dynamically distribute the layers of the UE to these two network nodes. However, any backhaul exchange between the two network nodes and the third network node may be slower, and static or semi-static cooperation and / or layer allocation would be more suitable for the third network node.

[0116] In the embodiments disclosed herein, the service can be considered to move with the UE. The cooperation between network nodes can be simplified, and seamless service can be provided to the UE as it moves between different coverage areas of the network.

[0117] The embodiments also provide multi-layer cooperation. Multi-site diversity can improve channel stability and make the communication channel less susceptible to channel aging caused by mobility.

[0118] The present invention can also be understood with reference to the following examples.

[0119] In an example, a method includes: configuring a first subset of network nodes in a communication network to send a first communication signal that can be decoded by a user equipment (UE) using decoding parameters associated with a communication signal layer in the communication network, each of the first communication signals being associated with a respective one of a plurality of communication signal layers; and configuring a second subset of network nodes in the communication network to send a second communication signal that can be decoded by the UE using the decoding parameters, the second subset of network nodes including at least one network node that is not in the first subset of network nodes, each of the second communication signals being associated with a respective one of the plurality of communication signal layers.

[0120] According to the foregoing example, the method further includes distributing the decoding parameters to the UE.

[0121] According to any of the foregoing examples, the method further includes allocating a communication signal layer of a plurality of communication signal layers to the UE; and tracking the location of the UE in the communication network. Configuring the first subset of network nodes includes: configuring the network nodes of the first subset of network nodes to transmit a communication signal associated with the communication signal layer when the UE is located in a first service area where the first subset of network nodes provides communication services. Configuring the second subset of network nodes includes: configuring the network nodes of the second subset of network nodes to transmit a communication signal associated with the communication signal layer when the UE moves from the first service area to a second service area where the second subset of network nodes provides communication services.

[0122] According to any of the foregoing examples, the method further includes allocating a plurality of communication signal layers to the network nodes. Configuring the first subset of network nodes and configuring the second subset of network nodes includes: configuring the network nodes of the first subset of network nodes and the second subset of network nodes to transmit communication signals respectively associated with the communication signal layers allocated to the network nodes.

[0123] According to any of the foregoing examples, the method further includes tracking the location of the UE in the communication network; determining, based on the current location of the UE, candidate decoding parameters among the decoding parameters distributed to the UE for use by the UE in decoding the received decoded communication signal, and sending information determining the candidate decoding parameters to the UE.

[0124] According to any of the foregoing examples, the method is executed at a central processing system in the communication network.

[0125] According to any of the foregoing examples, the method is executed at each of the network nodes of the first subset of network nodes and the second subset of network nodes. The configuration includes the network nodes communicating with each other to coordinate the configuration.

[0126] According to any of the foregoing examples, the method further includes scheduling the transmission of communication signals by the network nodes of the first subset of network nodes and the second subset of network nodes.

[0127] According to any of the foregoing examples, the scheduling is executed at a central processing system in the communication network.

[0128] According to any of the foregoing examples, the scheduling is executed at each of the network nodes of the first subset of network nodes and the second subset of network nodes.

[0129] According to any of the foregoing examples, configuring the first subset of network nodes and configuring the second subset of network nodes includes: configuring one of the network nodes of the first subset of network nodes and the second subset of network nodes to transmit a plurality of communication signals associated with a different one of the communication signal layers.

[0130] According to any of the foregoing examples, the method further includes: receiving, from a UE, an indication of decoding parameters that are used to decode a communication signal received by the UE; and tracking a location of the UE in a communication network based on the indication.

[0131] According to a further example, a processor-readable non-transitory medium storing instructions that, when executed by one or more processors, cause the processors to perform a method that includes: configuring a first subset of network nodes in a communication network to transmit a first communication signal that can be decoded by a user equipment (UE) using decoding parameters associated with a communication signal layer in the communication network, each of the first communication signals being associated with a respective one of a plurality of communication signal layers; and configuring a second subset of network nodes in the communication network to transmit a second communication signal that can be decoded by the UE using the decoding parameters, the second subset of network nodes including at least one network node that is not in the first subset of network nodes, each of the second communication signals being associated with a respective one of the plurality of communication signal layers.

[0132] According to a further example, an apparatus includes: a coordination controller configured to: configure a first subset of network nodes in the communication network to transmit a first communication signal that can be decoded by a user device (UE) using the decoding parameters associated with a communication signal layer in the communication network, each of the first communication signals being associated with a respective one of the plurality of communication signal layers; and configure a second subset of the network nodes in the communication network to transmit a second communication signal that can be decoded by the user device UE using the decoding parameters, the second subset of network nodes including at least one network node that is not in the first subset of network nodes, each of the second communication signals being associated with a respective one of the plurality of communication signal layers; and a coordination interface coupled to the coordination controller to communicate with the network nodes.

