A base station may transmit to a device an indication of codebook subset restriction (CBSR), which includes at least a restriction on a frequency basis. The device may receive the indication of CBSR, and may transmit to the base station channel state information (CSI) according to the received indication of CBSR. The indication of CBSR may also include a restriction on a spatial basis and restrict the device from reporting the CSI based on a subset of the frequency basis in addition to the spatial basis per configuration of the base station. The indication of CBSR may include a separately configured maximum allowed amplitude of a weighting coefficient for the spatial basis and the frequency basis, where the weighting coefficient is associated with a column vector of a precoding matrix used by the base station and the device. The number of frequency bases and the frequency compression units may be determined based on a number of different criteria, for example the number of antennas, the number of subbands, etc.

A user equipment (UE) for channel state information (CSI) feedback comprises a transceiver configured to receive, from a base station (BS), configuration information for the CSI feedback, the configuration information indicating a number of antenna panels (N.sub.g) at the BS and a codebook mode, wherein N.sub.g>1 and each of the antenna panels comprises antenna ports with a first polarization (P.sub.1) and antenna ports with a second polarization (P.sub.2). The UE further comprises a processor operably connected to the transceiver, the processor configured to identify the number of antenna panels (N.sub.g) at the BS, identify a codebook for the CSI feedback based on the codebook mode configured between a first codebook mode and a second codebook mode, and generate the CSI feedback using the identified codebook. The transceiver is further configured to transmit the generated CSI feedback to the BS.

Aspects of the subject disclosure may include, for example, obtaining, over an uplink (UL) using an aggregation of modular antenna arrays, a modulated signal that includes feedback transmitted by a user equipment (UE), wherein the aggregation of modular antenna arrays comprises multiple groups of antenna elements, after the obtaining the modulated signal, performing a demodulation of the modulated signal, determining demodulator constellation errors from the demodulation of the modulated signal, performing an error gradient weight adaptation responsive to the determining the demodulator constellation errors to derive revised weights for various antenna elements of the multiple groups of antenna elements, and applying the revised weights to the various antenna elements of the multiple groups of antenna elements to adjust signals received over the UL. Other embodiments are disclosed.

A signal generation method is used in a transmission device that transmits a plurality of transmission signals from a plurality of antennas at the same frequency and at the same time, in the case where larger power change is performed on a first transmission signal than on a second transmission signal during generation process of the first transmission signal and the second transmission signal, the first transmission signal and the second transmission signal are mapped before the power change such that a minimum Euclidian distance between possible signal points for the first signal is longer than a minimum Euclidian distance between possible signal points for the second signal.

A vehicular communication device is mounted on a vehicle and includes antenna elements, and a wireless circuit connected to the antenna elements and performing communication with another device using the antenna elements. Each antenna element of the antenna elements has a feeding point and a feeding direction in which the antenna element extends from the feeding point. The antenna elements include two antenna elements that are separated by a distance less than a predetermined coupling distance. Feeding directions of the two antenna elements are perpendicular to each other.

A method includes receiving (402) a plurality of reference signals (301-303) at an antenna port of a communication device (101). Each reference signal (301-303) is sent using a corresponding precoder. The precoder is selected from a first set of precoders. The method further includes determining (403) a channel estimate based on the received plurality of reference signals (301-303), and selecting (404) a precoder from a second set of precoders based on the determined channel estimate. The second set of precoders comprises at least one precoder in addition to the precoders of the first set of precoders. The method includes sending (405) an indication (304) relating to the selected precoder.

An object of the present disclosure is to provide a beamforming method for a massive MIMO system. Specifically, S routes of data streams to be transmitted via the antenna array are subjected to horizontal direction baseband beamforming processing, to obtain T routes of data streams; the T-routes of data streams are subjected to vertical direction digital beamforming processing to map the T routes of data streams onto a corresponding channel according to a predetermined rule; a data stream on each channel is subjected to analog beamforming processing to map the data stream on each channel onto a corresponding array element of the antenna array for transmission. Compared with the prior art, the present disclosure implements the following advantages: by combining the advantages of RF beamforming with the BB beamforming with limited antennas at the FH, a good flexibility regarding BB algorithm selection and RF beam design is provided, which balances the complexity and performance between BB and RF and implements a massive MIMO in sub-6 GHz.

A non-personal basic service set control point/access point (non-PCP/AP) communication apparatus includes a reception circuit, an estimation circuit, and a transmission circuit. The reception circuit receives a Directional Multi-Gigabit (DMG) Beacon frame including a sector sweep (SSW) field, the SSW field including a Parameter subfield indicating a value obtained by using a transmission Equivalent Isotropic Radiated Power (EIRP) of a PCP/AP communication partner apparatus and a reception antenna gain of the PCP/AP communication partner apparatus. The estimation circuit estimates an expected reception power at the PCP/AP communication partner apparatus by using the value of the Parameter subfield, and checks inequality between the estimated expected reception power and a receiver sensitivity value. The transmission circuit transmits a frame for Association Beamforming Training (A-BFT) if the estimated expected reception power is larger than the receive sensitivity value.

A method by a terminal, a method by a base station, a terminal, and a base station are provided. The method by the terminal includes receiving a first channel state information reference signal (CSI-RS) and a second CSI-RS from a base station; generating channel state information (CSI) based on both the first CSI-RS and the second CSI-RS; and reporting the CSI to the base station, wherein the CSI includes a rank indicator (RI) and a channel quality indicator (CQI).

A network node signals to a wireless communication device which precoders in a codebook are restricted from being used. The network node in this regard generates codebook subset restriction signaling that, for each of one or more groups of precoders, jointly restricts the precoders in the group by restricting a certain component (e.g., a certain beam precoder) that the precoders in the group have in common. This signaling may be for instance rank-agnostic signaling that jointly restricts the precoders in a group without regard to the precoders transmission rank. Regardless, the network node sends the generated signaling to the wireless communication device.