A method and a test device for testing the CSI Type 2 channel estimation capability of a DUT are provided. The method includes: a) stimulating certain variance of PMI feedback values from the DUT, especially those belonging to the finer grained Type 2 CSI, b) a statistical collection of one or more PMI reports received through CSI reporting from the DUT during the test execution, c) an identification of Type 1/Type 2 PMI feedback type based on the CSI reports received from the DUT, and d) applying a pass criterion: a minimum threshold of Type 2 specific feedback reports must have been received.

A method and apparatus are provided, where a data sequence for transmission is identified (1002) as part of evaluating transmitter performance involving multiple physical antennas. The data sequence is mapped (1004) to the multiple physical antennas to be involved in the transmission. The data sequence is then transmitted (1006) using the multiple physical antennas from which a signal quality metric of a transmitter corresponding to a difference between a received signal associated with the transmission of each respective data symbol of the data sequence and a respective ideal location of a predefined constellation point associated with the data symbol that was transmitted can be determined, wherein an error vector magnitude involving an aggregated difference associated with the data sequence involving the transmission via the multiple physical antennas is determined.

A wireless device (14) receives a downlink reference signal (24) from a radio network node (12) over a downlink channel (16), and determines channel information (28) based on measurement of the downlink reference signal (24). The wireless device (14) then transmits, to the radio network node (12) over an uplink channel (18), an uplink signal (30) that implicitly conveys the determined channel information (28). The radio network node (12) jointly (i) identifies which candidate uplink signal in a set (32) of candidate uplink signals (30-1 . . . 30-N) is received; and (ii) determines an estimate (42) of the uplink channel (18) from the received uplink signal (30). The radio network node (12) determines the channel information (28) implicitly conveyed by the identified candidate uplink signal, and then determines an estimate (22) of the downlink channel (16) based on the determined channel information (28) and the determined estimate (42) of the uplink channel (18).

Disclosed are a user detection technique, and a method and apparatus for channel estimation in a wireless communication system supporting massive multiple-input multiple-output. The method comprises the steps of: receiving a superimposed signal including a transmission signal of at least one user equipment (UE) from among a plurality of user equipments, wherein each transmission signal includes a pilot signal of a corresponding user equipment; calculating a sample covariance matrix from the received superimposed signal by using the number of antennas of a base station and a pilot signal matrix of the at least one user equipment; calculating a likelihood function indicating the likelihood probability of the received superimposed signal, on the basis of the number of antennas of the base station and the received superimposed signal; detecting a user index set indicating whether or not the plurality of user equipments have transmitted signals, by using the calculated likelihood function and sample covariance matrix; and performing channel estimation of the at least one user equipment that is transmitting the signal, on the basis of the detected user index set.

A method, apparatus and computer readable medium are provided for determining position information of a receiver device. The method includes determining a plurality of beams and combining received multipath signals from the plurality of the beams. The received multipath signals are generated by a transmitter device. The method also includes determining, based at least in part on the combined received multipath signals, a line of sight signal and determining, based at least in part on the line of sight signal, position information of a receiver device.

Embodiments of this application disclose methods and apparatuses for obtaining channel parameters. In an implementation, a method includes, sending, by a network device, a precoded reference signal and indication information indicating K selected frequency domain bases, wherein the precoded reference signal is generated on P ports by mapping K virtual ports associated with the K selected frequency domain bases to each of the P ports through beamforming, wherein K is an integer greater than 1, and wherein the P ports are precoded channel state information reference signal (CSI-RS) ports of the network device and user equipment, and receiving, by the network device, a linear superposition coefficient sent by the user equipment, wherein the linear superposition coefficient corresponds to M frequency domain bases in the K selected frequency domain bases and T ports in the P ports, wherein 1≤T≤P, and 1≤M≤K.

Aspects of the subject disclosure may include, for example, obtaining channel cross correlation data relating to multiple user equipment (UEs) being served in a cell, wherein the channel cross correlation data comprises a correlation coefficient associated with a first UE of the multiple UEs and a second UE of the multiple UEs, identifying that the first UE is experiencing decreasing throughput, responsive to the identifying that the first UE is experiencing decreasing throughput, determining whether the correlation coefficient associated with the first UE and the second UE satisfies a correlation threshold, and, based on a first determination that the correlation coefficient does not satisfy the correlation threshold, adjusting a downlink (DL) transmit power allocation for transmissions directed to the first UE. Other embodiments are disclosed.

In some embodiments, a method for mitigating interference in a channel having multiple users includes: transmitting, by a transmitter, a signal of interest (SOI) to a sequential interference cancellation (SIC) receiver at a transmit power; determining a packet drop rate as seen by the receiver; and decreasing the transmit power in response to determining the packet drop rate exceeds a predetermined maximum packet drop rate. The transmitter's coding rate and/or modulation level may also be lowered based on the decrease in transmit power.

In one embodiment, an electronic device may include a plurality of antennas, at least one wireless communication module configured to transmit and receive wireless signals through the plurality of antennas, and at least one processor operatively connected to the wireless communication module. The at least one wireless communication module or the at least one processor may be configured to, based on one or more ultra-wide band (UWB) signals received from a target device, obtain first pieces of phase information corresponding to first channel impulse response (CIR) indices and second pieces of phase information corresponding to second CIR indices, and determine information on the one or more UWB signals based on a slope between the first pieces of phase information and a slope between the second pieces of phase information.

Systems, methods, and devices to reduce the channel estimation overhead by collecting data from many UEs and building a location-based mathematical model are disclosed. During building of the model, a reference signal is used to collect location- and signal-related data from connected UEs. Once the model is successfully built, it is then transmitted and/or downloaded to each new UE that connects to the base station. The UEs and/or the base stations then use this model to determine their own transmission parameter values. The UEs also report their location to the base stations, which use the model to estimate channel conditions and adapt transmission parameters for themselves.