Patent Description:
Wireless communication is sometimes implemented using spatially-defined transmission paths of radio waves. Each transmission path corresponds to a respective channel.

Typically, implementations of a spatially-defined transmission path include using multiple antennas of an antenna panel. These techniques are generally referred to multiple antenna techniques.

Multiple antenna techniques can be implemented in various manners. In a first example, spatial multiplexing (often referred to as Multiple Input Multiple Output, MIMO) can be used to increase the overall data rate. Here, multiple spatially diverse transmission paths are set-up between transmitter and receiver. A second example includes beamforming: here, a spatial directivity for transmitting and/or receiving (communicating) is achieved by destructive and constructive interference at the multiple antennas. One or more beamformed transmission paths are set up.

Sometimes, a node can access multiple distinct antenna panels (sometimes also referred to as remote radio heads, RRH) that are spaced apart from each other and connected via a backhaul links are available, see, e.g., Third Generation Partnership Project (3GPP) TSG RAN WG1 Meeting #<NUM>: document R1-<NUM> or 3GPP TSG RAN Meeting #<NUM>: document RP-<NUM>. Such functionality is sometimes referred to as multi-transmission panel (multi-TRP). Typically, for multi-TRP, the RRHs are spaced apart at least <NUM> or at least <NUM>.

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

Documents "<NPL>" and <CIT> disclose UL transmission methods based on backhaul link conditions.

Therefore, a need exists for advanced multiple antenna techniques using multiple RRHs with non-ideal backhaul links.

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 on a wireless link using a multiple antenna technique, e.g., MIMO and/or beamforming.

In various examples described herein, multi-TRP is employed: here, the first node may have access to multiple RRHs. The multiple RRHs are connected with each other and/or the respective node via backhaul links. As a general rule, the backhaul links can also rely on the wireless transmission. Also, wired transmission would be possible.

According to various examples, at least one of the backhaul links faces data throughput limitations. This can be due to the distance between the multiple RRHs, a system load on the backhaul links, and/or core-network signaling limitations. Generally speaking, the at least one of the backhaul links can have a non-ideal system behavior. Limitations of the inter-RRH connectivity can result.

Hereinafter, 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 typically includes a radio access network (RAN) having one more base stations (BSs); and a core network (CN). The one or more BSs can be equipped with multiple RRHs according to multi-TRP. This set up of mobile wireless communication between the UE and the one or more BSs is an example; in other examples, it would also be possible that the wireless link employing multiple antenna techniques is implemented between two stationary nodes that each comprise multiple RRHs according to multi-TRP.

Hereinafter, techniques will be described in connection with uplink (UL) transmission from the UE to the RAN. Specifically, techniques will be described that allow configuring a multichannel UL transmission, wherein the multichannel UL transmission includes multiple channels that are associated with the multiple RRHs. As a general rule, one or more channels may be associated with each RRH. Different RRHs may be associated with different channels.

A channel as used herein may relate to the connectivity between two end nodes over-the-air, e.g., the connectivity between the UE and at least one RRH. The channel may be characterized by an over-the-air transmission path. The various transmission paths can be configured by antenna weights of antennas of an antenna panel. The antenna weights may define an amplitude and phase relationship between 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 repletion-based coverage enhancement (CE) policy that, e.g., my define a repetition level. The channel may be characterized by one or more parameters of a packetized data exchanged via the channel, e.g., data unit sizes, etc..

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

According to various examples, the configuration of the multiple channels of the multichannel UL transmission takes into account control data provided by the network.

For example, the network may provide a downlink (DL) message encoding the control data. For example, a Layer <NUM> Radio Resource Control (RRC) DL control message may be employed. For example, the DL control message may be communicated on a physical DL control channel (PDCCH). Then, the UE can configure the multichannel UL transmission based on the control data.

