Example communications methods and apparatus are described. One example method includes generating a first signal by a base station. The base station performs cyclic delay diversity (CDD) weighted processing on the first signal to obtain a second signal, and performs densified beam weighted processing on the second signal to obtain a third signal. The third signal is sent by the base station via an antenna. According to the foregoing method, the CDD weighted processing is performed on the first signal generated by the base station, so that time diversity can be obtained when the first signal is transmitted. In addition, the densified beam weighted processing is performed on the second signal obtained after the CDD weighted processing, so that a quantity of beams scanned by the base station can be increased.

Provided are M signal processors that respectively generate modulated signals for M reception apparatuses (where M is an integer equal to 2 or greater), a multiplexing signal processor, and N antenna sections (where N is an integer equal to 1 or greater). When transmitting multiple streams, each of the M signal processors generates two mapped signals, generates first and second precoded signals by precoding the two mapped signals, periodically changes the phase of signal points in the IQ plane with respect to the second precoded signal, outputs the phase-changed signal, and outputs the first precoded signal and the phase-changed second precoded signal as two modulated signals. When transmitting a single stream, each of the M signal processor outputs a single modulated signal. The multiplexing signal processor multiplexes the modulated signals output from the M signal processors, and generates N multiplexed signals. The N antenna sections respectively transmit the N multiplexed signals.

A control device causes a first transmission system in a MIMO transmission device to transmit a first transmitting-end clock transmission signal (first transmission signal), causes a second transmission system to transmit a second transmission signal, and causes the first transmission system to transmit a third transmission signal. The control device acquires a first phase value and a second phase value. The first phase value is a phase value of the second transmission signal received in the second reception system operating based on a receiving-end clock signal synchronous with a transmitting-end clock signal by the first transmission signal. The second phase value is a phase value of the third transmission signal received in the second reception system in synchronous operation. The control device calculates a first correction value for correcting a first delay amount set value of a delay adjustment processing unit based on the first and second phase values

A method for X2 interface communication is disclosed, comprising: at an X2 gateway for communicating with, and coupled to, a first and a second radio access network (RAN), receiving messages from the first RAN according to a first X2 protocol and mapping the received messages to a second X2 protocol for transmission to the second RAN; maintaining state of one of the first RAN or the second RAN at the X2 gateway; executing executable code received at an interpreter at the X2 gateway as part of the received messages; altering the maintained state based on the executed executable code; and receiving and decoding an initial X2 message from the first RAN; identifying specific strings in the initial X2 message; matching the identified specific strings in a database of stored scripts; and performing a transformation on the initial X2 message, the transformation being retrieved from the database for stored scripts, the stored scripts being transformations.

Systems and methods for signaling a pattern of cyclic shifts and orthogonal cover codes for use by a wireless device in multi-layer transmissions are presented. In one exemplary embodiment, a method includes receiving a signal that includes B bits for identifying a reference signal. Each of several available reference signals are defined by a cyclic shift and an orthogonal cover code. Further, the method includes using the B bits to identify the cyclic shift and orthogonal cover code according to pre-determined tables that map each value of the B bits to a pattern of cyclic shift and orthogonal cover code combinations for a multi-layer transmission scheme. The patterns for the multi-layer transmission scheme include first and second patterns based on the same cyclic shifts, but where some, but not all, of the cyclic shifts in the first pattern are associated with the same corresponding orthogonal cover codes in the second pattern. In addition, the method includes transmitting each of the one or more spatially multiplexed data streams using a corresponding reference signal for each data stream.

Disclosed are a method and a device for differently applying phase rotations for each antenna by dividing a frequency band in order to solve a problem in which reception performance deteriorates in a specific subcarrier when the correlation between antennas is high. According to the present invention, a method by which a transmitter transmits a signal comprises the steps of: estimating the transmission correlation between respective transmission paths; calculating a phase rotation value to be applied to a transmission signal on the basis of the estimated transmission correlation; applying a phase rotation in accordance with the phase rotation value to the transmission signal; and transmitting the transmission signal.

A phase shifter that includes an RF splitter is disclosed. The RF splitter is arranged so that an RF input signal is provided to, and split over portions of, a feed line that connects an antenna element with a radio transmitter/receiver/transceiver, thus realizing a feed line splitter. Feed line splitters described herein are provided with switches that allow changing a point at which the RF input signal is fed to the feed line, where the switches may be semiconductor-based or MEMS-based switches. The point at which the RF input signal is provided to the feed line to be split defines the electrical path length that the RF energy will travel down each respective path of the feed line splitter, which, in turn, changes the phase shift realized at each output of the feed line splitter. Different antenna elements may be coupled to different outputs of the feed line splitter.

Design of precoding and feedback for user equipment (UE)specific reference signals (UE-RS)based open-loop and semi-open-loop multiple input, multiple output (MIMO) systems is discussed. Aspects of the present disclosure provide for sub-resource block (RB) random precoding that allows for greater diversity gain in a lower bandwidth. In addition, the precoding may be performed using resource element (RE)level layer shifting that provides for a number of precoders to be assigned to a number of layers for every such continuous subcarrier. As such, two codewords may experience the same effective channel quality with channel quality indicators (CQI) being averaged across all of the layers.

A method, an apparatus, and a computer-readable medium for wireless communication are provided. In one aspect, the apparatus may determine whether to transmit a frame with CSDs based on a number of antennas, a number of streams, or both. In another aspect, the apparatus may determine a first set of CSD values for transmitting a first set of information associated with a first portion of the frame. In a further aspect, the apparatus may determine a second set of CSD values for transmitting a second set of information associated with a second portion of the frame. In yet another aspect, the apparatus may transmit the first set of information based on the first set of CSD values and the second set of information based on the second set of CSD values using the number of antennas, the number of streams, or both.

Methods, apparatuses, systems, devices, and computer program products directed to phase-continuous frequency selective precoding are provided. Included among these classes are methods for use in connection with dynamic precoding resource block group (PRG) configuration and with codebook based transmission configuration. A representative of such methods may include any of receiving signaling indicating transmit precoding information; determining a candidate PRG size using any of the transmit precoding information, a rule for determining a PRG size and configured PRG sizes; and configuring or reconfiguring a wireless transmit/receive device in accordance with the candidate PRG size. Another of the representative methods may include reporting a transmission coherence capability of a wireless transmit/receive unit; receiving a codebook subset restriction (CB SR) commensurate with the transmission coherence capability; determining a transmit precoding matrix indices (TPM1) size based on the CB SR; receiving a TPM1; and detecting or decoding the TPM1 based on the determined TPM1 size.