Abstract: The present disclosure relates in general to telecommunications. In one of its aspects, the technology presented herein concerns a method, implemented in an Access Point (AP), for transmitting data intended for a terminal in a cell-free massive Multiple-Input and Multiple-Output (MIMO) communications system. The AP is grouped into a cluster together with other APs and the cluster operates autonomously. The cluster is connected to, and managed by, one Central Processing Unit (CPU). A message that the AP is selected to serve the terminal and data intended for said terminal are received from the CPU. Power control is independently conducted, exclusively considering the terminals that are served by the AP itself. Thereafter, said intended data is transmitted to the terminal.

Abstract: The present disclosure relates to radio network communication. In one of its aspects, the present disclosure relates to a method, performed by a first APU, for sequential receive combining in a radio stripe system. The system comprises at least two APUs connected in series to a CPU and serves at least two UEs. According to the method, channel estimates for channels to said served UEs are received and based on these, a receive combining filter is determined. The receive combining filter is to be applied to received data signals. Thereafter, based on the obtained channel estimates and the determined receive combining filter, effective channels from said served UEs are determined. These represent the effective channel created after the receive combining filter being applied to each channel for said served UEs. The effective channels are transmitted from said served UEs to at least one subsequent second APU.

Abstract: A control node, a wireless device, an access point and methods therein, to achieve estimation of path loss and channel response in a radio link between the wireless device and the access point. The control node assigns one and the same pilot sequence to the wireless device and at least one other wireless device in communication with the access point, and further assigns different device-specific phase rotations to the wireless devices. The devices then apply their assigned phase rotations to the pilot sequence when transmitting the pilot sequence in consecutive coherence intervals to the access point which is thereby able to de-spread the received pilot sequences and estimate path loss and channel response in the radio link.

Abstract: The embodiments herein relate to a method performed by an APU (103) for handling data transmissions in a distributed massive MIMO communication system (100). The APU (103) is comprised in one of at least two non-co-located groups of APUs (103) in the system (100). The APU (103) determines a first pre-coding configuration and a DL reference signal. The APU (103) transmits, to a UE (125), the DL reference signal pre-coded with the first pre-coding configuration. The APU (103) receives information indicating at least one phase adjustment parameter from the UE (125), and determines a second pre-coding configuration based on the first pre-coding configuration adjusted with the phase adjustment parameter. The APU (103) transmits DL data pre-coded with the second pre-coding configuration to the UE (125).

Abstract: An antenna system includes at least a first antenna processing unit, APU1, and a second antenna processing unit, APU2, adjacently connected to each other through a serialized front haul. Each one of the APU1 and APU2 has at least two antenna elements. The antenna elements of APU1 are connected to their respective Radio Frequency, RF, chains via a first beamforming unit, and the antenna elements of APU2 are connected to their respective RF chains via a second beamforming unit. A network node configures the first beamforming unit and the second beamforming unit such that an absolute value of an angular difference between at least one of the beam directions generated by the first beamforming unit and each of the beam directions generated by the second beamforming unit exceeds or is equal to a threshold value.

Abstract: A method of a receiver is used for receiving an amplitude shift keyed signal provided over a multi-layered transmission from a plurality of antennas with different precoding of different symbols for the respective layers. The method comprises receiving a sequence of signal values of the signal, estimating, from the sequence of signal values, channels for the respective layers, and selecting one of a plurality of detection methods based on a difference in quality between the estimated channels A receiver and a computer program are also disclosed.

Abstract: A method, in a base station, for transmitting first control channel information to a first wireless device and second control channel information to a second wireless device in a wireless communications network. The method comprises obtaining an indication of whether a spatial relationship between the first wireless device and the second wireless device meets a predetermined condition and operating in one of a first mode and a second mode based on the indication. Operating in the first mode comprises transmitting the first control channel information and the second control channel information using common radio resources; and operating in the second mode comprises transmitting the first control channel information to the first wireless device and the second control channel information to the second wireless device using orthogonal radio resources. Methods and apparatus for obtaining control channel information in a first wireless device are also disclosed.

