Method for Transmitting Configuration, Wireless Communication Device, Network Node, and Operating Method

Abstract

The present application relates to a method for transmitting configuration, a wireless communication device, a network node, and an operation method. A method for configuring a multi-channel uplink transmission (199) is provided, the multi-channel uplink transmission including a plurality of channels (151, 152, 159, 451, 452) between a wireless communication device (102) and a plurality of receiving panels (1013-1, 1013-2) of at least one network node (101). The plurality of receiving panels (1013-1, 1013-2) and the at least one network node (101) are connected via a backhaul link (1018-1, 1018-2). The method is performed by the wireless communication device (102). The method includes the steps of: receiving control data (4001) encoded with a downlink message for the multi-channel uplink transmission (199) from the at least one network node (101), the control data (4001) being associated with the backhaul link. The method further includes the step of: configuring the multi-channel uplink transmission (199) based on the control data (4001).

Description

Technical Field

[0001] Various examples of the present invention generally relate to multi-channel uplink transmission using multiple antenna panels. Specific examples relate to the following scenario: the backhaul links of multiple antenna panels face operational limitations (e.g., regarding throughput, latency, etc.). Background Art

[0002] Sometimes, a spatially defined transmission path using radio waves is used to achieve wireless communication. Each transmission path corresponds to a respective channel.

[0003] Generally, the implementation of a spatially defined transmission path includes using multiple antennas of an antenna panel. These techniques are collectively referred to as multi-antenna techniques.

[0004] Multiple antenna techniques can be implemented in various ways. In a first example, spatial multiplexing (commonly known as multiple-input multiple-output MIMO) can be used to increase the overall data rate. Here, multiple spatially diverse transmission paths are established between a transmitter and a receiver. A second example includes beamforming: here, spatial directivity for transmission and / or reception (propagation) is achieved through constructive and destructive interference at multiple antennas. One or more beamformed transmission paths are established.

[0005] Sometimes, a node can access multiple different antenna panels (sometimes also referred to as remote radio heads RRHs), which are spaced apart from each other and connected via available backhaul links. For example, see Third Generation Partnership Project (3GPP) TSG RAN WG1 Meeting #88: document R1-1702673 or 3GPP TSG RAN Meeting #80: document RP-181453. Sometimes, this functionality is referred to as multi-transmission panel (multi-TRP). Generally, for multi-TRP, the RRHs are spaced apart by at least 100 m or at least 400 m.

[0006] It has been observed that in a multi-TRP scenario, the connectivity between multiple RRHs can be affected by the operational limitations imposed by the backhaul links. Such limitations in RRH-to-RRH connectivity can make it difficult to implement multi-antenna techniques. Summary of the Invention

[0007] Therefore, there is a need for advanced multi-antenna techniques that use multiple RRHs with non-ideal backhaul links.

[0008] A method for configuring multi-channel uplink transmission is provided. The multi-channel uplink transmission includes multiple channels between a wireless communication device and multiple receiving panels of at least one network node. The multiple receiving panels and the at least one network node are connected via a backhaul link. The method is executed by the wireless communication device. The method includes the following steps: receiving control data encoded in a downlink message for multi-channel uplink transmission from the at least one network node, the control data being associated with the backhaul link. The method further includes the following step: configuring the multi-channel uplink transmission based on the control data.

[0009] The at least one network node may use the multiple receiving panels.

[0010] The at least one network node may be an access node such as a base station of a communication network.

[0011] A computer program product or a computer program is provided. The computer program product or the computer program includes program code that can be executed by a control circuit. Executing the program code causes the control circuit to execute: a method for configuring multi-channel uplink transmission, the multi-channel uplink transmission including multiple channels between a wireless communication device and multiple receiving panels of at least one network node. The multiple receiving panels and the at least one network node are connected via a backhaul link. The method is executed by the wireless communication device. The method includes the following steps: receiving control data encoded in a downlink message for multi-channel uplink transmission from the at least one network node, the control data being associated with the backhaul link. The method further includes the following step: configuring the multi-channel uplink transmission based on the control data.

[0012] A computer-readable storage medium is provided. The computer-readable storage medium includes program code that can be executed by a control circuit. Executing the program code causes the control circuit to execute: a method for configuring multi-channel uplink transmission, the multi-channel uplink transmission including multiple channels between a wireless communication device and multiple receiving panels of at least one network node. The multiple receiving panels and the at least one network node are connected via a backhaul link. The method is executed by the wireless communication device. The method includes the following steps: receiving control data encoded in a downlink message for multi-channel uplink transmission from the at least one network node, the control data being associated with the backhaul link. The method further includes the following step: configuring the multi-channel uplink transmission based on the control data.

[0013] A wireless communication device is provided that is operable to configure a multi-channel uplink transmission, the multi-channel uplink transmission including a plurality of channels between the wireless communication device and a plurality of receiving panels of at least one network node, the plurality of receiving panels and the at least one network node being connected via a backhaul link, wherein the wireless communication device is configured to: receive control data encoded in a downlink message for the multi-channel uplink transmission from the at least one network node, the control data being associated with the backhaul link, and configure the multi-channel uplink transmission based on the control data.

[0014] A method of operating a network node is provided, the network node being capable of using a plurality of receiving panels. The plurality of receiving panels and the at least one network node are connected via a backhaul link. The method includes the steps of: sending control data encoded in a downlink message for the multi-channel uplink transmission to a wireless communication device, the control data being associated with the backhaul link. The method may further include the step of: participating in the multi-channel uplink transmission configured based on the control data.

[0015] A computer program product or a computer program is provided, the computer program product or the computer program including program code executable by a control circuit. Executing the program code causes the control circuit to perform: a method of operating a network node, the network node being capable of using a plurality of receiving panels. The plurality of receiving panels and the at least one network node are connected via a backhaul link. The method includes the steps of: sending control data encoded in a downlink message for the multi-channel uplink transmission to a wireless communication device, the control data being associated with the backhaul link. The method may further include the step of: participating in the multi-channel uplink transmission configured based on the control data.

