Abstract: The disclosed invention relates to a transceiver system having one or more receive antennas that receive a first radio frequency (RF) signal and a plurality of transmit antennas that wirelessly transmit a second RF signal. A local channel determination unit provides data corresponding to the environment of local communication channels (i.e., the communication channels between the transmit antennas and the receive antennas) to a beamforming element, which enables beamforming functionality within the transmit and/or receive antennas (e.g., by using analog or digital weights to vary the radiation pattern generated by the transmit antennas) so as to attenuate RF signals extending between the transmit antennas and the receive antennas. By attenuating signals extending between the transmit and the receive antennas, a high degree of isolation is achieved between transmission and reception paths.

Abstract: The present invention relates to a transmission beamforming method and apparatus in an orthogonal frequency division multiplexing (OFDM)-based MIMO wireless system. In particular, the present invention relates to a transmission beamforming method in an OFDM-based MIMO wireless system and an apparatus therefor, wherein the transmission beamforming method comprises: estimating a channel from a received pilot signal and obtaining time for the estimating channel and 2D channel correlation information of a frequency band; obtaining estimated channel information based on the channel correlation information; obtaining differential information that represents a difference between the current channel and the estimated channel and quantizing the differential information; and generating a transmission beam weight by using a predefined code book from the quantized differential information.

Abstract: Multiple-input multiple-output (MIMO) with multiple power amplifiers and antennas in a mobile transmitter, such as a user equipment for a cellular telephone communication system, has such great impacts on the transmitter's battery life, form factor, and complexity that it should not be used unless its benefits clearly outweigh its costs. Methods and apparatus enable the benefits of MIMO by beam-forming and antenna-switching to be obtained without incurring the drawbacks of increased current consumption due to multiple power amplifiers.

Abstract: This application relates to a transmitter for a near-field chip-to-chip multichannel transmission system such as the capacitive or inductive links used for vertical signal transmission between the stacked chips of a system-in-package. A transmitter for near-field chip-to-chip multichannel transmission providing 4 transmission channels for digital transmission between two monolithic integrated circuits comprises 4 coupling devices, each of said coupling devices being a planar winding sensitive to magnetic field variations. A multiple-input-port and multiple-output-port amplifier has 4 output ports, each of said output ports being connected to one and only one of said coupling devices. The transmitter also includes 4 signal shaping circuits, each of said signal shaping circuits having an input port connected to the source, each of said signal shaping circuits having an output port connected to one of the input ports of the multiple-input-port and multiple-output-port amplifier.

Abstract: The present application discloses a method for reporting channel status information in a multi antenna wireless communication system. In more detail, the method includes: receiving a reference signal from a base station; calculating the optimum precoding matrix index (PMI), at which the intensity of a signal from the base station is maximized, on the basis of the reference signal: determining at least one interference PMI from the base station on the assumption that a plurality of interference PMIs corresponding to the optimum PIM are applied; and transmitting information on at least one determined interference PMI to the base station. Beams corresponding to the plurality of interference PMIs are orthogonal to the beams corresponding to the optimum PMI.

Abstract: A method for determining a phase of each of a plurality of transmitting antennas in a multiple input and multiple output (MIMO) communication system includes: calculating, for first and second ones of the plurality of transmitting antennas, a value based on first and second groups of channel gains, the first group including channel gains between the first transmitting antenna and each of a plurality of receiving antennas, the second group including channel gains between the second transmitting antenna and each of the plurality of receiving antennas; and determining the phase of each of the plurality of transmitting antennas based on at least the value.

Abstract: System and methods of cellular communications network are described herein. In one system, an antenna array is described. The antenna array has a first beamforming arrangement for producing uplink beams and a second beamforming arrangement for producing downlink beams. The first and second beamforming arrangements are different from one another. The wireless communication network communicates with a mobile station by use of the uplink and downlink beamforming arrangements.

