Methods, systems, and devices for wireless communications are described. A user equipment (UE) having partially coherent antennas may be configured for simultaneous transmissions on groups of antennas To achieve the benefits of simultaneous transmissions using groups of antenna that are partially coherent, without having the transmissions affect each other, the UE may apply a hybrid closed-loop multiple-input multiple-output (MIMO) scheme among each antenna in the antenna groups where phase coherence can be maintained Following the hybrid closed-loop MIMO scheme, the UE may apply a transparent diversity scheme across each antenna of the groups. Alternatively, the UE may first apply the transparent diversity scheme and next apply the hybrid closed-loop MIMO scheme. By applying a hybrid closed-loop MIMO scheme, and a transparent diversity scheme, the UE may fully realize its resources and contribute to an improved spatial diversity for a MIMO system.

Methods, systems, and devices for wireless communications are described. A user equipment (UE) having partially coherent antennas may be configured for simultaneous transmissions on groups of antennas. To achieve the benefits of simultaneous transmissions using groups of antenna that are partially coherent, without having the transmissions affect each other, the UE may apply a hybrid closed-loop multiple-input multiple-output (MIMO) scheme among each antenna in the antenna groups where phase coherence can be maintained Following the hybrid closed-loop MIMO scheme, the UE may apply a transparent diversity scheme across each antenna of the groups. Alternatively, the UE may first apply the transparent diversity scheme and next apply the hybrid closed-loop MIMO scheme. By applying a hybrid closed-loop MIMO scheme, and a transparent diversity scheme, the UE may fully realize its resources and contribute to an improved spatial diversity for a MIMO system.

Certain aspects of the present disclosure provide techniques for precoding for multi-panel uplink transmission. For codebook-based uplink transmission, a user equipment (UE) can determine one or more preferred or selected precoders for uplink transmission. The precoders can be from an expanded UE codebook that maps a first number of transmit layers at the UE to a second number of antenna ports at the UE, the layers and/or antenna ports associated with multiple uplink transmit panels at the UE. The UE sends an indication to a base station (BS) of the determined precoders and/or sends an uplink transmission using the determined precoders. For non-codebook based uplink transmission the UE receives first and second reference signals (RSs), from first and second ports of a BS, with first and second UE antenna panels. The UE computes precoders to use for uplink transmission based on the RSs.

Aspects of the subject disclosure may include, for example, causing a reference antenna element of a first set of antenna elements of a first antenna array to transmit a first signal, determining for each antenna element of a second set of antenna elements of a second antenna array, a receive-related offset, relative to the reference element, based on inter-element propagation delays between the first and second sets of elements, causing each antenna element of the second set of elements to transmit a respective second signal, based on the reference antenna element receiving the respective second signals, calculating a respective transmit-related offset for each antenna element of the second set of antenna elements relative to the reference antenna element based on the inter-element propagation delays, and performing calibration between the first antenna array and the second antenna array based on the respective receive-related and transmit-related offsets. Other embodiments are disclosed.

A wireless device may support a plurality of channel state information (CSI) processes. The wireless device may send an indication of a number of supported CSI processes to a first base station. The first base station may send to the wireless device a handover command, instructing the wireless device to handover to a second base station. The handover command may comprise configuration parameters for CSI processes associated with the second base station. The configuration parameters may be based on the number of CSI processes supported by the wireless device.

A method for transmitting channel state information performed by a User Equipment (UE) may include receiving, from a base station, a bitmap for configuring codebook subset restriction (CSR) and reporting, to the base station, Channel State Information (CSI), when a number of antenna ports is configured as 16 or more and a number of layers associated with a rank indicator (RI) in the CSI is 3 or 4, a unit of multiple bits in a bitmap for configuring the CSR is associated with each precoder, and a reporting of precoding matrix indicator (PMI) corresponding to the precoder associated with the multiple bits is restricted in the CSI, when the CSR is indicated in any one of the multiple bits, and each bit in the bitmap for configuring the CSR is associated with each precoder.

A User Equipment (UE) receives, from a network node, codebook subset restriction (CBSR) signaling comprising a bitmap. The bitmap comprises a plurality of sets and each set comprises a plurality of bits. Each of the bits indicates whether a respective vector in a first set of vectors is restricted. Each set of bits indicates whether a respective vector in a second set of vectors is restricted. The UE restricts precoders selectable from a plurality of codebooks based on either a first vector in the first set of vectors or a second vector in the second set of vectors being indicated as restricted.

A terminal apparatus mounted on a movable body is provided to communicate with an external communication apparatus outside the movable body. The terminal apparatus includes an antenna, and a communicator device. The antenna includes a plurality of antenna elements to be arranged along a traveling direction of the movable body. The communicator device is configured to communicate with the external communication apparatus using a communicating antenna element that is at least one of the plurality of antenna elements. The communicating antenna element is selected from the plurality of antenna elements so as to belong to a specified region. The specified region is defined by propagation environment information of an electric wave propagation path of a signal transmitted to and received from the external communication apparatus.

Embodiments of the present disclosure provide a method of processing received signal using a massive MIMO base station (BS). The BS comprises a radio unit (RU), a distributed unit (DU) and an interface. The method comprises receiving a plurality of signals corresponding to the plurality of antennas, said signals comprises at least one of data signals, demodulation reference signals (DMRS) and sounding reference signals (SRS). The RU or DU performs a grouping operation on a subset of the plurality of signals corresponding to a subset of antennas to generate signal groups. The RU performs a first stage filtering on the signals associated with each group using group specific filters to obtain group specific filtered signals. The DU performs a second stage filtering on the group specific filtered signals to obtain second stage filtered signals.

Aspects of the subject disclosure may include, for example, receiving sounding reference signal (SRS) symbols from antenna elements of each of multiple modular antenna arrays, wherein the multiple modular antenna arrays are operatively combined to form a coherent antenna system, performing an uplink (UL) channel estimation and a downlink (DL) channel estimation, across a plurality of physical resource blocks (PRBs), based on the SRS symbols, calculating, for the antenna elements, a plurality of uplink (UL) combining weights based on the UL channel estimation and a plurality of downlink (DL) precoder weights based on the DL channel estimation, and causing the plurality of UL combining weights and the plurality of DL precoder weights to be applied to the antenna elements, thereby adjusting beamforming of the coherent antenna system. Other embodiments are disclosed.