US20190199379A1 - Methods and Devices for Determination of Beamforming Information - Google Patents

Methods and Devices for Determination of Beamforming Information Download PDF

Info

Publication number
US20190199379A1
US20190199379A1 US16/330,514 US201716330514A US2019199379A1 US 20190199379 A1 US20190199379 A1 US 20190199379A1 US 201716330514 A US201716330514 A US 201716330514A US 2019199379 A1 US2019199379 A1 US 2019199379A1
Authority
US
United States
Prior art keywords
beamforming
rec
information per
interface
beamforming information
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Abandoned
Application number
US16/330,514
Other languages
English (en)
Inventor
Jacob Österling
Fredrik Huss
Jonas Karlsson
Oskar Mauritz
Christer Östberg
Jan Roxbergh
Alex Stephenne
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Telefonaktiebolaget LM Ericsson AB
Original Assignee
Telefonaktiebolaget LM Ericsson AB
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Telefonaktiebolaget LM Ericsson AB filed Critical Telefonaktiebolaget LM Ericsson AB
Priority to US16/330,514 priority Critical patent/US20190199379A1/en
Assigned to TELEFONAKTIEBOLAGET LM ERICSSON (PUBL) reassignment TELEFONAKTIEBOLAGET LM ERICSSON (PUBL) ASSIGNMENT OF ASSIGNORS INTEREST (SEE DOCUMENT FOR DETAILS). Assignors: STEPHENNE, ALEX, HUSS, FREDRIK, ÖSTERLING, Jacob, Östberg, Christer, ROXBERGH, JAN, KARLSSON, JONAS, MAURITZ, OSKAR
Publication of US20190199379A1 publication Critical patent/US20190199379A1/en
Abandoned legal-status Critical Current

Links

Images

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
    • H04B7/0615—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal
    • H04B7/0617—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal for beam forming
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
    • H04B1/0003—Software-defined radio [SDR] systems, i.e. systems wherein components typically implemented in hardware, e.g. filters or modulators/demodulators, are implented using software, e.g. by involving an AD or DA conversion stage such that at least part of the signal processing is performed in the digital domain
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03M—CODING; DECODING; CODE CONVERSION IN GENERAL
    • H03M7/00—Conversion of a code where information is represented by a given sequence or number of digits to a code where the same, similar or subset of information is represented by a different sequence or number of digits
    • H03M7/30—Compression; Expansion; Suppression of unnecessary data, e.g. redundancy reduction
    • H03M7/3068—Precoding preceding compression, e.g. Burrows-Wheeler transformation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B10/00—Transmission systems employing electromagnetic waves other than radio-waves, e.g. infrared, visible or ultraviolet light, or employing corpuscular radiation, e.g. quantum communication
    • H04B10/25—Arrangements specific to fibre transmission
    • H04B10/2575—Radio-over-fibre, e.g. radio frequency signal modulated onto an optical carrier
    • H04B10/25752—Optical arrangements for wireless networks
    • H04B10/25758—Optical arrangements for wireless networks between a central unit and a single remote unit by means of an optical fibre
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
    • H04W88/02—Terminal devices
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04W—WIRELESS COMMUNICATION NETWORKS
    • H04W88/00—Devices specially adapted for wireless communication networks, e.g. terminals, base stations or access point devices
    • H04W88/08—Access point devices
    • H04W88/085—Access point devices with remote components

