A system and method for uplink multi-antenna power control in a communications system are provided. A method for user equipment operations includes determining a transmit power level for transmit antennas of the user equipment having at least two transmit antennas, and setting a power amplifier output level for each of the at least two transmit antennas in accordance with a respective transmit power level.

An operating method of a wireless communication device includes calculating an effective channel matrix between the wireless communication device and a base station based on transmission characteristic information and channel information, the transmission characteristic information corresponding to the wireless communication device, and the channel information corresponding to a channel between the wireless communication device and the base station, determining a precoding matrix based on the effective channel matrix, and determining a transmission beamforming vector based on the precoding matrix.

Embodiments of the disclosure provide methods and apparatuses for three-dimensional beamforming. The method may comprise: mapping vertical virtual antenna ports to physical antenna ports based on vertical reference signals to obtain mapped vertical reference signals; transmitting the mapped vertical reference signals to a user equipment; receiving a tilting indicator from the user equipment, wherein the tilting indicator is obtained based on the mapped vertical reference signals at the user equipment; determining a tilting vector based on the received tilting indicator, wherein the tilting vector indicates adjustment for traffic data in antenna vertical tilting; and adjusting traffic data with the tilting vector.

A system includes a direct radiating array antenna and one or more processors. The antenna includes an array of elements configured to radiate radiofrequency (RF) energy to form a beam having multiple frequency channels. The one or more processors are configured to generate an excitation plan for powering the elements to form the beam. The excitation plan assigns multiple corresponding beamforming coefficients to each element in a group of the elements. Each beamforming coefficient designates power allocated to the assigned element for radiating RF energy at an associated frequency channel. The excitation plan provides a substantially uniform power distribution among the elements in the group, and at least some of the elements in the group have different allocations of power among the multiple frequency channels of the beam than other elements in the group.

The present disclosure provides an omnidirectional beamforming method. In the omnidirectional beamforming method, a space-time block coding is performed on a data stream to be sent to obtain the coded data stream. Omnidirectional beamforming matrices corresponding to a uniform rectangular antenna array are constructed. The beamforming is performed on the coded data stream through the omnidirectional beamforming matrices, to generate a signal to be sent of the uniform rectangular antenna array.

A method for transmitting an uplink signal based on a codebook by a UE in a wireless communication system includes: receiving, from a base station, downlink control information (DCI) for determining a precoding matrix applied to transmission of the uplink signal; determining the precoding matrix applied to the transmission of the uplink signal from a codebook subset related to the transmission of the uplink signal based on the DCI; and transmitting, to the base station, the uplink signal based on the determined precoding matrix, I which based on that a difference between phase values applied to antenna ports for the transmission of the uplink signal is maintained in some antenna ports among all antenna port pairs, the codebook subset includes at least one specific precoding matrix applying different phase values to antenna ports included in all or some of the some antenna ports.

One or more elements of a communication system receives a first indicator that a first wireless device is within a first coverage area of a first access node and is also within a second coverage area of a second access node. The first access node and the second access node are both configured to provide a multi-user multiple-input multiple-output (MU-MIMO) operating mode. The communication system determines a first number of wireless devices attached to the first access node that are utilizing the MU-MIMO operating mode. The communication system identifies the first wireless devices as being configured as a relay node. The communication system, based on the first number meeting a first threshold, instructs the first wireless device to attach to the second access node.

Beamforming methods and systems include determining a tradeoff curve between scanning beamwidth and transmission beamwidth based on a channel distribution for a base station. A set of scanning beams is selected based on the tradeoff curve. Devices around the base station are scanned for using the set of scanning beams. A set of transmission beams is selected for communications with the devices based on information received during the scanning. The set of transmission beams are used for transmission with a beamforming transmitter.

Disclosed is an apparatus and a method of deriving an optimal precoder, in which a precoder is derived using water filling power allocation, and then is multiplied with some unitary matrix satisfying certain conditions to meet a per layer power constraint. Since the multiplication with the unitary matrix does not change the capacity, the derived precoder is optimal in achieving maximum capacity in a multiple input multiple output (MIMO) wireless communication scheme.

In a closed-loop wireless communication system, a codebook-based feedback mechanism is provided to enable non-unitary precoding for multi-stream transmission, where each stream is optimized with suitable transmission power allocation and AMC. The codebook-based feedback mechanism uses a precoding codebook having a power allocation matrix which is constrained to specify that beamforming always applies full power to a predetermined beam. With this constraint, a one-bit power allocation feedback index may be used to switch between beamforming and spatial multiplexing.