[0016] A computer-readable storage medium is provided, the computer-readable storage medium including program code executable by a control circuit. Executing the program code causes the control circuit to perform: a method of operating a network node, the network node being capable of using a plurality of receiving panels. The plurality of receiving panels and the at least one network node are connected via a backhaul link. The method includes the steps of: sending control data encoded in a downlink message for the multi-channel uplink transmission to a wireless communication device, the control data being associated with the backhaul link. The method may further include the step of: participating in the multi-channel uplink transmission configured based on the control data.

[0017] A network node is provided that is capable of using multiple receiving panels. The multiple receiving panels and the at least one network node are connected via a backhaul link. The network node is configured to send control data encoded with a downlink message for multi-channel uplink transmission to a wireless communication device, the control data being associated with the backhaul link. The network node may also be configured to participate in a multi-channel uplink transmission configured based on the control data.

[0018] It should be understood that, without departing from the scope of the present invention, the above features and those features to be described below can be used not only in the indicated corresponding combinations, but also in other combinations or in isolation. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A wireless communication system according to various examples is schematically illustrated.

[0020] Figure 2 is schematically illustrated in more detail Figure 1 a wireless communication system of, wherein the base station of the wireless communication system includes a plurality of RRHs.

[0021] Figure 3 is schematically illustrated for Figure 1 and Figure 2 a beamforming scenario of a wireless communication system of.

[0022] Figure 4 is schematically illustrated for Figure 1 and Figure 2 a MIMO scenario of a wireless communication system of.

[0023] Figure 5 is a signaling diagram according to various examples.

[0024] Figure 6 is schematically illustrated for configuring a multi-channel UL transmission according to various examples.

[0025] Figure 7 is a flowchart of a method according to various examples.

[0026] Figure 8 is a flowchart of a method according to various examples. DETAILED DESCRIPTION

[0027] Hereinafter, with reference to the drawings, embodiments of the present invention will be described in detail. It should be understood that the following description of the embodiments is not to be taken in a limiting sense. The scope of the present invention is not intended to be limited by the embodiments described below or by the drawings, but is only considered illustrative.

[0028] The accompanying drawings are to be regarded as schematic representations and the elements illustrated in the drawings need not be shown to scale. On the contrary, the various elements are represented such that their function and general purpose will be apparent to a person skilled in the art. Any connection or coupling between functional modules, devices, components or other physical or functional units shown in the drawings or described herein may also be implemented by means of an indirect connection or coupling. The couplings between components may also be established by wireless connections. The functional modules may be implemented in hardware, firmware, software, or a combination thereof.

[0029] The various examples described herein relate to wireless communication between a first node and a second node of a wireless communication system. The first node and the second node communicate over a wireless link using multi-antenna techniques such as MIMO and / or beamforming.

[0030] In the various examples described herein, multi-TRP is employed: here, the first node may use multiple RRHs. The multiple RRHs are connected to each other and / or connected to respective nodes via a backhaul link. As usual, the backhaul link may also rely on wireless transmission. Moreover, wired transmission is also possible.

[0031] According to various examples, at least one of the backhaul links in the backhaul link faces data throughput limitations. This may be due to the distance between the multiple RRHs, the system load on the backhaul link, and / or core network signaling limitations. Generally, the at least one backhaul link in the backhaul link may have non-ideal system behavior. This may result in limitations in the connectivity between RRHs.

[0032] Hereinafter, the techniques will be described in connection with mobile wireless communication between a wireless communication device such as a terminal (user equipment UE) and a communication network. The communication network generally includes a radio access network (RAN) having one or more base stations (BSs); and a core network (CN). The one or more BSs may be equipped with multiple RRHs according to multi-TRP. This establishment of mobile wireless communication between the UE and the one or more BSs is an example; in other examples, according to multi-TRP, it is also possible to implement a wireless link using multi-antenna techniques between two fixed nodes, each fixed node including multiple RRHs.

[0033] Hereinafter, the techniques will be described in connection with uplink (UL) transmission from the UE to the RAN. Specifically, techniques will be described that allow for the configuration of multi-channel UL transmission, where the multi-channel UL transmission includes multiple channels associated with the multiple RRHs. As usual, one or more channels may be associated with each RRH. Different RRHs may be associated with different channels.

[0034] As used herein, a channel may relate to the connectivity in the air between two terminal nodes. For example, the connectivity between a UE and at least one RRH. The channel may be characterized by an air transmission path. Various transmission paths may be configured by the antenna weights of the antennas of the antenna panel. The antenna weights may define the amplitude and phase relationships between the signals transmitted by the various antennas. The channel may be characterized by a certain modulation scheme and / or a certain coding scheme. The channel may be characterized by a certain repetition-based coverage enhancement (CE) strategy, which may define, for example, the repetition level. The channel may be characterized by one or more parameters of the packet data exchanged via the channel (such as the data unit size, etc.).

[0035] By using multiple channels associated with multiple RRHs, spatial multiplexing can be achieved. This can increase the overall data throughput between the UE and the RAN.

[0036] According to various examples, the configuration of the multiple channels for multi-channel UL transmission takes into account the control data provided by the network. For example, the network may provide a downlink (DL) message that encodes the control data. For example, a layer 3 radio resource control (RRC) DL control message may be adopted. For example, the DL control message may be transmitted on the physical DL control channel (PDCCH). Then, the UE may configure the multi-channel UL transmission based on the control data.

[0037] Associate the control data with the backhaul link. By providing the control data and accordingly configuring the multi-channel UL transmission, certain criteria can be considered at the UE for the backhaul link that was originally not usable / opaque to the UE. For example, certain limitations of the backhaul link may be considered. This helps to optimize the overall end-to-end throughput between the UE and the communication network.

[0038] For example, the control data may be determined according to one or more characteristics of the backhaul link. Alternatively or additionally, the control data may indicate the one or more characteristics of the backhaul link.

[0039] Generally, there are various options available for configuring multi-channel UL transmission. Some example options are described below. In one example, for example, by setting the modulation scheme and / or the coding scheme and / or by choosing between beamforming and MIMO techniques and / or by setting the repetition level, the channels for configuring multi-channel UL transmission will be configurable. Alternatively or additionally, by configuring the inflow traffic shaping upstream of the multiple channels, it will also be possible to configure multi-channel UL transmission. For example, rate allocation rules may be used to distribute the incoming data between the multiple channels, and one or more combining characteristics may be appropriately set, etc.