[0133] According to any of the foregoing examples, the apparatus further includes a decoding parameter distributor to distribute decoding parameters to the UE.

[0134] According to any of the foregoing examples, the coordination controller is further configured to: allocate a communication signal layer of the plurality of communication signal layers to the UE; configure the network nodes of the first subset of network nodes to transmit a communication signal associated with the communication signal layer when the UE is located in a first service area where the first subset of network nodes provides communication services; and configure the network nodes of the second subset of network nodes to transmit a communication signal associated with the communication signal layer when the UE moves from the first service area to a second service area where the second subset of network nodes provides communication services.

[0135] According to any of the foregoing examples, the coordination controller is further configured to allocate a plurality of communication signal layers to network nodes, and configure network nodes of a first subset of network nodes and a second subset of network nodes to transmit communication signals respectively associated with the communication signal layers allocated to the network nodes.

[0136] According to any of the foregoing examples, the coordination controller is further configured to: track the location of the UE in the communication network; determine candidate decoding parameters used by the UE in decoding the received communication signals from among the decoding parameters distributed to the UE based on the current location of the UE, and send information determining the candidate decoding parameters to the UE.

[0137] According to any of the foregoing examples, the apparatus is implemented at a central processing system in the communication network.

[0138] According to any of the foregoing examples, the apparatus includes a coordination controller implemented at each of the network nodes of a first subset of network nodes and a second subset of network nodes, the coordination controllers being configured to communicate with each other to coordinate the configuration of the network nodes.

[0139] According to any of the foregoing examples, the apparatus further includes a scheduler to schedule the transmission of communication signals through the network nodes of a first subset of network nodes and a second subset of network nodes.

[0140] According to any of the foregoing examples, the apparatus is implemented at a central processing system in the communication network.

[0141] According to any of the foregoing examples, the apparatus includes a scheduler at each of the network nodes of a first subset of network nodes and a second subset of network nodes.

[0142] According to any of the foregoing examples, the coordination controller is configured to configure one of the network nodes of a first subset of network nodes and a second subset of network nodes to transmit a plurality of communication signals associated with different ones of the plurality of layers in the communication signal layer.

[0143] According to any of the foregoing examples, the apparatus further includes a receiver to receive signals from the UE. The coordination controller is coupled to the receiver and is further configured to receive an indication of the decoding parameters among the decoding parameters used by the UE to decode the communication signals received by the UE; and track the location of the UE in the communication network based on the indication.

[0144] Additionally, although mainly described in the context of methods and systems, other embodiments are also conceivable, for example, as instructions stored on a non-transitory processor-readable medium.

Claims

1. A communication method, characterized in that, Comprising: Receiving control information related to spatial domain layers via a Physical Downlink Control Channel (PDCCH), the control information being used to identify spatial domain layers in a communication network; Receiving a plurality of communication signals from a subset of network nodes in the communication network, each of the plurality of communication signals being associated with one of the spatial domain layers in the communication network; Decoding the plurality of communication signals according to spatial domain layer decoding parameters; Sending acknowledgement / negative acknowledgement (ACK / NAK) signaling to the subset of network nodes, the ACK / NAK signaling including feedback information for each of the spatial domain layers, the feedback information indicating whether the communication signals associated with each spatial domain layer are successfully decoded.

2. The method according to claim 1, characterized in that, The method further comprises receiving high-layer signaling comprising the spatial domain layer decoding parameters, the spatial domain layers being allocated to the subset of network nodes in the communication network.

3. The method according to claim 1, characterized in that, The decoding comprises decoding the plurality of communication signals using a Multiple-Input Multiple-Output (MIMO) decoder.

4. A communication device, characterized in that, Comprising: A processor; A memory storing instructions which, when executed by the processor, cause the apparatus to: Receive control information related to spatial domain layers via a Physical Downlink Control Channel (PDCCH), the control information being used to identify spatial domain layers in a communication network; Receive a plurality of communication signals from a subset of network nodes in the communication network, each of the plurality of communication signals being associated with one of the spatial domain layers in the communication network; Decoding the plurality of communication signals according to spatial domain layer decoding parameters; Sending acknowledgement / negative acknowledgement (ACK / NAK) signaling to the subset of network nodes, the ACK / NAK signaling including feedback information for each of the spatial domain layers, the feedback information indicating whether the communication signals associated with each spatial domain layer are successfully decoded.

5. The device according to claim 4, characterized in that, The memory stores the instructions which, when executed by the processor, cause the apparatus to receive high-layer signaling comprising the spatial domain layer decoding parameters, the spatial domain layers being allocated to the subset of network nodes in the communication network.

6. The device according to claim 4, characterized in that The decoding comprises decoding the plurality of communication signals using a Multiple-Input Multiple-Output (MIMO) decoder.

7. A computer-readable storage medium having a computer program or instructions stored thereon, characterized in that, When the computer program or instructions are executed, cause a computer to perform the method according to any one of claims 1 to 3.

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