Patent Description:
In communications systems, there may be a challenge to obtain good performance and capacity for a given communications protocol, its parameters and the physical environment in which the communications system is deployed.

For example, the introduction of digital beamforming antenna systems in access nodes, such as radio base stations, etc., could allow multiple simultaneous narrow beams to be used to provide network access to, and thus server, multiple simultaneous served terminal devices, such as user equipment (UE), etc. However, the current split in the access nodes between a radio equipment controller (REC) and a radio equipment (RE) as interconnected by the Common Public Radio Interface (CPRI) may no longer be feasible as passing the data for each individual radio chain over the CPRI interface could drive prohibitively high data rates.

In more detail, the bit rate of the current CPRI interface scales directly to the number of independent radio chains in the RE. When having e.g., a <NUM> carrier bandwidth and <NUM> physical antenna elements in the beamforming antenna system, a bit rate of <NUM> Gbps would be needed for the CPRI interface with currently used sample coding. A further potential drawback with CPRI is the extra latency from uplink (UL; from terminal device to access node) sampling to the time the data can be used in downlink (DL; from access node to terminal device), as any information needs to loop in the REC.

One way to address the above-mentioned issues is to collapse the CPRI based architecture by removing the CPRI interface and putting the functionality of the REC in the RE. This approach has at least two drawbacks. Firstly, due to faster technological development of the REC compared to the RE, the technical lifetime of the REC is assumed to be shorter than that of the RE.

Replacing the RE is more costly than replacing the REC. From this aspect it could thus be beneficial to keep the functionality of the RE as simple as possible. Secondly, the REC could be configured to make decisions spanning over multiple REs in order to make coordinated multi-sector decisions, e.g. when some REs represent coverage regions of the access node within the coverage regions of other REs (e.g. a so-called micro cell within a so-called macro cell). A collapsed architecture loses this overarching coordination possibility.

<CIT> relates to a base station comprising center and remote units. The antenna weights are calculated by the center unit and provided to the remote unit. The remote unit stores the weights for each user, and updates when array weights for the user are updated. When a data packet is sent to the user, it has an array weights ID number that is used by the remote unite for picking the right antenna weights for the transmission. The received antenna weights may be compensated by the remote unit, meaning that the remote unit must receive beamforming weights from the center unit before any can be applied in the communication over the radio interface.

<CIT> shows that when a new terminal requires communication, beamformers calculate the beam radiation pattern based on information received from the cell controller. The resulting beam weight vector may be stored by the beamformers for later use so the beam weights as calculated by the beamformers must be based on information received from the cell controller.

Hence, there is a need for an improved communication between the REC and the RE.

An object of embodiments herein is to provide efficient communication between the REC and the RE, as described in the appended claims.

<FIG> is a schematic diagram illustrating an access node <NUM> where embodiments presented herein can be applied. The access node could be a radio base station such as a radio access network node, base transceiver station, node B, evolved node B, or access point. As disclosed above, the access node comprises at least one Radio Equipment Controller (REC) <NUM> and at least one Radio Equipment (RE) <NUM>. In the illustrative example of <FIG> the access node comprises one REC and two REs, where the REC has one interface <NUM> to each of the REs. Properties of the interface <NUM> between the REC and the RE will be disclosed below. The REs are configured to perform DL transmissions to, and UL receptions from, terminal devices <NUM> in beams <NUM> by using appropriate beamforming weights at the antennas <NUM>. The beamforming weights define at least the pointing direction and the width of the beams. How to determine the beamforming weights will be disclosed below.

As defined herein the REC does not send in-phase/quadrature (I/Q) samples per physical radio branch to the RE, but rather multiple-input multiple-output (MIMO) streams, i.e., I/Q samples per layer. According to the current CPRI specification, the REC can directly address the antennas in the RE, but in the herein disclosed access node that is configured to perform beamforming, the RE performs the functionality of mapping a MIMO stream to a set of physical antenna elements in order to generate a wanted beam form. Further, in order to enable efficient simultaneous multi user beamforming, the Fast Fourier Transform (FFT) and Inverse Fast Fourier Transform (IFFT) functions are performed in the RE. In addition, the execution of the beamforming data plane functionality is added to the RE. Further, the interface between REC and RE could be a packet-based interface, and hence no longer a streaming interface, sending the (frequency domain) samples to the RE symbol by symbol. This allows for quick and flexible allocation of resources on the interface to different terminal devices. The REC is configured to maintain knowledge about the terminal devices, and schedules the air interface between the access node and the terminal devices. The RE is configured to act on commands received from the REC.