[0040] Figure 1FIG. 0 schematically illustrates a communication network 100 that may benefit from the techniques disclosed herein. The communication network 100 may be implemented according to 3GPP standardized networks such as 3G, 4G, or the upcoming 5G NR. Other examples include point-to-point networks such as those specified by the Institute of Electrical and Electronics Engineers (IEEE), such as the 802.11x Wi-Fi protocol or the Bluetooth protocol. Further examples include 3GPP NB-IOT or eMTC networks.

[0041] The communication network 100 includes BS101 and UE 102. BS101 is part of the RAN ( Figure 1 not illustrated in FIG.). The RAN may include multiple BSs.

[0042] A wireless link 111 is established between BS101 (e.g., a gNB in the 3GPP NR framework) and UE 102. The wireless link 111 includes a DL wireless link from BS101 to UE 102; and also includes a UL wireless link from UE 102 to BS 101.

[0043] As usual, for communication over the wireless link 11, various multi-antenna techniques may be implemented, e.g., including MIMO and / or beamforming.

[0044] UE 102 may be one of the following: a smart phone; a cellular phone; a tablet; a laptop; a computer; a smart TV; an MTC wireless communication device; an eMTC wireless communication device; an IoT wireless communication device; an NB-IoT wireless communication device; a sensor; an actuator; etc.

[0045] Figure 2 FIG. 18 more schematically illustrates the communication system 1000, BS101, and UE 102.

[0046] BS110 includes: a processor 1011, a memory 1015, and an interface 1012.

[0047] The interface 1012 is configured to transmit and / or receive (communicate) via the wireless link 111. To this end, the interface 1012 is connected to two RRHs 1013-1, 1013-2 via backhaul links 1018-1, 1018-2. Each of the RRHs 1013-1, 1013-2 includes a plurality of antennas 1014. As Figure 2As shown, the RRHs 1013-1 and 1013-2 are spaced apart from each other by a certain distance, typically at least several meters or even hundreds of meters. Each antenna 1014 may include one or more electrical traces to carry radio frequency current. Each antenna 1014 may include one or more LC oscillators implemented by the electrical traces. Each trace may radiate electromagnetic waves with a specific beam pattern. In some examples, the BS 101 may include multiple antenna panels ( Figure 2 not illustrated in

[0048] Generally, each of the RRHs 1013-1 and 1013-2 may include at least 40 antennas or a count of at least 400 antennas.

[0049] The BS 101 may include more than two RRHs 1013-1 and 1013-2.

[0050] The processor 1011 and the memory 1015 form a control circuit. The memory 1015 may store program code that can be executed by the processor 1011. Executing the program code may cause the processor 1011 to perform techniques regarding: providing control data for multi-channel transmission from the BS 101 to the UE 102 or from the UE 102 to the BS 101; participating in multi-channel UL transmission; participating in MIMO transmission; participating in beamformed transmission; etc.

[0051] The UE 102 includes: a processor 1021, a memory 1025, and an interface 1022. The interface 1022 is coupled to an antenna panel 1023 including multiple antennas 1024 via an antenna port ( Figure 2 not shown in Figure 2 not illustrated in

[0052] The processor 1021 and the memory 1025 form a control circuit. The memory 1025 may store program code that can be executed by the processor 1021. Executing the program code may cause the processor 1021 to perform techniques regarding: receiving control data for UL multi-channel transmission; configuring the multi-channel UL transmission based on the control data; participating in multi-channel UL transmission; participating in MIMO transmission; participating in beamformed transmission; etc.

[0053] Figure 3 More specifically, the communication system 1000, BS 101, and UE 102 are illustrated schematically in more detail. Figure 3 The scenario corresponding to Figure 2 the scenario. Figure 3 Aspects related to multi-channel UL transmission 199 are illustrated. Specifically, Figure 3 a first implementation of multi-channel UL transmission 199 is illustrated. Figure 3 Aspects regarding beamforming are illustrated.

[0054] In Figure 3 the example, multi-channel UL transmission 199 includes two channels 151, 152. In Figure 3 the example, the two channels 151, 152 are implemented using beamforming. Specifically, spatial multiplexing across the multiple channels 151, 152 is achieved by using two beamformed transmission paths, each beamformed transmission path being associated with a respective RRH 1013-1, 1013-2. For example, line-of-sight (LOS) or non-LOS transmission paths can be used. The non-LOS transmission paths include one or more reflections.

[0055] Channel 151 is from UE 102 to RRH 1013-1, and the second channel 152 is from UE 102 to RRH 1013-2. Channel 151 is associated with a transmit beam 311, which is achieved by appropriate antenna weights of antenna 1024 of antenna panel 1023 at UE 102. Channel 151 is also associated with a receive beam 311, which is achieved by appropriate antenna weights of antenna 1014 of RRH 1013-1. Similarly, channel 152 is associated with a transmit beam 312 and a receive beam 332. The beams 311, 312, 331, 332 define the spatial orientation of the respective transmission paths.

[0056] The receive beam 331 is achieved by the phase-coherent reception of the antenna 1014 of the RRH 1013-1. The receive beam 332 is achieved by the phase-coherent reception of the antenna 1014 of the RRH 1013-2. For achieving the receive beam 331, the signals received at the antenna 1014 of the RRH 1013-2 do not need to be considered; similarly, for achieving the receive beam 332, the amplitude and phase of the signals received at the antenna 1014 of the RRH 1013-1 do not need to be considered. This is because the beamformed transmission paths of the channels 151 and 152 are respectively non-coherently targeted at the RRH 1013-1 and the RRH 1013-2. In other words, there is no strict phase relationship required between the signals transmitted along the channel 151 and the signals transmitted along the channel 152. Therefore, generally no time and / or frequency synchronization is required between the operations of multiple RRHs 1013-1 and 1013-2. The signals received at the RRH 1013-1 can be decoded independently of the signals received at the RRH 1013-2. Combining Figure 4 illustrates a slightly different scenario.

