Embodiments of the present disclosure relate to methods and devices for channel state information (CSI) transmission. In example embodiments, a method implemented in a terminal device includes performing a channel estimate between the terminal device and a network device across a predetermined frequency range for a set of beams having different spatial directions; determining, based on the channel estimate, first indication information indicating at least one beam selected from the set of beams and second indication information indicating frequency-related information for the at least one selected beam at a plurality of frequency locations in the predetermined frequency range; and transmitting to the network device the first indication information in a first part of a channel state information (CSI) report and the second indication information in a second part of the CSI report.

Embodiments of the present disclosure relate to methods and devices for channel state information (CSI) transmission. In example embodiments, a method implemented in a terminal device includes performing a channel estimate between the terminal device and a network device across a predetermined frequency range for a set of beams having different spatial directions; determining, based on the channel estimate, first indication information indicating at least one beam selected from the set of beams and second indication information indicating frequency-related information for the at least one selected beam at a plurality of frequency locations in the predetermined frequency range; and transmitting to the network device the first indication information in a first part of a channel state information (CSI) report and the second indication information in a second part of the CSI report.

A method is provided for channel sounding in a wireless local area network. A responding station receives a null data packet announcement (NDPA) frame and a null data packet (NDP) frame for the channel sounding from a requesting station. The NDP frame follows the NDPA frame. The responding station receives a first poll frame from the requesting station. In response to the first poll frame, the responding station transmits a first feedback data field including beamforming feedback information and signal to noise ratio (SNR) information to the requesting station. The responding station receives a second poll frame including a segment retransmission bitmap field indicating at least one segment of the first feedback data field from the requesting station. In response to the second poll frame, the responding station transmits a second feedback data field including the at least one segment of the first feedback data field to the requesting station.

Provided is a precoding method for generating, from a plurality of baseband signals, a plurality of precoded signals to be transmitted over the same frequency bandwidth at the same time, including the steps of selecting a matrix F[i] from among N matrices, which define precoding performed on the plurality of baseband signals, while switching between the N matrices, i being an integer from 0 to N−1, and N being an integer at least two, generating a first precoded signal z1 and a second precoded signal z2, generating a first encoded block and a second encoded block using a predetermined error correction block encoding method, generating a baseband signal with M symbols from the first encoded block and a baseband signal with M symbols the second encoded block, and precoding a combination of the generated baseband signals to generate a precoded signal having M slots.

Provided is a precoding method for generating, from a plurality of baseband signals, a plurality of precoded signals to be transmitted over the same frequency bandwidth at the same time, including the steps of selecting a matrix F[i] from among N matrices, which define precoding performed on the plurality of baseband signals, while switching between the N matrices, i being an integer from 0 to N−1, and N being an integer at least two, generating a first precoded signal z1 and a second precoded signal z2, generating a first encoded block and a second encoded block using a predetermined error correction block encoding method, generating a baseband signal with M symbols from the first encoded block and a baseband signal with M symbols the second encoded block, and precoding a combination of the generated baseband signals to generate a precoded signal having M slots.

Systems and methods for passive dynamic geofencing on a mobile device are discussed. For example, a method for passive dynamic geofencing can include operations such as monitoring a first parent geofence and a first plurality of child geofences; detecting crossing a boundary of the first parent geofence into a second parent geofence; loading the second parent geofence and a second plurality of child geofences encompassed by the second parent geofence; and monitoring the second parent geofence and the second plurality of child geofences.

According to one of the aspects, there is provided a method for providing channel state feedback related to a wireless link between a transmitter having multiple transmit antennas and a receiver having at least one receive antenna. The method comprises determining (S1) channel estimates for at least a subset of the effective channels between the transmitter and the receiver, each effective channel including a propagation channel, and signal paths in the transmitter and the receiver. The method also comprises determining (S2) frequency-independent and/or inter-antenna-independent channel state information associated with phase relaxation of at least the subset of the effective channels based on the channel estimates, and generating (S3) channel state feedback including at least a representation of the frequency-independent and/or inter-antenna-independent channel state information associated with the phase relaxation. The method further comprises transmitting (S4) the channel state feedback to the transmitter.

According to one of the aspects, there is provided a method for providing channel state feedback related to a wireless link between a transmitter having multiple transmit antennas and a receiver having at least one receive antenna. The method comprises determining (S1) channel estimates for at least a subset of the effective channels between the transmitter and the receiver, each effective channel including a propagation channel, and signal paths in the transmitter and the receiver. The method also comprises determining (S2) frequency-independent and/or inter-antenna-independent channel state information associated with phase relaxation of at least the subset of the effective channels based on the channel estimates, and generating (S3) channel state feedback including at least a representation of the frequency-independent and/or inter-antenna-independent channel state information associated with the phase relaxation. The method further comprises transmitting (S4) the channel state feedback to the transmitter.

This invention presents methods for estimating the uplink SINR and channel estimation error level in MU-MIMO wireless communication systems comprising the BS obtaining the channel coefficients between each receiving antenna of a BS and a transmitting antenna of a UE in the uplink; for the BS estimating the SU-MIMO SINR of a UE using the channel coefficients between a UE and the BS; for the BS estimating the channel estimation error level of a UE using the channel coefficients between a UE and the BS.

This invention presents methods for estimating the uplink SINR and channel estimation error level in MU-MIMO wireless communication systems comprising the BS obtaining the channel coefficients between each receiving antenna of a BS and a transmitting antenna of a UE in the uplink; for the BS estimating the SU-MIMO SINR of a UE using the channel coefficients between a UE and the BS; for the BS estimating the channel estimation error level of a UE using the channel coefficients between a UE and the BS.