Abstract: Coordinated multi-point transmission of user data from a first cell serving a wireless terminal and a neighboring second cell site is performed. The first cell site maps control signals and user data to time-frequency resources according to a first mapping pattern. The second cell site maps control data and traffic data to time-frequency resources according to a second mapping pattern. A wireless terminal extracts user data according to the first mapping pattern and detects a control element transmitted by the first cell site. The control element indicates that user data associated with the control element is mapped to the time-frequency resources according to the second mapping pattern. In response, the wireless device extracts user data according to the second mapping pattern from time-frequency resources of a second transmission for the wireless terminal transmitted from the second cell site.

Abstract: A network node signals to a wireless communication device which precoders in a codebook are restricted from being used. The network node in this regard generates codebook subset restriction signaling that, for each of one or more groups of precoders, jointly restricts the precoders in the group by restricting a certain component (e.g., a certain beam precoder) that the precoders in the group have in common. This signaling may be for instance rank-agnostic signaling that jointly restricts the precoders in a group without regard to the precoders' transmission rank. Regardless, the network node sends the generated signaling to the wireless communication device.

Abstract: Techniques disclosed herein provide for prohibiting use by a User Equipment (UE) (12) of configured Tracking Reference Signals (TRSs) (30). For example, under certain conditions or circumstances, the UE (12) is prohibited from using any configured TRS (30) for time or frequency tracking, for reception by the UE (12) of a physical downlink channel (32). For example, when TRS usage is prohibited for time or frequency tracking for reception of a physical downlink channel (32), the UE (12) uses Demodulation Reference Symbols (DMRS) transmitted for the physical downlink channel (32), for such time or frequency tracking.

Abstract: Base station and UE and methods therein for broadcast in a wireless communication network. The method in the base station comprises determining a set of transmission resources, out of a number of sets of transmission resources, based on a property associated with a synchronization signal of the base station, and further transmitting the synchronization signal and/or system information, such as a MIB, in the determined set of transmission resources.

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: A method, system and apparatus are disclosed for channel state information reference signal (CSI-RS) transmission. In one embodiment, a wireless device (WD) is configured to receive a configuration of at least one CSI-RS resource. The configuration indicates at least one parameter for at least one modifier for the at least one CSI-RS resource, optionally: the at least one modifier being one of at least one multiplier sequence, at least one CSI-RS port to orthogonal cover code, OCC, index permutation sequence and at least one CSI-RS port to OCC index cyclic shifting; at least one of the at least one parameter being used as a seed to generate the at least one multiplier sequence; and/or at least one of the at least one parameter being at least one cyclic shift value for cyclic shifting of the at least one CSI-RS port.

Abstract: Systems and methods for low complexity multi-configuration Channel State Information (CSI) reporting are provided. In some embodiments, a method of operating a wireless device in a cellular communications network to provide CSI feedback from multiple CSI reporting configurations is provided. The method includes receiving a first and second CSI reporting configuration and then reporting updated CSI in a CSI report for only one of the first CSI reporting configuration and the second CSI reporting configuration. In this way, rich CSI feedback with many ports, different codebooks, mixed beamformed and non-precoded CSI-RS configurations, etc., can be supported while requiring less computational complexity in the wireless device.

Abstract: A network node signals to a wireless communication device which precoders in a codebook are restricted from being used. The network node in this regard generates codebook subset restriction signaling that, for each of one or more groups of precoders, jointly restricts the precoders in the group by restricting a certain component (e.g., a certain beam precoder) that the precoders in the group have in common. This signaling may be for instance rank-agnostic signaling that jointly restricts the precoders in a group without regard to the precoders transmission rank. Regardless, the network node sends the generated signaling to the wireless communication device.

Abstract: A method performed by a base station of enabling a User Equipment (UE) to determine a precoder codebook in a wireless communication system is provided. The base station transmits, to the UE, information regarding precoder parameters enabling the UE to determine the precoder codebook. The precoder parameters are associated with a plurality of antenna ports of the base station. The precoder parameters relate to a first dimension and a second dimension of the precoder codebook. The plurality of antenna ports comprises a number of antenna ports that is a function of a number of antenna ports in the first dimension, and a number of antenna ports in the second dimension.

Abstract: Radio alignment of downlink and uplink channels between a wireless device and a multi-antenna base station. A method performed by a network node comprises obtaining downlink channel data, wherein the downlink channel data comprises: estimates of a plurality of downlink channels each associated with a downlink reference signal being received from one of the antennas at the wireless device, and time synchronization information associated with each of the downlink channels; obtaining uplink channel data, wherein the uplink channel data comprises: estimates of a plurality of uplink channels each associated with an uplink reference signal being received at one of the antennas from the wireless device, and time synchronization information associated with each of the uplink channels; comparing the downlink channel data and the uplink channel data to determine whether the downlink channel and uplink channel between the wireless device and the multi-antenna base station are aligned.

Abstract: A method for assisting the adaptation of a signal from a first node to a second node is provided. The first node communicates with the second node in a wireless communication system over a radio link. The second node has a codebook comprising a set of possible information alternatives for assisting the adaptation of a signal received from the first node. The second node may select an information alternative from the codebook and send it to the first node to assist the first node in adapting the signal. The first node is configured with a number of subsets, each comprising a part of the possible information alternatives. The first node requests that the second node restrict the selection of information alternatives to one of the subsets, and in response, receives an information alternative from the second node that is selected from among the subsets configured according to the configuration request.

