Abstract: Examples are described relating to methods, apparatus and computer programs for configuring a user equipment in a cellular wireless network. Certain exemplary methods involve receiving (440), at the user equipment (430), control information regarding one or more of a plurality of channel-state information (CSI) reference signals. The plurality of CSI reference signals are receivable by the user equipment (430) from one or more of a plurality of antenna ports that form part of the cellular wireless network, the plurality of CSI reference signal being associated with corresponding antenna ports. The control information is for use in configuration of the user equipment (430) and is received over a radio communications downlink from a node (410) in the cellular wireless network. If estimation of one or more radio communication channels at the user equipment (430) is configured (450) based on the received control information, improvements in demodulation and CSI feedback are achieved.

Abstract: A first precoding matrix W1 is selected from a first codebook comprising sets of rank specific precoding matrices. The first codebook is characterized by there being fewer precoding matrices associated with higher ranks than associated with lower ranks, and characterized by precoding matrices associated with ranks above a certain rank all being diagonal matrices. The selected first precoding matrix W1 is used to select a rank-specific second precoding matrix W2 from a second codebook, such that the selected first and second precoding matrices form a joint precoder specific to a desired rank. The second codebook is characterized by differently sized precoding matrices associated with each of N total ranks, in which N is an integer greater than one. Information on the joint precoder is reported to a network node over an uplink transmission channel.

Abstract: In an embodiment, state of a wireless channel on which information is received is measured; the measured state is used to select from a codebook a plurality of N codewords which optimize a predefined measure, and first and second codewords of the plurality are reported which best optimizes and next-best optimizes the predefined measure. If by example the above is done by a user equipment UE, in another embodiment the network receives first and second indications, searches a codebook using the first and second indications to find the first and second codewords; and utilizes them to improve the channel state information, such as by interpolating between them to find an estimate of the channel. In examples the channel is a MIMO channel that is estimated at two or more antenna ports, there are interpolation weights sent with the codeword indications, and the interpolating uses a geodesic algorithm.

Abstract: In accordance with the exemplary embodiments of the invention there is deriving multiple input-multiple output feedback information using a set of precoding matrices associated with at least one precoding codebook, signaling, in a first plurality of resource elements, channel state information associated with a first precoding matrix indicator of the set of precoding matrices jointly with a transmission rank, and signaling separately, in a second plurality of resource elements, channel state information associated with a second precoding matrix indicator of the set of precoding matrices.

Abstract: Messages containing interference vectors are transmitted efficiently to user equipments over a downlink channel. A pre-coding indicator channel is used for transmission in an over-the-air packet-based communication system. A table of pre-coding matrix indices or pre-coding vector information is transmitted to user equipments configured in a spatially multiplexed multiple user MIMO configuration. The UEs receive the pre-coding vector information that allows them to determine the pre-coding vectors used to communicate in the downlink direction from a MIMO base station to other MIMO UEs in the cell or system. The UEs use this information to actively suppress inter-user interference.

Abstract: A method, apparatus and computer program product are provided for reporting low rank feedback information for each transmission point up to a maximum rank per transmission point. In this regard, a method includes determining a transmission rank and a precoding matrix for each of at least two transmission points of a plurality of transmission points. A method also includes determining a joint transmission rank based on at least two of the plurality of transmission points. A method also includes selecting a joint transmission precoding matrix based on the determined precoding matrix for each of the at least two transmission points and the determined joint transmission rank. The method further includes causing channel state information “CSI” to be transmitted to an access point, wherein the CSI describes the selected joint transmission precoding matrix.

Abstract: Examples are described relating to methods, apparatus and computer programs for configuring a user equipment in a cellular wireless network. Certain exemplary methods involve receiving (440), at the user equipment (430), control information regarding one or more of a plurality of channel-state information (CSI) reference signals. The plurality of CSI reference signals are receivable by the user equipment (430) from one or more of a plurality of antenna ports that form part of the cellular wireless network, the plurality of CSI reference signal being associated with corresponding antenna ports. The control information is for use in configuration of the user equipment (430) and is received over a radio communications downlink from a node (410) in the cellular wireless network. If estimation of one or more radio communication channels at the user equipment (430) is configured (450) based on the received control information, improvements in demodulation and CSI feedback are achieved.

Abstract: The invention teaches a solution, for example, for Long Term Evolution (LTE) networks. The solution comprises determining a measurement pattern for at least one automatic gain control tracking loop when resource restrictions have been configured for a user equipment, the resource restrictions comprising at least one measurement restriction pattern, wherein each automatic gain control tracking loop is associated with at least one measurement restriction pattern; and performing automatic gain control measurements according to the measurement patterns of the at least one automatic gain control tracking loop.

Abstract: In accordance with the exemplary embodiments of the invention there is at least a method, apparatus, and a computer program to perform operations including receiving information descriptive of a type of radio access which a user equipment is acting on, and in response to receiving the information descriptive of a particular type of radio access, transmitting from a multiple transmit antenna user equipment so that the transmission appears, at a receiver, to have been made by a single antenna user equipment, or by a user equipment that supports antenna switching/selection.

Abstract: A method, apparatus and computer program product are provided for reporting low rank feedback information for each transmission point up to a maximum rank per transmission point. In this regard, a method includes determining a transmission rank and a precoding matrix for each of at least two transmission points of a plurality of transmission points. A method also includes determining a joint transmission rank based on at least two of the plurality of transmission points. A method also includes selecting a joint transmission precoding matrix based on the determined precoding matrix for each of the at least two transmission points and the determined joint transmission rank. The method further includes causing channel state information “CSI” to be transmitted to an access point, wherein the CSI describes the selected joint transmission precoding matrix.