[0057] Figure 4 More specifically, the communication system 1000, the BS 101, and the UE 102 are schematically illustrated. Figure 4 The scenario corresponding to Figure 2 the scenario. Figure 4 illustrates aspects regarding multi-channel UL transmission. Specifically, Figure 4 illustrates a second implementation of multi-channel UL transmission. Figure 4 illustrates aspects regarding MIMO.

[0058] In Figure 4 the scenario, multi-channel UL transmission is achieved using MIMO across two RRHs 1013-1 and 1013-2. There are many channels 159. Specifically, there is a channel between each antenna of the antennas 1024 in the antenna panel 1023 and each antenna of the antennas 1014 in the two RRHs 1013-1 and 1013-2. Again, each channel 159 is associated with a corresponding spatial transmission path.

[0059] The channels 159 can be set to be independent of each other and the coupling can be reduced based on the singular value decomposition of the channel matrix. The signals received by the receiver along different channels can be decorrelated, sometimes called zero-forcing. A closed-loop MIMO technique with feedback (precoding matrix indicator PMI) can be used on the precoding matrix.

[0060] There is a phase relationship between the signals transmitted along the channels 159. Therefore, the multiple RRHs 1013-1 and 1013-2 are coherently targeted by the channels 159.

[0061] This requires coherent decoding of the signals received at the antennas 1014 of all the RRHs 1013-1 and 1013-2. In other words, it may be necessary to provide information on the amplitude and phase of the signals received at the antennas 1014 of the RRH 1013-1 via the backhaul link 1018-1, and / or provide information on the amplitude and phase of the signals received at the antennas 1014 of the RRH 1013-2 via the backhaul link 1018-2. Moreover, time and / or frequency synchronization may be required between the operations of the RRHs 1013-1 and 1013-2.

[0062] Because for Figure 3 scenarios, such information exchange on amplitude and / or phase is generally not required, and synchronization is not required, so compared with Figure 3 scenarios, for Figure 4 scenarios, there is a tendency for a larger total traffic load to be imposed on the backhaul links 1018-1 and 1018-2. For non-ideal backhaul links 1018-1 and 1018-2, this may cause delays. This in turn can limit the end-to-end UL data throughput from the UE 102 to the BS 101. On the other hand, compared with Figure 4 MIMO scenarios, for Figure 3 beamforming scenarios, spatial multiplexing tends to be smaller. In terms of end-to-end UL data throughput, this again favors Figure 4 MIMO scenarios.

[0063] Multiple techniques are based on the discovery that if the characteristics of the backhaul links 1018-1 and 1018-2 are considered when configuring the multi-channel UL transmission 199, the end-to-end UL data throughput can be optimized. Specifically, various techniques are based on the discovery that given the limitations imposed by the non-ideal backhaul links 1018-1 and 1018-2, the end-to-end UL data throughput can be increased by tailoring the multi-channel UL transmission 199. Details of such techniques are described below.

[0064] Figure 5 is a signaling diagram of the communication on the radio link 111 between the BS 101 and the UE 102.

[0065] In 3001, control data 4001 is sent by BS101 and received by terminal 102. The control data 4001 can be encoded, for example, using layer 3 RRC coding. For example, the control data 4001 can be included in a layer 3 DL control message. It is possible to include the control data 4001 in the broadcast message; for example, the system information block (SIB). The control data 4001 can be distributed at the per-cell level, that is, distributed to all UEs connected to or resident in the cells of the cellular communication network.

[0066] The information content of the control data 4001 can vary with the implementation. Depending on the information content of the control data 4001, the logic implemented at the UE 102 can change.

[0067] For example, such a scenario is easy to conceive: BS101 (to a greater or lesser extent) stipulates UE behavior regarding the configuration of multi-channel UL transmission 199. Below, several examples of the implementation of the control data 4001 are given in a scenario where BS101 can control UE behavior to a greater extent.

[0068] For example, in the first scenario, the control data can indicate the antenna weights of the antenna panel 1023 that implements the spatial transmission paths of channels 151, 152, 159. The codebook method can be used. The UE 102 can determine the antenna weights by reading the corresponding information elements of the control data 4001.

[0069] In the second scenario, the control data can indicate the configuration of multiple channels 151, 152, 159 selected from multiple candidate configurations. This can correspond to a codebook-based method. For example, the candidate configurations can be related to Figure 4 the MIMO scenario Figure 3 the beamforming scenario. For example, the candidate configurations can specify the modulation scheme and / or coding scheme and / or repetition level of the CE policy. The UE can configure the multi-channel UL transmission 199 by reading the corresponding information elements of the control data 4001.

[0070] In the third scenario, the control data can indicate one or more rate allocation rules for the incoming traffic shaping to be applied by the UE in combination with the multi-channel UL transmission 199. For example, it may be required that certain channels 151, 152, 159 comply with a threshold of the associated data rate that is lower than that of other channels.

[0071] In the fourth example, BS101 can, for example, without considering the backhaul links 1018-1, 1018-2, notify the UE 102 to transmit in a way that maximizes the throughput on the radio link 111. This scenario can be applicable when the backhaul links 1018-1, 1018-2 provide a sufficient large capacity.

[0072] Above, a scenario has been described in which the decision logic for selecting a suitable transmission strategy for multi-channel UL transmission 199 resides entirely or at least in part at BS 101. Thus, BS 101 dictates the behavior of UE 102.

[0073] However, other scenarios can be envisioned in which the decision logic for selecting a suitable strategy for multi-channel UL transmission 199 is at least partially moved from BS 101 to UE 102.

[0074] For example, control data can indicate the quality of service of one or more of the backhaul links 1018-1, 1018-2. Then, UE 102 can infer a suitable transmission strategy for multi-channel UL transmission 199 based on the quality of service of the one or more backhaul links 1018-1, 1018-2.

[0075] As usual, the quality of service can include at least one of latency, error rate, priority, and throughput. For example, the quality of service of each of the multiple backhaul links 1018-1, 1018-2 can be indicated; in an alternative scenario, the quality of service of a particular backhaul link 1018-1, 1018-2 facing the strongest limitations (e.g., the backhaul link with the highest latency, highest error rate, and / or lowest throughput) can be indicated. Such a scenario will facilitate a worst-case approach and limit control signaling overhead. Different backhaul links among the backhaul links 1018-1, 1018-2 can be prioritized relative to each other.

