Telefonaktiebolaget Lm Ericsson (publ)

Huawei Technologies Co., Limited

Dzevdan Kapetanovic

Thomas Nilsson

Leif Wilhelmsson

Rocco Di Taranto

Magnus Åström

Meng Wang

Joao Vieira

Naveed Butt

Bengt Lindoff

Christofer Lindheimer

Filip Mestanov

Guido Roland Hiertz

Håkan Persson

Tai Do

Johan Söder

Luis Felipe Del Carpio Vega

Eric Nordström

Pramod Jacob Mathecken

Athanasios Stavridis

Sha Hu

Michal Stala

Chaitanya Tumula

Sergei Semenov

Neng Wang

Xiaohui Liu

Eric NORDSTRÖM

There is provided mechanisms for interference aware packet transmission. A method is performed by a radio transceiver device. The method comprises obtaining an estimate of interference in a surrounding of the radio transceiver device. The method comprises determining how many symbols for channel estimation to include in a packet to be transmitted based on amount of estimated interference. The method comprises transmitting the packet towards another radio transceiver device, where the packet comprises the determined amount of symbols for channel estimation.

Interference aware packet transmission

A method is disclosed for a system comprising a transmitter apparatus and a receiver apparatus. The transmitter apparatus is configured to transmit signals to the receiver apparatus using an available transmission beam. The receiver apparatus is configured to receive the signals using an available reception beam. The method comprises the transmitter apparatus determining a collection of linear combinations of transmission beams and a collection of linear combinations of reception beams, providing an indication of the collection of linear combinations of reception beams to the receiver apparatus and transmitting each of the linear combinations of transmission beams of the collection of linear combinations of transmission beams. The method also comprises the receiver apparatus acquiring the indication of the collection of linear combinations of reception beams from the transmitter apparatus, receiving each of the linear combinations of transmission beams of the collection of linear combinations of transmission beams using each of the linear combinations of reception beams of the collection of linear combinations of reception beams, and performing beam selection measurements on the received linear combinations of transmission beams for selection of the transmission beam from the plurality of available transmission beams and for selection of the reception beam from the plurality of available reception beams. Methods for each of the transmitter apparatus and the receiver apparatus are also disclosed, as well as corresponding apparatuses, network node, wireless communication device, system and computer program product.

Approaches for beam selection

A method is disclosed for a transmitter apparatus configured to transmit signals to a receiver apparatus using a beam selected from a plurality of available beams, wherein a set of the plurality of available beams is for beam selection measurements by the receiver apparatus. The method comprises determining a collection of linear combinations of beams of the set, wherein the cardinality of the collection is lower than a cardinality of the set, and transmitting each of the linear combinations of beams for beam selection measurements by the receiver apparatus. A method is also disclosed for a receiver apparatus configured to receive signals from a transmitter apparatus via a beam selected from a plurality of available beams. The method comprises receiving a number of measurement signals for beam selection measurements from the transmitter apparatus, wherein the number of measurement signals correspond to a collection of linear combinations of beams of a set of the plurality of available beams, wherein the cardinality of the collection is lower than a cardinality of the set, and performing beam selection measurements on the number of measurement signals for selection of the beam from the plurality of available beams. Corresponding transmitter apparatus, receiver apparatus, network node, wireless communication device and computer program products are also disclosed.

There is provided mechanisms for mitigating interference in a communications network. A method is performed by a network node. The method comprises obtaining a packet. The packet has been wirelessly received in an uplink direction by a transmission and reception point of the network node and from a packet sender. The packet is indicative of scheduled transmission of a further packet within a predefined time interval from the transmission and reception point has wirelessly received the packet. The method comprises determining beamforming weights such that interference caused by transmission from the transmission and reception point of the network node in a downlink direction being reversed to the uplink direction is less than a threshold interference value. The method comprises initiating transmission in at least one beam using the determined beamforming weights. The beamforming weights are used for the transmission at least within the predefined time interval.

Interference mitigation in a communications network

A broadcast signal transmission occurs concurrently with device-specific, directional transmissions but without substantially interfering with the directional transmissions, based on transmitting the broadcast signal in the null spaces of the directional transmissions. Specifically, transmission of the broadcast signal relies on beamforming precoder values formed from one or more orthonormal basis vectors for the null space of a channel estimate matrix representing the channels between a multi-element antenna array and the wireless devices targeted by the device-specific transmissions. The approach concentrates most of the broadcast signal energy for each subcarrier on a single antenna element for good broadcast-signal coverage while still yielding a beamforming solution that substantially avoids broadcast-signal interference at the devices targeted for directional transmission.

Methods and apparatus for signal transmission and reception in a wireless communication network

A network node obtains, via a transmission and reception point (TRP) and from a terminal device not served by the network node, a packet comprising channel state information feedback indicating that a further packet is expected to be transmitted from the TRP on a downlink within a predefined time interval. The network node initiates transmission via the downlink of the TRP responsive to the channel state information feedback such that the transmission interferes with an uplink of the terminal device by less than a threshold amount during the predefined time interval.