Abstract: An apparatus and method for selecting a beam group and a subset of beams in a communication system are disclosed. The method includes: measuring channel state information (CSI) on a downlink from a base station (920); identifying a selected beam group out of a set of beam groups according to a wideband property of the CSI (930); identifying a selected subset of beams in the selected beam group according to at least one subband (940). Wherein the characteristic of the set of beam groups depends on a transmission rank and the number of beams in the selected subset of beams is equal to the transmission rank. The method further includes: generating encoded feedback information identifying the selected beam group and the selected subset of beams for each subband in a double codebook format (950), transmitting the encoded feedback information to the base station.

Abstract: A first precoding matrix W1 is selected from a first codebook comprising sets of rank specific precoding matrices. The first codebook is characterized by there being fewer precoding matrices associated with higher ranks than associated with lower ranks, and characterized by precoding matrices associated with ranks above a certain rank all being diagonal matrices. The selected first precoding matrix W1 is used to select a rank-specific second precoding matrix W2 from a second codebook, such that the selected first and second precoding matrices form a joint precoder specific to a desired rank. The second codebook is characterized by differently sized precoding matrices associated with each of N total ranks, in which N is an integer greater than one. Information on the joint precoder is reported to a network node over an uplink transmission channel.

Abstract: The present invention provides a method, apparatus and a computer program product for spatial hashing for enhanced control channel search spaces. The present invention includes defining a control channel search space for searching for control channel candidates, defining search space locations within the search space, grouping the search space locations into a plurality of subsets of search space locations, associating each subset of search space locations with an antenna port, for each of a plurality of subframes, changing the search space locations from a first subset of search space locations to a second subset of search space locations.

Abstract: The invention teaches a solution, for example, for Long Term Evolution (LTE) networks. The solution comprises determining a measurement pattern for at least one automatic gain control tracking loop when resource restrictions have been configured for a user equipment, the resource restrictions comprising at least one measurement restriction pattern, wherein each automatic gain control tracking loop is associated with at least one measurement restriction pattern; and performing automatic gain control measurements according to the measurement patterns of the at least one automatic gain control tracking loop.

Abstract: There is provided a mechanism providing a flexible feedback framework operating in different scenarios, such as heterogeneous network deployments. Antenna information are sent from a scheduler element to a UE, the antenna information including information indicating a grouping of one or more antenna in closely spaced antenna groups of one or more transmit points. The UE selects at least one of precoding codewords and amplitude weight parameters for each closely spaced antenna group, and determines information related to a sub-band precoder and a transmit point related combiner. The processing results are indicated to the scheduler by means of sending indices related to a wide-band long-term precoder and a sub-band short-term precoder. The scheduler processes these results for determining a joint precoder.

Abstract: A set of J predetermined power level offsets that scale transmission power per user are stored in a local computer-readable memory. A set of N users to which are allocated overlapping downlink frequency resources are selected. From the stored set is then selected a power level offset. An indication of the selected power level offset is signaled to at least one of the N users; and the at least one of the N users are also sent a multiplexed transmission using the selected power level offset. N is an integer at least equal to two, J is an integer at least equal to two, and at least one member of the set is other than 1/n in which n is any positive integer less than Nmax in which Nmax is a maximum number of users that can be multiplexed together. Various embodiments include an apparatus such as a network access node, a method, and a stored computer program. Also detailed are apparatus and method and stored computer program for practicing the invention from the perspective of the user/UE.

Abstract: Systems and methods for providing an efficient mechanism for transmitting interference vectors to communications terminals, such as user equipments (UEs), in an over the air radio telecommunications network with spatially multiplexed multiple user multiple input multiple output (MU-MIMO) capability. A new pre-coding information downlink channel is defined. Messages containing semi-persistent interference vector information for MU-MIMO user equipment are defined and transmitted over the new channel in a manner that allows infrequent transmission and efficient use of resources. Using the interference vectors and applying inter-user interference adaptation to received messages, the UEs may receive spatially multiplexed MIMO transmissions and actively remove inter-user interference after reception of the messages. Compression of the pre-coding vector information transmitted over the pre-coding information channel may result in additional increases in efficiency in the system.

Abstract: In accordance with the exemplary embodiments of the invention there is deriving multiple input-multiple output feedback information using a set of precoding matrices associated with at least one precoding codebook, signaling, in a first plurality of resource elements, channel state information associated with a first precoding matrix indicator of the set of precoding matrices jointly with a transmission rank, and signaling separately, in a second plurality of resource elements, channel state information associated with a second precoding matrix indicator of the set of precoding matrices.

Abstract: An apparatus, method and system for signaling of interfering spatial layers with dedicated reference signals in a communication system. In one embodiment, an apparatus includes a processor (520) and memory (550) including computer program code. The memory (550) and the computer program code are configured to, with the processor (520), cause the apparatus to receive an allocation of communication resources and a dedicated reference signal index for a spatial layer associated with the communication resources, receive information about spatial interference for a user equipment, and identify spatial interference with respect to at least one communication resource within the communication resources allocated to the user equipment in another spatial layer.

Abstract: A method and apparatus are provided for an apparatus. The apparatus includes at least one memory including computer program code, and at least one processor. The at least one memory and the computer program code are configured to, with the at least one processor, cause the apparatus at least to receive an indication of a set of codeword groups to be included in a codebook, and to select a precoding matrix index based on the indicated set of codeword groups in the codebook. The apparatus is also cause to transmit the precoding matrix index to a network node.