[0076] For example, the quality of service of one or more of the backhaul links 1018-1, 1018-2 can be indicated by means of a quantized quantity (e.g., 2 bits per second per Hz). The quality of service can also be indicated by means of a quality index according to a codebook. For example, a 3-bit indicator can be used to distinguish 8 quality of service levels. The quality of service level can generally be indicated explicitly or implicitly. Examples of implicit indication of the quality of service level can include: according to Figure 4 the example of, signaling a common identifier of multiple RRHs 1013-1, 1013-2 to indicate that the backhaul links 1018-1, 1018-2 have the ability to support coherent decoding across multiple MIMO transmission paths; differently, according to Figure 4 the example of, signaling different identifiers of multiple RRHs 1013-1, 1013-2, which can indicate that the backhaul links 1018-1, 1018-2 do not have the ability to support coherent decoding across multiple MIMO transmission paths.

[0077] Next, at block 3002, the UE 102 configures multi-channel UL transmission 199. As usual, at 3002, there are various options available for configuring the multi-channel UL transmission 199. Generally, multiple channels 151, 152, 159 can be configured; and / or the inflow traffic shaping upstream of the air transmission along the wireless link 111 can be configured.

[0078] Some examples of how to configure the multi-channel UL transmission 199 are demonstrated below.

[0079] (i) For example, the multi-channel UL transmission 199 can be configured according to the Figure 3 scenario, that is, using the beamformed transmission paths of each RHH in the RRHs 1013-1, 1013-2 that are non-coherently aimed at the BS 101; or it can be configured according to the Figure 4 scenario, that is, using the spatial diversity MIMO transmission paths that are coherently aimed at the RRHs 1013-1, 1013-2. At 3002, the UE 102 can make the corresponding selection between these scenarios based on the control data 4001.

[0080] As mentioned above, by selecting between MIMO and beamforming, the load imposed on the backhaul links 1018-1, 1018-2 can be customized; thus, in turn, the end-to-end UL data throughput can be customized, as described above.

[0081] (ii) As another example, at 3002, the configuration of the multiple channels 151, 152, 159 can include: determining the appropriate antenna weights of the antenna panel 1023 at the UE 102. There are generally various options available for determining the antenna weights. For example, for the Figure 3 beamforming scenario, a codebook-based method can be used to determine the antenna weights of the transmit beams 311, 312. Here, this beam scanning can be implemented, for example, DL beam scanning (under the assumption of reciprocity) and / or UL beam scanning. One or more pilot signals can be transmitted on the beams of the beam scanning; then, the appropriate beam can be selected based on the reception characteristics of the one or more pilot signals. In particular, the appropriate beam can be selected from the codebook, that is, from a predefined set of candidate beams. For different RRHs 1013-1, 1013-2, different beam scans can be implemented. In an alternative implementation, the antenna weights of the transmit beams 311, 312 can be calculated based on the reception characteristics (such as amplitude and / or phase) of one or more DL pilot signals and / or one or more UL pilot signals. This can be based on the detection of different channels of the wireless link 111, for example, in combination with the singular value decomposition of the associated channel matrix. Then, for the Figure 3For the beamforming scenario, for implementing the transmission path of channel 151, the dominant singular value associated with the transmission between RRH 1013-1 and antenna panel 1023 can be selected; and for implementing the transmission path of channel 152, the dominant singular value associated with the transmission between RRH 1013-2 and antenna panel 1023 can be selected. For Figure 4 For the MIMO scenario of Figure 4 , the full rank of the channel matrix can be used to transmit data across various spatial diversity channels 15. Here, interference nulling can be utilized to zero-force (i.e., decorrelate) the signals along the transmission paths of different channels 159 at the receiver. Thus, the crosstalk between the signals transmitted along various transmission paths can be restricted. The corresponding techniques are known, for example, according to "Fundamentals of Wireless Communication" by David Tse and Pramod Viswanath, Cambridge University Press, 2005, section 8.3.1, "Linear decorrelator". This facilitates the flexible and individual selection of the modulation and coding schemes and / or the transmission power of different channels.

[0082] As mentioned above, by determining appropriate antenna weights, one or more of the RRHs in RRH 1013-1 and 1013-2 can be selectively addressed. Thereby, the load imposed on the backhaul links 1018-1 and 1018-2 can be customized; thereby, the end-to-end UL data throughput can be further customized, as described above.

[0083] (iii) As another example, in 3002, the configuration of multiple channels 151, 152, and 159 can include: determining the modulation scheme and / or coding scheme and / or the repetition count based on repeated CEs of different channels 151, 152, and 159.

[0084] By determining the coding scheme, modulation scheme, and / or repetition level of different channels 151, 152, and 159, the per-channel and per-time data throughput can be customized. Thereby, the load imposed on the backhaul links 1018-1 and 1018-2 can be customized; thereby, the end-to-end UL data throughput can be further customized, as described above.

[0085] (iv) As another example, as already mentioned above, at 3003, the configuration of multiple channels of the multi-channel UL transmission 199 may include: performing inflow traffic shaping for multiple channels 151, 152, 159. The inflow traffic shaping can appropriately control the inflow of data to each of the channels 151, 152, 159. This may include Layer 2 Medium Access Control (MAC) layer processing; for example, packets can be distributed among different channels. To this end, the rate allocation rules for the inflow traffic shaping can be considered. The combination of multiple channels 151, 152, 159 can be implemented. The combination may involve techniques for splitting and / or fusing together the data streams of the UL data across multiple channels 151, 152, 159.

[0086] Then, at 3003, the multi-channel UL transmission 199 is implemented according to the configuration of 3002 based on the control data 4001. When participating in the multi-channel UL transmission 199, the UL data 4002 is sent by the UE 102 and received by the BS 101.

[0087] Figure 6 Aspects of the multi-channel UL transmission 199 of the UL data 401 from the UE 102 to the BS 101 are illustrated. In Figure 6 the signaling flow is from top to bottom.

[0088] Initially, the UL data 401 arrives at the transmission buffer at the UE 102, for example, through the MAC layer. The UL data 401 can arrive at the MAC layer in the form of sub-packets, for example, in the form of MAC service data units (SDUs).