The control data is associated with the backhaul links. By providing the control data and configuring the multichannel UL transmission accordingly, it becomes possible to take into account certain criteria at the UE in view of the backhaul links that would otherwise be inaccessible / transparent to the UE. For example, certain restrictions of the backhaul links can be taken into account. This helps to optimize the overall end-to-end throughput between the UE and the communication network.

For example, the control data can be determined in accordance with the one or more properties of the backhaul links. Alternatively or additionally, the control data can be indicative of the one or properties of the backhaul links.

There are generally various options available to configure the multichannel UL transmission. Some example options are described below. In one example, it would be possible to configure the channels of the multichannel UL transmission, e.g., by setting the modulation scheme and/or the coding scheme and/or by selecting between beamforming and MIMO techniques and/or by setting a repetition level. Alternatively or additionally, it would also be possible to configure the multichannel UL transmission by configuring inflow traffic shaping upstream of the multiple channels. For example, a rate allocation rule may be used to distribute incoming data between the multiple channels, one or more bonding properties may be set appropriately, etc..

<FIG> schematically illustrates a communication system <NUM> that may benefit from the techniques disclosed herein. The communication system <NUM> may be implemented in accordance with a 3GPP-standardized network such as <NUM>, <NUM>, or upcoming <NUM> NR. Other examples include point-to-point networks such as Institute of Electrical and Electronics Engineers (IEEE)-specified networks, e.g., the <NUM>. 11x Wi-Fi protocol or the Bluetooth protocol. Further examples include 3GPP NB-IOT or eMTC networks.

The communication system <NUM> includes a BS <NUM> and a UE <NUM>. The BS <NUM> is part of a RAN (not illustrated in <FIG>). The RAN may include multiple BSs.

A wireless link <NUM> is established between the BS <NUM> - e.g., a gNB in the 3GPP NR framework - and the UE <NUM>. The wireless link <NUM> includes a DL wireless link from the BS <NUM> to the UE <NUM>; and further includes an UL wireless link from the UE <NUM> to the BS <NUM>.

As a general rule, various multi-antenna techniques may be implemented for communication on the wireless link <NUM>; e.g., including MIMO and/or beamforming.

The UE <NUM> may be one of the following: a smartphone; a cellular phone; a tablet; a notebook; 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..

<FIG> schematically illustrates the communication system <NUM>, the BS <NUM>, and the UE <NUM> in greater detail.

The BS <NUM> includes a processor <NUM>, a memory <NUM>, and an interface <NUM>.

The interface <NUM> is configured to transmit and/or receive (communicate) via the wireless link <NUM>. For this, the interface <NUM> is connected via backhaul links <NUM>-<NUM>, <NUM>-<NUM> with two RRHs <NUM>-<NUM>, <NUM>-<NUM>. Each RRH <NUM>-<NUM>, <NUM>-<NUM> includes multiple antennas <NUM>. As illustrated in <FIG>, the RRHs <NUM>-<NUM>, <NUM>-<NUM> are separated from each other by a certain distance, typically at least a few meters or even a few <NUM> meters. Each antenna <NUM> may include one or more electrical traces to carry a radio frequency current. Each antenna <NUM> may include one or more LC-oscillators implemented by the electrical traces. Each trace may radiate electromagnetic waves with a certain beam pattern. In some examples the BS <NUM> may include multiple antenna panels (not illustrated in <FIG>).

Typically, each RRH <NUM>-<NUM>, <NUM>-<NUM> may include a count of at least <NUM> antennas, or at least <NUM> antennas.

The BS <NUM> may include more than two RRHs <NUM>-<NUM>, <NUM>-<NUM>.

The processor <NUM> and the memory <NUM> form a control circuit. The memory <NUM> may store program code that can be executed by the processor <NUM>. Executing the program code may cause the processor <NUM> to perform techniques with respect to providing control data for a multichannel transmission from the BS <NUM> to the UE <NUM> or from the UE <NUM> to the BS <NUM>; participate in a multichannel UL transmission; participate in a MIMO transmission; participate in a beamformed transmission; etc..