Abstract: Allocation of multiple training sequences transmitted in a MIMO timeslot from multiple transmit antenna elements is provided. For example, a method of generating signals in a MIMO timeslot, the method comprising: selecting a first training sequence; preparing a first data payload; generating a first signal including the prepared first data payload and the first training sequence; transmitting the first signal in a MIMO timeslot from a first antenna of a network element; selecting a second training sequence, wherein the second training sequence is different from first training sequence; preparing a second data payload; generating a second signal including the prepared second data payload and the second training sequence; and transmitting the second signal in the MIMO timeslot from a second antenna of the network element.

Abstract: A method for multi-beam forming based on joint receiving and transmitting end information is provided. The method includes: a transmitting end decomposing a channel matrix H using a geometric mean decomposition (GMD) way to obtain a unitary matrix P; the transmitting end using the unitary matrix P as a weight matrix of GMD beam forming and executing multi-beam forming processing on an original transmission signal x. The present invention also provides a system for multi-beam forming based on joint receiving and transmitting end information, and a transmitting device and receiving device for supporting multi-beam forming based on joint receiving and transmitting end information. By using geometric mean decomposition way to decompose the channel matrix H, the sub channels corresponding to various beams obtain the equal gain. When the channel is ill-conditioned, the channel equalization will not interfere with searching the perturbation vector, thereby avoiding the performance degradation.

Abstract: Systems, methods, and devices to enable monitoring of wireless networks are described herein. In some aspects, a low power receiver or a receiver operating in a low power mode scans for signals with a moderate or low duty cycle. If a signal identifying a device or user of the receiver, or a signal indicating that there will be a subsequent data communication, is received, a high power receiver or a receiver operating in a high power mode is activated to receive data communications.

Abstract: When a determination is made that communication by an SM scheme is suitable, a setting unit performs switching from a communication level by an STC scheme to the communication level by the SM scheme, between the communication level at a first level of MCS by the space-time coding scheme and the communication level at a second level of MCS by the SM scheme. When a determination is made that communication by the SM scheme is unsuitable, the setting unit performs switching from the communication level by the STC scheme to the communication level by the spatial multiplexing scheme, between the communication level at a third level of MCS, which is higher than the first level, by the space-time coding scheme and a fourth level of the modulation scheme and the coding rate, which is higher than the second level, by the SM scheme.

Abstract: Wireless communication techniques for cellular deployment of wireless communication systems with transmitters in each cell to have partially overlapped transmission patterns between two adjacent transmitters. Implementations of the described techniques can provide transmit diversity with intentional partial beam pattern overlays to improve cell sectorization or frequency re-use factor, at the same time, reduce intra-cell and inter-cell interference. Various modulations may be used in the described systems, including FDMA, TDMA, and OFDMA modulation schemes.

Abstract: A system is provided for transmitting a low code rate spatially multiplexed channel on multiple antennas. The system includes a transmitter and a processor. The processor is configured such that the processor encodes a block of information bits to form channel coded bits, wherein the ratio of the number of channel coded bits to the number of information bits is greater than one; and the processor maps the channel coded bits to modulation symbols, and each channel coded bit is mapped once to a modulation symbol. The transmitter is configured to transmit a first portion of the modulation symbols using a spreading sequence on a first antenna of the multiple antennas and to transmit a second portion of the modulation symbols using the spreading sequence on a second antenna of the multiple antennas.

Abstract: Disclosed are a control method and a control device for implementing two-way communication in a wireless network. A repeater can measure a channel matrix, which indicates channel information of each of a plurality of nodes based on signals received simultaneously from the plurality of the nodes, and calculate a first basic lattice size, which initializes the lattice sizes of the received signals according to predefined rules. Then, the repeater uses the channel matrix of each of the nodes and the initialized first lattice size to calculate for each of the nodes a first normalization factor, which normalizes the sizes of the signals simultaneously received from each of the nodes, and a minimum normalized factor, which is equivalent to the minimum value of the first normalization factor.