[0089] Then, inflow traffic shaping is implemented to configure channels 451, 452. This can generally be implemented according to Figure 3 the beamforming scenario of Figure 4 or the MIMO scenario of

[0090] In the illustrated example, the inflow traffic shaping includes a combination 412; the combination 412, as part of the inflow traffic shaping, controls the distribution of the UL data 401 across the channels 451, 452 of the multi-channel UL transmission 199. For example, if the UL data 401 arrives at the MAC layer transmission buffer, the combination 412 can be implemented for MAC service data units, etc. The combination 412 can consider the rate allocation rule 411. The rate allocation rule 411 can specify the distribution of the UL data 401 among the respective channels 451, 452.

[0091] Typically, the incoming traffic shaping is not limited to the combination 412. For example, the incoming traffic shaping can also consider the queue lengths of the transmit buffers (such as the Layer 1 PHY transmit buffers, etc.) associated with the respective channels 451, 452. Alternatively or additionally, for example, if compared with certain delay constraints imposed by the channels 451, 452, then the incoming traffic shaping can consider the quality of service levels associated with the individual packets of the UL data 401.

[0092] As a rule, when configuring the multiple channels 451, 452, the characteristics of the incoming traffic shaping can be set according to the control data 4001. For example, the control data 4001 can indicate the rate allocation rule 411; or the rate allocation rule 411 can be determined based on the control data 4001.

[0093] Next, the UL data 401 allocated to the channel 451 through the combination 412 is transmitted along the corresponding spatial transmission path. At block 472, the UL data 401 allocated to the channel 452 is transmitted along the corresponding spatial transmission path. This includes Layer 1 PHY processing. The coherent control of each antenna 1024 of the antenna panel 1023 is used to implement these spatial transmission paths.

[0094] At 481, 482, signals are received along the channels 451, 452. This includes Layer 1 PHY processing. In a beamforming scenario (refer to Figure 3 ), the receptions at 481 and 482 can be independent of each other. In a MIMO scenario, the receptions at 481 and 482 are coupled, and corresponding control signaling 492 may have to be exchanged between the RRHs 1013-1, 1013-2 along the backhaul links 1018-1, 1018-2. This may introduce additional delay.

[0095] When the reception of the data 401 is completed, the data 401 is transferred along the backhaul links 1018-1, 1018-2. Again, due to the limitations of the capacities of the backhaul links 1018-1, 1018-2, this may introduce delay.

[0096] Finally, the combination 412 is implemented again to gather the individual data streams associated with the channels 451, 452.

[0097] According to some examples, the end-to-end throughput between the input side of the combination 412 at the UE 102 and the output side of the combination 412 at the BS 101 can be optimized (refer to the vertical arrow in Figure 6 ). To this end, the combination 412 at the UE 102 can consider the qualities of the channels 451, 452 and the backhaul links 1018-1, 1018-2.

[0098] Figure 7It is a flowchart of a method according to various examples. Figure 7 The method is implemented by a UE. The UE can be connectable or can be connected to a cellular network. For example, it can be implemented by the control circuits 1021, 1025 of the UE 102 (refer to Figure 2 ). Figure 7 The method. Figure 7 Illustrates aspects of multi-channel UL transmission from a UE to one or more BSs of a network. The one or more BSs can use multiple RRHs via a backhaul link. Thereby, multi-antenna technology is implemented.

[0099] Initially, at block 2001, control data is received from the network. Control data encoded by the following downlink messages (e.g., layer 3 control messages or broadcast system information blocks) can be received (refer to Figure 5 , control data 4001).

[0100] The control data is associated with the backhaul links of multiple RRHS of one or more BSs of the network. For example, the control data can be determined based on one or more characteristics of the backhaul link; and / or can indicate one or more characteristics of the backhaul link.

[0101] Next, at block 2002, based on the control data, multi-channel UL transmission from the UE to the network is configured. For example, one or more of the channels of the multi-channel UL transmission can be configured based on the control data. Alternatively or additionally, the inflow traffic shaping of multiple channels of the multi-channel UL transmission can also be configured.

[0102] Various options can be used to configure one or more of the channels of the multi-channel UL transmission: for example, antenna weights defining the spatial transmission paths associated with multiple channels can be determined. Alternatively or additionally, the repetition count of the CE policy can be set for each of the channels. Alternatively or additionally, the modulation scheme and / or coding scheme can be set for each of the channels. A choice can be made between MIMO and beamforming. Multiple RRHs can be targeted phase-coherently; or one or more of the multiple RRHs can be targeted individually such that phase-coherent decoding across multiple RRHs is not required.

[0103] Various options can be used to configure the inflow traffic shaping of the multi-channel UL transmission: for example, the maximum queue length of the transmission buffer associated with multiple channels can be set. The rate allocation can be set, for example, by setting the corresponding rate allocation rules. For example, the quality of service rules associated with multiple channels can be set.

[0104] When performing block 2002, optimization of one or more of such parameters of the one or more channels and / or optimization of inflow traffic shaping can generally be achieved. Specifically, the optimization can have an objective function defined with respect to the end-to-end data throughput between the UE and the cellular network.

[0105] At block 2003, the UE participates in multi-channel UL transmission, e.g., by receiving packetized UL data from the upper layer, distributing the packetized UL data across multiple channels, and transmitting the packetized UL data along multiple channels.

[0106] Figure 8 is a flowchart of a method according to various examples. For example, the method can be performed by the BS or generally a network node Figure 8 of the method. For example, it can be performed by the control circuits 1011, 1015 of BS101 (refer to Figure 2 ) to perform Figure 8 of the method. Figure 8 Illustrates aspects of multi-channel UL transmission from the UE to one or more BSs. The one or more BSs can use multiple RRHs via a backhaul link. Thereby, multi-antenna technology is implemented.

[0107] Initially, at block 2011, control data is determined. The control data can be determined based on one or more characteristics of the backhaul link. Depending on the situation, block 2011 can involve more or less logic at the BS.

