Method and arrangement in a user equipment for adjusting signals transmitted in uplink to a network node, based on a feedback value received from the network node. The method comprises transmitting a signal, to be received by the network node. Further, the method comprises receiving a feedback signal from the network node, providing feedback on the transmitted signal. In addition, the method comprises obtaining a value of a time delay of the received feedback signal. Furthermore, the method comprises adjusting signals transmitted in the uplink according to the received feedback signal, wherein compensation is made for the obtained time delay value of the received feedback signal.

A method and apparatus for synchronizing multiple transmitters is disclosed. A global time reference is used to synchronize the arrival of data from a plurality of secondary transmitters in a receiver station. In one embodiment, the global time reference is provided by a GPS satellite, and may also be used to synchronize the carriers of the signals received at the receiver station from each of the plurality of transmitters. In one embodiment, a pilot signal used for ATSC applications is added by the secondary transmitters.

The present invention relates to a method and device for measuring channel quality by a base station having a two-dimensional active antenna system including multiple antennas. Particularly, the method comprises: receiving channel state information (CSI) generated on the basis of a first reference signal relating to a part of multiple antennas, from a terminal; selecting a precoding and a rank based on a precoding matrix indicator (PMI) and a rank indicator (RI) of the received CSI; generating a port by applying the selected precoding and the selected rank; through the generated port, transmitting, to the terminal, a physical downlink shared channel (PDSCH) and a demodulation-reference signal (DM-RS) configured for the terminal; and receiving, from the terminal, a channel quality indication (CQI) feedback for reducing a mismatch for the CQI of the CSI, wherein the CQI feedback may be generated based on the DM-RS.

A gateway for X2 interface communication is disclosed, comprising: an X2 internal interface for communicating with, and coupled to, a first and a second radio access network (RAN); an X2 language processing module for 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; and an X2 external interface for communicating with, and coupled to, a gateway in a wireless telecommunications core network. The gateway may further comprise a database for storing a plurality of rules for performing mapping at the X2 language processing module, and a state machine for maintaining state of one of the first RAN or the second RAN, and an interpreter for executing executable code received as part of the received messages and altering the state machine based on the executed executable code, and a regular expression pattern matcher for identifying patterns in the received messages that are present in the first X2 protocol but not present in the second X2 protocol.

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.

A method and apparatus for generating and transmitting modulation signals includes generating a plurality of modulation signals each of which is to be transmitted from a different one of a plurality of antennas. Each modulation signal includes a pilot symbol sequence and/or a pilot subcarrier including a plurality of pilot symbols used for demodulation. Each of the pilot symbol sequences and/or pilot subcarriers is inserted at the same temporal point in each modulation signal. The pilot symbol sequences and/or pilot subcarriers are orthogonal to each other, each pilot symbol having a non-zero amplitude. The quantity of the plurality of pilot symbols in each pilot symbol sequence and/or pilot subcarrier is greater than a quantity of the plurality of modulation signals to be transmitted. The plural modulation signals are transmitted from the plurality of antennas in an identical frequency band. Each modulation signal includes different transmission data and one of the pilot symbol sequences and/or pilot subcarriers.

A method and an apparatus of transmitting information in a wireless communication system are provided. The method includes transmitting information based on a first resource index through a first antennae and transmitting the information based on a second resource index through a second antennae.

A system for beamforming employing true time delay. The system includes a deserializer configured to receive a serial data stream and to convert the serial data stream into a plurality of parallel data streams, a zero-insertion block configured to insert zeroes into each of the parallel data streams, and a crossbar switch having a plurality of inputs and an equal number of outputs. The inputs are connected to the zero-insertion block, each of the outputs corresponding to one of the inputs. The crossbar switch is configured, in a first state, to connect each output to the corresponding input, and in a second state, to connect each output to an input different from the corresponding input, the set of outputs being a circular shift of the set of inputs.

Various embodiments are described that relate to radio beamforming waveform transmission. Transmission can occur, for example, in three manners. The first manner is time-based where waveform transmission is staggered at the same frequency. The second manner is frequency-based where different frequencies are used at one time. This third manner is a combination of time and frequency such that simultaneous transmission occurs, but at different times different frequencies are used.

Various embodiments are described that relate to radio beamforming waveform transmission. Transmission can occur, for example, in three manners. The first manner is time-based where waveform transmission is staggered at the same frequency. The second manner is frequency-based where different frequencies are used at one time. This third manner is a combination of time and frequency such that simultaneous transmission occurs, but at different times different frequencies are used.