Definitions

  • Embodiments presented herein relate to a method, an RE, a computer program, and a computer program product for determining beamforming weights or decoding user data for terminal devices. Embodiments presented herein further relate to a method, an REC, a computer program, and a computer program product for determining beamforming weights or decoding user data for terminal devices.
  • the introduction of digital beamforming antenna systems in access nodes 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.
  • UE user equipment
  • 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.
  • REC radio equipment controller
  • RE radio equipment
  • CPRI Common Public Radio Interface
  • bit rate of the current CPRI interface scales directly to the number of independent radio chains in the RE.
  • a bit rate of 530 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.
  • 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.
  • An object of embodiments herein is to provide efficient communication between the REC and the RE.
  • a method for obtaining information for determining beamforming weights for terminal devices is performed by an RE of an access node.
  • the RE has an interface to an REC of the access node.
  • the method comprises obtaining beamforming information per direction from the REC over the interface.
  • the method comprises transforming the beamforming information per direction to beamforming information per antenna, the beamforming information per antenna representing the beamforming weights.
  • the method comprises applying the beamforming weights.
  • an RE of an access node for obtaining information for determining beamforming weights for terminal devices.
  • the RE has an interface to an REC of the access node and comprises processing circuitry.
  • the processing circuitry is configured to cause the RE to obtain beamforming information per direction from the REC over the interface.
  • the processing circuitry is configured to cause the RE to transform the beamforming information per direction to beamforming information per antenna, the beamforming information per antenna representing the beamforming weights.
  • the processing circuitry is configured to cause the RE to apply the beamforming weights.
  • an RE of an access node for obtaining information for determining beamforming weights for terminal devices.
  • the RE has an interface to an REC of the access node.
  • the RE comprises an obtain module configured to obtain beamforming information per direction from the REC over the interface.
  • the RE comprises a transform module configured to transform the beamforming information per direction to beamforming information per antenna, the beamforming information per antenna representing the beamforming weights.
  • the RE comprises an apply module configured to apply the beamforming weights.
  • a computer program for obtaining information for determining beamforming weights for terminal devices.
  • the computer program comprises computer program code which, when run on processing circuitry of an RE, causes the RE to perform a method according to the first aspect.
  • a sixth aspect there is presented a method for providing information for determining beamforming weights for terminal devices.
  • the method is performed by an REC of an access node.
  • the REC has an interface to an RE of the access node.
  • the method comprises obtaining beamforming information per antenna, the beamforming information per antenna representing the beamforming weights.
  • the method comprises transforming the beamforming information per antenna to beamforming information per direction.
  • the method comprises providing the beamforming information per direction to the RE over the interface.
  • an REC of an access node for providing information for determining beamforming weights for terminal devices.
  • the REC has an interface to an RE of the access node and comprises processing circuitry.
  • the processing circuitry is configured to cause the REC to obtain beamforming information per antenna, the beamforming information per antenna representing the beamforming weights.
  • the processing circuitry is configured to cause the REC to transform the beamforming information per antenna to beamforming information per direction.
  • the processing circuitry is configured to cause the REC to provide the beamforming information per direction to the RE over the interface.
  • an REC of an access node for providing information for determining beamforming weights for terminal devices.
  • the REC has an interface to an RE of the access node and comprises processing circuitry and a computer program product.
  • the computer program stores instructions that, when executed by the processing circuitry, causes the REC to perform operations, or steps.
  • the operations, or steps, cause the REC to obtain beamforming information per antenna, the beamforming information per antenna representing the beamforming weights.
  • the operations, or steps, cause the REC to transform the beamforming information per antenna to beamforming information per direction.
  • the operations, or steps, cause the REC to provide the beamforming information per direction to the RE over the interface.
  • an REC of an access node for providing information for determining beamforming weights for terminal devices.
  • the REC has an interface to an RE of the access node.
  • the REC comprises an obtain module configured to obtain beamforming information per antenna, the beamforming information per antenna representing the beamforming weights.
  • the REC comprises a transform module configured to transform the beamforming information per antenna to beamforming information per direction.
  • the REC comprises a provide module configured to provide the beamforming information per direction to the RE over the interface.
  • the computer program comprises computer program code which, when run on processing circuitry of an REC, causes the REC to perform a method according to the sixth aspect.
  • a method for determining beamforming weights for terminal devices is performed by an RE of an access node.
  • the RE has an interface to an REC of the access node.
  • the method comprises obtaining beamforming information per antenna from at least one of the terminal devices, the beamforming information per antenna representing the beamforming weights.
  • the method comprises transforming the beamforming information per antenna to beamforming information per direction.
  • the method comprises providing the beamforming information per direction to the REC over the interface.
  • an RE of an access node for determining beamforming weights for terminal devices.
  • the RE has an interface to an REC of the access node and comprises processing circuitry.
  • the processing circuitry is configured to cause the RE to obtain beamforming information per antenna from at least one of the terminal devices, the beamforming information per antenna representing the beamforming weights.
  • the processing circuitry is configured to cause the RE to transform the beamforming information per antenna to beamforming information per direction.
  • the processing circuitry is configured to cause the RE to provide the beamforming information per direction to the REC over the interface.
  • an RE of an access node for determining beamforming weights for terminal devices.
  • the RE has an interface to an REC of the access node and comprises processing circuitry and a computer program product.
  • the computer program stores instructions that, when executed by the processing circuitry, causes the RE to perform operations, or steps.
  • the operations, or steps cause the RE to obtain beamforming information per antenna from at least one of the terminal devices, the beamforming information per antenna representing the beamforming weights.
  • the operations, or steps cause the RE to transform the beamforming information per antenna to beamforming information per direction.
  • the operations, or steps, cause the RE to provide the beamforming information per direction to the REC over the interface.
  • an RE of an access node for determining beamforming weights for terminal devices.
  • the RE has an interface to an REC of the access node.
  • the RE comprises an obtain module configured to beamforming information per antenna from at least one of the terminal devices, the beamforming information per antenna representing the beamforming weights.
  • the RE comprises a transform module configured to transform the beamforming information per antenna to beamforming information per direction.
  • the RE comprises a provide module configured to provide the beamforming information per direction to the REC over the interface.
  • the computer program comprises computer program code which, when run on processing circuitry of an RE, causes the RE to perform a method according to the eleventh aspect.
  • a sixteenth aspect there is presented a method for obtaining information for determining beamforming weights for terminal devices.
  • the method is performed by an REC of an access node.
  • the REC has an interface to an RE of the access node.
  • the method comprises obtaining beamforming information per direction from the RE over the interface.
  • the method comprises determining the beamforming weights per direction based on the beamforming information per direction.
  • the method comprises providing the beamforming weights per direction to the RE over the interface.
  • an REC of an access node for providing information for obtaining information for determining beamforming weights for terminal devices.
  • the REC has an interface to an RE of the access node and comprises processing circuitry.
  • the processing circuitry is configured to cause the REC to obtain beamforming information per direction from the RE over the interface.
  • the processing circuitry is configured to cause the REC to determine the beamforming weights per direction based on the beamforming information per direction.
  • the processing circuitry is configured to cause the REC to provide the beamforming weights per direction to the RE over the interface.
  • an REC of an access node for obtaining information for determining beamforming weights for terminal devices.
  • the REC has an interface to an RE of the access node and comprises processing circuitry and a computer program product.
  • the computer program stores instructions that, when executed by the processing circuitry, causes the REC to perform operations, or steps.
  • the operations, or steps, cause the REC to obtain beamforming information per direction from the RE over the interface.
  • the operations, or steps, cause the REC to determine the beamforming weights per direction based on the beamforming information per direction.
  • the operations, or steps, cause the REC to provide the beamforming weights per direction to the RE over the interface.
  • an REC of an access node for obtaining information for determining beamforming weights for terminal devices.
  • the REC has an interface to an RE of the access node.
  • the REC comprises an obtain module configured to obtain beamforming information per direction from the RE over the interface.
  • the REC comprises a determine module configured to determine the beamforming weights per direction based on the beamforming information per direction.
  • the REC comprises a provide module configured to provide the beamforming weights per direction to the RE over the interface.
  • a computer program for obtaining information for determining beamforming weights for terminal devices.
  • the computer program comprises computer program code which, when run on processing circuitry of an REC, causes the REC to perform a method according to the sixteenth aspect.
  • a computer program product comprises a computer program according to at least one of the fifth aspect, the tenth aspect, the fifteenth aspect, and the twentieth aspect and a computer readable storage medium on which the computer program is stored.
  • the computer readable storage medium could be a non-transitory computer readable storage medium.
  • FIGS. 1, 2, 3, 4, 5, and 6 are schematic diagrams illustrating an access node according to embodiments
  • FIG. 7 is a schematic illustration of a time-frequency resource grid according to embodiments.
  • FIG. 8 is a schematic illustration comparing energy in antenna space and direction space
  • FIG. 9 is a schematic illustration of a compression subsystem according to an embodiment
  • FIGS. 10, 11, 12, and 13 are flowcharts of methods according to embodiments