As an illustrative example, consider a communications system having an air interface with a system bandwidth of <NUM> and that provides support for <NUM> MIMO streams and utilizes access nodes with <NUM> antennas for beamforming. Using CPRI interfaces between the REC and the RE exposing all <NUM> antennas for the REC would require approximately <NUM> CPRI interfaces of <NUM> Gbps, since a CPRI interface carries about <NUM>. Further, an interface using virtual antenna ports would require <NUM> MIMO streams of <NUM>, and would require about <NUM> CPRI interfaces of <NUM> Gbps, since one <NUM> Gbps CPRI interface still carries data for about <NUM>. By also moving the modulation DL to the RE, the <NUM> MIMO streams of <NUM> would require <NUM> Gbps (assuming 256QAM and <NUM> LTE <NUM> carriers), or one <NUM> Gbps CPRI interface. A higher bitrate of the CPRI interface is required in the UL if the whole system bandwidth is used, as demodulation is still performed in the REC.

Consider the REC and RE illustrated in <FIG> where the REC and RE are interconnected via an interface denoted RUI, for Radio Unit Interface. In the DL direction the REC sends unmodulated bits for each terminal device. The RE modulates the data, places it on the correct subcarrier (thus performing resource mapping), applies beamforming weights (individual per radio branch) defining e.g. width and/or direction of the beams and finally convert it to time domain and transmits it to the terminal devices. <FIG> shows <NUM>-<NUM> DL MIMO layers on <NUM> radio branches. In the UL direction the RE samples the signals for each individual radio branch, converts it to frequency domain, applies beamforming weights, combines the signals from the different radio branches and sends a selection of the modulated combined signal to the REC for further demodulation. <FIG> shows <NUM> radio branches and <NUM>-<NUM> receive beams. The receive beams weakly relates to UL MIMO branches as the more MIMO branches the more receive beams are needed. Typically, more receive beams than MIMO branches are required. <FIG> also shows beamforming as performed before de-mapping in the RE. The two stages are interlinked as the beamforming is performed individually per terminal device. <FIG> further illustrates User Plane Control (UPC) with its air interface scheduling and link adaptation placed in the REC.

<FIG> shows an embodiment of an REC and an RE similar to those in <FIG>. In <FIG> the RE is configured to decode reference symbols such as Sounding Reference symbols (SRS) in the UL, to store information of how the reference symbols are best received (e.g., what beamforming weights maximizes the SNR of the reference symbols) and to use this stored information when performing beamforming in the DL and UL. In <FIG> the RE could thus be regarded as autonomous in this respect. To accomplish this, the RU needs to maintain a storage of information identifying the best beam shapes for each terminal device, and be configured to apply that information when the corresponding terminal device is scheduled. This minimizes the communication needed over the interface between the REC and the RE with respect to beamforming, but also hides the channel for the UPC.

The operations as performed by the REC and RE in <FIG> could be preferred when the available bitrate of the interface between the REC and the RE is comparatively low. In more detail, assume that the beam dimension not is used for multi-user MIMO (MU-MIMO). Instead the beamforming antenna gain is primarily wanted for extended service coverage. This could imply that neither the UPC nor the Link Adaption (LA) needs information about the resolution of the fixed beam direction space.

The operations as performed by the REC and RE in <FIG> could be preferred when an absolutely minimum latency is wanted between reception of reference symbols and its application. An additional scenario is when beam weights are only calculated for the UL. This could be applicable for radio channels where the resources already are scheduled for the UL, i.e., so-called contention based channels, with the aim to keep down the overall latency. The weight calculations could then be based on reference symbols that arrive simultaneously with user data.