The UE <NUM> includes a processor <NUM>, a memory <NUM>, and an interface <NUM>. The interface <NUM> is coupled via antenna ports (not shown in <FIG>) with an antenna panel <NUM> including a plurality of antennas <NUM>. In some examples, the antenna panel <NUM> may include at least <NUM> antennas, optionally at least <NUM> antennas, further optionally at least <NUM> antennas. Generally, the antenna panel <NUM> of the UE <NUM> may include fewer antennas <NUM> than the RRHs <NUM>-<NUM>, <NUM>-<NUM> of the BS <NUM>. Each antenna <NUM> may include one or more electrical traces to carry a radio frequency current. Each antenna <NUM> may include one or more LC-oscillators implemented by the electrical traces. Each trace may radiate electromagnetic waves with a certain beam pattern. Also the UE <NUM> may include multiple antenna panels <NUM> (not illustrated in <FIG>).

The processor <NUM> and the memory <NUM> form a control circuit. The memory <NUM> may store program code that can be executed by the processor <NUM>. Executing the program code may cause the processor <NUM> to perform techniques with respect to receiving control data for an UL multichannel transmission; configuring the multichannel UL transmission based on the control data; participate in the multichannel UL transmission; participate in a MIMO transmission; participate in a beamformed transmission; etc..

<FIG> schematically illustrates the communication system <NUM>, the BS <NUM>, and the UE <NUM> in greater detail. The scenario of <FIG> corresponds to the scenario of <FIG>. <FIG> illustrates aspects in connection with the multichannel UL transmission <NUM>.

Specifically, <FIG> illustrates a first implementation of the multichannel UL transmission <NUM>. <FIG> illustrates aspects with respect to beamforming.

In the example of <FIG>, the multichannel UL transmission <NUM> includes two channels <NUM>, <NUM>. The two channels <NUM>, <NUM>, in the example of <FIG>, are implemented using beamforming. In detail, spatial multiplexing across the multiple channels <NUM>, <NUM> is achieved by using two beamformed transmission paths, each beamformed transmission path being associated with a respective RRH <NUM>-<NUM>, <NUM>-<NUM>. For example, line-of-sight (LOS) or non-LOS transmission paths may be used. Non-LOS transmission paths include one or more reflections.

The channel <NUM> is from the UE <NUM> to the RRH <NUM>-<NUM> and a second channel <NUM> is from the UE <NUM> to the RRH <NUM>-<NUM>. The channel <NUM> is associated with a transmit beam <NUM> implemented by appropriate antenna weights for the antennas <NUM> of the antenna panel <NUM> at the UE <NUM>. The channel <NUM> is also associated with a receive beam <NUM> implemented by appropriate antenna weights for the antennas <NUM> of the RRH <NUM>-<NUM>. Likewise, the channel <NUM> is associated with a transmit beam <NUM> and a receive beam <NUM>. The beams <NUM>, <NUM>, <NUM>, <NUM> define the spatial orientation of the respective transmission paths.

The receive beam <NUM> is implemented by phase-coherent reception of the antennas <NUM> of the RRH <NUM>-<NUM>. The receive beam <NUM> is implemented by phase-coherent reception of the antennas <NUM> of the RRH <NUM>-<NUM>. For implementing the receive beam <NUM>, it is not required to take into account signals received at the antennas <NUM> of the RRH <NUM>-<NUM>; likewise, for implementing the receive beam <NUM>, it is not required to take into account the amplitude and phase of the signals received at the antennas <NUM> of the RRH <NUM>-<NUM>. This is because the beamformed transmission paths of the channels <NUM>, <NUM> non-coherently target the RRH <NUM>-<NUM> and the RRH <NUM>-<NUM>, respectively. In other words, there is no strict phase relationship required between signals communicated along the channel <NUM> and signals communicated along the channel <NUM>. Thus, typically time and/or frequency synchronization is not required between the operation of the multiple RRHs <NUM>-<NUM>, <NUM>-<NUM>. Signals received at the RRH <NUM>-<NUM> can be decoded independently signals received at the RRH <NUM>-<NUM>. A somewhat different scenario is illustrated in connection with <FIG>.