  • FIG. 14 is a schematic diagram showing functional units of an RE according to an embodiment
  • FIG. 15 is a schematic diagram showing functional modules of an RE according to an embodiment
  • FIG. 16 is a schematic diagram showing functional units of an REC according to an embodiment
  • FIG. 17 is a schematic diagram showing functional modules of an REC according to an embodiment.
  • FIG. 18 shows one example of a computer program product comprising computer readable means according to an embodiment.
  • FIG. 1 is a schematic diagram illustrating an access node 100 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.
  • the access node comprises at least one Radio Equipment Controller (REC) 300 and at least one Radio Equipment (RE) 200 .
  • REC Radio Equipment Controller
  • RE Radio Equipment
  • the access node comprises one REC and two REs, where the REC has one interface 700 to each of the REs.
  • the REs are configured to perform DL transmissions to, and UL receptions from, terminal devices boo in beams 500 by using appropriate beamforming weights at the antennas 400 .
  • 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.
  • 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.
  • MIMO multiple-input multiple-output
  • 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.
  • the FFT Fast Fourier Transform
  • IFFT Inverse Fast Fourier Transform
  • the execution of the beamforming data plane functionality is added to the RE.
  • the interface 700 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.
  • a communications system having an air interface with a system bandwidth of 400 MHz and that provides support for 4 MIMO streams and utilizes access nodes with 64 antennas for beamforming.
  • CPRI interfaces between the REC and the RE exposing all 64 antennas for the REC would require approximately 54 CPRI interfaces of 10 Gbps, since a CPRI interface carries about 480 MHz.
  • an interface using virtual antenna ports would require 4 MIMO streams of 400 MHz, and would require about 4 CPRI interfaces of 10 Gbps, since one 10 Gbps CPRI interface still carries data for about 480 MHz.
  • the 4 MIMO streams of 400 MHz would require 7 Gbps (assuming 256QAM and 20 LTE 20 MHz carriers), or one 10 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.
  • FIG. 2 shows 1-8 DL MIMO layers on 128 radio branches.
  • FIG. 2 shows 128 radio branches and 1-16 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. 2 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. 2 further illustrates User Plane Control (UPC) with its air interface scheduling and link adaptation placed in the REC.
  • UPC User Plane Control
  • FIG. 3 shows an embodiment of an REC and an RE similar to those in FIG. 2 .
  • 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.
  • SRS Sounding Reference symbols
  • the RE could thus be regarded as autonomous in this respect.
  • 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 scheduling and the LA are based on the dimension reduced information while further dimensions are used for the determination of beamforming weights. This is equally applicable for UL and DL.
  • the radio channel should typically be dispersive to be able to gain from adding more dimensions to the beam calculation.
  • FIG. 4 shows an embodiment of an REC and an RE similar to those in FIG. 2 .
  • 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.
  • 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.
  • a linear combination of 3 predetermined beams could be expressed as 3 times 24 bits (an 8-bit beam number+an 8-bit amplitude+an 8-bit phase) rather than 128 times 16 bits (an 8-bit amplitude+an 8-bit phase for each of the 128 physical antenna elements).
  • the transformation from the physical antenna element space to the beam direction 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. 4 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. 4 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.
  • 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. 3 ).
  • FIG. 5 illustrates an embodiment of an REC and an RE combining the functionality of the REC and RE in the embodiments of FIG. 3 and FIG. 4 .
  • the embodiment of FIG. 5 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.
  • 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.
  • MRC maximum-ratio combining
  • the UPC will order more beams than layers, and then the demodulation will combine these to improve SNR or suppress interferers.
  • 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.
  • the determination of beamforming weights is executed by the RE (as in FIG. 3 ), otherwise the determination is executed by the REC (as in FIG. 4 ). 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.
  • the RE can determine beamforming weights in parallel and thus combine these internally determined beamforming weights with the beamforming weights received from the REC.
  • the dual loops 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 beamforming coefficient calculation in the REC will be the same as performed in the RE, and the REC can send a minimal message requesting the RE to use its locally calculated values. In case of heavy dimensioning reduction, this may even improve the beamforming gain as the RE has uncompressed channel estimation data.
  • constraints have changed any beamforming weights, it can be evaluated if the constraints have less bits than the new beamforming weights, and can be transferred instead.
  • 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 Discrete Fourier Transform (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.
  • 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.
  • 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.
  • 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.
  • 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). Further, as will be further disclosed below the local stored channel estimates can be used to calculate a default setting of the beamforming weights to which the REC sends differential information, see the compression chapter below.
  • the RE can signal to the REC if it has stored a local copy of the channel estimate. This allows the REC to know if such compression is possible.
  • the RE can run out of local memory, thus such a signalling is recommended (but not mandated).
  • 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.
  • FIG. 7 gives an example of a time-frequency resource grid 1700 applicable to embodiments disclosed herein.
  • the time-frequency resource grid illustrates a possible allocation of resources to terminal devices in terms of a scheduled entity comprising symbols, where each symbol corresponds to a Resource Element.
  • Each Resource Element in time corresponds to one orthogonal frequency-division multiplexing (OFDM) symbol and in frequency corresponds to a subcarrier.
  • One subframe comprises 7 symbols; one subcarrier group comprises 24 subcarriers, one subcarrier chunk comprises 10 subcarrier groups; and one carrier comprises at least one subcarrier chunk.
  • OFDM orthogonal frequency-division multiplexing
  • FIG. 10 illustrating methods for determining beamforming weights for terminal devices as performed by the RE of the access node according to embodiments.
  • the REC in step S 206 provides beamforming information per direction to the RE 200 over the interface 700 .
  • the RE 200 is configured to perform step S 102 :
  • the RE 200 obtains beamforming information per direction from the REC 300 over the interface 700 .
  • the beamforming information is to be applied not per direction but per antenna.
  • the RE 200 is therefore configured to perform step S 106 :
  • the RE 200 transforms the beamforming information per direction to beamforming information per antenna.
  • the beamforming information per antenna represents the beamforming weights.
  • the RE 200 is configured to perform step S 108 :
  • the beamforming weights are to be applied at antennas 400 of the RE 200 .
  • the number of beamforming weights in the direction space is smaller than the number of beamforming weights in the antenna space.
  • the transformation thus results in an expansion of dimensionality of the of beamforming information. That is, according to an embodiment the beamforming information per antenna is associated with a first dimensionality, and the beamforming information per direction is associated with a second dimensionality being smaller than the first dimensionality.
  • the beamforming information is transmitted between the RE 200 and the REC 300 as linear combinations of predetermined beams.
  • the beamforming information per direction is obtained as a linear combination of predetermined beamforming weights per direction.
  • the transformation is achieved based on using a DFT.
  • the beamforming information is transformed using a DFT.
  • indices i 0 , i 1 , . . . could be used that appoint which of the fixed beam directions (as defined by the predetermined beams) to use.
  • the RE 200 is configured to perform (optional) step S 104 :
  • the RE 200 obtains information appointing fixed beam directions from the REC 300 over the interface 100 .
  • the beamforming information per direction is then transformed to the beamforming information per antenna only for the appointed beam directions.
  • FIG. 11 illustrating methods for determining beamforming weights for terminal devices as performed by the REC of the access node according to embodiments.
  • the REC 300 is configured to perform step S 202 :
  • the REC 300 obtains beamforming information per antenna.
  • the beamforming information per antenna represents the beamforming weights.
  • the REC 300 is configured to perform step S 204 :
  • the REC 300 transforms the beamforming information per antenna to beamforming information per direction.
  • the beamforming information is to be applied by the RE 200 and is therefore provided to the RE 200 . That is, the REC 300 is configured to perform step S 206 :
  • the REC 300 provides the beamforming information per direction to the RE 200 over the interface 100 .
  • the beamforming information per antenna could be obtained from at least one of the terminal devices boo.
  • the number of beamforming weights in the direction space is smaller than the number of beamforming weights in the antenna space. That is, the embodiment wherein the beamforming information per antenna is associated with a first dimensionality, and wherein the beamforming information per direction is associated with a second dimensionality being smaller than the first dimensionality is also applicable for the REC 300 .
  • only high quality beamforming information per direction is provided.
  • only the beamforming information per direction having a signal quality measure above a threshold is provided to the RE 200 over the interface 700 in step S 206 .
  • the beamforming information per direction that does not fulfil the requirement defined by the threshold is thus not transmitted over the interface 100 , thus enabling a reduction in bitrate in comparison to transmitting all the beamforming information per direction or all the beamforming information per antenna.
  • the transformation is achieved based on using a DFT. That is, the embodiment wherein the beamforming information is transformed using a DFT is also applicable for the REC 300 .
  • indices i 0 , i 1 , . . . could be used that appoint which of the fixed beam directions to use. That is, according to an embodiment the REC 300 is configured to perform (optional) step S 208 :
  • the REC 300 provides information to the RE 200 over the interface 700 appointing which fixed beam directions to use when transforming the beamforming information per direction to beamforming information per antenna.
  • FIG. 12 illustrating methods determining beamforming weights for terminal devices as performed by the RE of the access node according to embodiments.
  • the RE 200 obtains beamforming information per antenna from at least one of the terminal devices boo.
  • the beamforming information per antenna represents the beamforming weights.
  • the RE 200 is configured to perform step 3204 :
  • S 304 The RE 200 transforms the beamforming information per antenna to beamforming information per direction.
  • the beamforming information is then provided to the REC 300 . That is, the RE 200 is configured to perform step S 306 :
  • the RE 200 provides the beamforming information per direction to the REC 300 over the interface 700 .