<FIG> shows an embodiment of an REC and an RE similar to those in <FIG>. In <FIG> the beamforming control is performed primarily by the UPC in the REC. The RE still receives the reference symbols and determines information of how the reference symbols are best received. This information is then sent to the REC. The REC uses this information to make an optimal decision on MIMO streams, link adaptation and coordinated scheduling with other terminal devices, such as MU-MIMO or nulling.

To make the communication and functionality performed in the UPC generic and not heavy dependent on the actual implementation of the RE (e.g., in terms of number of branches, antenna layout, etc.) or operating mode (e.g., power save, faulty branches, etc.), the communications between the REC and the RE regarding beamforming properties is expressed in beam direction space rather than antenna element space. That is, instead of presenting a beam as a set of weights of physical antenna elements the beam is presented as a combination of a set of predetermined beams. This also allows for a more compressed format for this communication, thus saving bit rate on the interface between the REC and the RE. For instance, a linear combination of <NUM> predetermined beams could be expressed as <NUM> times <NUM> bits (an <NUM>-bit beam number + an <NUM>-bit amplitude + an <NUM>-bit phase) rather than <NUM> times <NUM> bits (an <NUM>-bit amplitude + an <NUM>-bit phase for each of the <NUM> physical antenna elements). The transformation from the physical antenna element space to the beam space is performed by a Dimensions Reduction entity, and the inverse transformation is performed by a Beam Weight Transformation entity.

The operations as performed by the REC and RE in <FIG> could be preferred when the load of the access node is comparatively high and UPC needs to determine the channel state for the best decision on link adaptation.

The operations as performed by the REC and RE in <FIG> could be preferred when MU-MIMO or nulling is used, as the UPC then needs channel state information for the LA of the combination, and to determine which users are suitable for simultaneous scheduling, so called MU-MIMO scheduling. Note that nulling may also be applied between terminal devices served by different REs, and is therefore impossible to perform within one autonomous RE (as in <FIG>).

<FIG> illustrates an embodiment of an REC and an RE combining the functionality of the REC and RE in the embodiments of <FIG> and <FIG>. In comparison to <FIG> and <FIG>, the embodiment of <FIG> comprises a channel state memory, an UL/DL BF coefficient calculation entity (where BF is short for beamforming), an UL/DL quality calculation entity, an UL/DL SNR calculation entity (where SNR is short for signal to noise ratio), and a CSI feedback function (where CSI is short for Channel State Information).

The channel state memory is configured to store reference symbols since the reference symbols are not sent continuously. The transmission rate of the reference symbols is controlled by the access node, and different terminal devices could have different transmission rates of the reference symbols to allow for the access node to follow channel state changes. Although the channel state memory is illustrated as storing data expressed in the beam space in both the RE and the REC, the RE could instead have the channel state memory storing data expressed in the physical antenna element space.

The UL/DL BF coefficient calculation entity is configured to determine beamforming weights based on the channel state memory and possible other constraints (such as nulling and MU-MIMO) in the RE.

The UL RX weights calculation entity (where RX is short for reception) is configured to determine beamforming weights for the uplink. The UL beamforming weight determination can be part of maximum-ratio combining (MRC) in the UL demodulator/equalizer. The UPC will order more beams than layers, and then the demodulation will combine these to improve SNR or suppress interferers. In the REC, the determination of beamforming weights could be performed in conjunction with the link adaptation whereas in the case of beamforming weights determined by the RE, the link adaptation is done independently.

The UL/DL quality calculation entity is configured to determine a quality estimate in respect of each terminal device subject to MU-MIMO scheduling. This quality estimate should reflect the spatial separation between wireless terminals as well as the quality achieved when co-scheduling wireless terminals on the same time/frequency resource. The quality estimate is based on the information in the channel state memory.

The UL/DL SNR calculation entity is configured to determine the beamforming weights for each terminal device, and to provide the link adaptation function with estimates of the resulting SNR for each of the terminal devices being scheduled, including the mutual effect of co-scheduled terminal devices, so called MU-MIMO scheduling. The UE feedback (CSI) entity is configured to extract information about the channel provided by the terminal devices (in the UL data plane). Especially, in the case of FDD, where the reciprocity of the DL and UL of the channel to the terminal device is not perfect, it can be beneficial for the terminal device to send measurements (e.g., CSI) on the DL signal back to the access node. The CSI reports are extracted by the REC and used in the channel state memory and thus being considered in the determination of the beamforming weights.