<FIG> schematically illustrates the communication system <NUM>, the BS <NUM>, and the UE <NUM> in greater detail. The scenario of <FIG> corresponds to the scenario of <FIG>. <FIG> illustrates aspects in connection with the multichannel UL transmission. Specifically, <FIG> illustrates a second implementation of the multichannel UL transmission. <FIG> illustrates aspects with respect to MIMO.

In the scenario of <FIG>, the multichannel UL transmission is implemented using MIMO across the two RRHs <NUM>-<NUM>, <NUM>-<NUM>. There are many channels <NUM>, specifically there are channels between each one of the antennas <NUM> of the antenna panel <NUM> and each one of the antennas <NUM> of both RRHs <NUM>-<NUM>, <NUM>-<NUM>. Again, each channel <NUM> is associated with a respective spatial transmission path.

The channels <NUM> can be set to be independent of each other with reduced coupling, based on a singular value decomposition of the channel matrix. Decorrelation of the signals received along the various channels at the receiver is possible, sometimes referred to as zero-forcing. Closed-loop MIMO techniques with feedback on the precoding matrix can be used (precoding matrix indication, PMI).

There is a phase relationship between the signals communicated along the channels <NUM>. Hence, the multiple RRHs <NUM>-<NUM>, <NUM>-<NUM> are coherently targeted by the channels <NUM>.

This requires coherent decoding of the signals received at the antennas <NUM> of all RRHs <NUM>-<NUM>, <NUM>-<NUM>. In other words, it may be required to provide information on the amplitude and phase of signals received at the antennas <NUM> of the RRH <NUM>-<NUM> via the backhaul link <NUM>-<NUM> and/or to provide information on the amplitude and phase of signals received at the antennas <NUM> of the RRH <NUM>-<NUM> via the backhaul link <NUM>-<NUM>. Also, a timing and/or frequency synchronization may be required between the operation of the RRHs <NUM>-<NUM>, <NUM>-<NUM>.

Because such an exchange of information on amplitude and/or phase, as well as synchronization is typically not required for the scenario of <FIG>, there is a tendency that the overall traffic load imposed on the backhaul links <NUM>-<NUM>, <NUM>-<NUM> is larger for the scenario of <FIG> than for the scenario of <FIG>. For non-ideal backhaul links <NUM>-<NUM>, <NUM>-<NUM>, this may result in latency. This, in turn, may limit the end-to-end UL data throughput from the UE <NUM> to the BS <NUM>. On the other hand, the spatial multiplexing tends to be smaller for the beamforming scenario of <FIG> than for the MIMO scenario of <FIG>. This again favors the MIMO scenario of <FIG> in terms of the end-to-end UL data throughput.

Various techniques are based on the finding that the end-to-end UL data through can be optimized if the properties of the backhaul links <NUM>-<NUM>, <NUM>-<NUM> are taken into account when configuring the multichannel UL transmission <NUM>. Specifically, various techniques are based on the finding that by tailoring the multichannel UL transmission <NUM> in view of limitations imposed by non-ideal backhaul links <NUM>-<NUM>, <NUM>-<NUM>, the end-to-end UL data throughput can be increased. Details of such techniques are described hereinafter.

<FIG> is a signaling diagram of communication on the wireless link <NUM> between the BS <NUM> and the UE <NUM>.

At <NUM>, control data <NUM> is transmitted by the BS <NUM> and received by the UE <NUM>. The control data <NUM> can be encoded, e.g., using Layer <NUM> RRC encoding. For example, the control data <NUM> can be included in a Layer <NUM> DL control message. IT would be possible that the control data <NUM> is included in a broadcasted message; e.g., a system information block (SIB). The control data <NUM> can be distributed on a per-cell level, i.e., to all UEs connected to or camping on a cell in a cellular communication network.