Abstract: Systems and methods for combining signals from multiple active wireless transmitters are discussed herein. An exemplary system comprises a radio enclosure, a first transmitting RFU, a second transmitting RFU, and a combiner. The first transmitting RFU may be configured to receive a signal, upconvert the signal, compare a phase of the upconverted signal to a predetermined phase value, and adjust the phase of the signal based on the comparison to provide a first phase-adjusted upconverted signal. The second transmitting RFU may be configured to receive the signal, upconvert the signal, compare a phase of the upconverted signal to the predetermined phase value, and adjust the phase of the signal based on the comparison to provide a second phase-adjusted upconverted signal. The coupler may be configured to combine the first and second phase-adjusted upconverted signals to create an output signal and provide the output signal to an antenna for transmission.

Abstract: A method, program and apparatus for transmitting from a transmitter to a receiver over a channel using a transmit diversity scheme. The method comprises: receiving power-related information fed back from the receiver to the transmitter; and at the transmitter, using the power-related information to generate channel state information. The method further comprises using the generated channel state information to control for subsequent transmission to the receiver from the multiple transmit antennas of the transmitter.

Abstract: Systems and techniques relating to wireless communication are described. A described technique includes transmitting a first signal wirelessly to a wireless communication device in accordance with a first transmit mode that is selected from a plurality of transmit modes; receiving a shortlist from the wireless communication device, the shortlist identifying a subset of the transmit modes, the subset of the transmit modes including two or more modes that are different from the first transmit mode; selecting a second transmit mode from the shortlist; transmitting a second signal wirelessly to the wireless communication device in accordance with the second transmit mode; and selectively cycling through any remaining modes of the shortlist based on a lack of reception of an acknowledgement to the second signal. The wireless communication device can be configured to generate the shortlist based on a channel quality analysis of a received version of the first signal.

Abstract: A Mobile Station (MS) is operable to select a precoding matrix in a multi-antenna wireless communication system. The method includes receiving, from a serving Base Station (BS), information on a precoding matrix of which use is prohibited and a precoding matrix to be used by a neighbor BS, estimating an interference signal for the precoding matrix to be used by the neighbor BS, and selecting a precoding matrix to be used by the serving BS by considering the estimated interference signal from the remaining precoding matrixes except for the precoding matrix of which use is prohibited among precoding matrixes used by the serving BS.

Abstract: A novel terrestrial wireless communications technique for terrestrial portable terminals including hand-held mobile devices and fixed wireless instruments, utilizing a spoke-and-hub communications system, having a plurality of individual hubs and/or base-stations all in communications with the portable terminals. The portable terminals and the hubs are assigned to use incompatible polarity formats in terms of circularly polarity (CP) and linearly polarity (LP). In forward links, a signal processed by the LP ground telecommunications hubs is radiated through multiple antennas with various LP polarities to an individual CP user simultaneously. The multiple paths are organized via assignments of a plurality of polarities, frequency slots, and directions by wavefront multiplexing/demultiplexing techniques such that the same communications assets including frequency spectrum may be re-used by other users. The same polarity diversity methods can be extended to peer-to-peer communications.

Abstract: Systems and methods for allocating transmit power among multiple interfaces in a wireless communication system are disclosed. In one embodiment, the method comprises determining a first power level used for transmission over a first air interface, determining a second power level used for transmission over a second air interface, comparing a composite of the first power level and the second power level to a threshold power level, and adjusting the second power level based on the comparison.

Abstract: Rate selection with margin sharing in a system with independent data stream rates is presented. Signal-to-Noise Ratio (SNR) estimates are obtained for each stream. Rates are selected for the streams based on the SNR estimates, such that at least one data stream has an SNR margin below a threshold, each remaining data stream has an SNR margin above a respective threshold, and the total SNR margin for all streams is above a total threshold. For rate selection with margin sharing with a vector-quantized rate set, SNR estimates are obtained for usable transmission channels. The total SNR margin is determined for each rate combination based on the estimates. Each rate combination is associated with a specific number of data streams to transmit, a specific rate for each data stream, and a specific overall throughput. The combination with the highest overall throughput and non-negative total SNR margin is selected.