In configurations where the bitrate of the interface between the REC and the RE is low (such as below a threshold), the determination of beamforming weights is executed by the RE (as in <FIG>), otherwise the determination is executed by the REC (as in <FIG>). That is, in case of limited available capacity of the interface between the REC and the RE, the REC (such as in the UPC) determines that the determination of beamforming weights is to be executed by the RE. Cell performance of the access node could be maximized by determining the beamforming weights in the REC for all co-scheduled terminal devices (within the same time and frequency domain) in order to accomplish best link adaptation and orthogonality. This requires that the RE sends extra information to the REC to allow for such determination, and that the REC sends the determined beamforming weights to the RE.

Still further, although the REC sends the determined beamforming weights to the RE, the RE can determine beamforming weights in parallel and thus combine these internally determined beamforming weights with the beamforming weights received from the REC. For access nodes where the interface between the REC and the RE is constrained but not minimized, the dual loops (as defined by the embodiment in <FIG>) allow for the access node to select some terminal devices which can be handled locally in the RE, thereby making bitrate of the interface between the REC and the RE available to handle terminal devices which are eligible to MU-MIMO scheduling, e.g. terminal devices using a streaming service.

The embodiments disclosed herein thus relate to mechanisms for configuring resources for terminal devices and configuring resources for terminal devices. In order to obtain such mechanisms there is provided an RE, a method performed by the RE, a computer program product comprising code, for example in the form of a computer program, that when run on processing circuitry of the RE, causes the RE to perform the method. In order to obtain such mechanisms there is further provided an REC, a method performed by the REC, and a computer program product comprising code, for example in the form of a computer program, that when run on processing circuitry of the REC, causes the REC to perform the method.

<FIG> are flow charts illustrating embodiments of methods for configuring resources for terminal devices as performed by the RE. <FIG> are flow charts illustrating embodiments of methods for configuring resources for terminal devices as performed by the REC. The methods are advantageously provided as computer programs 1520a, 1520b.

Reference is now made to <FIG> illustrating a method for configuring resources for terminal devices as performed by the RE of the access node according to an embodiment. As disclosed above the RE has an interface to the REC of the access node.

S110: The RE configures the resources for at least one of uplink reception and downlink transmission selectively using beamforming weights determined either based on internal information obtained locally in the RE, or based on external information received from the REC over the interface.

Embodiments relating to further details of configuring resources for terminal devices as performed by the RE will now be disclosed.

There could be different kinds of interfaces between the RE and the REC. As disclosed above, the interface between the REC and the RE could be a packet-based interface. Further, the interface between the REC and the RE could be a RUI. Further, the interface between the REC and the RE could be regarded as an evolved CPRI interface. The interface between the REC and the RE could be wired. However, this does not necessarily mean that the interface between REC and RE is a direct interface. Rather, it is foreseen that at least one intermediate entity could be physically located between the REC and the RE along the interface.

Reference is now made to <FIG> illustrating methods for configuring resources for terminal devices as performed by the RE according to further embodiments. It is assumed that step S110 is performed as described above with reference to <FIG> and a thus repeated description thereof is therefore omitted.

There may be different examples of internal information. According to an embodiment the internal information is based on channel estimates determined by the RE and information stored in a channel state memory in the RE.

The internal information could be provided to the REC. Hence, according to an embodiment the RE is configured to perform step S102:
S102: The RE provides the internal information to the REC over the interface.

The external information is then based on the internal information.

According to an embodiment the internal information is provided to the REC using incrementally higher resolution and/or incrementally lower priority.

According to an embodiment the external information is based on CSI reports.

There may be different examples of internal information. According to an embodiment the external information comprises initial beamforming weights.

There may be different ways for the RE to act depending on whether the resource are configured for uplink reception or downlink transmission. According to an embodiment the RE is configured to perform step S112a when resources for uplink reception are configured:
S112a: The RE determines reception beams using the beamforming weights.

According to an embodiment the RE is configured to perform step S112b when resources for downlink transmission are configured:
S112b: The RE determines transmission beams using the beamforming weights.