The information content of the control data <NUM> can vary from implementation to implementation. Depending on the information content of the control data <NUM>, the logic implemented at the UE <NUM> may vary.

For example, scenarios are conceivable in which the BS <NUM> dictates - to a larger or smaller degree - the UE behavior with respect to the configuration of the multichannel UL transmission <NUM>. Below, a few examples are given for the implementation of the control data <NUM> in scenarios in which the BS <NUM> can control the UE behavior to a larger degree.

For example, in a first scenario, the control data may be indicative of the antenna weights for the antenna panel <NUM> that implement the spatial transmission paths of the channels <NUM>, <NUM>, <NUM>. A codebook approach may be used. The UE <NUM> can the determine the antenna weights by reading the respective information element of the control data <NUM>.

In a second scenario, according to the claimed invention the control data could be indicative of a configuration of the multiple channels <NUM>, <NUM>, <NUM> selected from a plurality of candidate configurations. This can correspond to a codebook-based approach. For example, the candidate configurations may pertain to the MIMO scenario of <FIG> vs. the beamforming scenario of <FIG>. For example, the candidate configurations may specify a modulation scheme and/or a coding scheme and/or a repetition level of a CE policy. The, the UE can configure the multichannel UL transmission <NUM> by reading the respective information element of the control data <NUM>.

In a third scenario, the control data could be indicative of one or more rate allocation rules for inflow traffic shaping to be applied by the UE in connection with the multichannel UL transmission <NUM>. For example, it would be possible that certain channels <NUM>, <NUM>, <NUM> are required to obey a lower threshold of the associated data rate than others, etc..

In a fourth example, the BS <NUM> may inform the UE <NUM> to transmit in a way that maximizes the throughput on the wireless link <NUM>, e.g., without considering the backhaul links <NUM>-<NUM>, <NUM>-<NUM>. Such a scenario may be applicable where the backhaul links <NUM>-<NUM>, <NUM>-<NUM> provide a sufficiently large capacity.

Above, scenarios have been described in which the decision logic for selecting the appropriate transmission strategy for the multichannel UL transmission <NUM> fully or at least partly resides at the BS <NUM>. The BS <NUM> hence dictates the behavior of the UE <NUM>.

However, other scenarios are conceivable in which the decision logic for selecting the appropriate strategy for the multichannel UL transmission <NUM> is at least partly shifted from the BS <NUM> to the UE <NUM>.

For example, the control data could be indicative of service qualities of one or more of the backhaul links <NUM>-<NUM>, <NUM>-<NUM>. Then, the UE <NUM> can conclude on the appropriate transmission strategy for the multichannel UL transmission <NUM> based on the service qualities of the one or more backhaul links <NUM>-<NUM>, <NUM>-<NUM>.

As a general rule, the service quality may include at least one of latency, error rate, priority, and throughput rate. For example, the service qualities of each one of the multiple backhaul links <NUM>-<NUM>, <NUM>-<NUM> may be indicated; in an alternative scenario it would be possible to indicate the service quality of the particular backhaul link <NUM>-<NUM>, <NUM>-<NUM> that faces the strongest restriction, e.g., the backhaul link having the highest latency, the highest error rate, and/or the lowest throughput rate. Such a scenario would facilitate a worst-case approach and limit control signaling overhead. Different ones of the backhaul links <NUM>-<NUM>, <NUM>-<NUM> may be prioritized with respect to each other.

For example, the service quality of one or more of the backhaul links <NUM>-<NUM>, <NUM>-<NUM> may be indicated by means of a quantitative number, e.g., <NUM> bits per second per Hz. The service quality could also be indicated by means of a quality index according to a codebook. For example, a <NUM> bit indicator could be used to discriminate between <NUM> service quality levels. The service quality level can be generally indicated explicitly or implicitly. An example for an implicit indication of the service quality level can include signaling a common identity for the multiple RRHs <NUM>-<NUM>, <NUM>-<NUM> to indicate that the backhaul links <NUM>-<NUM>, <NUM>-<NUM> have the capacity for supporting coherent decoding across multiple MIMO transmission paths according to the example of <FIG>; differently, with different identities are signaled for the multiple RRHs <NUM>-<NUM>, <NUM>-<NUM> this may indicate that the backhaul links <NUM>-<NUM>, <NUM>-<NUM> do not have the capacity for supporting coherent decoding across multiple MIMO transmission paths according to the example of <FIG>.