Abstract: In an ad hoc peer-to-peer communication network between wireless devices, a high priory first receiver device is configured to perform successive interference cancellation. A first pilot signal is received by the first receiver device from the first transmitter device. Similarly, a second pilot signal is received from a second transmitter device, the second pilot signal indicating that the second transmitter device intends to transmit a second traffic signal. The first receiver device determines a first and a second transmission rates for traffic transmissions from the first transmitter device. A control message is then transmitted by the first receiver device to the first transmitter device including the first and second transmission rates. Subsequently, the first receiver device wirelessly receives a traffic signal including a first traffic signal from the first transmitter device including a first and a second signal components generated from a first and a second codewords, respectively.

Abstract: A first radio communication apparatus includes receiving antennas, an antenna selection processing unit that selects a transmitting antenna from transmitting antennas included in a second radio communication apparatus, generates a set that includes antenna indexes each indicating each of transmitting antennas, rearranges the antenna indexes in sequence starting from an antenna index indicating the selected transmitting antenna, generates a channel matrix in which a column corresponding to the selected transmitting antenna is located at a top, and a selected-channel matrix composed of the column, multiplies an inverse matrix of the channel matrix by the selected-channel matrix to generate an evaluation matrix, rearranges the antenna indexes in the set according to values of elements in the evaluation matrix, and selects an antenna to be used according to the rearranged antenna indexes, and a transmitting unit that transmits an antenna index indicating the selected antenna to the second radio communication appa

Abstract: In an ad hoc peer-to-peer communication network between wireless devices, a high priory first receiver device is configured to perform successive interference cancellation (SIC). The first receiver device sends a first rate report signal and a second rate report signal to a first transmitter device indicating a first and second transmission rates. A connection is established between the first transmitter device and the first receiver device in which the first receiver device is the intended receiver of traffic signals from the first transmitter device. The first receiver device receives a traffic signal in a subsequent traffic channel, the traffic signal including a first traffic signal from the first transmitter device having a first traffic transmission rate not exceeding the first transmission rate. The received traffic signal also includes a second traffic signal transmitted by an interfering second transmitter device having a second traffic transmission rate not exceeding the second transmission rate.

Abstract: In a system of MIMO communications in a wireless network, a number of wireless units are logically divided into a plurality of user groups, through operation of a semi-orthogonal user selection sub-system. For example, the user selection sub-system may implement a heuristic user selection algorithm based on near-orthogonality. Each user group is assigned a discrete transmission channel, which may be orthogonally defined in terms of frequency, time, or code. Data is transmitted over the channels (e.g., from network base stations) in a coherently coordinated manner, according to a zero-forcing beamforming operation. The system may be configured for operation in a time/frequency selective manner, e.g., over time/frequency selective fading channels. The wireless units may be allocated to the time/frequency slots based on prioritization of channel strength and considerations of fairness, in conjunction with the application of a semi-orthogonal user selection algorithm.

Abstract: There is provided a method, an apparatus and a computer program product, which introduces a phase shift between radiation phase patterns of associated antennas which are applicable in transmitting and/or receiving radio frequency signals simultaneously via an air interface, wherein the phase shift is introduced in order to obtain orthogonality between the associated radio frequency signals.

Abstract: Devices and methods for determining transmission rates based on a virtual diversity receiver (VDR) scheme are disclosed. Performance is improved through determination of appropriate transmission rates, which are determined based on one or more signal to interference plus noise ratios (SINRs). The SINRs are calculated using virtual noise and channel coefficient values obtained as part of the VDR scheme. Utilizing an underlying pilot structure a user device may receive several sets of symbols. These symbols are then used to obtain both real and virtual channel noise power values and channel coefficients. These values and coefficients are then used to determine first and second SINR values indicative of one or more channels in the communication network. These SINR values may correlate to transmission rates (modulation order and/or coding rate). The SINRs may be sent to a base station, or the user device itself may determine one or more transmission rates.

