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: Method and apparatus for enabling accurate link quality estimation of a wireless link between a sending node and a receiving node. When the sending node receives link state reports from the receiving node, it estimates the current state of the wireless link. The sending node also determines a measurement adjusting parameter if the link state reports are deemed inaccurate in relation to the estimated link state, based on a deviation between the received link state reports and the estimated actual link state. The sending node then sends the determined measurement adjusting parameter to the receiving node, and the receiving node provides a link state report based on signal measurements adjusted by the measurement adjusting parameter. The adjusted link state report can then be used for link adaptation of the wireless link and/or for packet scheduling decisions.

Abstract: The invention relates to devices and methods for signalling control information associated with transmission of data over a wireless channel. A second communication device receives (S2) data from a first communication device, wherein the data comprises an indication of recommended precoders and a recommendation of a first transmission rank to possibly use during transmission. The second communication device determines (S4) a second transmission rank to use for transmitting data, and transmits (S6) a confirmation message to the first communication device. The confirmation message comprises a confirmation that transmission of data from the second communication device is using at least parts of each recommended precoder associated with a frequency resource that falls within the transmission of data and an indicator of the second transmission rank to use.

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: In some embodiments, a network node has an associated cell identifier (“cell ID”). The network node creates a primary synchronization signal (PSS), a first secondary synchronization signal, and one or more additional secondary synchronization signals. The combination of signals defines the cell ID. The cell ID is one of N possible cell IDs and N is determined by multiplying: a number of possible values for the PSS; a number of possible values for the first secondary synchronization signal; and for each additional secondary synchronization signal, a number of possible values for the additional secondary synchronization signal, such that N is greater than a legacy number of possible cell IDs determined by multiplying the number of possible values for the PSS and the number of possible values for the first secondary synchronization signal. The network node transmits the combination of the created signals.

Abstract: Embodiments described herein provide a method in a network node for configuring interference measurements for a wireless device. According to the method, the network node receives (804) information indicating whether a channel state information interference measurement, CSI-IM, resource configuration restriction applies for the wireless device. The network node further configures (806) CSI-IM resources for the wireless device based on the information.

Abstract: Embodiments of systems and methods for flexible Channel State Information (CSI) feedback in a cellular communications network are disclosed. In some embodiments, a base station configures a wireless device with a set of CSI-RS resources, dynamically configures a CSI-RS resource from the set of CSI-RS resources for measurement, and receives a CSI report from the wireless device determined from the CSI-RS resource dynamically configured for measurement. In this manner, the base station is enabled to dynamically configure and re-configure the CSI-RS resource(s) for measurement by the wireless device, which in turn provides flexible CSI feedback that is particularly well-suited for embodiments in which the base station transmits beamformed CSI-RS.

Abstract: There is disclosed a method of operating a transmitter arrangement for a wireless communication network, the transmitter arrangement adapted for beamforming. The method comprises determining a maximum power level mask for the power of transmission and/or beams in a critical angular interval, the maximum power level mask covering at least the critical angular interval and controlling beamforming based on the maximum power level mask.

Abstract: Embodiments herein relate to a methods performed by a wireless device (121) for handling discovery signals from one or more transmission points (111, 112) or cells (115, 116) in a radio communications network (100). Embodiments herein further relates to methods performed by a network node (110) for handling discovery signals from one or more transmission points (111, 112) or cells (115, 116) in a radio communications network (100). The method performed by the UE (121) comprises: determining (1101) an identity of a cell associated with received synchronization signals and/or Channel State Information Reference Symbol, CSI-RS, configuration information; and applying (1102) CSI-RS configurations when receiving discovery signals on radio resources associated with CSI-RS based on the determined identity of the cell and/or CSI-RS configuration information. Embodiments of the wireless device (121) and the network node (110) are also described.