Next, at block <NUM>, the UE <NUM> configures multichannel UL transmission <NUM>. As a general rule, there are various options available for configuring the multichannel UL transmission <NUM> at <NUM>. Generally speaking, it would be possible to configure the multiple channels <NUM>, <NUM>, <NUM>; and/or configure the inflow traffic shaping upstream of the over-the-air transmission along the wireless link <NUM>.

Some examples of how the multichannel UL transmission <NUM> can be configured are proved below.

The multichannel UL transmission <NUM> is then implemented at <NUM>, in accordance with the configuration of <NUM> that is based on the control data <NUM>. UL data <NUM> is transmitted by the UE <NUM> and received by the BS <NUM> when participating in the multichannel UL transmission <NUM>.

<FIG> illustrates aspects with respect to the multichannel UL transmission <NUM> of UL data <NUM> from the UE <NUM> to the BS <NUM>. The signaling flow is from top to bottom in <FIG>.

Initially, the UL data <NUM> arrives at a transmit buffer at the UE <NUM>, e.g., on MAC layer. The UL data <NUM> can arrive in packetized form, e.g., on the MAC layer in the form of MAC Service Data Units (SDUs).

Then, inflow traffic shaping is implemented to configure the channels <NUM>, <NUM>. The that may be generally implemented according to the beamforming scenario of <FIG> or the MIMO scenario of <FIG>. The inflow traffic shaping affects the data throughput across each one of the channels <NUM>, <NUM>.

In the illustrated example, the inflow traffic shaping includes bonding <NUM>; the bonding <NUM>, as part of inflow traffic shaping, controls the distribution of the UL data <NUM> across the channels <NUM>, <NUM> of the multichannel UL transmission <NUM>. For example, if the UL data <NUM> arrives at a MAC layer transmit buffer, then the bonding <NUM> may be implemented for MAC service data units, etc.. The bonding <NUM> may take into account rate allocation rules <NUM>. The rate allocation rules <NUM> may specify the distribution of the UL data <NUM> between the various channels <NUM>, <NUM>.

Generally, the inflow traffic shaping is not limited to the bonding <NUM>. For example, the inflow traffic shaping may also take into account a queue length of transmit buffers associated with each channel <NUM>, <NUM>, e.g. Layer <NUM>, PHY transmission buffers, etc.. Alternatively or additionally, the inflow traffic shaping may take into account a quality of service level associated with the individual packets of UL data <NUM>, e.g., if compared to certain latency restrictions imposed by the channels <NUM>, <NUM>.

As a general rule, properties of the inflow traffic shaping may be set depending on the control data <NUM> when configuring the multiple channels <NUM>, <NUM>. For example, the control data <NUM> could be indicative of the rate allocation rule <NUM>; or the rate allocation rule <NUM> may be determined based on the control data <NUM>.

Next, the UL data <NUM> allocated, by the bonding <NUM>, to the channel <NUM> is transmitted along the respective spatial transmission path. At block <NUM>, the UL data <NUM> allocated to the channel <NUM> is transmitted along the respective spatial transmission path. This includes PHY Layer <NUM> processing. A coherent control of the various antennas1024 of the antenna panel <NUM> is used to implement these spatial transmission paths.