  • the number of beamforming weights in the direction space is smaller than the number of beamforming weights in the antenna space. That is, the embodiment wherein the beamforming information per antenna is associated with a first dimensionality, and wherein the beamforming information per direction is associated with a second dimensionality being smaller than the first dimensionality is also applicable for the RE 200 .
  • only high quality beamforming information per direction is provided. That is, the embodiment wherein only the beamforming information per direction having a signal quality measure above a threshold is provided to the REC 300 over the interface 700 is also applicable for the RE 200 .
  • the transformation is achieved based on using a DFT. That is, the embodiment wherein the beamforming information is transformed using a DFT is also applicable for the RE 300 .
  • the REC 300 provide beamforming weights per direction to the RE 200 over the interface 700 .
  • the RE 200 is configured to perform (optional) step S 308 :
  • the beamforming weights per direction are transformed to beamforming weights per antenna. That is, according to this embodiment the RE 200 is configured to perform (optional) step S 310 :
  • the RE 200 obtains transforms the updated beamforming weights per direction to updated beamforming weights per antenna.
  • the beamforming weights per antenna can then be used by the RE 200 .
  • the RE 200 is configured to perform (optional) step S 312 :
  • the updated beamforming weights could be applied at antennas 400 of the RE 200 .
  • FIG. 13 illustrating a method for determining beamforming weights for terminal devices as performed by the REC of the access node according to embodiments.
  • the RE 200 in step S 306 provides beamforming information per direction to the REC 300 over the interface 700 . Therefore, the REC 300 is configured to perform step S 402 :
  • the REC 300 obtains beamforming information per direction from the RE 200 over the interface 700 .
  • Beamforming weight to be applied at the RE 200 are then determined.
  • the REC 300 is configured to perform step S 406 :
  • the REC 300 determines the beamforming weights per direction based on the beamforming information per direction.
  • the beamforming weights are then provided to the RE 200 .
  • the REC 300 is configured to perform step S 408 :
  • the REC 300 provides the beamforming weights per direction to the RE 200 over the interface 700 .
  • only high quality beamforming information per direction is used. That is, according to an embodiment only the beamforming information per direction having a signal quality measure above the threshold is used when determining the beamforming weights per direction.
  • the beamforming weights are determined based on the rank of the radio channel, either for multiple users or a single user (where each user is defined by a respective terminal device 600 ). Therefore, according to an embodiment the REC 300 is configured to perform (optional) step S 404 :
  • the REC 300 obtains channel rank information from the RE 200 over the interface 700 .
  • the beamforming weights per direction are then determined based on the channel rank information.
  • the energy or Signal-to-Noise and Interference Ratio (SNIR) of the signals is approximately the same for all the individual antennas. However, since the received UL signals (or transmitted DL signals) are associated with pointing directions due to the beamforming weights, the energy or SNIR will be unevenly distributed between different pointing directions. This is illustrated in FIG. 8 . At 1800 a is illustrated energy per antenna and at 1800 b is illustrated energy per direction. The energy or SNIR will be high in pointing directions from the access node to the terminal devices and low in other directions. This motivates beamforming information per direction to be communicated between the RE 200 and the REC 300 in accordance with embodiments disclosed above.
  • SNIR Signal-to-Noise and Interference Ratio
  • the beamforming information per antenna is associated with a first dimensionality
  • the beamforming information per direction is associated with a second dimensionality being smaller than the first dimensionality
  • beam information such as information relating to the beamforming weights
  • the beamforming information per direction could be represented by a linear combination of predetermined beamforming weights per direction
  • the UL OFDM FFT in FIG. 6 provides the output of Resource Elements for all antennas with N a antenna elements used for beamforming.
  • the Resource Elements include either data or pre-known Reference Symbols.
  • a transformation to a beam direction space from the antenna space is done.
  • a transformation to a beam direction space from the antenna space is done.
  • Each value in the N a long output from the transform provides information about the quality of the signal in one of the N a fixed beam directions.
  • All beamforming weight calculation can thereby be made in the beam direction space to minimize complexity.
  • the beamforming weights can be determined based on the rank of the radio channel either for multiple users or a single user and be determined to limit the influence of UL interference as well as spreading of interference in the DL. This could be accomplished by combining enough of the discrete beam directions properly weighted to capture the majority of the energy that will result in a small throughput loss on network level.
  • the beamforming weights in the direction space (of size N d ) for beam b are given by:
  • the beamforming weights in the antenna space (of size N a ) for beam b are given by:
  • the number of bits for per physical resource block (PRB) group and beam is N a B weight
  • the number of bits for w d b per PRB group and beam is N d B weight .
  • the beamforming weights can be transferred from the REC to the RE in the direction space.
  • the number of beamforming weights N d in the direction space is smaller than the number of beamforming weights N a , in the antenna space. That is, the beamforming information per antenna is associated with a first dimensionality, and the beamforming information per direction is associated with a second dimensionality being smaller than the first dimensionality.
  • the indices i 0 , i 1 , . . . appointing which of the fixed beam directions to use are also transferred to the beamforming weight transformation block.
  • the number of bits to transmit for the indices per PRB group and beam is ⁇ N d B ind .
  • the beam weight transformation block also include a hardware abstraction transformation function that hide the radio physical implementation and is capable to handle different configurations of number of antenna elements in the beamforming array antenna and other implementation aspects and states.
  • a hardware abstraction transformation function that hide the radio physical implementation and is capable to handle different configurations of number of antenna elements in the beamforming array antenna and other implementation aspects and states.
  • Compression of the beamforming weights could be achieved by applying different encoding techniques to reduce the channel estimate in the UL direction and the beamforming weights in the DL direction.
  • the encoding techniques could be based on reducing the resolution of information in a transform domain, and/or sending differential information.
  • FIG. 9 shows a compression subsystem 1900 according to an embodiment where the interface 700 separates the REC 300 and the RE 200 .
  • the compression subsystem comprises a quantizer (“Quant.”) placed in the REC and respective compression memories (“Compression DB” where DB is short for database) in the REC and RE.
  • Quantizer (“Quant.”) placed in the REC
  • Compression DB” where DB is short for database
  • the compression subsystem could be controlled by the UPC in the REC.
  • the use of beam direction space as disclosed above is optionally part of the compression subsystem.
  • the quantizer can apply reduction of word widths, have variable length lists of coefficients and/or apply other compression techniques.
  • the beamforming weights are applied per OFDM symbol.
  • a first reduction of the data is to use the same beamforming weights for a set of consecutive OFDM symbols (e.g., a set of consecutive subcarriers) in the time domain, typically for a complete transmission.
  • a second reduction is to use the same beamforming weights for a set of consecutive OFDM symbols in the frequency domain.
  • the REC could then inform which beamforming weights to use for each N subcarriers, and the RE could then perform interpolation for determining the beamforming weights of the subcarriers between these N subcarriers.
  • the value of N is dependent on the channel coherence.
  • the channel estimate can be processed in order for the REC to determine a value of N that is small enough to give sufficient beamforming performance.
  • Each value of N will give a certain SNR performance, so the choice of N can be determined jointly with other related parameters in the link adaptation, such as output power and modulation and coding scheme (MCS).
  • MCS modulation and coding scheme
  • beamforming weights are first transmitted with a coarse resolution and then more refined, e.g. first using a large value N and then with incrementally smaller values of N.
  • the RE could be configured to determine the beamforming weights from its locally stored channel estimate.
  • the REC is satisfied (e.g., the RE's assumption of single-user transmission is correct; one example where the REC is not satisfied is when it has received additional information (e.g. about interference) that it wants to use to create better beamforming weights) with the beamforming weights determined by the RE (e.g.
  • the REC can indicate this to the RE, thus requiring less signaling on the interface between the REC and the RE than if beamforming weight information is transmitted. This allows the REC to only send beamforming weights for terminal devices which beamforming weights have by the REC been modified (e.g. as optimized for multi-user operation).
  • An advantage of using the herein disclosed compression memories is that a communications system with stationary terminal devices will have very little signaling relating to the beamforming weights over the interface between the REC and the RE since such stationary terminal devices could use the same beamforming weights for two or more consecutive transmissions.
  • a first example is to provide additive differential information whereby differential beamforming weights are added to the stored beamforming weights.
  • a second example is to provide interpolating differential information whereby complementary beamforming weights, e.g. in frequency domain, are sent in order to improve the resolution (of beamforming weights having been sent with lower value of N) of the beamforming weights.
  • a second example is to provide multiplicative differential information whereby sending a beam form to multiply the beamforming weights with in direction space. Assuming that the beamforming weights are represented as beamforming weight vectors, then each element of the beamforming weight vector corresponds to one direction. Setting one of those elements to zero (by multiply with zero) will create a beam pattern with a null in that direction. This can be very efficient to express a nulling, i.e. setting a restriction on a transmission.
  • the transmission of information over the interface between the REC and the RE in the UL generally is based on the same features as for the DL, but with information relating to channel estimates being transferred (instead of information relating to beamforming weights).
  • the (S)RS channel estimation function is configured to set a suitable value of N, and a suitable quatization.
  • the UPC can, ahead of a measurement, state the maximum amount to data to send, not to overload the interface between the REC and the RE.
  • One way is for the UPC in the REC to provide the RE with a value of N and where the RE then executes.
  • the UL beams are selected based on the channel state information. Selecting as a few beams as possible could reduce the bit rate on the interface between the REC and the RE. At the same time, more beams allow for more energy to be received and better suppression of interferers.
  • DTF-beams imply that a fixed set of beams that evenly cover the whole spatial view seen from the RE is used.
  • the DTF-beams can be spread out one-dimensionally (either spread out vertically or horizontally) or they can be spread out two-dimensionally (spread out both vertically and horizontally).