Abstract: A mobile communications method, device, and system for adjusting a phase parameter in a diversity signal, based at least in part on phase feedback from a base station. While in uplink communication with a base station, a mobile device may receive a phase feedback signal from the base station. The mobile device may calculate a modified value of a phase parameter based on the phase feedback signal in order to transmit diversity signals with a gradual change in phase difference. The modified value may be between a phase parameter value indicated by the base station's phase feedback signal and a phase parameter value initially transmitted by the mobile device.

Abstract: A method and apparatus for providing channel feedback is provided herein. During operation a covariance matrix at time t (R) is calculated as a function of a received downlink signal. Matrix Ct is also calculated and is based on a previous quantized covariance matrix (Rqt?1), the covariance matrix (R) at time t, and a forgetting factor (?) that is applied to Rqt?1. The Ct is then used to create a DERC feedback message (signal or waveform) and may be transmitted with pilots on a proper feedback channel to a base unit. The base unit receives the feedback (Ct) as a DERC waveform on a proper feedback channel. The base unit uses non-coherent or coherent detection to detect the DERC values send by the remote unit and uses the DERC values with a previous quantized covariance matrix estimate, a forgetting factor, and a weighting value to compute a covariance matrix estimate to use for beamforming.

Abstract: A mobile communication system employs moving base stations moving in the direction of flow of traffic moving along a roadway. The moving base station communicates with fixed radio ports connected to a gateway office. A plurality of moving base stations are spaced apart on a closed loop and move with the flow of traffic along one roadway on one leg of the loop and with a flow of traffic on another roadway in another leg of the loop. The moving base stations communicate with a plurality of fixed radio ports connected by a signal transmission link to a gateway office which, in turn, is connected to the wire line network. The moving base stations are each provided with a pair of directional antennas with one antenna directed toward the flow of traffic and another antenna directed to the fixed radio ports.

Abstract: A spatial multiplexing scheduler in, for example, an eNB or other base station, determines rank n precoders for UEs. Each UE reports the preferred precoder from this set of rank n precoders. The preferred precoder results in imbalance in performance over m layers compared to the rest of (n?m) layers. The UEs also report channel quality to the eNB, from which the eNB determines which layer(s) is better for the UE. For example, when n=2 and m=1, the eNB may then select two UEs such that, for the same precoder used by the UEs, the first UE has much higher layer 1 performance than layer 2, and the second UE has much higher layer 2 performance than layer 1. These two UEs may then share the same frequency-time domain resources, with the first UE information sent/received on layer 1, while the second UE information is sent/received on layer 2.

Abstract: Techniques for transmitting data with short-term interference mitigation in a wireless communication system are described. In one design, a first station (e.g., a base station or a terminal) may send a first message to at least one interfering station to request reduction of interference on at least one resource. The first station may send the first message in anticipation of receiving data on the at least one resource. An interfering station may receive the first message from the first station and may reduce interference on the at least one resource by reducing its transmit power and/or by steering its power in a direction different from the first station. The first station may thereafter receive data from a second station on the at least one resource. The techniques may be used for data transmission on the forward and reverse links.

Abstract: The method and apparatus disclosed herein improve throughput conditions limited by multiplicative noise by determining precoder weights for each data stream communicated between a MIMO transmitter node and a MIMO receiver node. The precoder weights are determined based on information derived from non-precoded reference symbols to decrease the energy allocated to the dominant signal path relative to the energy allocated to the non-dominant signal paths.

Abstract: When a mobile station to which receive diversity is applied performs measurement of best cell, the method for considering the plurality of antennas in the receive diversity is changed for each cell. The base station determines the method for considering the plurality of antennas for the receive diversity, and reports it to the mobile station as broadcast information or measurement control information.