At <NUM>, <NUM>, signals are received along the channels <NUM>, <NUM>. This includes PHY Layer <NUM> processing. The reception at <NUM> and <NUM> can be independent of each other in a beamforming scenario (cf. In a MIMO scenario, the reception at <NUM> and <NUM> is coupled and respective control signaling <NUM> may have to be exchanged between the RRHs <NUM>-<NUM>, <NUM>-<NUM> along the backhaul links <NUM>-<NUM>, <NUM>-<NUM>. This can introduce additional latency.

Upon completion of the reception of the data <NUM>, the data <NUM> is passed along the backhaul links <NUM>-<NUM>, <NUM>-<NUM>. Again, due to limitations in the capacity of the backhaul links <NUM>-<NUM>, <NUM>-<NUM>, this can introduce latency.

Finally, bonding <NUM> is again implemented to bring together the individual streams of data associated with the channels <NUM>, <NUM>.

According to some examples, the end-to-end throughput between the input-side of the bonding <NUM> at the UE <NUM> and the output-side of the bonding <NUM> at the BS <NUM> can be optimized (cf. vertical arrow in <FIG>). To do so, the bonding <NUM> at the UE <NUM> may take into consideration the quality of the channels <NUM>, <NUM> as well as the backhaul links <NUM>-<NUM>, <NUM>-<NUM>.

<FIG> is a flowchart of a method according to various examples. The method of <FIG> is implemented by a UE. The UE may be connectable or may be connected to a cellular network. For example, the method of <FIG> may be implemented by the control circuitry <NUM>, <NUM> of the UE <NUM> (cf. <FIG> illustrates aspects with respect to a multichannel UL transmission from a UE to one or more BSs of the network. The one or more BSs have access to multiple RRHs via backhaul links. Thereby, a multi-antenna technique is implemented.

Initially, at block <NUM>, control data is received from a network. The control data can be received encoded in a downlink message, e.g., a Layer <NUM> control message or a broadcasted system information block (cf. <FIG>, control data <NUM>).

The control data is associated with backhaul links of multiple RRHS of one or more BSs of the network. For example, the control data may be determined based on one or more properties of the backhaul links; and/or may be indicative of one or more properties of the backhaul links.

Next, at block <NUM>, a multichannel UL transmission from the UE to the network is configured, based on the control data. For example, it would be possible to configure one or more of the channels of the multichannel UL transmission based on the control data. Alternatively or additionally, it would also be possible to configure inflow traffic shaping of the multiple channels of the multichannel UL transmission.

Various options are available for configuring the one or more channels of the multichannel UL transmission: for example, antenna weights defining spatial transmission paths associated with the multiple channels could be determined. Alternatively or additionally, it would be possible to set a repetition count of the CE policy for each one of the channels. Alternatively or additionally, a modulation scheme and/or a coding scheme could be set for each one of the channels. It would be possible to select between MIMO and beamforming. It would be possible to phase-coherently target multiple RRHs; or individually target one or more of the multiple RRHs, such that no phase-coherent decoding is required across multiple RRHs.

Various options are available for configuring the inflow traffic shaping of the multichannel UL transmission: for example, a maximum queue length of transmission buffers associated with the multiple channels could be set. Rate allocation could be set, e.g., by setting a corresponding rate allocation rule. For example, quality of service rules associated with the multiple channels could be set.

It would be generally possible to implement an optimization of one or more of such parameters of the one or more channels and/or of the inflow traffic shaping when executing block <NUM>. Specifically, the optimization may have a target function that is defined with respect to an end to end data throughput between the UE and the cellular network.

At block <NUM>, the UE participates in the multichannel UL transmission, e.g., by receiving from higher layers packetized UL data, distributing the packetized UL data across the multiple channels, and transmitting the packetized UL data along the multiple channels.

<FIG> is a flowchart of a method according to various examples. For example, the method of <FIG> may be executed by a BS, or generally a network node. For example, the method of <FIG> may be executed by the control circuitry <NUM>, <NUM> of the BS <NUM> (cf. <FIG> illustrates aspects with respect to a multichannel UL transmission from a UE to one or more BSs. The one or more BSs have access to multiple RRHs via backhaul links. Thereby, a multi-antenna technique is implemented.