  • DFT is one example of creating fixed beams. As understood by the person skilled in the art other methods for creating fixed beams, optionally including uneven spread of the beams, are equally applicable.
  • SVD-beams imply that the set of beams are dynamically decided depending on the received signals from the desired terminal devices and optionally also dependent on received signals from the interfering terminal devices. As understood by the person skilled in the art other methods for creating dynamic beams are equally applicable.
  • the selection of beams can be based on channel estimates of reference symbol signals, or on channel estimates of demodulation reference signals (DMRS) embedded in an LTE physical uplink shared channel (PUSCH).
  • DMRS demodulation reference signals
  • the selection of beams can be performed for each resource block, or for groups of resource blocks, or even with one common selection for the whole carrier bandwidth.
  • the selection of beams can be performed with one single, common, selection for the whole carrier bandwidth, since the beams generally correspond to physical directions and even though the phase of the radio propagation is frequency dependent, the physical directions are not.
  • the selections can be made as the union of the beams needed for each terminal device. If, for example, three beams are selected for a first terminal device and three beams are selected for a second terminal device and one of the beams is common for the first terminal device and the second terminal device, then only five beams need to be transferred from the RE to the REC. If, on the other hand, the RE is connected to two RECs, and the first terminal device is handled by one REC and the second terminal device is handled by another REC, then three beams need to be sent to each REC.
  • the maximum number of beams that can be selected is controlled by the REC.
  • the information about how many beams that can be selected are then provided by the REC to the RE over the interface.
  • This information can be expressed in different ways. According to a first example the information specifies the maximum number of beams selected per terminal device. According to a second example the information specifies the maximum number of beams selected in total. According to a third example the information specifies a combined restriction of both the maximum number of beams selected per terminal device and the maximum number of beams selected in total. Given these limitations, the RE will decide how many beams that should be selected per terminal device. This can be done by the RE comparing the signal quality for the terminal devices in each of the beams, and select beams with the given limitations. In additions to the limitations given by the REC, the RE could also need to make the selection such that each terminal gets at least M ⁇ 1 number of beams selected.
  • FIG. 14 schematically illustrates, in terms of a number of functional units, the components of an RE according to an embodiment.
  • Processing circuitry 210 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 1810 a (as in FIG. 18 ), e.g. in the form of a storage medium 230 .
  • the processing circuitry 210 may further be provided as at least one application specific integrated circuit (ASIC), or field programmable gate array (FPGA).
  • ASIC application specific integrated circuit
  • FPGA field programmable gate array
  • the processing circuitry 210 is configured to cause the RE to perform a set of operations, or steps, S 102 -S 108 , S 302 -S 312 , as disclosed above.
  • the storage medium 230 may store the set of operations
  • the processing circuitry 210 may be configured to retrieve the set of operations from the storage medium 230 to cause the RE to perform the set of operations.
  • the set of operations may be provided as a set of executable instructions.
  • the processing circuitry 210 is thereby arranged to execute methods as herein disclosed.
  • the storage medium 230 may also comprise persistent storage, which, for example, can be any single one or combination of magnetic memory, optical memory, solid state memory or even remotely mounted memory.
  • the RE may further comprise a communications interface 220 for communications at least with the REC and the terminal devices.
  • the communications interface 220 may comprise one or more transmitters and receivers, comprising analogue and digital components.
  • the processing circuitry 210 controls the general operation of the RE e.g. by sending data and control signals to the communications interface 220 and the storage medium 230 , by receiving data and reports from the communications interface 220 , and by retrieving data and instructions from the storage medium 230 .
  • Other components, as well as the related functionality, of the RE are omitted in order not to obscure the concepts presented herein.
  • FIG. 15 schematically illustrates, in terms of a number of functional modules, the components of an RE 200 according to an embodiment.
  • the RE 200 comprises an obtain module 210 a configured to perform step S 102 , an obtain module 210 b configured to perform step S 104 , a (optional) transform module 210 C configured to perform step S 106 , and an apply module 210 d configured to perform step S 108 .
  • the RE 200 comprises an obtain module 210 e configured to perform step S 302 , a transform module 210 of configured to perform step S 304 , a provide module 210 g configured to perform step S 306 , an (optional) obtain module 210 h configured to perform step S 308 , a (optional) transform module 210 i configured to perform step S 310 , and an (optional) apply module 210 j configured to perform step S 312 .
  • each functional module 210 a - 210 j may be implemented in hardware or in software.
  • one or more or all functional modules 210 a - 210 j may be implemented by the processing circuitry 210 , possibly in cooperation with functional units 220 and/or 230 .
  • the processing circuitry 210 may thus be arranged to from the storage medium 230 fetch instructions as provided by a functional module 210 a - 210 j and to execute these instructions, thereby performing any steps of the RE as disclosed herein.
  • FIG. 16 schematically illustrates, in terms of a number of functional units, the components of an REC according to an embodiment.
  • Processing circuitry 310 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 1810 b (as in FIG. 18 ), e.g. in the form of a storage medium 330 .
  • the processing circuitry 310 may further be provided as at least one application specific integrated circuit (ASIC), or field programmable gate array (FPGA).
  • ASIC application specific integrated circuit
  • FPGA field programmable gate array
  • the processing circuitry 310 is configured to cause the REC to perform a set of operations, or steps, S 202 -S 208 , S 402 -S 408 , as disclosed above.
  • the storage medium 330 may store the set of operations
  • the processing circuitry 310 may be configured to retrieve the set of operations from the storage medium 330 to cause the REC to perform the set of operations.
  • the set of operations may be provided as a set of executable instructions.
  • the processing circuitry 310 is thereby arranged to execute methods as herein disclosed.
  • the storage medium 330 may also comprise persistent storage, which, for example, can be any single one or combination of magnetic memory, optical memory, solid state memory or even remotely mounted memory.
  • the REC may further comprise a communications interface 320 for communications at least with the RE.
  • the communications interface 320 may comprise one or more transmitters and receivers, comprising analogue and digital components.
  • the processing circuitry 310 controls the general operation of the REC e.g. by sending data and control signals to the communications interface 320 and the storage medium 330 , by receiving data and reports from the communications interface 320 , and by retrieving data and instructions from the storage medium 330 .
  • Other components, as well as the related functionality, of the REC are omitted in order not to obscure the concepts presented herein.
  • FIG. 17 schematically illustrates, in terms of a number of functional modules, the components of an REC according to an embodiment.
  • the REC 300 comprises an obtain module 310 a configured to perform step S 302 , a transform module 310 b configured to perform step S 304 , a provide module 210 C configured to perform step S 306 , and a (optional) provide module 210 d configured to perform step S 308 .
  • the REC 300 comprises an obtain module 310 e configured to perform step S 402 , an (option) obtain module 210 f configured to perform step S 404 , a determine module 310 g configured to perform step S 406 , and a provide module 310 h configured to perform step S 408 .
  • each functional module 310 a - 310 h may be implemented in hardware or in software.
  • one or more or all functional modules 310 a - 310 h may be implemented by the processing circuitry 310 , possibly in cooperation with functional units 320 and/or 330 .
  • the processing circuitry 310 may thus be arranged to from the storage medium 330 fetch instructions as provided by a functional module 310 a - 310 h 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.
  • the RE and REC may be provided in an access node.
  • functionality of the RE and the REC may be distributed between at least two devices, or nodes.
  • 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.
  • 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 210 , 310 is illustrated in FIGS. 14 and 16 the processing circuitry 210 , 310 may be distributed among a plurality of devices, or nodes. The same applies to the functional modules 210 a - 210 j , 310 a - 310 h of FIGS. 15 and 17 and the computer programs 1820 a , 1820 b , 1820 c , 1820 d of FIG. 18 (see below).
  • FIG. 18 shows one example of a computer program product 1810 a , 1810 b , 1810 c , 1810 d comprising computer readable means 1830 .
  • a computer program 1820 a , 1820 c can be stored, which computer program 1820 a , 1820 c can cause the processing circuitry 210 and thereto operatively coupled entities and devices, such as the communications interface 220 and the storage medium 230 , to execute methods according to embodiments described herein.
  • the computer program 1820 a , 1820 c and/or computer program product 1810 a , 1820 c may thus provide means for performing any steps of the RE as herein disclosed.
  • a computer program 1820 b , 1820 d can be stored, which computer program 1820 b , 1820 d can cause the processing circuitry 310 and thereto operatively coupled entities and devices, such as the communications interface 320 and the storage medium 330 , to execute methods according to embodiments described herein.
  • the computer program 1820 b , 1820 d and/or computer program product 1810 b , 1810 d may thus provide means for performing any steps of the REC as herein disclosed.
  • the computer program product 1810 a , 1810 b , 1810 c , 1810 d is illustrated as an optical disc, such as a CD (compact disc) or a DVD (digital versatile disc) or a Blu-Ray disc.
  • an optical disc such as a CD (compact disc) or a DVD (digital versatile disc) or a Blu-Ray disc.
  • the computer program product 1810 a , 1810 b , 1810 c , 1810 d 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.
  • RAM random access memory
  • ROM read-only memory
  • EPROM erasable programmable read-only memory
  • EEPROM electrically erasable programmable read-only memory
  • the computer program 1820 a , 1820 b , 1820 c , 1820 d is here schematically shown as a track on the depicted optical disk
  • the computer program 1820 a , 1820 b , 1820 c , 1820 d can be stored in any way which is suitable for the computer program product 1810 a , 1810 b , 1810 c , 1810 d.
  • the inventive concept has mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the inventive concept, as defined by the appended claims.
  • TDD time division duplex
  • FDD frequency division duplex
  • One difference in FDD compared to TDD is that the UL measurements cannot for sure be used for DL, due to the different frequencies UL and DL.
  • the terminal device sends information about what beam direction the terminal device deems is best (from a raster of predetermined beams that the access node is repeatedly transmitting, i.e. a “code book”). In this case, the REC may need to provide beamforming weights to the RE (thus defining the external information).

