Abstract: Systems and methods of sharing channel information between co-located radio nodes are provided. In one exemplary embodiment, a method performed by a second radio node (111, 200, 300a, b, 1111) of sharing channel information between a first radio node (101, 500, 600a, b, 1101) and the second radio node that are co-located (107) may include obtaining (403), by the second radio node, first channel information characterizing a communication channel (105a-c) between a third radio node (121, 1121) and the first radio node in a first frequency band. Further, the method may include using (405), by the second radio node, the first channel information for communication with the third radio node or a fourth radio node (123) in a second frequency band.

Abstract: Systems and methods of sharing channel information between co-located radio nodes are provided. In one exemplary embodiment, a method performed by a second radio node (111, 200, 300a, b, 1111) of sharing channel information between a first radio node (101, 500, 600a, b, 1101) and the second radio node that are co-located (107) may include obtaining (403), by the second radio node, first channel information characterizing a communication channel (105a-c) between a third radio node (121, 1121) and the first radio node in a first frequency band. Further, the method may include using (405), by the second radio node, the first channel information for communication with the third radio node or a fourth radio node (123) in a second frequency band.

Abstract: The present application discloses systems and methods for adjusting a back-off value for a rank. In some embodiment, the method includes the steps of: (a) determining whether the rank is underutilized and (b) in response to determining that the rank is underutilized, decreasing the back-off value as a function of time while the rank remains underutilized.

Abstract: It is presented a method for determining a rank indicating the number of layers to be used by a multiple input multiple output, MIMO, transmitter in a mobile communication network, the method being executed in a network node of the mobile communication network. The method comprises the steps of: obtaining success measurements indicating whether data frames, comprising user data, have been successfully transmitted between the network node and a mobile communication terminal for each one of a plurality of ranks; determining usage frequencies for each one of the plurality of ranks based on the success measurements for the respective ranks; and determining the rank to be used for transmission between the network node and the mobile communication terminal based on the usage frequencies. A corresponding network node, base station, computer program and compute program product are also presented.

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 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: 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 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: The present invention relates to a method of improving the performance of a mobile radio communications system comprising at least one stationary radio transmitter for communicating with user equipments in the communications system, wherein the radio transmitter is connected to an antenna system for which the antenna pattern can be varied, the method comprising: receiving direction-of-propagation information relating to a plurality of user equipment transmission samples; selecting, based on the direction-of-propagation information, active directions for the communication of common channels from the radio transceiver; and adjusting the antenna pattern used for communication of common channels in accordance with the selected active directions in a manner so that the gain of at least one direction which has not been selected as active is lower than the gain of the selected active directions.

Abstract: According to the teachings presented herein, a wireless communication apparatus compensates for timing misalignment in its received signal processing. In at least one embodiment, the apparatus estimates a set of path delays for a received signal and sets processing delays on the estimated path delays. The apparatus jointly hypothesizes combinations of fractional timing offsets for two or more paths, and computes a decision metric for each joint hypothesis that indicates the accuracy of the joint hypothesis. As non-limiting examples, the decision metric may be a signal quality metric, or a distance metric (such as between a measured net channel response and an effective net channel response reconstructed as a function of the combination of fractional timing offsets included in the joint hypothesis). The apparatus evaluates the decision metrics to identify a best estimate of timing misalignment, and correspondingly compensates coherent processing of the received signal.

Abstract: A communication method for use in a wireless communications network is proposed, said method comprising the steps of—monitoring at least one property representative of the channel variability in time and/or frequency, for each of at least two channels in the cell, used to communicate with said at least two user terminals; —using the result of the monitoring to control, by a control node in the network or in one of the user terminals, the communication in the cell. The control of the communication may include artificially inducing time selectivity and/or frequency selectivity or selecting an operating mode for the cell.

Abstract: The present application discloses systems and methods for adjusting a back-off value for a rank. In some embodiment, the method includes the steps of: (a) determining whether the rank is underutilized and (b) in response to determining that the rank is underutilized, decreasing the back-off value as a function of time while the rank remains underutilized.

Abstract: The present invention relates to a method of improving the performance of a mobile radio communications system comprising at least one stationary radio transmitter for communicating with user equipments in the communications system, wherein the radio transmitter is connected to an antenna system for which the antenna pattern can be varied, the method comprising: receiving direction-of-propagation information relating to a plurality of user equipment transmission samples, wherein a user equipment transmission sample includes information relating to at least one direction of propagation by which successful communication between a user equipment and the radio transmitter has been established at a particular point in time; selecting (303), based on the direction-of-propagation information, active directions for the communication of common channels from the radio transceiver; and adjusting (305) the antenna pattern used for communication of common channels in accordance with the selected active directions in a man

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: A communication method for use in a wireless communications network is proposed, said method comprising the steps of—monitoring at least one property representative of the channel variability in time and/or frequency, for each of at least two channels in the cell, used to communicate with said at least two user terminals;—using the result of the monitoring to control, by a control node in the network or in one of the user terminals, the communication in the cell. The control of the communication may include artificially inducing time selectivity and/or frequency selectivity or selecting an operating mode for the cell.

Abstract: According to the teachings presented herein, a wireless communication apparatus compensates for timing misalignment in its received signal processing. In at least one embodiment, the apparatus estimates a set of path delays for a received signal and sets processing delays on the estimated path delays. The apparatus jointly hypothesizes combinations of fractional timing offsets for two or more paths, and computes a decision metric for each joint hypothesis that indicates the accuracy of the joint hypothesis. As non-limiting examples, the decision metric may be a signal quality metric, or a distance metric (such as between a measured net channel response and an effective net channel response reconstructed as a function of the combination of fractional timing offsets included in the joint hypothesis). The apparatus evaluates the decision metrics to identify a best estimate of timing misalignment, and correspondingly compensates coherent processing of the received signal.