Telefonaktiebolaget Lm Ericsson (publ)

Mohammadreza Malek-Mohammadi

Karl Werner

Niklas Jaldén

Bo Lincoln

Amin Azari

Cicek Cavdar

A method performed by a first network entity () for authenticating an event in a communications network () is provided. The first network entity () is configured to receive an event signal. The first network entity () is also configured to authenticate the event if the received event signal correlates with an 5 output signal of a closed-loop shift register in the first network entity (). Furthermore, the first network entity () is configured to trigger a change in the closed-loop shift register in order to obtain a subsequent output signal from the closed-loop shift register. A first network entity () for authenticating an event is also provided. Further, a wake-up receiver circuit () comprising the first network entity 10 () is provided, as well as, a wireless device () comprising the wake-up receiver circuit (). Furthermore, a second network entity () and a method therein for authenticating an event in at least one first network entity () in a communications network () are also provided. Also, a radio base station comprising the second network entity () is provided, as well as, 15 computer programs and communications networks.

Network entities, methods, apparatuses and communications networks for authenticating an event

Systems and methods for coverage enhanced reciprocity-based precoding schemes are provided. In some embodiments, a method performed by a base station for determining precoding information includes: determining channel estimates for at least a channel between the wireless device and another device; determining a plurality of precoding hypotheses based on the channel estimates; determining a figure of merit for each of the plurality of precoding hypotheses; and determining the precoding information based on the figure of merit for each of the plurality of precoding hypotheses. In some embodiments, this precoding method enables the use of reciprocity-based precoding down to a lower Signal to Noise Ratio, SNR, than what existing state of the art reciprocity-based precoding can offer.

Coverage enhanced reciprocity-based precoding scheme

A channel matrix representing characteristics of a multi-path channel between a transmitter device () equipped with multiple transmitter antennas () and at least one receiver device () equipped with one or more receiver antennas (). The channel matrix is organized in one or more channel vectors each associated with a corresponding one of the one or more receiver antennas (). An iterative optimization algorithm is applied to determine a precoding matrix from the channel matrix. At least one step size of the iterative optimization algorithm is set depending on a vector norm of at least one of the channel vectors. Multi-antenna transmission by the transmitter device () is then controlled based on the determined precoding matrix.

Channel-matrix dependent step size for iterative precoding matrix calculation

A channel matrix representing characteristics of a multi-path channel between a transmitter device () equipped with multiple transmitter antennas () and a receiver device () equipped with multiple receiver antennas () is determined. The channel matrix is organized in a first number of channel vectors each associated with a different one of the multiple receiver antennas (). The channel vectors are combined to a smaller second number of linear combinations of the channel vectors and a reduced channel matrix is composed from the linear combinations of the channel vectors. A precoding matrix is determined based on the reduced channel matrix, and multi-antenna transmission by the transmitter device is controlled based on the determined precoding matrix.

Channel-matrix reduction for precoding control

A reciprocity-based precoding algorithm is provided that accommodates for the specific type of uncertainty arising from the delay in channel estimation as a function of the velocity of moving wireless communication devices (-). Account is taken of time delay from reference symbols previous sounding times as well as the velocity of the wireless communication devices (-) thereby providing an effective precoding scheme for beamforming.

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Sollentuna, Sweden

Mohammadreza Malek-Mohammadi