Landscapes

  • Engineering & Computer Science (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Signal Processing (AREA)
  • Theoretical Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Electromagnetism (AREA)
  • Mobile Radio Communication Systems (AREA)
  • Radio Transmission System (AREA)
US16/330,514 2016-09-06 2017-06-22 Methods and Devices for Determination of Beamforming Information Abandoned US20190199379A1 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US16/330,514 US20190199379A1 (en) 2016-09-06 2017-06-22 Methods and Devices for Determination of Beamforming Information

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
US201662383871P 2016-09-06 2016-09-06
US16/330,514 US20190199379A1 (en) 2016-09-06 2017-06-22 Methods and Devices for Determination of Beamforming Information
PCT/SE2017/050690 WO2018048333A1 (en) 2016-09-06 2017-06-22 Methods and devices for determination of beamforming information

Publications (1)

Publication Number Publication Date
US20190199379A1 true US20190199379A1 (en) 2019-06-27

Family

ID=59295280

Family Applications (3)

Application Number Title Priority Date Filing Date
US16/330,514 Abandoned US20190199379A1 (en) 2016-09-06 2017-06-22 Methods and Devices for Determination of Beamforming Information
US16/330,447 Active US10879941B2 (en) 2016-09-06 2017-06-22 Methods and devices for determination of beamforming information
US17/111,910 Active US11128322B2 (en) 2016-09-06 2020-12-04 Methods and devices for determination of beamforming information

Family Applications After (2)

Application Number Title Priority Date Filing Date
US16/330,447 Active US10879941B2 (en) 2016-09-06 2017-06-22 Methods and devices for determination of beamforming information
US17/111,910 Active US11128322B2 (en) 2016-09-06 2020-12-04 Methods and devices for determination of beamforming information

Country Status (4)

Country Link
US (3) US20190199379A1 (de)
EP (2) EP3510704A1 (de)
CN (1) CN109644026B (de)
WO (2) WO2018048333A1 (de)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021051417A1 (en) * 2019-09-20 2021-03-25 Nokia Shanghai Bell Co., Ltd. Compressed channel state information transfer
US20220312404A1 (en) * 2021-03-25 2022-09-29 At&T Intellectual Property I, L.P. Facilitation of beamforming utilizing interpolation for 5g or other next generation network

Families Citing this family (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US10819414B2 (en) * 2018-03-26 2020-10-27 Intel Corporation Methods and devices for beam tracking
US10348386B1 (en) 2018-08-09 2019-07-09 At&T Intellectual Property I, L.P. Facilitation of user equipment specific compression of beamforming coefficients for fronthaul links for 5G or other next generation network
US11539420B2 (en) 2018-11-30 2022-12-27 Telefonaktiebolaget Lm Ericsson (Publ) Transmitting frequency varying beam weights from a lower-layer split central unit to a radio unit
EP4277153A3 (de) * 2018-11-30 2023-12-27 Telefonaktiebolaget LM Ericsson (publ) Übertragung von je ressourcenelement unterschiedlichen strahlgewichten von einer unteren geteilten zentraleinheit zu einer funkeinheit oder zum betrieb einer unteren geteilten zentraleinheit
EP3896860B1 (de) * 2020-03-27 2023-10-11 Mavenir Systems, Inc. Uplink-decodierung in einem massiven mimo-drahtloskommunikationssystem für ein offenes funkzugangsnetzwerk
US20240195472A1 (en) * 2021-04-14 2024-06-13 Telefonaktiebolaget Lm Ericsson (Publ) Baseband unit, radio unit and methods in a wireless communications network
WO2023152180A1 (en) 2022-02-08 2023-08-17 Telefonaktiebolaget Lm Ericsson (Publ) Massive multiple input multiple output radio unit uplink interface
WO2023211323A1 (en) * 2022-04-26 2023-11-02 Telefonaktiebolaget Lm Ericsson (Publ) Method and one or more network entities for improved uplink channel estimation