Methods of a wireless communication node are disclosed. The methods are for mitigating interference caused during an upcoming downlink transmission by a second wireless communication access point to a first wireless communication station by one or more second wireless communication stations served by a first (neighboring) wireless communication access point, wherein the first wireless communication station is served by the second wireless communication access point. The one or more second wireless communication stations are adapted to communicate using a second frequency interval and the first wireless communication station is adapted to communicate using a first (smaller) frequency interval, comprised within the second frequency interval. In one aspect, a method of the first wireless communication access point comprises receiving (from the first wireless communication station) an indication signal indicative of the upcoming downlink transmission.

Interference mitigation for narrowband devices in wideband environments

A method is disclosed for a wireless communication device (WCD) configured to receive, using a combiner selected from a plurality of combiners available at the WCD, downlink transmissions from a wireless communication node (WCN) via a downlink transmission beam selected from a plurality of downlink transmission beams available at the WCN. The method comprises, for each of the plurality of combiners, estimating an interference level experienced at the WCD. The method also comprises transmitting a measurement signal on each of a plurality of uplink transmission beams for selection of the downlink transmission beam by the WCN. Each of the plurality of uplink transmission beams corresponds to a respective one of the plurality of combiners available at the WCD. A signal strength of the measurement signal on an uplink transmission beam is responsive to the estimated interference level for the corresponding combiner. Corresponding arrangement, WCD and computer program product are also disclosed.

Signal strength scaling of an uplink measurement signal and corresponding uplink transmission beam according to an estimated interference level

Determining timing of an OFDM signal comprises performing () an auto-correlation with a received signal, using a delay chosen to correspond to the duration of an OFDM symbol excluding the cyclic prefix, with the number of terms used in the summation in the correlation is at least as large as the smallest number of samples in any cyclic prefix of a subframe. Based on the auto-correlation, first and second correlation peaks meeting one or more predetermined detection criteria are detected (), and evaluated to determine () that they are separated in time by an interval corresponding to an OFDM symbol interval. The method further comprises identifying (), based on the two correlation peaks, one of the correlation peaks as corresponding to an OFDM symbol having a larger cyclic prefix than an adjacent OFDM symbol, and determining () a subframe and/or slot timing for the received signal, based on said identifying.

Detecting subframe timing in an OFDM licensed-assisted access signal

Embodiments herein relate to a method performed by a network node for enabling channel estimation in a wireless communications network. The wireless communications network includes at least a first and a second Access Point, AP, having overlapping cells using contention-based transmission resources of the same frequency. The first network node controls the first AP to transmit information indicating that wireless devices served by the first AP are not to contend for the contention-based transmission resources when the second AP is transmitting a Null Data Packet, NDP. Then, the first network node controls the second AP to transmit a NDP. Embodiments of the first network node are also described. Embodiments herein also relate to a method performed by a wireless device for enabling channel estimation in a wireless communications network, and embodiments of the wireless device.

Network node, a wireless device and methods therein for enabling channel estimations in a wireless communications network

The present disclosure relates to methods, a device and a system for evaluation of channel estimate. One method is performed in a first access point arranged to communicate with one or more wireless devices through information streams that are created using multiple co-located antennas. The method comprises transmitting or receiving a packet A, to/from, the first wireless device, wherein the packet A is transmitted using a precoder determined using the channel estimate, retrieving information about possibly interfering transmissions C between further access points in the vicinity of the first access point, and respective second wireless devices; wherein the information comprises location information and timing information related to the possibly interfering transmissions, determining spatial separations between the transmissions A and C and evaluating the channel estimate, based on the determined spatial separations.

Channel estimation evaluation in MIMO systems

Methods and apparatus for selecting between downlink beamforming training and uplink beamforming training for hybrid beamforming. The decision whether to perform downlink beamforming training or uplink beamforming training for hybrid beamforming can be used by a network node to reduce training overhead and increase system capacity. A selection value is computed, indicative of the relative costs of signaling overhead for downlink beamforming training and uplink beamforming training to support downlink transmissions by the network node to the group of wireless devices using hybrid beamforming. The selection between uplink beamforming training and downlink beamforming training is based on the selection value.

Mechanism for switching between uplink and downlink training in hybrid beamforming systems

A relay node in a mesh network receives a plurality of broadcasted path request (PREQ) messages. The relay node updates cluster information in a cluster table of the relay node based on the received PREQ messages. This cluster information identifies a cluster transmitter node and a list of cluster receiver nodes that describes a path from the cluster transmitter node to the relay node via the cluster receiver nodes. The relay node receives a Path Reply (PREP) message, and in response, transmits a modified PREP message created based on the received PREP message.

Path setup in a mesh network

One dimension (real or imaginary) is selected for each of a first plurality of devices that receives one-dimensional modulated complex signals from an access point (AP). The AP uses the selected dimension to generate a modulated complex signal for transmission to each such device, where the signal received by such devices is substantially free of inter-user interference on the dimension selected for the corresponding device. The AP then transmits the complex signal to the devices. As a result, the AP puts the modulated symbols received by of the first plurality of devices are received on either a real part or an imaginary part, but not both, and thus reduces the energy consumption associated with the transmission. Each of the first plurality of wireless devices considers either the real part or the imaginary part of the received signals.

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Lund, Sweden

Dzevdan Kapetanovic