Initially, at block <NUM>, control data is determined. The control data may be determined based on one or more properties of the backhaul links. Depending on the scenario, block <NUM> may involve more or less logic at the BS.

For example, in some scenarios, the control data is indicative of antenna weights to be used by the UE; then, channel sounding of a wireless link between the UE and the network may be taken into account to appropriately steer multiple channels of the multichannel UL transmission using the antenna weights, e.g., towards one or more of the RRHs. In other examples, a simple report on a service quality of the backhaul links. For this, block <NUM> may including sounding the backhaul links.

In, at block <NUM>, the control data determined at block <NUM> is transmitted to the UE. As such, block <NUM> is interrelated to block <NUM> of <FIG>.

Next, at block <NUM>, the BS participates in the multichannel UL transmission. As such, block <NUM> is interrelated to block <NUM> of <FIG>.

The UE has configured the multichannel UL transmission based on the control data of block <NUM>. Depending on the configuration of the multichannel UL transmission reception of signals communicated along multiple channels of the multichannel UL transmission may or may not include phase-coherent decoding across multiple RRHs.

Block <NUM> includes signaling of UL data along the backhaul links. As the UL data transmission has been configured in accordance with the control data, certain limitations imposed by the backhaul links can be effectively mitigated. For example, the UL data can be actively steered to a first one of the RRHs that as a capable backhaul link and can be actively steered away from a second one of the RRHs that has a less capable backhaul link.

Summarizing, multiple antenna techniques have been described in which the BS includes two or more RRHs. In some examples, a DL communication between BS and UE is implemented the BS can inform the UE about the quality of at least one of the backhaul links; the BS then leaves it up to the UE to select a suitable transmission strategy. Alternatively, the BS may dictate the transmission strategy and operations to be carried out at the UE, depending on the exchange capability of the backhaul links.

These techniques help to overcome limitations of conventional techniques in which properties of the backhaul links are unknown to the UE. In such conventional techniques, the UE typically takes a conservative position and assume the worst possible case, thereby exacting a considerable loss to overall UL data throughput.

Although the invention has been shown and described with respect to certain preferred embodiments, equivalents and modifications will occur to others skilled in the art upon the reading and understanding of the specification. The present invention includes all such equivalents and modifications and is limited only by the scope of the appended claims.

For illustration, above, various techniques have been described in which multiple antenna panels are connected to a given BS via backhaul links. In some scenarios, multiple antenna panels may also be connected via backhaul links to more than a single BS. Then, there may be additional connectivity between the BSs by core network signaling.

For further illustration, above, various scenarios have been described with respect to a UE communicating with one or more BSs. Similar scenarios may also be applied to communication between any wireless communication device and other kinds and types of network nodes - e.g., Wireless Local Area Network, WLAN, access nodes.

Claim 1:
A method of configuring a multichannel uplink transmission (<NUM>) comprising multiple channels (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) between a wireless communication device (<NUM>) and multiple receive panels (<NUM>-<NUM>, <NUM>-<NUM>) of at least one network node (<NUM>), the multiple receive panels (<NUM>-<NUM>, <NUM>-<NUM>) and the at least one network node (<NUM>) being connected via backhaul links (<NUM>-<NUM>, <NUM>-<NUM>), the method being carried out by the wireless communication device (<NUM>),
wherein the method comprises:
- receiving, from the at least one network node (<NUM>), a downlink message encoding control data (<NUM>) for the multichannel uplink transmission (<NUM>), the control data (<NUM>) being associated with the backhaul links, and
- based on the control data (<NUM>): configuring the multichannel uplink transmission (<NUM>),
wherein said configuring comprises selecting between (i) beamformed transmission paths that non-coherently target each one of the multiple receive panels (<NUM>-<NUM>, <NUM>-<NUM>); and (ii) spatially-diverse transmission paths that coherently target the multiple receive panels (<NUM>-<NUM>, <NUM>-<NUM>).