Family Cites Families (69)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5914946A (en) 1996-11-08 1999-06-22 Lucent Technologies Inc. TDM-based fixed wireless loop system
US10355720B2 (en) 2001-04-26 2019-07-16 Genghiscomm Holdings, LLC Distributed software-defined radio
US7856029B2 (en) * 2003-11-17 2010-12-21 Telefonaktiebolaget Lm Ericsson (Publ) Pre-start-up procedure for internal interface of distributed radio base station
US7529215B2 (en) * 2003-11-17 2009-05-05 Telefonaktiebolaget Lm Ericsson (Publ) Encapsulation of independent transmissions over internal interface of distributed radio base station
EP1810534B1 (de) 2004-10-12 2015-06-17 Telefonaktiebolaget LM Ericsson (publ) Kommunikation zwischen einem funkgeräte -steuerknoten und mehreren abgesetzten funkgeräte-knoten
US7649861B2 (en) 2004-11-30 2010-01-19 Intel Corporation Multiple antenna multicarrier communication system and method with reduced mobile-station processing
JP4528236B2 (ja) 2005-09-29 2010-08-18 株式会社日立製作所 無線基地局装置および通信方法
CN100403826C (zh) 2006-02-27 2008-07-16 华为技术有限公司 通用公共无线接口传输多体制无线业务iq数据的方法
KR20080073196A (ko) 2007-02-05 2008-08-08 엘지전자 주식회사 Ｍｉｍｏ 시스템에서 효율적인 채널 품질 정보 전송 방법
US8699602B2 (en) 2007-12-13 2014-04-15 Texas Instruments Incorporated Channel quality report processes, circuits and systems
US8064546B2 (en) 2007-06-14 2011-11-22 Texas Instruments Incorporated Random access preamble detection for long term evolution wireless networks
JP5256298B2 (ja) 2007-11-21 2013-08-07 テレフオンアクチーボラゲット エル エム エリクソン（パブル） 通信システムにおける方法及び無線基地局
US8150399B2 (en) * 2007-12-21 2012-04-03 Intel Corporation Techniques for wireless communications networks employing beamforming
US8477874B2 (en) * 2007-12-31 2013-07-02 Mobilicom Ltd. Method, device and system of wireless communication
JP5347401B2 (ja) 2008-09-19 2013-11-20 富士通株式会社 無線装置、及び、無線装置の制御及び監視方法
US8229416B2 (en) 2008-09-23 2012-07-24 Ixia Methods, systems, and computer readable media for stress testing mobile network equipment using a common public radio interface (CPRI)
BRPI0823409B1 (pt) * 2008-12-30 2020-04-22 Telecom Italia Spa método de arranjar troca de sinais entre terminais de usuário em um sistema de comunicação celular e pelo menos uma estação base, sistema de antena distribuída, e, memória legível por computador
WO2010075864A1 (en) * 2008-12-30 2010-07-08 Telecom Italia S.P.A A method for distributed mobile communications, corresponding system and computer program product
KR101607988B1 (ko) 2009-04-23 2016-04-12 삼성전자주식회사 무선통신시스템에서 간섭 완화를 위한 장치 및 방법
EP2892293A1 (de) 2009-05-22 2015-07-08 Fujitsu Limited Funkkommunikationssystem, Basisstationsvorrichtung, Mobilstationsvorrichtung und Funkkommunikationsverfahren in einem Funkkommunikationssystem
KR101715939B1 (ko) 2009-06-18 2017-03-14 엘지전자 주식회사 채널 상태 정보 피드백 방법 및 장치
US8644368B1 (en) 2009-09-23 2014-02-04 Marvell International Ltd. Transparent implicit beamforming in a communication system
US8280426B2 (en) * 2009-10-29 2012-10-02 Cisco Technology, Inc. Adaptive power balancing and phase adjustment for MIMO-beamformed communication systems
CN102656931A (zh) 2009-12-18 2012-09-05 株式会社Ntt都科摩 无线基站以及中继装置
US8509338B2 (en) 2010-05-05 2013-08-13 Motorola Mobility Llc Method and precoder information feedback in multi-antenna wireless communication systems
CN102291855A (zh) * 2010-06-18 2011-12-21 普天信息技术研究院有限公司 一种降低Ir接口带宽的方法及分布式基站
CN102299735B (zh) * 2010-06-25 2014-03-12 普天信息技术研究院有限公司 一种降低Ir接口带宽的方法及分布式基站
US8923386B2 (en) 2011-02-11 2014-12-30 Alcatel Lucent Method and apparatus for signal compression and decompression
US9136994B2 (en) 2011-05-11 2015-09-15 Lg Electronics Inc. Method and device for transmitting data in a multi antenna wireless communication system
WO2011144085A2 (zh) 2011-05-25 2011-11-24 华为技术有限公司 数据传输方法和基站
US20120300710A1 (en) 2011-05-27 2012-11-29 Nokia Siemens Networks Oy Distributing L2 Baseband Processing in a Radio Network
EP2533431B1 (de) 2011-06-10 2014-10-29 Alcatel Lucent Verfahren zu Empfang von Uplink-Hochfrequenzsignalen in einem Funkkommunikationssystem, Maser-Einheit und Slave-Einheit dafür
TW201304448A (zh) 2011-07-07 2013-01-16 Alcatel Lucent 通訊系統中傳輸資料之方法及其第一網路節點及第二網路節點
GB2493154A (en) 2011-07-25 2013-01-30 Nec Corp Communicating control channel reference signal patterns in the control region of a sub-frame in a cellular communication system
JP5715924B2 (ja) 2011-10-05 2015-05-13 京セラ株式会社 無線通信基地局
WO2013076898A1 (ja) 2011-11-25 2013-05-30 日本電気株式会社 無線局、及び無線局によるユーザーデータの処理方法
US9622260B2 (en) 2011-11-25 2017-04-11 Nec Corporation Radio station and method of processing user data with radio station
WO2013169149A1 (en) 2012-05-07 2013-11-14 Telefonaktiebolaget L M Ericsson (Publ) Methods and nodes for radio communication with a user equipment
EP2685755B1 (de) 2012-07-12 2015-12-09 Alcatel Lucent Örtlich begrenzte Klassifizierung eines mobilen Endgeräts innerhalb einer Zelle
WO2014076004A2 (en) 2012-11-16 2014-05-22 Telefonica, S.A. Method and system for lossless compression and decompression of baseband digital signals in distributed lte-advanced radio access networks
EP2739105B1 (de) 2012-11-30 2020-02-12 Alcatel Lucent Vorrichtung, Verfahren und Computerprogrammprodukt für eine zentrale Einheit eines Basisstations-Sender-Empfängers
WO2014109782A1 (en) * 2013-01-14 2014-07-17 Andrew Llc Interceptor system for characterizing digital data in telecommunication system
JP2014204305A (ja) * 2013-04-05 2014-10-27 株式会社Ｎｔｔドコモ 無線通信システム、無線基地局装置、およびユーザ装置
US9647735B2 (en) * 2013-05-31 2017-05-09 Intel IP Corporation Hybrid digital and analog beamforming for large antenna arrays
US9306645B2 (en) 2013-07-26 2016-04-05 Marvell World Trade Ltd. Interference avoidance for beamforming transmissions in wireless communication devices and systems
US9806774B2 (en) * 2013-09-09 2017-10-31 Taiwan Semiconductor Manufacturing Company, Ltd. CSI feedback reduction for MIMO interference alignment
US9806926B2 (en) * 2013-11-04 2017-10-31 Samsung Electronics Co., Ltd. Multistage beamforming of multiple-antenna communication system
US9313300B2 (en) * 2013-11-07 2016-04-12 Integrated Device Technology, Inc. Methods and apparatuses for a unified compression framework of baseband signals
EP2911331B1 (de) 2014-02-25 2018-12-26 Alcatel Lucent Vorrichtung, Verfahren und Computerprogramm zum Steuern eines Übertragungsformats, Fernbedienungsteil und Zentraleinheit eines Basisstations-Senders-/-empfängers
WO2015172277A1 (zh) * 2014-05-12 2015-11-19 华为技术有限公司 一种基带单元bbu与远端射频单元rru之间的数据传输方法和装置
EP3158823B1 (de) 2014-06-23 2020-04-08 Telecom Italia S.p.A. Dynamische verringerung der fronthaul-last in zentralisierten funkzugangsnetzwerken
US10334478B2 (en) 2014-06-23 2019-06-25 Telecom Italia S.P.A. Method for reducing fronthaul load in centralized radio access networks (C-RAN)
JP6680676B2 (ja) * 2014-07-25 2020-04-15 株式会社Ｎｔｔドコモ 無線送信局および無線通信ネットワーク
US10064242B2 (en) 2014-09-10 2018-08-28 Intel IP Corporation Modified architecture for cloud radio access networks and approach for compression of front-haul data
US10887663B2 (en) 2015-01-24 2021-01-05 Valens Semiconductor Ltd. Smooth switching of video sources sharing a common link
US10355895B2 (en) 2015-03-11 2019-07-16 Phluido, Inc. Baseband unit with adaptive fronthaul link for a distributed radio access network
EP3304762B1 (de) 2015-06-03 2019-08-14 Telefonaktiebolaget LM Ericsson (publ) Signalisierung von strahlformungsmessungen
WO2016195556A1 (en) 2015-06-03 2016-12-08 Telefonaktiebolaget Lm Ericsson (Publ) Distributed realization of beam forming
US10608734B2 (en) 2015-10-22 2020-03-31 Phluido, Inc. Virtualization and orchestration of a radio access network
US10651568B2 (en) * 2016-07-19 2020-05-12 Quintel Cayman Limited Base station antenna system with enhanced array spacing
JP2018029242A (ja) * 2016-08-16 2018-02-22 富士通株式会社 送信回路、受信回路、通信システム、送信方法、受信方法、及び、通信方法
EP3510832B1 (de) 2016-09-06 2023-08-16 Telefonaktiebolaget LM Ericsson (PUBL) Ressourcenkonfiguration von drahtlosen vorrichtungen
US11063795B2 (en) 2016-11-16 2021-07-13 Telefonaktiebolaget Lm Ericsson (Publ) Methods and devices for adapting load on a fronthaul network
CN110235421B (zh) * 2017-01-23 2022-04-29 瑞典爱立信有限公司 用于mimo系统中的接收波束控制的方法和控制器以及无线电单元和基站
WO2018174767A1 (en) 2017-03-23 2018-09-27 Telefonaktiebolaget Lm Ericsson (Publ) First network node, third network node, wireless device, and methods performed thereby for facilitating cell selection
US10313917B2 (en) 2017-04-24 2019-06-04 Huawei Technologies Co., Ltd. UE load-sensitive front-haul controller
US10171150B1 (en) * 2017-06-26 2019-01-01 Sprint Communications Company L.P. Dynamic optimization of beamforming weights
US10484063B1 (en) * 2018-05-04 2019-11-19 At&T Intellectual Property I, L.P. Transmission of beamforming weight coefficients from digital baseband unit to remote radio unit
WO2020081404A1 (en) * 2018-10-15 2020-04-23 Blue Danube Systems, Inc. Enhancing throughput using agile beam switching and user scheduling in cellular systems