Abstract: Apparatus for providing antenna diversity for a radio transmitter/receiver (TR) comprising measuring means for measuring relative received signal strengths in a plurality of antennas in a selectable frequency range, means for selecting the selectable frequency range according to a transmission frequency of the TR, and connecting means for connecting the antenna having the greatest received signal strength to the TR. The apparatus may be combined with a plurality of antennas to form a diversity antenna system, for example for use with a personal radio. The antennas may then be disposed spaced apart on the user's body e.g. by being incorporated into a garment.

Abstract: A communication apparatus capable of simultaneously receiving signals from a plurality of users by an SC-FDMA scheme reduces its circuit size. A communication apparatus BS1, BS2 is capable of simultaneously receiving signals from a plurality of users by the SC-FDMA scheme. The communication apparatus BS1, BS2 includes a plurality of antennas 1a and 1b; a processing unit 6 that performs multi-antenna signal processing on a plurality of received SC-FDMA signals in a frequency domain, the received SC-FDMA signals being received by the plurality of antennas 1a and 1b; and a user separating unit 7 that demultiplexes a signal obtained through the multi-antenna signal processing, into signals for each user based on user allocation information in the SC-FDMA scheme.

Abstract: A communications terminal may include: a plurality of antennas; and a transmitter configured to transmit a signal on an antenna of the plurality of antennas, wherein the transmitter further may be configured to transmit a delayed signal on another antenna of the plurality of antennas, and wherein the delayed signal may be generated by delaying the signal by a time delay.

Abstract: A first network device including a first calibration module to generate training signals for each of a plurality of subcarriers. The training signals are transmitted from the first network device to a second network device via antennas of the first network device using the subcarriers. A first steering module receives a first matrix for each subcarrier, which includes channel state information for each of the training signals received by the second network device, from the second network device according to a transmission schedule and generates a steering matrix based on the first matrix. The transmission schedule is predetermined or is transmitted to the second network device prior to transmitting the training signals. A first control module adjusts, based on the steering matrix, first beamforming weights associated with the antennas to direct first radio frequency signals to be transmitted toward the second network device.

Abstract: Several open-loop solutions encompass the small delay CDD codeword cycling and codeword cycling between different re-transmissions of both small and large delay CDD, and include an open-loop codeword cycling method for an SFBC+FSTD scheme, as well as its extension to SFBC+FSTD based HARQ. In one method, a plurality of information bits are encoded, scrambled and modulated to generate a plurality of modulation symbols. The plurality of modulation symbols are mapped onto the subcarriers in at least one transmission layer of a transmission resource. The modulation symbols are then precoded using a matrix for cyclic delay diversity and a set of codewords from a certain codebook to generate a plurality of precoded symbols. The codewords are cycled for every a certain number of subcarriers. Finally, the precoded symbols are transmitted via a plurality of transmission antennas.

Abstract: A combination of antennas to be used is selected based on a distance between a plurality of antennas or the polarization direction of a radio signal to be transmitted/received.

Abstract: A communication method and apparatus for coordinated multi-point (CoMP) transmission, is provided. Sizes of codebooks for a plurality of base stations may be adjusted based on a status of channels between a target terminal and a plurality of base stations. The terminal feeds back, to at least one of the plurality of base stations, channel direction information (CDI) including a number of bits of feedback.

Abstract: A mechanism for controlling transmit power associated with a plurality of transmit chains of a beamforming transceiver system. A plurality of beamforming steering matrices associated with a plurality of subcarriers of an RF signal received at the transceiver system are generated. A maximum transmit power associated with each of the plurality of transmit chains of the transceiver system is calculated. A power scaling factor for each of the plurality of transmit chains is determined based, at least in part, on the beamforming steering matrices and the maximum transmit power associated with each transmit chain. At least one of the power scaling factors is applied to the plurality of transmit chains to control the transmit power associated with each transmit chain.

