Abstract: The invention relates to the technical field of radio communications, and in particular to an antenna device for a radio base station, and a method of operating an antenna device in a Multiple-Input Multiple-Output system. Embodiments of the invention disclose a secondary precoder (24) in series with a Multiple-Input Multiple-Output precoder (22). The Multiple-Input Multiple-Output precoder (22) has a first plurality of inputs (26, 28) for one or more Multiple-Input Multiple-Output data streams, and a first plurality of outputs (30, 32) for the one or more Multiple-Input Multiple-Output data streams. The secondary precoder has a second plurality of inputs (34, 36) and a second plurality of outputs (38, 40). The first plurality of outputs (30, 32) are in communication with the second plurality of inputs (34, 36).

Abstract: An antenna (100,200,300, 400, 500) comprising first (110, 210, 310, 410, 430) and second (120, 220, 320, 420, 440) structures for guiding electromagnetic waves, each comprising groups (111, 130, 150, 230, 330; 140,160, 240, 340, 445, 470) of radiation elements. For adjacent sections in 5 the structures, at least one applies: ?Groups of radiation elements are distributed along the two structures such that a group (110, 130, 150) in the first structure overlaps a group (120, 140,160) in the second structure partially or not at all. ?Radiation elements within said groups (230; 240) exhibit a common 10 main direction of extension within the group, and differs between the first and the second groups by an angle of at least 10 degrees. ?The radiation elements of the groups (330, 340) are distributed along the structures (310, 320) on sides of the structures which face different directions.

Abstract: Throughput conditions limited by multiplicative noise may be improved by distributing a transmission power across MIMO data streams communicated between MIMO communication nodes. In particular, the transmission power is distributed based on knowledge at the transmitter of the MIMO channel to decrease the transmission power allocated to one or more of the data streams associated with a dominant signal path relative to the transmission power allocated to one or more data streams associated with a weaker signal path to increase at least one of a quality and a throughput condition of the MIMO channel.

Abstract: The method and apparatus disclosed herein improve throughput conditions limited by multiplicative noise by determining precoder weights for each data stream communicated between a MIMO transmitter node and a MIMO receiver node. The precoder weights are determined based on information derived from non-precoded reference symbols to decrease the energy allocated to the dominant signal path relative to the energy allocated to the non-dominant signal paths.

Abstract: The MIMO method and apparatus disclosed herein improve throughput conditions limited by multiplicative noise by reducing the gain of the data streams associated with one or more dominant signal paths between MIMO communication nodes. As used herein, multiplicative noise refers to any noise dependent on or proportional to a signal strength at a transmitting node and/or a receiving node of a wireless communication network. An additional method and apparatus are included for determining that multiplicative noise limits the throughput conditions.

Abstract: A method and a network node (110, 111) for determining first channel state information in an upcoming time slot for use by a first radio network node (111) when determining a set of radio transmission parameters for a transmission between the first radio network node (111) and a second radio network node (121) are provided. The net work node (110, 111) receives (201) second channel state information for said upcoming time slot. Furthermore, the network node (110, 111) determines (207) third channel state information for said upcoming time slot. The second and third channel state information are at least partly non-overlapping with each other. Next, the network node (110, 111) determines (208) the first channel state information, for said upcoming time slot, based on the second channel state information and the third channel state information.

Abstract: The invention relates to a wireless outdoor-indoor multiple-input multiple-output (MIMO) communications system for communicating with user equipment located inside a physical structure such as a building. The MIMO communication system is comprised of a node having at least two node antennas, wherein the node is configured for line of sight (LOS) wireless MIMO communication with at least two outdoor-indoor repeaters, and of at least two outdoor-indoor repeaters adapted for LOS wireless MIMO communication with the node. The repeaters have at least one repeater antenna each, provided outside the physical structure, for LOS MIMO communication with the node and at least two DASs each, provided inside the physical structure, for indoor MIMO communication with the user equipment located inside the physical structure.

Abstract: The invention relates to a wireless outdoor-indoor multiple-input multiple-output (MIMO) communications system for communicating with user equipment located inside a physical structure such as a building. The MIMO communication system is comprised of a node having at least two node antennas, wherein the node is configured for line of sight (LOS) wireless MIMO communication with at least two outdoor-indoor repeaters, and of at least two outdoor-indoor repeaters adapted for LOS wireless MIMO communication with the node. The repeaters have at least one repeater antenna each, provided outside the physical structure, for LOS MIMO communication with the node and at least one leaky cable each, provided inside the physical structure, for indoor MIMO communication with the user equipment located inside the physical structure.

Abstract: Throughput conditions limited by multiplicative noise may be improved by distributing a transmission power across MIMO data streams communicated between MIMO communication nodes. In particular, the transmission power is distributed based on knowledge at the transmitter of the MIMO channel to decrease the transmission power allocated to one or more of the data streams associated with a dominant signal path relative to the transmission power allocated to one or more data streams associated with a weaker signal path to increase at least one of a quality and a throughput condition of the MIMO channel.

Abstract: The method and apparatus disclosed herein improve throughput conditions limited by multiplicative noise by determining precoder weights for each data stream communicated between a MIMO transmitter node and a MIMO receiver node. The precoder weights are determined based on information derived from non-precoded reference symbols to decrease the energy allocated to the dominant signal path relative to the energy allocated to the non-dominant signal paths.