There may be different ways for the RE to selectively determine whether to use beamforming weights determined based on the internal information or based on the external information. According to a first example the determination is based on instructions received from the REC. Hence, according to an embodiment the RE is configured to perform step S104:
S104: The RE receives instructions from the REC over the interface. The instructions specifies whether the RE is to use beamforming weights determined based on the internal information or based on the external information.

According to a second example the determination is made internally in the RE. Hence, according to an embodiment the RE is configured to perform step S106:
S106: The RE determines internally in the RE whether to use beamforming weights determined based on the internal information or based on the external information.

According to some aspects the access node provides network access to a set of the terminal devices. According to an embodiment the RE is then configured to perform step S108:
S108: The RE determines for which of the terminal devices to use beamforming weights determined based on the internal information, and for which others of the terminal devices to use beamforming weights determined based on the external information.

There may be different ways for the RE to make the determination in step S108. According to an embodiment all terminal devices for which beamforming weights are determined based on the external information are co-scheduled by the access node. According to an embodiment the determining in step S108 is based on at least one of load on the interface, load of air interface between the access node and the terminal devices, and services used by the terminal devices.

Reference is now made to <FIG> illustrating a method for configuring resources for terminal devices as performed by the REC of the access node according to an embodiment. As disclosed above the REC has an interface to the RE of the access node.

S208: The REC instructs the RE to selectively configure the resources for at least one of uplink reception and downlink transmission using beamforming weights determined either based on internal information obtained locally in the RE, or based on external information received from the REC over the interface.

Embodiments relating to further details of configuring resources for terminal devices as performed by the REC will now be disclosed.

Reference is now made to <FIG> illustrating methods for configuring resources for terminal devices as performed by the REC according to further embodiments. It is assumed that step S208 is performed as described above with reference to <FIG> and a thus repeated description thereof is therefore omitted.

As disclosed above, according to an embodiment the internal information is based on channel estimates determined by the RE and information stored in a channel state memory in the RE.

As disclosed above, according to an embodiment the RE provides the internal information to the REC. Hence, according to an embodiment the REC is configured to perform step S202:
S202: The REC obtains the internal information from the RE over the interface. The external information is then based on the internal information.

According to an embodiment the internal information is received from the RE using incrementally higher resolution and/or incrementally lower priority.

As disclosed above, according to an embodiment the external information comprises initial beamforming weights.

According to an embodiment the REC determines a quality measure based on information received from the RE. Hence, according to an embodiment the REC is configured to perform step S204:
S204: The REC determines a quality measure of the internal information, and wherein the external information is based on the internal information.

According to some aspects the access node provides network access to a set of the terminal devices. According to an embodiment the REC is then configured to perform step S206:
S206: The REC determines for which of the terminal devices to use beamforming weights determined based on the internal information, and for which others of the terminal devices to use beamforming weights determined based on the external information.

According to an embodiment the external information is also based on CSI reports.

There may be different ways for the REC to make the determination in step S206. According to an embodiment all terminal devices for which beamforming weights are determined based on the external information are co-scheduled by the access node. According to an embodiment the determining in step S206 is based on at least one of load on the interface, load of air interface between the access node and the terminal devices, and services used by the terminal devices.

The beamforming weights can be calculated in the RE when the beam shaped antenna gain primarily is wanted for extended service coverage. This is possible when the beam dimension not is used for MU-MIMO. Other reasons to perform the beamforming weight calculation in the RE could be to save bit rate on the interface between the REC and the RE or to minimize latency.

To be capable to dynamically control if the beamforming weights to use in the RE either come from the RE or from the REC, the RE is configured to selectively either combine or select between the two sources of beamforming weights (i.e., between internally determined beamforming weights and beamforming weights received from the REC). The REC may also reselect over time the type of source for beamforming weights that is used for a specific terminal device.

Further aspects applicable to both the embodiments of the RE and the REC will now be disclosed with reference to the embodiment of REC and RE illustrated in <FIG>. The description of those entities already having been described with reference to any of <FIG> is omitted for brevity.

A reference symbol extraction entity is configured to extract the reference symbols from the Resource Elements that are provided by the UL OFDM FFT from all antenna ports.

