A transmission apparatus includes a plurality of orthogonal frequency division multiplexing (OFDM) modulation signal generators, which generate a first OFDM modulation signal and a second OFDM modulation signal. The transmission apparatus also includes a transmitter that transmits the first OFDM modulation signal from a first antenna and the second OFDM modulation signal from a second antenna, in an identical frequency band. A reception apparatus is provided, which includes a plurality of antennas that receive a plurality of OFDM modulation signals; a plurality of OFDM demodulators that transform the plurality of OFDM modulation signals to a plurality of reception signals using Fourier transform; an estimator that outputs a distortion estimation signal using one or more symbols for demodulation included in the plurality of reception signals; and a demodulator that compensates for distortion of the reception signals using the distortion estimation signal and demodulates a data symbol included in the reception signals.

A radio transmission apparatus includes a first antenna, a second antenna, and circuitry configured, based on information associated with an estimated communications channel condition, to generate a single modulation signal or a plurality of modulation signals based on the estimated communications channel condition information, and to (i) transmit the single modulation signal from the first antenna or (ii) transmit the plurality of modulation signals which include different information from each other over an identical frequency band from the first antenna and the second antenna at an identical temporal point. The single modulation signal and the plurality of modulation signals contain parameter information indicating a number of modulation signals transmitted at the same time.

A method for a transmitter of a mobile communication system transmitting and receiving signals according to an embodiment of the present specification comprises the steps of: transmitting to a receiver system information for transmitting a signal to the receiver including a connection between a wireless resource and a transmitting antenna; transmitting a reference signal to the receiver based on the system information; and receiving from the receiver feedback information generated based on the reference signal. According to an embodiment of the present specification, in a beamforming transmission method of a mobile communication system, a transmitter can determine whether to perform digital pre-coding without advance information from a receiver and can consequently perform a transmission, and can thereby perform lower-overhead and efficient signal transmission/reception.

Systems and methods for closed loop MIMO (multiple input and multiple output) wireless communication are provided. Various transmit formats including spatial multiplexing and STTD are defined in which vector or matrix weighting is employed using information fed back from receivers. The feedback information may include channel matrix or SVD-based feedback.

Provided is a method of calibrating power for a MIMO-OFDM transmitter. The method includes receiving a CDD delay signal output from the MIMO-OFDM transmitter to obtain a starting point of a frame of a corresponding signal; performing an FFT on a sample preceded from the starting point of the frame by an extent of a maximum CDD delay; calculating a channel coefficient H(n) by using an FFT calculated training symbol Y(n) and an ideal training symbol X(n); calculating a channel impulse response h(k) by IFFT calculating the channel coefficient H(n) to calculate power p(k) of the channel impulse response; converting CDD delay values of each MIMO transmission antenna into values in units of samples by using a sampling rate in the channel impulse response; mapping a position of a power peak point of the channel impulse response to each MIMO transmission antenna by using the CDD delay value; and performing power calibration of each MIMO transmission antenna based on each peak point power of the MIMO transmission antennas at a time.

The present invention relates to a method for a base station transmitting a precoded signal to user equipment in a wireless communication system supporting a multi-antenna. More specifically, precoding is conducted by using a precoding matrix to which large delay-cyclic delay diversity (LD-CDD) is applied, wherein the precoding matrix is determined by dividing into matrices for a horizontal direction antenna and a perpendicular direction antenna.

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.

A plurality of modulation signals is generated. Each of the plurality of modulation signals includes a pilot symbol sequence having a plurality of pilot symbols. Each pilot symbol sequence is inserted at a same temporal point in each modulation signal, and each pilot symbol in the pilot symbol sequence has a non-zero amplitude. A quantity of the plurality of pilot symbols in each pilot symbol sequence is greater than or equal to a quantity of the plurality of modulation signals to be transmitted. The plurality of modulation signals are transmitted in an identical frequency band from a plurality of antennas. Each of the transmitted plurality of modulation signals includes transmission data and one of the pilot symbol sequences.

There is provided an arrangement for a wireless communication system that includes a set of power amplifiers and a set of antennas based on which at least two different configurations are provided, including a first configuration of power amplifiers and antennas and a second configuration of power amplifier(s) and antennas. The arrangement also includes switching circuitry configured to switch between the configurations. The second configuration employs a smaller number of power amplifiers than the first configuration, and the second configuration has fewer power amplifiers than antennas where at least one power amplifier is connected to at least two antennas via respective antenna branches that are configured with different delays, as represented by delay elements. A difference in delay between a pair of these antenna branches is based on a measure representative of the inverse bandwidth of a signal to be transmitted through the antennas.

In a particular embodiment, a method of controlling a radiation pattern includes selecting a signal processing characteristic to vary based on a radiation pattern to be emitted by an antenna array of a wireless device, wherein the antenna array includes a plurality of antennas, wherein the signal processing characteristic provides a target resultant radiation pattern, and wherein the signal processing characteristic is applies to less than all elements of the antenna array, and varying the signal processing characteristic across time, frequency, or a combination thereof.