Abstract: A network node signals to a wireless communication device which precoders in a codebook are restricted from being used. The network node in this regard generates codebook subset restriction signaling that, for each of one or more groups of precoders, jointly restricts the precoders in the group by restricting a certain component (e.g., a certain beam precoder) that the precoders in the group have in common. This signaling may be for instance rank-agnostic signaling that jointly restricts the precoders in a group without regard to the precoders' transmission rank. Regardless, the network node sends the generated signaling to the wireless communication device.

Abstract: Methods and arrangements are described for Multi User Multiple-Input-Multiple-Output (MU-MIMO) signaling via Multiple-Input-Multiple-Output (MIMO) antennas between a base station and one of a plurality of mobile terminals supporting both Single User and Multi User Multiple-Input-Multiple-Output (SU-MIMO and MU-MIMO) signaling modes. Switching between the modes is supported, and the modes have partly shared signaling. SU-MIMO mode signaling which is not needed for MU-MIMO mode signaling is identified. Data bits of the identified signaling is interpreted to comprise signaling information associated with MU-MIMO mode.

Abstract: Methods, apparatus and computer programs are disclosed for controlling the output of a transmission point for a wireless communications network. One embodiment provides a method for controlling the output of a transmission point for a wireless communications network. The method comprises determining an average output power of the transmission point over a period of time; comparing the average output power to an output power reference value; and allocating data, to be transmitted by the transmission point to one or more wireless devices, to a pool of radio resources. The pool of radio resources is adjusted as a function of the comparison between the average output power and the output power reference value, and the output power reference value varies as a function of a maximum antenna gain of an antenna array of the transmission point during the period of time.

Abstract: Methods and arrangements are described for Multi User Multiple-Input-Multiple-Output (MU-MIMO) signaling via Multiple-Input-Multiple-Output (MIMO) antennas between a base station and one of a plurality of mobile terminals supporting both Single User and Multi User Multiple-Input-Multiple-Output (SU-MIMO and MU-MIMO) signaling modes. Switching between the modes is supported, and the modes have partly shared signaling. SU-MIMO mode signaling which is not needed for MU-MIMO mode signaling is identified. Data bits of the identified signaling is interpreted to comprise signaling information associated with MU-MIMO mode.

Abstract: Coordinated multi-point transmission of user data from a first cell serving a wireless terminal and a neighboring second cell site is performed. The first cell site maps control signals and user data to time-frequency resources according to a first mapping pattern. The second cell site maps control data and traffic data to time-frequency resources according to a second mapping pattern. A wireless terminal extracts user data according to the first mapping pattern and detects a control element transmitted by the first cell site. The control element indicates that user data associated with the control element is mapped to the time-frequency resources according to the second mapping pattern. In response, the wireless device extracts user data according to the second mapping pattern from time-frequency resources of a second transmission for the wireless terminal transmitted from the second cell site.

Abstract: Method performed by a network node (210) to indicate a first and a second set of antenna ports. The network node (210) indicates (803) to a wireless device (250) at least one of: a) a first indication of a first set (M?) of antenna ports for first measurements on first radio signals, the first measurements associated with periodic reporting, and b) a second indication of a second set (M) of antenna ports for second measurements on second radio signals, the second measurements associated with aperiodic reporting. The first set is different than the second set. The periodic and the aperiodic reporting are by the wireless device (250) and correspond to a same Channel State Information, CSI, process. The network node (210) also transmits (804), to the wireless device (250), the first radio signals, periodically, over the first set and the second radio signals over the second set.

Abstract: Methods and apparatus are disclosed for receiving user data in a wireless communication system that employs coordinated multi-point transmission of the user data from a first cell serving a wireless terminal and a second cell site neighboring the first cell site. In an exemplary system, the first cell site maps control signals and user data to a time-frequency resources according to a first mapping pattern, while the second cell site maps control data and traffic data to the time-frequency resources according to a second mapping pattern.

Abstract: The teachings herein present a method and apparatus that implement and use a factorized precoder structure that is advantageous in terms of performance and efficiency. In particular, the teachings presented herein disclose an underlying precoder structure that allows for certain codebook reuse across different transmission scenarios, including for transmission from a single Uniform Linear Array (ULA) of transmit antennas and transmission from cross-polarized subgroups of such antennas. According to this structure, an overall precoder is constructed from a conversion precoder and a tuning precoder. The conversion precoder includes antenna-subgroup precoders of size NT/2, where NT represents the number of overall antenna ports considered. Correspondingly, the tuning precoder controls the offset of beam phases between the antenna-subgroup precoders, allowing the conversion precoder to be used with cross-polarized arrays of NT/2 antenna elements and with co-polarized arrays of NT antenna elements.

Abstract: According to some embodiments, a wireless device receives (1020) a discovery burst from a network node (115). The same discovery burst includes multiple signals within at least one subframe, each of the multiple signals having one or more associated measurement functions. At least one of the multiple signals is received with multiple repetitions within the same discovery burst and two or more repetitions of the same type of signal can be combined by the wireless device. The wireless device performs (1024) at least one radio measurement based at least in part on a particular one of the signals of the discovery burst. The performed at least one radio measurement corresponds to a measurement function associated with the particular signal of the discovery burst.