The spatial DFT entity and the channel estimation entity are configured to collectively provide a quality value for the fixed beam directions. The quality value is typically based on a filtering of the reference symbols per involved transmission antennas at the terminal device or MIMO layer within the resource block or for a filtering of a further processed channel estimate per involved transmission antennas at the terminal device or MIMO layer and extracted reference symbols. The beam direction space is provided by processing the reference symbols from all antennas through the spatial DFT entity.

A Dimension Reduction entity is configured to reduce dimension of data being inputted to the Dimension Reduction entity. For beamforming weight determination performed via the REC, the dimension of which fixed beam directions to use for the beamforming is reduced in order to limit the processing load when calculating the weights and the interface rate from the RE to the REC. The dimension reduction is based on the quality values from the Spatial DFT entity and the channel estimation entity. For beamforming weight determination performed internally in the RE, more dimensions can be stored, and thus providing better SNR in case of SU-MIMO transmission.

A Channel state memory is provided in the REC when beamforming weight determination is performed via the REC. For the terminal devices that are scheduled to be measured, the reference symbol based channel estimates can be sent to the REC and stored in the REC Channel State Memory. These stored channel estimates can then be used for link adaption as well as determination of beamforming weights. The content of the Channel state memory can be used when the data channel is active and is updated for every new measurement of reference symbols. In addition to this the Channel state memory can also store a covariance matrix for all beam directions that have been measured. Those values can be calculated in the REC. If no MU-MIMO pairing shall be done the beam direction related information does not need to be stored in the Channel state memory, which will lower the demand on the interface between the REC and the RE.

A Channel state memory is provided in the RE when beamforming weight determination is performed internally in the RE. For the reference symbols of the terminal devices that are scheduled to be measured, the reference symbol based Channel estimates are stored in the RE Channel State Memory. These stored channel estimates can be used for determining beamforming weights. The content of the Channel state memory can be used when the data channel is active and could be updated for every new measurement of reference symbols. If no MU-MIMO pairing is done, if no beam direction related information is stored in the REC based channel state memory, and if the covariance matrix will be used, the same covariance matrix as described in the channel state memory in the REC can instead be stored in the channel state memory in the RE.

A Source Select entity is configured to select and/or combine the beamforming weights that either originate from the REC or locally from the RE.

Even in the case where the channel estimate is sent to the REC, a local copy of the channel estimate can be stored in the RE. In case the REC will not send beamforming weights, the RE will have to use beamforming weights as determined internally. This can be due to the REC being satisfied with the beamforming weights determined internally or that the beamforming weights are not received properly by the RE (e.g., due to a lost message). The RE can signal to the REC if it has stored a local copy of the channel estimate. The RE can run out of local memory, thus such a signalling is recommended (but not mandated). Also, the REC can explicitly order the RE to store a local copy. Also in case no complete channel estimate is sent to the REC, a reduced channel estimate could be transmitted from the RE to the REC to aid the link adaptation and rank selection.

The UPC in the REC is configured to adaptively select which terminal devices that shall have their channel estimates sent to the REC and which terminal devices shall (only) have their channel estimates stored in the RE. Examples of which this adaptive selection can be made are the load of the interface between the REC and the RE, the load of the air interface between the access node and the terminal devices, and the type of services used by the terminal devices. These examples will now be disclosed in more detail.

The load of the interface between the REC and the RE can be used to determine if there is available capacity to send the channel estimate to the REC and if is there a good likelihood to send the updated channel estimate back to the RE. The channel estimate could, for link adaptation purposes, be sent to the REC even if no channel back to the RE is available. The latter could require the RE to also store the channel estimate in its memory.

In general terms, the more optimization of the beamforming function that is needed to improve the air interface efficiency, the more data the REC needs to have and to control. Thus, at a comparatively high load of the air interface, it can be better to prioritize channel estimation data than user payload data (which in case of poor link adaptation would need to be retransmitted). In such cases, a higher portion of the terminal devices will be selected to send their channel estimates to the REC.