Abstract: The MIMO method and apparatus disclosed herein improve throughput conditions limited by multiplicative noise by reducing the gain of the data streams associated with one or more dominant signal paths between MIMO communication nodes. As used herein, multiplicative noise refers to any noise dependent on or proportional to a signal strength at a transmitting node and/or a receiving node of a wireless communication network. An additional method and apparatus are included for determining that multiplicative noise limits the throughput conditions.

Abstract: The invention relates to the technical field of radio communications, and in particular to an antenna device for a radio base station, and a method for precoding data in a Multiple-Input Multiple-Output (MIMO) system. Embodiments of the invention disclose a secondary precoder 24 in series with a multiple-input multiple-output precoder 22. The secondary precoder 24 has a plurality of inputs 34, 36 and a plurality of outputs 38, 40. The second plurality of inputs being in communication with each plurality of outputs 38, 40 such that one or more signals input to a respective one or more of the second plurality of inputs 34, 36 provides a substantially equal power of signals at the second plurality of outputs 38, 40.

Abstract: An antenna arrangement 30 comprising a leaky cable 31 is disclosed. The leaky cable 31 includes subsections 32, 33, 34 and each subsection exhibits a longitudinal direction of extension L32, L33, L34 and a radiation pattern. The longitudinal directions of adjacent subsections are oriented in different directions to create a predetermined radiation pattern by superpositioning of the radiation pattern of each subsection. Additionally, a method of creating a predetermined radiation pattern of such an antenna arrangement 30 is described.

Abstract: The present invention relates to an intermediate node which is arranged to relay information between a donor node and at least one served node, and comprises a served antenna arrangement that communicates by means of at least a first and second electrically steerable antenna radiation lobe. During a first mode of operation, all antenna radiation lobes are directed towards a first donor node. During a second mode of operation, the antenna radiation lobes are directed such that the intermediate node is in contact with both the first donor node and the second donor node. During a third mode of operation, all antenna radiation lobes are directed towards the second donor node. A first polarization is associated with each lobe directed towards the second donor node during the second mode of operation and a second polarization is associated with each lobe directed towards the first donor node during the second mode of operation.

Abstract: An antenna arrangement comprising at least a first and a second elongated structure, e.g., a coaxial cable, for guiding an electromagnetic wave is provided. Each of said structures comprises a plurality of radiation elements. The structures are positioned alongside each other in their longitudinal direction of extension forming a bundle. The elongated structures are arranged within the bundle such that the radial positions of said structures are alternated in the longitudinal direction of extension.

Abstract: The present invention relates to a method for adapting transmission parameters in a transmitter Tx in communication with at least one antenna 27; 38; 47; 57; 77, 88. The method comprises: transmitting a signal from the transmitter Tx measuring at least one reflection coefficient S11 of said signal for each antenna 27; 38; 47; 57; 77, 88, and adapting the transmission parameters based on the measured reflection coefficient S11. The antenna could be a transmit antenna and/or a receive antenna. In a preferred embodiment antenna calibration may be performed by measuring propagation time for each individual transmitter chain 481, 482; 781, 782, and compensate for differences in time delay between the individual transmitter chains 481, 482; 781, 782 to assure that the signal is transmitted simultaneously from all transmit antennas.

Abstract: An antenna device and method for precoding data in a MIMO system. The antenna device comprises a plurality of physical antennas in a distributed antenna system and a MIMO precoder. The MIMO precoder has a plurality of inputs for a plurality of data streams and a plurality of outputs for the plurality of data streams. A second precoder is disposed in series with the MIMO precoder. The second precoder maps a data stream to an output associated with a physical antenna port associated with at least one of the plurality of physical antennas.

Abstract: The invention relates to the technical field of radio communications, and in particular to an antenna device for a radio base station, and a method of operating an antenna device in a Multiple-Input Multiple-Output system. Embodiments of the invention disclose a secondary precoder (24) in series with a Multiple-Input Multiple-Output precoder (22). The Multiple-Input Multiple-Output precoder (22) has a first plurality of inputs (26, 28) for one or more Multiple-Input Multiple-Output data streams, and a first plurality of outputs (30, 32) for the one or more Multiple-Input Multiple-Output data streams. The secondary precoder has a second plurality of inputs (34, 36) and a second plurality of outputs (38, 40). The first plurality of outputs (30, 32) are in communication with the second plurality of inputs (34, 36).

Abstract: The antenna weight selection solution disclosed herein selects antenna weights for a multiple antenna communication system that transmits uplink or downlink data using multiple radiation patterns based on channel variability metrics determined for two or more sets of candidate antenna weights. In so doing the antenna weight selection solution disclosed herein reduces the channel variability associated with data transmissions, and therefore reduces the amount of feedback and/or the feedback rates required for the multiple antenna communication system.

Abstract: The invention relates to a wireless communications system for communicating with user equipment located inside a physical structure. The system comprise a node having at least two antenna ports and being adapted for wireless communication with the user equipment, and at least one leaky cable having two ends wherein each end of the at least one leaky cable is connected to one of the antenna ports of the node. The at least one leaky cable is provided at least partially inside the physical structure and being adapted for wireless communication over a radio channel with the user equipment.