The present invention discloses methods and apparatuses for quantizing, and feeding back channel information and precoding data. In the above methods, a channel measurement pilot signal is received from a base station. The channel information is acquired by performing channel measurement according to the channel measurement pilot signal. CMatrix1 and CMatrix2 are calculated using the channel information, herein CMatrix1 and CMatrix2 are used to quantize the channel information or indicate the base station to perform precoding. And first indication information of CMatrix1 and/or second indication information of CMatrix2 are fed back to the base station. According to the technical solutions of the present invention, as the influence of the polarization leakage is considered in the feedback design, a significant performance gain exists in a case that the polarization leakage actually occurs.

Method performed by a UE for providing a channel state information (CSI) feedback in a wireless communication system including at least the UE and a gNB or a radio network node. The UE is operative to: estimate the MIMO channel between the gNB and the UE based on received DL reference signals for the configured resource blocks. The UE is further operative to calculate, based on a performance metric, a precoder matrix, for a number of antenna ports of the gNB and configured subbands, the precoder matrix being based on two codebooks and a set of combination coefficients for complex scaling/combining one or more of vectors selected from a first codebook and a second codebook, and the UE is operative to report a CSI feedback and/or a PMI and/or a PMI/RI, to the gNB, used to indicate the precoder matrix for the configured antenna ports and resource blocks.

Components, systems, and methods for reducing location-based interference in distributed antenna systems operating in multiple-input, multiple-output (MIMO) configuration are disclosed. Interference is defined as issues with received MIMO communications signals that can cause a MIMO algorithm to not be able to solve a channel matrix for MIMO communications signals received by MIMO receivers in client devices. These issues may be caused by lack of spatial (i.e., phase) separation in the received MIMO communications signals. Thus, to provide phase separation of received MIMO communication signals, multiple MIMO transmitters are each configured to employ multiple transmitter antennas, which are each configured to transmit in different polarization states. In certain embodiments, one of the MIMO communications signals is phase shifted in one of the polarization states to provide phase separation between received MIMO communication signals. In other embodiments, multiple transmitter antennas in a MIMO transmitter can be offset to provide phase separation.

The present invention relates to a wireless communication system and, more specifically, to a method and an apparatus for reporting channel status information (CSI). Particularly, the method by which a terminal in the wireless communication system reports the CSI, comprises the steps of: receiving a reference signal from a base station; and reporting, to the base station, the CSI generated by using the reference signal, wherein the CSI includes channel information for a plurality of antenna ports mapped according to a first parameter, and the first parameter is a value related to vertical domain antenna ports indicated through upper layer signaling.

A transmitting radio node (10) precodes a transmission from an antenna array (12)to a receiving radio node (50). The array (12) includes co-polarized antenna elements (14) aligned in a given spatial dimension of the array (12). The transmitting radio node (10) precodes the transmission from different subarrays (34a, 34b) of the antenna elements (14) using respective coarse-granularity precoders that are factorizable from a multi-granular precoder targeting the given spatial dimension of the array (12) at different granularities, so as to virtualize the subarrays (34a, 34b) as different auxiliary elements (38a, 38b). The transmitting radio node (10) also precode the transmission from the different auxiliary elements (38a, 38b) using one or more finer-granularity precoders that are also factorizable from the multi-granular precoder. In this case, the coarse granularity precoders and the one or more finer-granularity precoders are represented within one or more codebooks (26) used for said precoding

Apparatuses, methods, and systems are disclosed for preparing channel state information (“CSI”). One apparatus includes a processor and a transceiver configured to communicate with a base unit over a radio access network using at least one transmission layer and determining a total number of non-zero coefficients over a set of layers. The processor determines an indication of the total number of non-zero coefficients, where determining the indication of the total number of non-zero coefficients comprises encoding the total number of non-zero coefficients by selecting a codeword from a plurality of candidate codewords. The processor prepares CSI, where the CSI comprises the indication of the total number of non-zero coefficients and the transceiver transmits the CSI to the base unit.

An antenna arrangement (1) comprising a dual polarized antenna array (10) and a reconfigurable feed network (17) connected thereto is provided. The dual polarized antenna array (10) comprises a number of radiating antenna elements and the reconfigurable feed network (17) comprises switching means (20) for switching the feed network (17) between: a first mode providing single polarization beamforming, SPBF, in which first mode the feed network (17) is arranged such as to connect all antenna elements having a first polarization P1 to a first port, A, and all antenna elements having a second polarization P2 to a second port, B, and a second mode providing dual-polarization beamforming, DPBF, in which second mode the feed network (17) connects a part of all antenna elements having a first polarization P1 and a part of all antenna elements having a second polarization to the first port, A, and a remaining part of all antenna elements having the first polarization P1 and the remaining part of all antenna elements having the second polarization P2 to the second port, B. A method (30), computer program (42) and computer program product (41) are also provided.

This application provides a communication method, a communications apparatus, and a system. The method may include receiving, by a terminal device, a first group of precoded reference signals and a second group of precoded reference signals. The method may also include feeding back first indication information based on a channel state information (CSI) feedback-based transmission scheme, where the first indication information is used to determine a plurality of precoding vectors, at least one of the plurality of precoding vectors is determined by using the first group of precoded reference signals, and at least one of the plurality of precoding vectors is determined by using the second group of precoded reference signals.

Systems and methods are disclosed herein for correcting beam weighting factors for a radio system that uses transmit and/or receive beamforming in such a manner as to correct for self-coupling between antenna elements. In some embodiments, a radio system comprises an antenna system and a processing unit associated with the antenna system. The processing unit is adapted to obtain measurements of cross-polarization transfer functions between respective pairs of dual-polarized antenna elements in the antenna system and compute coupling values for respective pairs of the antenna elements and reflection coefficient values by numerically solving a system of equations in which a subset of the coupling values are set to zero. The processing unit is further adapted to compute correction factors for the antenna elements based on the computed values and calculate beam weighting factors for at least some of the antenna elements based on the respective correction factors.

An ultra-wideband (UWB) beam forming system is disclosed. In one or more embodiments, the UWB beam forming system includes a plurality of radiating elements forming a circular, cylindrical, conical, spherical, or multi-faceted array and a beamformer coupled to the radiating elements. The beamformer includes one or more transformable reconfigurable integrated units (TRIUNs) configured to independently control individual radiating elements or groups of radiating elements of the plurality of radiating elements.