Abstract: Methods and apparatus are provided. In an example aspect, a method of calibrating a wireless communication device having a plurality of antennas is provided. The method includes transmitting a first calibration signal from at least one first antenna of the plurality of antennas in a first time-frequency resource, determining first measurements of the first calibration signal in the first time-frequency resource from at least one second antenna of the plurality of antennas, wherein the at least one second antenna includes at least one of the at least one first antenna, and determining calibration parameters for the wireless communication device based on the first measurements.

Abstract: Embodiments include methods for beamforming using an antenna array. Such methods include, for each pair of beamforming vectors (bk,bl) of a codebook comprising a plurality of beamforming vectors corresponding to orientations (1 . . . N), determining at least one corresponding pair of tapering vectors (tk,tl) based on minimizing at least one function f(?,?), such that when tapered beamforming vectors (tk-bk, tl-bl) are applied to the antenna array for transmitting concurrent beams of orientations (k,l), k?l, radiated power in orientations (k,l) are at least (1??) of peak radiated powers in orientations (k,l) of beams formed by (bk,bl); and the beams of orientations (k,l) have sidelobes that are lower than ? in respective orientations (l,k). Such methods also include transmitting data concurrently in orientations (i,j), i?j, based on weighting the antenna array by tapered beamforming vectors (ti-bi, tj-bj) corresponding to orientations (i,j). Embodiments also include nodes configured to perform such methods.

Abstract: A method of calibrating a wireless communication device having a plurality of antennas. The method includes transmitting a first calibration signal from at least one first antenna of the plurality of antennas in a first time-frequency resource, determining first measurements of the first calibration signal in the first time-frequency resource from at least one antenna of the plurality of antennas other than the at least one first antenna, and transmitting a second calibration signal from at least one second antenna of the plurality of antennas in a second time-frequency resource. The method also includes determining second measurements of the second calibration signal in the second time-frequency resource from at least one antenna of the plurality of antennas other than the at least one second antenna, and determining calibration parameters for the wireless communication device based on the first measurements and the second measurements.

Abstract: Embodiments described herein relate to methods and apparatuses for configuring communication between a base station and at least one wireless device, the base station using an antenna array, wherein antenna ports in the antenna array are coupled to radio frequency branches. The method comprises determining a first radio frequency bandwidth for a first radio frequency branch based on one or more factors associated with traffic served by a plurality of radio frequency bandwidth parts, and configuring the first radio frequency branch to serve frequencies within the first radio frequency bandwidth.

Abstract: A method and apparatus for signaling scheduling information in a spatial multiplexing wireless communications system, as well as corresponding methods and apparatus for processing such signaling information, are disclosed. Signaling scheduling information includes scheduling first and second transport blocks for simultaneous transmission during a first transmission interval on first and second data substreams, respectively, and assigning a single re-transmission process identifier for the first transmission interval and transmitting first scheduling information for the first transmission interval. The first scheduling information includes the re-transmission process identifier and first disambiguation data. Additionally, at least one of the first and second transport blocks is scheduled for re-transmission during a second transmission interval.

Abstract: Embodiments described herein relate to methods and apparatuses for providing communication between a base station and at least one wireless device using a first beam. A method in a base station comprises receiving an indication of two or more beams, wherein the two or more beams meet a quality criterion associated with the at least one wireless device; obtaining a combined beam vector, w, based on a weighted sum of two or more beam vectors, bk, associated with the two or more beams; and communicating with the at least one wireless device using the first beam, wherein the first beam is generated using the combined beam vector.

Abstract: An Advanced Antenna System (AAS) receiver and related methods are provided. According to one aspect an AAS receiver comprises a digital processing block of a Radio Frequency Integrated Circuit (RFIC). The digital processing block comprises an interface for communicating with a Central Unit (CU), and a plurality of Antenna Signal Processing Blocks (ASPBs), each receiving a digitized receive signal from a respective antenna element of an antenna array. Each ASPB comprises one or more receivers, each of which receives and processes the signal from the respective antenna element. Some receivers within the ASPB beamform the respective processed signal to produce one or more data streams to be sent to the CU. Other receivers within the ASPB provide the respective processed signal to a processing block that buffers the processed signal and sends it to the CU at a later time, e.g., when traffic to the CU is relatively lower.

Abstract: According to a first aspect, it is provided a method for estimating angular spread of a wireless channel between a first node and a second node, wherein the first node is a radio network node and the second node is a user equipment, UE, or vice versa. The method is performed in a spread estimator. The method comprises the steps of: obtaining a wide-beam signal strength for a signal over the wireless channel using a selected wide-beam configuration of an antenna of the first node; obtaining a narrow-beam signal strength for a signal over the wireless channel using a selected narrow-beam configuration of the antenna of the first node; determining a difference between the wide-beam signal strength and the narrow-beam signal strength; and estimating angular spread of the wireless channel based on the difference.

Abstract: There is provided mechanisms for mitigating interference in a network node. A method is performed by a control device (200). The method comprises receiving (S102) radio signals comprising at least one desired signal and interference, estimating (S104) a characteristic of the interference, wherein the estimation comprises calculating correlation statistics of power levels of frequency sub-bands comprising the interference with frequency sub-bands comprising the received radio signals. The method comprises determining (S106) an interference suppression matrix to suppress the interference in the frequency sub-bands of the received radio signals based on the estimated characteristic of the interference, wherein the interference suppression matrix is further determined based on information from inter-band interference observed across distinct sub-bands of the received radio signals.