Abstract: The present disclosure relates to radio network communication. In one of its aspects, the present disclosure relates to a method, performed by a first APU, for sequential transmit precoding in a radio stripe system. The system comprises at least two APUs connected 5 in series from a CPU and serves at least two UEs. According to the method, channel estimates for channels to the served UEs are obtained and based on these, a precoding filter is determined. The precoding filter is going to be applied to signals that are to be transmitted from the first APU to the UEs. Thereafter, based on the determined precoding filter and the obtained channel estimates, effective precoded channels for the 0 signals to the UEs are determined. These represent the effective channel created after the precoding filter being applied to each channel for the UEs. The effective precoded channels are transmitted to at least one subsequent second APU. To be published with FIG.

Abstract: An antenna system includes at least a first antenna processing unit, APU1, and a second antenna processing unit, APU2, adjacently connected to each other through a serialized front haul. Each one of the APU1 and APU2 has at least two antenna elements. The antenna elements of APU1 are connected to their respective Radio Frequency, RF, chains via a first beamforming unit, and the antenna elements of APU2 are connected to their respective RF chains via a second beamforming unit. A network node configures the first beamforming unit and the second beamforming unit such that an absolute value of an angular difference between at least one of the beam directions generated by the first beamforming unit and each of the beam directions generated by the second beamforming unit exceeds or is equal to a threshold value.

Abstract: Embodiments herein disclose, e.g., an arrangement for handling radio signals, wherein the arrangement has an elongated housing. The elongated housing has at least one antenna processing unit (APU) and at least two groups of antenna elements, wherein each group of antenna elements includes antenna elements and a beamforming unit that generates one or more beams. The at least one APU is connected to both the groups of antenna elements.

Abstract: The present disclosure relates to radio network communication. In one of its aspects, the present disclosure relates to a method, performed by a first APU, for sequential receive combining in a radio stripe system. The system comprises at least two APUs connected in series to a CPU and serves at least two UEs. According to the method, channel estimates for channels to said served UEs are received and based on these, a receive combining filter is determined. The receive combining filter is to be applied to received data signals. Thereafter, based on the obtained channel estimates and the determined receive combining filter, effective channels from said served UEs are determined. These represent the effective channel created after the receive combining filter being applied to each channel for said served UEs. The effective channels are transmitted from said served UEs to at least one subsequent second APU.

Abstract: A method (200) of transmitting a block of data in a distributed MIMO system is disclosed. The distributed MIMO system comprises a plurality of access points (A1, . . . , AK), wherein access points (Aj) are grouped into a first set of M groups and a second set of M groups, different from the first set, wherein M is an integer. A first antenna port mapping assigns each group of the first set to a unique one of M antenna ports. A second antenna port mapping assigns each group of the second set to a unique one of M antenna ports. The method comprises transmitting (220) the block of data using both the first and the second antenna port mapping.

Abstract: A method of transmitting an amplitude shift keyed signal uses a multi-layered transmission over a plurality of transmit antennas with different precoding of different symbols for the respective layers. The method comprises obtaining a sequence of bits to be conveyed, keying the sequence of bits to a signal, precoding the signal to respective layer, and transmitting the precoded signal. A transmitter for transmitting the amplitude shift keyed signal, and a computer program for implementing the method are also disclosed.

Abstract: Methods, wireless device (200) and network node (202), for communication between the wireless device and the network node in a wireless network. The wireless device transmits (2:1, 2:3) a predetermined first pilot P1 associated with the wireless device, to indicate that the wireless device is in idle state. The wireless device further transmits (2:5) transmit a predetermined second pilot P2 associated with the wireless device, to indicate that the wireless device is in active state. Thereby, the network node is able to perform positioning (2:2) of the wireless device based on the first pilot P1, and to allow access (2:7) to the network when receiving the second pilot P2.