Abstract: According to some embodiments, a method performed by a network node (115A) for providing interference mitigation assistance to a wireless device (110C) includes associating demodulation reference signal (DMRS) sequence information with at least one transmission parameter that applies to the DMRS sequence information. An indication of the association of the DRMS sequence information with the at least one transmission parameter is transmitted to the wireless device (110C) for use in performing mitigation of an interfering signal from a first transmission point (115A or 115B).

Abstract: A high-power point and one or more low-power points transmit signals associated with the same cell-identifier in a heterogeneous cell deployment. Coverage areas corresponding to the low-power points fall at least partly within the coverage area for the high-power point, so that mobile stations within range of a low-power point are also within range of the high-power point. Channel-state-information reference symbols, CSI-RS, are transmitted using different CSI-RS resources on different transmission points within the cell, while configuration of CSI-RS measurement resources is conducted on a UE-specific basis. The choice of measurement resources to be used is determined by the network, based on the properties of the channels from the transmission points to the UE. As the UE moves around within the cell, the network tracks the channel properties and reconfigures the CSI-RS resources measured by the UE, to correspond to the resource of the closest transmission point or points.

Abstract: Some embodiments provide a method for channel estimation in a wireless device. According to the method, the wireless device obtains (1010) an indication that a set of antenna ports, or antenna port types, share at least one channel property. The wireless device then estimates (1020) one or more of the shared channel properties based at least on a first reference signal received from a first antenna port included in the set, or having a type corresponding to one of the types in the set. Furthermore, the wireless device performs (1030) channel estimation based on a second reference signal received from a second antenna port included in the set, or having a type corresponding to one of the types in the set, wherein the channel estimation is performed using at least the estimated channel properties.

Abstract: Methods and arrangements in a communication system 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 in the system and the modes have partly shared signaling. SU-MIMO mode signaling which is redundant for MU-MIMO mode signaling is identified. Data bits of the identified redundant signaling is re-interpreted or re-defined to comprise signaling information associated with MU-MIMO mode. The signaling information associated with MU-MIMO mode is signaled to the mobile terminal using the reinterpreted redundant bits.

Abstract: Embodiments herein relate to a method in a user equipment for performing channel estimation of one or more long term channel properties at the user equipment, wherein the user equipment is served by a radio network node.

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: 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 (303) 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 NT of antenna ports that is a function of a number Nh of antenna ports in the first dimension, and a number Nv of antenna ports in the second dimension.

Abstract: A method (100) in a network node serving a User Equipment (UE) capable of network assisted interference cancellation is disclosed. The method involves a signaling (104) of an indication to the UE indicating whether the UE should enable or disable (108) the network assisted interference cancellation, or whether the UE should autonomously choose (110) to enable or disable the network assisted interference cancellation. The enabling or disabling is done for at least one of demodulating the downlink channel or computing the channel state information. The method further involves a receiving (106) of information from the UE about whether the network assisted interference cancellation has been used by the UE for at least one of demodulating the downlink channel and computing the channel state information. A related method in a UE is also disclosed, together with the network node and the UE as such.

Abstract: A network node, a UE and respective methods therein are provided for enabling transmission of data using a resource element reserved for CRS. The method in the network node for scheduling a downlink data transmission to the UE currently connected to the network node, comprises determining to schedule data transmission to the UE using at least one resource element reserved for transmitting CRSs during at least one subframe; and transmitting data to the UE using the at least one resource element reserved for transmitting the at least one CRS during the at least one subframe.

Abstract: Methods and devices provide a feedback message having unequal error protection. The feedback message may include channel quality indicators. The channel quality indicators may have different levels of error protection based on a transmission property.

Abstract: Systems and methods for search area-based control channel monitoring are provided. According to one exemplary embodiment, a method is performed by a control node for communication with a user equipment. Further, the communication is structured in frames with each frame having subframes. The method includes transmitting, by the control node, a control channel in a search area that is in a subset of the subframes for a frame so as to enable the user equipment to monitor the control channel in only the subset of the subframes for that frame.