Telefonaktiebolaget Lm Ericsson (publ)

Mathias Riback

Henrik Asplund

Jonas Medbo

Karl Werner

Andreas Nilsson

Mikael Coldrey

Andres Reial

Stephen J Grant

Bo Göransson

Johan Furuskog

Arne Simonsson

Peter Ökvist

Patrick Svedman

Douglas Allan Cairns

Magnus Thurfjell

Jan-Erik Berg

Paul Mihkel Teder

Anders Elgcrona

Jonas FRÖBERG Olsson

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 () of sharing channel information between a first radio node () and the second radio node that are co-located () may include obtaining (), by the second radio node, first channel information characterizing a communication channel (-) between a third radio node () and the first radio node in a first frequency band. Further, the method may include using (), by the second radio node, the first channel information for communication with the third radio node or a fourth radio node () in a second frequency band.

Systems and methods of sharing channel information between co-located radio nodes

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.

Link adaptation systems and methods

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.

Transmission power distribution for MIMO communications when multiplicative noise limited

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.

Precoder weight selection for MIMO communications when multiplicative noise limited

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.

Antenna reconfiguration for MIMO communications when multiplicative noise limited

The present invention relates to a method for adapting transmission parameters in a transmitter Tin communication with at least one antenna. The method comprises: transmitting a signal from the transmitter Tmeasuring at least one reflection coefficient Sof said signal for each antenna, and adapting the transmission parameters based on the measured reflection coefficient S. 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, and compensate for differences in time delay between the individual transmitter chainsto assure that the signal is transmitted simultaneously from all transmit antennas.

Adaptive antenna transmission and antenna calibration

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.

Method and apparatus for improving the performance of a mobile radio communications system by adjusting antenna patterns

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.

Method and apparatus for compensating for processing timing misalignment in a communication receiver

A communication method for use in a wireless communications network is proposed, said method comprising the steps of&#x2014;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; &#x2014;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.

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Danderyd, Sweden

Mathias Riback