One reason for modifying the beamforming weights in the REC is for multi-user optimization purposes, either for terminal devices in the same served region or terminal devices in in neighbouring served regions. Such optimizations could be most efficient if the terminal device has a continuous service (as compared to a bursty service) with repetitive transmissions. The REC can then use channel estimates to match terminal devices that are likely to transmit at the same time into MU-MIMO groups, and determine optimal beamforming weights for each terminal device in such a group. The REC determines when transmissions occur (and can thus maintain such a group), but this is only meaningful if the transmissions are not bursty. Thus services such as audio or video streaming are suitable for MU-MIMO matching and terminal devices running such services can be selected to have their channel estimates sent to the REC.

Further, the RE could first reduce channel estimates to the REC and then sends as many channel estimates as possible to the REC. In case of time division multiplex (TDD), there will be room for further channel estimates being transferred in the DL time slots. The REC could then be configured to steer the DL transmission of the beamforming weights and possibly the order/priority of the UL channel estimates if some are more urgent than others.

<FIG> schematically illustrates, in terms of a number of functional units, the components of an RE according to an embodiment. Processing circuitry <NUM> is provided using any combination of one or more of a suitable central processing unit (CPU), multiprocessor, microcontroller, digital signal processor (DSP), etc., capable of executing software instructions stored in a computer program product 1510a (as in <FIG>), e.g. in the form of a storage medium <NUM>. The processing circuitry <NUM> may further be provided as at least one application specific integrated circuit (ASIC), or field programmable gate array (FPGA).

Particularly, the processing circuitry <NUM> is configured to cause the RE to perform a set of operations, or steps, S102-S112b, as disclosed above. For example, the storage medium <NUM> may store the set of operations, and the processing circuitry <NUM> may be configured to retrieve the set of operations from the storage medium <NUM> to cause the RE to perform the set of operations. Thus the processing circuitry <NUM> is thereby arranged to execute methods as herein disclosed.

The RE may further comprise a communications interface <NUM> for communications with the REC. As such the communications interface <NUM> may comprise one or more transmitters and receivers, comprising analogue and digital components.

The processing circuitry <NUM> controls the general operation of the RE e.g. by sending data and control signals to the communications interface <NUM> and the storage medium <NUM>, by receiving data and reports from the communications interface <NUM>, and by retrieving data and instructions from the storage medium <NUM>. Other components, as well as the related functionality, of the RE are omitted in order not to obscure the concepts presented herein.

<FIG> schematically illustrates, in terms of a number of functional modules, the components of an RE according to an embodiment. The RE of <FIG> comprises a configure module 210e configured to perform step S110. The RE of <FIG> may further comprise a number of optional functional modules, such as any of a provide module 210a configured to perform step S102, a receive module 210b configured to perform step S104, a determine module 210c configured to perform step S106, a determine module 210d configured to perform step S108, a determine module 210f configured to perform step S112a, and a determine module <NUM> configured to perform step S112b.

In general terms, each functional module 210a-<NUM> may be implemented in hardware or in software. Preferably, one or more or all functional modules 210a-<NUM> may be implemented by the processing circuitry <NUM>, possibly in cooperation with functional units <NUM> and/or <NUM>. The processing circuitry <NUM> may thus be arranged to from the storage medium <NUM> fetch instructions as provided by a functional module 210a-<NUM> and to execute these instructions, thereby performing any steps of the RE as disclosed herein.

<FIG> schematically illustrates, in terms of a number of functional units, the components of an REC according to an embodiment. Processing circuitry <NUM> is provided using any combination of one or more of a suitable central processing unit (CPU), multiprocessor, microcontroller, digital signal processor (DSP), etc., capable of executing software instructions stored in a computer program product 1510b (as in <FIG>), e.g. in the form of a storage medium <NUM>. The processing circuitry <NUM> may further be provided as at least one application specific integrated circuit (ASIC), or field programmable gate array (FPGA).

Particularly, the processing circuitry <NUM> is configured to cause the REC to perform a set of operations, or steps, S202-S208, as disclosed above. For example, the storage medium <NUM> may store the set of operations, and the processing circuitry <NUM> may be configured to retrieve the set of operations from the storage medium <NUM> to cause the REC to perform the set of operations. Thus the processing circuitry <NUM> is thereby arranged to execute methods as herein disclosed.