Abstract: A radio unit for TDD multi-band operation in a wireless communication system is disclosed. The radio unit comprises a transmitting power amplifier for multi-band operation; one or more receiving amplifiers for multi-band operation and an antenna element. The radio unit further comprises one or more switch networks coupled in parallel between the power amplifier and the antenna element. Each of the one or more switch networks comprises one or more shunt switches coupled between an output of the transmitting power amplifier and a signal ground. Each of the one or more switch networks is configured to operate at a certain frequency band in transmitting or receiving mode and is controlled separately by a switching control unit based on un-synchronized TDD time slots configured according to user data traffic scheduling requirements.

Abstract: There is provided mechanisms for calibrating transmit antenna chains and receive antenna chains of an antenna system. A method is performed by a network node. The method comprises obtaining a set of observations from bi-directional sounding of pairs of antennas of the antenna system. Each of the antennas has one transmit antenna chain and one receive antenna chain. The observations are represented by a composite product of transmit calibration weights, receive calibration weights, and signal leakage terms. The method comprises estimating the transmit calibration weights and the receive calibration weights from a decomposition of the composite product. The method comprises calibrating the transmit antenna chains and the receive antenna chains by applying as calibration factors the estimated transmit calibration weights to the transmit antenna chains and the receive calibration weights to the receive antenna chains.

Abstract: There is provided a method at a network node equipped with an advance antenna system, AAS. The AAS comprises a plurality of antenna elements and one or more radio frequency integrated circuits, RFICs. Each of the one or more RFICs is associated with one or more of the plurality of antenna elements. The method comprising: capturing a plurality of signal samples of one or more signal chains of each of the one or more RFICs. Each of the one or more signal chains correspond to one or more of the plurality of antenna elements and a signal sample is associated with an envelope power level at an output of the respective signal chain; and summing at least a subset of the plurality of signal samples to obtain a short term average power value at the AAS.

Abstract: A method for providing signals for beam-formed transmission comprises retrieving, from a memory, of first vector-associated data defined by an obtained first beam index, assigned to a first signal, scheduled to be transmitted by beamforming in a first direction. The memory has vector-associated data characterizing at least two sets of beamforming vectors for each polarization and for each one of a plurality of beam directions. The beamforming vectors for each polarization and plurality of directions present different tapering and/or non-tapering. The first vector-associated data characterizes a first selected set of beamforming vectors that are designed to give a beam in the first direction. The first beam index comprises information for defining vector-associated data characterizing a particular one of the at least two sets for the first direction. A beamforming of the first signal is initiated by use of the first vector-associated data.

Abstract: There is provided a method for controlling interference in a received signal when scheduling in a network node for wireless communication with a set of user equipment's, UEs, said set comprising a first UE and at least a second UE, wherein the interference is passive-intermodulation interference, PIM. The method comprises receiving a scheduling request from at least the first UE transmitting on a first frequency and scheduling at least the first UE based on an interference scenario report and available PIM cancellation resources to enable efficient PIM control. The method is performed by a control device.

Abstract: A method and apparatus for signaling scheduling information in a spatial multiplexing wireless communications system, as well as corresponding methods and apparatus for processing such signaling information, are disclosed. Signaling scheduling information includes scheduling first and second transport blocks for simultaneous transmission during a first transmission interval on first and second data substreams, respectively, and assigning a single re-transmission process identifier for the first transmission interval and transmitting first scheduling information for the first transmission interval. The first scheduling information includes the re-transmission process identifier and first disambiguation data. Additionally, at least one of the first and second transport blocks is scheduled for re-transmission during a second transmission interval.

Abstract: An objective problem of the invention is to provide a mechanism for improving the performance of a radio access network. According to a first aspect of the present invention, the object is achieved by a method in a first node for adapting a multi-antenna transmission to a second node over an effective channel. The first node and the second node are comprised in a wireless communication system. The method comprises the steps of obtaining at least one symbol stream and determining a precoding matrix having a block diagonal structure. The method comprises the further steps of precoding the at least one symbol stream with the determined precoding matrix, and transmitting the at least one precoded symbol stream over the effective channel to the second node.

Abstract: There is provided mechanisms for enabling time synchronized and coordinated downlink transmission of data from a radio unit. A method is performed by a network node. The method comprises configuring at least two baseband units. The at least two baseband units are operatively connected to the radio unit for downlink transmission of data. The at least two baseband units are configured with time synchronization information for compensating for a difference in time delay between each of the at least two baseband units and the radio unit for the downlink transmission of data. The at least two baseband units are configured with time scheduling information identifying which transmission slots per frame that are allowed to be used by the at least two baseband units for the downlink transmission of data.

Abstract: Embodiments herein may relate to a method performed by a radio network node for handling communication for a user equipment, UE, in a wireless communication network. The radio network node configures a bandwidth to use for an antenna panel of the radio network node or a part of the antenna panel based on whether communication is for DL communication or UL communication, by configuring a number of elements of the antenna panel, of the radio network node, per carrier for the UE, wherein the number of elements is based on whether communication is for DL communication or UL communication.

Abstract: A method and apparatus for signaling scheduling information in a spatial multiplexing wireless communications system, as well as corresponding methods and apparatus for processing such signaling information, are disclosed. Signaling scheduling information includes scheduling first and second transport blocks for simultaneous transmission during a first transmission interval on first and second data substreams, respectively, and assigning a single re-transmission process identifier for the first transmission interval and transmitting first scheduling information for the first transmission interval. The first scheduling information includes the re-transmission process identifier and first disambiguation data. Additionally, at least one of the first and second transport blocks is scheduled for re-transmission during a second transmission interval.

Abstract: A method performed by a network node comprising an active antenna system in a telecommunication network. The network node can identify a plurality of available branches from a plurality of branches of the active antenna system for supporting a narrowband signal. The network node can further map at least two available branches from the plurality of available branches to at least one subcarrier of a plurality of subcarriers from the narrowband signal, wherein each of the at least two available branches are mapped to different sets of subcarriers from the plurality of subcarriers.