Abstract: A communication device comprising at least first and second antennas wherein a quality of communication between the communication device 2 and a further device 20 is assessed when using the at least first and second antennas 8, 10, 12 so as to select one of the at least first and second antennas for further communications between the communication device and the further device.

Abstract: A wireless telecommunication system and method including at least two transmit antennae and means for implementing a downlink switched sub-channels diversity scheme during transmission. The method includes splitting a total bandwidth allocated for transmission of a transmitted signal to individual sub-channels or groups of sub-channels; boosting each of the sub-channels or groups of sub-channels; and routing each of the sub-channels or groups of sub-channels to a different transmit antenna.

Abstract: Allocation of multiple training sequences transmitted in a MIMO timeslot from multiple transmit antenna elements is provided. For example, a method of generating signals in a MIMO timeslot, the method comprising: selecting a first training sequence; preparing a first data payload; generating a first signal including the prepared first data payload and the first training sequence; transmitting the first signal in a MIMO timeslot from a first antenna of a network element; selecting a second training sequence, wherein the second training sequence is different from first training sequence; preparing a second data payload; generating a second signal including the prepared second data payload and the second training sequence; and transmitting the second signal in the MIMO timeslot from a second antenna of the network element.

Abstract: A method, apparatus and computer program product are provided for conveying information regarding the antenna configuration and/or the transmission diversity scheme to a recipient, such as a mobile device. In particular, information regarding the antenna configuration and/or the transmission diversity scheme can be conveyed by masking, such as cyclic redundancy check masking, to provide information regarding the antenna configuration and/or the transmission diversity scheme. In this regard, a set of masks can be determined based upon hamming distances between the masks and bit diversities between the masks and where each of the masks within the set is associated with an antenna configuration and a transmission diversity scheme.

Abstract: A method and a system is provided for Coordinate Rotation Digital Computer (CORDIC) based matrix inversion of input digital signal streams from multiple antennas using an bi-directional ring-bus architecture. The bi-directional ring bus includes a first ring bus having signals flow in a clockwise direction, and a second ring bus having signals flow in a counter-clockwise direction. An I/O controller is coupled to the first and the second ring bus, respectively. A plurality of processing elements (PEs), where each of the plurality of PEs is coupled to the first and the second ring bus, respectively, wherein each of the plurality of PEs includes at least one CORDIC core for performing CORDIC iterations on the plurality of input digital stream signals to produce inversed matrix signals.

Abstract: A base station is arranged for performing channel coding and link adaptation. The base station comprises one or more processors and physical layer circuitry arranged to decode symbols received from a user station to determine an error rate, the symbols received through a plurality of antennas, receive signaling from the user station, the signaling including channel quality information for channel resources of an orthogonal frequency division multiplexed (OFDM) channel, select a modulation and coding rate for transmission of symbols to the user station based at least in part on the error rate, and transmit a transmit power control command to the user station, the transmit power control command based at least in part on a downlink path loss estimate. The base station may also transmit additional transmit power control commands to the user station based on the error rate of subsequently decoded symbols.

Abstract: A wireless communication system which performs data transmission from a first terminal including N antennas to a second terminal including M antennas using spatially multiplexed streams (N and M are integers larger than or equal to 2 and N<M) is disclosed. The system includes training request means, training means, channel matrix preparing means, transmission weight matrix computation means, and beamforming means.

Abstract: An apparatus and method for transmitting/receiving data in a mobile communication system using multiple antennas are provided. A receiver estimates a fading channel of received data, selects a weight set relative to a maximum data transmission rate from at least one weight set with elements of a plurality of orthogonal weight vectors, and transmits feedback information including the selected weight set and channel-by-channel state information to a transmitter. The transmitter demultiplexes data to be transmitted on a basis of the feedback information into at least one sub-data stream, multiplies each sub-data stream by an associated weight, and transmits the data.