The REC may further comprise a communications interface <NUM> for communications with the RE. As such the communications interface <NUM> may comprise one or more transmitters and receivers, comprising analogue and digital components.

The processing circuitry <NUM> controls the general operation of the REC e.g. by sending data and control signals to the communications interface <NUM> and the storage medium <NUM>, by receiving data and reports from the communications interface <NUM>, and by retrieving data and instructions from the storage medium <NUM>. Other components, as well as the related functionality, of the REC are omitted in order not to obscure the concepts presented herein.

<FIG> schematically illustrates, in terms of a number of functional modules, the components of an REC according to an embodiment. The REC of <FIG> comprises an instruct module 310d configured to perform step S208. The REC of <FIG> may further comprise a number of optional functional modules, such as any of an obtain module 310a configured to perform step S202, an obtain module 310b configured to perform step S204, and a determine module 310c configured to perform step S206. In general terms, each functional module 310a-310d may be implemented in hardware or in software. Preferably, one or more or all functional modules 310a-310d may be implemented by the processing circuitry <NUM>, possibly in cooperation with functional units <NUM> and/or <NUM>. The processing circuitry <NUM> may thus be arranged to from the storage medium <NUM> fetch instructions as provided by a functional module 310a-310d and to execute these instructions, thereby performing any steps of the REC as disclosed herein.

The RE and REC may be provided as standalone devices or as a part of at least one further device. For example, as disclosed above the RE and REC may be provided in an access node. Alternatively, functionality of the RE and the REC may be distributed between at least two devices, or nodes.

Thus, a first portion of the instructions performed by the RE or REC may be executed in a first device, and a second portion of the of the instructions performed by the RE or REC may be executed in a second device; the herein disclosed embodiments are not limited to any particular number of devices on which the instructions performed by the RE or REC may be executed. Hence, the methods according to the herein disclosed embodiments are suitable to be performed by an RE or REC residing in a cloud computational environment. Therefore, although a single processing circuitry <NUM>, <NUM> is illustrated in <FIG> the processing circuitry <NUM>, <NUM> may be distributed among a plurality of devices, or nodes. The same applies to the functional modules 210a-<NUM>, 310a-310d of <FIG> and the computer programs 1520a, 1520b of <FIG> (see below).

<FIG> shows one example of a computer program product 1510a, 1510b comprising computer readable means <NUM>. On this computer readable means <NUM>, a computer program 1520a can be stored, which computer program 1520a can cause the processing circuitry <NUM> and thereto operatively coupled entities and devices, such as the communications interface <NUM> and the storage medium <NUM>, to execute methods according to embodiments described herein. The computer program 1520a and/or computer program product 1510a may thus provide means for performing any steps of the RE as herein disclosed. On this computer readable means <NUM>, a computer program 1520b can be stored, which computer program 1520b can cause the processing circuitry <NUM> and thereto operatively coupled entities and devices, such as the communications interface <NUM> and the storage medium <NUM>, to execute methods according to embodiments described herein. The computer program 1520b and/or computer program product 1510b may thus provide means for performing any steps of the REC as herein disclosed.

In the example of <FIG>, the computer program product 1510a, 1510b is illustrated as an optical disc, such as a CD (compact disc) or a DVD (digital versatile disc) or a Blu-Ray disc. The computer program product 1510a, 1510b could also be embodied as a memory, such as a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), or an electrically erasable programmable read-only memory (EEPROM) and more particularly as a non-volatile storage medium of a device in an external memory such as a USB (Universal Serial Bus) memory or a Flash memory, such as a compact Flash memory. Thus, while the computer program 1520a, 1520b is here schematically shown as a track on the depicted optical disk, the computer program 1520a, 1520b can be stored in any way which is suitable for the computer program product 1510a, 1510b.

Claim 1:
A method for configuring resources for terminal devices (<NUM>), the method being performed by a radio equipment, RE, (<NUM>) of an access node (<NUM>), the RE having an interface (<NUM>) to a radio equipment controller, REC, (<NUM>) of the access node, the method comprising:
configuring (S110) the resources for at least one of uplink reception and downlink transmission using beamforming weights determined according to a selected one among two available alternatives of:
based on internal information on channel estimates obtained locally in the RE, and based on external information received from the REC over the interface.