[0108] For example, in some scenarios, the control data indicates the antenna weights to be used by the UE; then, channel sounding of the radio link between the UE and the network can be considered to, e.g., appropriately direct the multiple channels of the multi-channel UL transmission towards one or more of the RRHs using the antenna weights. In other examples, a simple report on the quality of service of the backhaul link. For this, block 2011 can include sounding the backhaul link.

[0109] At block 2012, the control data determined at block 2011 is sent to the UE. Thus, block 2012 is associated with Figure 7 block 2001 of

[0110] Next, at block 2013, the BS participates in multi-channel UL transmission. Thus, block 2013 is associated with Figure 7 block 2003 of

[0111] The UE has configured multi-channel UL transmission based on the control data of block 2012. Depending on the configuration of the multi-channel UL transmission, the reception of the signals transmitted along the multiple channels of the multi-channel UL transmission may or may not include phase-coherent decoding across multiple RRHs.

[0112] The frame 2013 includes signaling of UL data along the backhaul link. Since the UL data transmission has been configured according to the control data, certain limitations imposed by the backhaul link can be effectively alleviated. For example, the UL data can be actively directed to the first RRH that is a capable backhaul link among the RRHs, and the UL data can be actively directed away from the second RRH that has a poor - capacity backhaul link among the RRHs.

[0113] In summary, multi - antenna techniques have been described in which the BS includes two or more RRHs. In some examples, for DL communication between the BS and the UE, the BS can notify the UE about the quality of at least one of the backhaul links; then, the BS leaves it to the UE to select a suitable transmission strategy. Alternatively, the BS can specify the transmission strategy and operations to be performed at the UE according to the switching capabilities of the backhaul link.

[0114] These techniques help to overcome the limitation that the characteristics of the backhaul link are unknown to the UE in conventional techniques. In such conventional techniques, the UE usually takes a conservative stance and assumes the worst - case scenario, thus causing a significant loss in the overall UL data throughput.

[0115] In summary, the following examples have been described:

[0116] Example 1. A method for configuring a multi - channel uplink transmission (199), the multi - channel uplink transmission including multiple channels (151, 152, 159, 451, 452) between a wireless communication device (102) and multiple receiving panels (1013 - 1, 1013 - 2) of at least one network node (101), the multiple receiving panels (1013 - 1, 1013 - 2) and the at least one network node (101) being connected via backhaul links (1018 - 1, 1018 - 2), the method being performed by the wireless communication device (102), wherein the method includes the steps of: receiving control data (4001) encoded in a downlink message for the multi - channel uplink transmission (199) from the at least one network node (101), the control data (4001) being associated with the backhaul link, and configuring the multi - channel uplink transmission (199) based on the control data (4001).

[0117] Example 2. The method according to Example 1, wherein the step of configuring includes: selecting between (i) a beam - formed transmission path that non - coherently targets each of the multiple receiving panels (1013 - 1, 1013 - 2); and (ii) a spatial - diversity transmission path that coherently targets the multiple receiving panels (1013 - 1, 1013 - 2).

[0118] Example 3. The method according to Example 1 or 2, wherein the wireless communication device (102) includes an antenna, and wherein the configuring step includes: determining an antenna weight of the antenna. For example, the control data may indicate the antenna weight. The plurality of channels may enable spatially diverse transmission paths that coherently target the plurality of receiving panels. For example, the antenna weight may be determined such that zero interference of signals transmitted along different transmission paths of the multi-channel uplink transmission along the spatially diverse transmission paths can be decorrelated.

[0119] Example 4. The method according to any one of the preceding examples, wherein the configuring step includes: performing optimization of the end-to-end throughput between the wireless communication device (102) and the at least one network node (101).

[0120] Example 5. The method according to any one of the preceding examples, wherein the configuring step includes: performing inflow traffic shaping for the plurality of channels (151, 152, 159, 451, 452) of the multi-channel uplink transmission (199).

[0121] Example 6. The method according to Example 5, wherein the step of performing inflow traffic shaping includes: combining (412) the plurality of channels (151, 152, 159, 451, 452) of the multi-channel uplink transmission (199).

[0122] Example 7. The method according to Example 5 or 6, wherein the control data (4001) indicates a rate allocation for the inflow traffic shaping of the plurality of channels (151, 152, 159, 451, 452) of the multi-channel uplink transmission (199).

[0123] Example 8. The method according to any one of the preceding examples, wherein the configuring step includes: setting at least one of a modulation scheme and a coding scheme for the multi-channel uplink transmission. Alternatively or additionally, the configuring step may include: setting a repetition count for coverage enhancement based on repetition for the multi-channel uplink transmission (199).

[0124] Example 9. The method according to any one of the preceding examples, wherein the control data (4001) indicates a quality of service of at least one of the backhaul links (1018-1, 1018-2). For example, the quality of service may include at least one of a delay, an error rate, a priority, and a throughput rate associated with at least one of the backhaul links.

[0125] In the various examples described above, the control data may generally indicate the configuration of multiple channels selected from multiple candidate configurations.

[0126] In the various examples described above, at least one of the backhaul links in the backhaul may have limited data throughput due to at least one of the following: the distance between the multiple receiving panels; the throughput of the transmission medium between the multiple receiving panels; the system load of the backhaul link; and core network signaling limitations.

[0127] Example 10. A method of operating a network node that is capable of using multiple receiving panels (1013-1, 1013-2), the multiple receiving panels (10 13-1, 1013-2) and the at least one network node (101) being connected via a backhaul link (1018-1, 1018-2), wherein the method comprises the steps of: sending control data (4001) encoded in a downlink message for multi-channel uplink transmission (199) to a wireless communication device (102), the control data (4001) being associated with the backhaul link, and participating in the multi-channel uplink transmission (199) configured based on the control data (4001).

[0128] Example 11. A wireless communication device operable to configure a multi-channel uplink transmission (199), the multi-channel uplink transmission comprising multiple channels (151, 152, 159, 451, 452) between the wireless communication device (102) and multiple receiving panels (1013-1, 1013-2) of at least one network node (101), the multiple receiving panels (1013-1, 1013-2) and the at least one network node (101) being connected via a backhaul link (1018-1, 1018-2), wherein the wireless communication device is configured to: receive control data (4001) encoded in a downlink message for the multi-channel uplink transmission (199) from the at least one network node (101), the control data (4001) being associated with the backhaul link, and configure the multi-channel uplink transmission (199) based on the control data (4001).