Abstract: A technique for assigning pilot signals to user equipments is described. The UEs access an RBS that provides radio access. As to a method aspect of the technique, an access burst including initial pilot signals is received from the UEs, wherein at least two of the UEs apply simultaneously the same initial pilot signal. A multicast channel to the at least two UEs is estimated based on the received access burst. A combined signal power received at the RBS is computed for the at least two UEs based on the estimated multicast channel. A message to the at least two UEs is sent using the multicast channel. The message is indicative of the combined signal power and assigns different pilot signals to the at least two UEs, wherein the assignment depends for each of the at least two UEs on the combined signal power and a signal power received at the respective UE.

Abstract: A method performed by a network node for broadcasting beamformed signals of a data transmission to a User Equipment (UE). For each specific data transmission from a number of data transmissions the network node allocates a set of Reference Signals, RS, for the data transmission, the number of RSs in the set of RSs being based on a measure of popularity for UEs receiving the specific data transmission. The network node sends an indication of the allocated set of SRs for each specific data transmission. The network node receives from a UE requesting a particular data transmission out of the number of data transmissions an RS from the set of RS allocated for the particular data transmission. The network node broadcasts beamformed signals of the particular data transmission. The signals are beamformed based on estimated composite channels from all UEs that transmit any RS included in the set of RS allocated for the particular data transmission.

Abstract: The present disclosure relates in general to telecommunications. In one of its aspects, the technology presented herein concerns a method, implemented in an Access Point (AP), for transmitting data intended for a terminal in a cell-free massive Multiple-Input and Multiple-Output (MIMO) communications system. The AP is grouped into a cluster together with other APs and the cluster operates autonomously. The cluster is connected to, and managed by, one Central Processing Unit (CPU). A message that the AP is selected to serve the terminal and data intended for said terminal are received from the CPU. Power control is independently conducted, exclusively considering the terminals that are served by the AP itself. Thereafter, said intended data is transmitted to the terminal.

Abstract: A method is disclosed of a wireless receiver configured for spatial selective reception. The method is for mitigation of an interfering signal leaked into a frequency range of a desired signal due to non-linearity of hardware components of the receiver. The method comprises receiving a composite signal comprising the desired signal and the interfering signal, filtering the composite signal using a spatial filter for a channel response of the desired signal to provide a first intermediate signal component, and filtering the composite signal using a spatial filter for a channel response of the interfering signal to provide a second intermediate signal component. The method also comprises estimating a squared amplitude of the interfering signal based on the second intermediate signal component and a model of the non-linearity, and estimating the desired signal based on the first intermediate signal component, the estimated squared amplitude of the interfering signal, and the model of the non-linearity.

Abstract: A network node (110) and a method for downlink pilot signal assignment and transmission, and for data transmission. The network node has a plurality of antenna elements distributed over an area. The network node determines a respective Channel State Information (CSI) and/or a respective channel hardening degree for a wireless device (120) based on an uplink pilot signal. Possibly, the network node determines a mobility condition for the wireless device. Based on one or more out of: the determined respective CSI, the determined respective channel hardening degree and the determined respective mobility condition, the network node obtains a pilot utility metric for the wireless device. Further, the network node assigns a downlink pilot signal to at least one wireless device having a pilot utility metric exceeding a predetermined threshold value. Furthermore, the network node transmits, to the at least one wireless device, data and possibly an assigned downlink pilot signal.

Abstract: A method (200) of transmitting a block of data in a distributed MIMO system is disclosed. The distributed MIMO system comprises a plurality of access points (A1, . . . , AK), wherein access points (Aj) are grouped into a first set of M groups and a second set of M groups, different from the first set, wherein M is an integer. A first antenna port mapping assigns each group of the first set to a unique one of M antenna ports. A second antenna port mapping assigns each group of the second set to a unique one of M antenna ports. The method comprises transmitting (220) the block of data using both the first and the second antenna port mapping.