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2021051417A1 (en) * 2019-09-20 2021-03-25 Nokia Shanghai Bell Co., Ltd. Compressed channel state information transfer
CN114402539A (zh) * 2019-09-20 2022-04-26 上海诺基亚贝尔股份有限公司 压缩的信道状态信息传递
US20220312404A1 (en) * 2021-03-25 2022-09-29 At&T Intellectual Property I, L.P. Facilitation of beamforming utilizing interpolation for 5g or other next generation network
US11464017B1 (en) * 2021-03-25 2022-10-04 At&T Intellectual Property I, L.P. Facilitation of beamforming utilizing interpolation for 5G or other next generation network
US20220408427A1 (en) * 2021-03-25 2022-12-22 At&T Intellectual Property I, L.P. Facilitation of beamforming utilizing interpolation for 5g or other next generation network

Also Published As

Publication number Publication date
US10879941B2 (en) 2020-12-29
US20200127717A1 (en) 2020-04-23
CN109644026A (zh) 2019-04-16
CN109644026B (zh) 2022-03-08
EP3510704A1 (de) 2019-07-17
WO2018048332A1 (en) 2018-03-15
US11128322B2 (en) 2021-09-21
US20210091795A1 (en) 2021-03-25
EP3510703A1 (de) 2019-07-17
WO2018048333A1 (en) 2018-03-15

Similar Documents

Publication Publication Date Title
US11128322B2 (en) Methods and devices for determination of beamforming information
KR102382603B1 (ko) 다운링크 및 업링크 채널 상태 정보를 획득하기 위한 방법 및 장치
US9893777B2 (en) Method and apparatus for precoding channel state information reference signal
US9787379B2 (en) Method and apparatus for precoding channel state information reference signal
US10524273B2 (en) Resource configuration of wireless devices
WO2018202206A1 (en) Methods and apparatus for acquiring channel state information with channel reciprocity
EP3510832B1 (de) Ressourcenkonfiguration von drahtlosen vorrichtungen
WO2019098897A1 (en) Methods, systems and units of a distributed base staton system for handling of downlink communication
CN110233693B (zh) 发送装置和发送方法
EP3987673A1 (de) Verfahren, verteiltes basisstationssystem, entfernte funkeinheit und basisbandeinheitssystem zur handhabung von downlink-signalen
CN111788785B (zh) 一种预编码矩阵索引上报方法、通信装置及介质
KR102441982B1 (ko) 무선 통신 시스템에서 빔 포밍을 수행하는 방법 및 장치
EP3487135B1 (de) Verfahren und vorrichtung zur signalübertragung durch phasenumschaltung in einem mobilkommunikationssystem
WO2021032286A1 (en) Approaches for beam measurements
WO2011033904A1 (ja) 無線通信システム、通信制御装置、通信端末装置および通信制御装置の制御プログラム
CN111418163B (zh) 无线装置以及无线通信控制方法
JP6207760B2 (ja) 無線通信装置および無線通信方法
US20240195472A1 (en) Baseband unit, radio unit and methods in a wireless communications network

Legal Events

Date Code Title Description
AS Assignment

Owner name: TELEFONAKTIEBOLAGET LM ERICSSON (PUBL), SWEDEN

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNORS:OESTERLING, JACOB;HUSS, FREDRIK;KARLSSON, JONAS;AND OTHERS;SIGNING DATES FROM 20170622 TO 20170823;REEL/FRAME:048505/0221

STPP Information on status: patent application and granting procedure in general

Free format text: NON FINAL ACTION MAILED

STPP Information on status: patent application and granting procedure in general

Free format text: RESPONSE TO NON-FINAL OFFICE ACTION ENTERED AND FORWARDED TO EXAMINER

STCB Information on status: application discontinuation

Free format text: ABANDONED -- FAILURE TO RESPOND TO AN OFFICE ACTION