[0129] The wireless communication device may be configured to perform the method according to any one of Examples 1 to 9.

[0130] Example 12. A network node that is capable of using a plurality of receiving panels, the plurality of receiving panels (1013-1, 1013-2) and the at least one network node (101) being connected via a backhaul link (1018-1, 1018-2), wherein the network node is configured to: send control data (4001) encoded with a downlink message for multi-channel uplink transmission (199) to a wireless communication device (102), the control data (4001) being associated with the backhaul link, and optionally participate in the multi-channel uplink transmission (199) configured based on the control data (4001).

[0131] Although the invention has been shown and described with reference to particular preferred embodiments, equivalents and modifications will occur to those skilled in the art upon reading and understanding this specification. The invention includes all such equivalents and modifications and is limited only by the scope of the appended claims.

[0132] For illustration, various techniques for connecting a plurality of antenna panels to a given BS via a backhaul link have been described above. In some scenarios, a plurality of antenna panels may also be connected to a plurality of individual BSs via a backhaul link. Then, there may be additional connectivity between the BSs via core network signaling.

[0133] For further illustration, various scenarios have been described above for a UE communicating with one or more BSs. Similar scenarios may also apply to the communication between any wireless communication device and other types and types of network nodes (e.g., a wireless local area network WLAN access node).

[0134] For further illustration, various scenarios have been described above regarding uplink transmission from a UE to a network. Similar scenarios may also be implemented for the communication between two fixed nodes.

Claims

1. A method for configuring a multi-channel uplink transmission (199), the multi-channel uplink transmission including a plurality of channels (151, 152, 159, 451, 452) between a wireless communication device (102) and a plurality of receiving panels (1013-1, 1013-2) of at least one network node (101), the plurality of receiving panels (1013-1, 1013-2) and the at least one network node (101) being connected via a backhaul link (1018-1, 1018-2), the method being performed by the wireless communication device (102), Among them, The method includes the following steps: - Receiving control data (4001) encoded in a downlink message for the multi-channel uplink transmission (199) from the at least one network node (101), the control data (4001) being associated with the backhaul link, and - Based on the control data (4001): Configuring the multi-channel uplink transmission (199), Wherein the step of configuring includes: Selecting between (i) a beamformed transmission path that non-coherently targets each of the plurality of receiving panels (1013-1, 1013-2) and (ii) a spatial diversity transmission path that coherently targets the plurality of receiving panels (1013-1, 1013-2).

2. The method according to claim 1, Among them, The wireless communication device (102) includes an antenna, Wherein the step of configuring includes: Determining an antenna weight of the antenna.

3. The method according to claim 1 or 2, Among them, The step of configuring includes: Performing an optimization of the end-to-end throughput between the wireless communication device (102) and the at least one network node (101).

4. The method according to claim 1 or 2, Among them, The step of configuring includes: Performing inflow traffic shaping for the plurality of channels (151, 152, 159, 451, 452) of the multi-channel uplink transmission (199).

5. The method according to claim 4, Among them, The step of inflow traffic shaping includes: Combining (412) the plurality of channels (151, 152, 159, 451, 452) of the multi-channel uplink transmission (199).

6. The method according to claim 4, Among them, The control data (4001) indicates a rate allocation for the inflow traffic shaping for the plurality of channels (151, 152, 159, 451, 452) of the multi-channel uplink transmission (199).

7. The method according to claim 1 or 2, Among them, The step of configuring includes: Setting at least one of a modulation scheme, a coding scheme, and a repetition count for coverage enhancement based on repetition for the multi-channel uplink transmission (199).

8. The method according to claim 1 or 2, Among them, The control data (4001) indicates a quality of service of at least one of the backhaul links (1018-1, 1018-2).

9. A method of operating a network node, the network node being capable of using a plurality of receiving panels (1013-1, 1013-2), the plurality of receiving panels (1013-1, 1013-2) and the network node being connected via a backhaul link (1018-1, 1018-2), Among them, The method comprises the steps of: - sending control data (4001) encoded with a downlink message for multi-channel uplink transmission (199) to a wireless communication device (102), the control data (4001) being associated with the backhaul link, and - participating in the multi-channel uplink transmission (199) configured based on the control data (4001), wherein configuring the multi-channel uplink transmission (199) based on the control data (4001) includes: selecting between (i) a beamformed transmission path that non-coherently targets each of the plurality of receiving panels (1013-1, 1013-2) and (ii) a spatial diversity transmission path that coherently targets the plurality of receiving panels (1013-1, 1013-2).

10. A wireless communication device capable of operating to configure a multi-channel uplink transmission (199), the multi-channel uplink transmission comprising a plurality of channels (151, 152, 159, 451, 452) between the wireless communication device and a plurality of receiving panels (1013-1, 1013-2) of at least one network node (101), the plurality of receiving panels (1013-1, 1013-2) and the at least one network node (101) being connected via a backhaul link (1018-1, 1018-2), Among them, The wireless communication device is configured to: - receive control data (4001) encoded with a downlink message for the multi-channel uplink transmission (199) from the at least one network node (101), the control data (4001) being associated with the backhaul link, and - configure the multi-channel uplink transmission (199) based on the control data (4001), wherein the wireless communication device is configured to: select between (i) a beamformed transmission path that non-coherently targets each of the plurality of receiving panels (1013-1, 1013-2) and (ii) a spatial diversity transmission path that coherently targets the plurality of receiving panels (1013-1, 1013-2).

11. A network node capable of using a plurality of receiving panels, the plurality of receiving panels and the network node being connected via a backhaul link (1018-1, 1018-2), Among them, The network node is configured to: - send control data (4001) encoded with a downlink message for multi-channel uplink transmission (199) to a wireless communication device (102), the control data (4001) being associated with the backhaul link, and - Optionally participate in the multi-channel uplink transmission (199) configured based on the control data (4001), wherein configuring the multi-channel uplink transmission (199) based on the control data (4001) includes: selecting between (i) a beamformed transmission path that non-coherently targets each of the plurality of receiving panels and (ii) a space diversity transmission path that coherently targets the plurality of receiving panels.

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