Abstract: A method for processing a preamble of a data unit transmitted via a communication channel includes receiving a signal via a plurality of antennas, applying a plurality of distinct steering vectors to the received signal to generate a plurality of respective outputs, and using the plurality of outputs to perform at least one of carrier sensing and symbol timing synchronization associated with the preamble.

Abstract: An apparatus and method for generating a codebook in a wireless communication system are disclosed. The codebook generation apparatus includes a processor for generating a covariance matrix of a channel between the transmitting end and a receiving end, using a unitary matrix including a first vector corresponding to at least one quantized dominant singular singular vector of the channel and a second vector corresponding to at least one basis vector of a null space of the first vector, and transforming a predefined first codebook by applying the covariance matrix of the channel to the first codebook.

Abstract: Pilot, preamble and midamble patterns are provided that are particularly suited for four transmit antenna OFDM systems. Pilots are inserted in a scattered manner for each of the four antennas, either uncoded, space-time coded in pairs, space-time frequency coded in pairs, or space-time-frequency coded.

Abstract: Methods and apparatus are provided for directing a beam towards a receiving device in the presence of interference. A beam transmitted by a transmission source is received by a received device. The beam shape is affected by signals transmitted by interfering sources. The receiving device computes channel estimates associated with the transmission source and the interfering sources. A feedback signal that represents the channel estimates associated with the transmission and interfering sources is transmitted to the transmission source. The transmission source changes characteristics of the beam to compensate for the interference caused by the interfering sources. The transmission source may change the characteristics of the beam by performing precoding algorithms.

Abstract: A method for taking measurements with a smart antenna in a wireless communication system having a plurality of STAs begins by sending a measurement request from a first STA to a second STA. At least two measurement packets are transmitted consecutively from the second STA to the first STA. Each measurement packet is received at the first STA using a different antenna beam. The first STA performs measurements on each measurement packet and selects an antenna beam direction based on the measurement results.

Abstract: A spectral arrangement for radio resources is usable for transmitting radio data within a telecommunication network. The spectral arrangement includes (a) a first radio resource usable for transmitting radio data in a first data flow direction, wherein the first data flow direction is either an uplink direction or a downlink direction, (b) a second radio resource usable for transmitting radio data in a second data flow direction, wherein the second data flow direction is opposite to the first data flow direction, (c) a third radio resource usable for transmitting radio data in the second data flow direction and (d) a guard band, which on the frequency scale is located between the first radio resource and the second radio resource such that the first radio resource is separated from the second radio resource Between the second radio resource and the third radio resource there is provided no guard band.

Abstract: A method and system for transmitting three distinct electromagnetic signals on a same frequency are provided. One or more transmitting devices transmit a first data signal and an inverse of the first data signal in two orthogonal linear polarities of an antenna maintaining their inverted phase relationship and a same amplitude as propagated. Transmitting devices also transmit a second data signal in a linear polarity with a 45 degree rotation around the transmit axis of the first data signal. Transmitting devices also transmit a third data signal in linear polarity orthogonal to the second data signal and consequently 315 degree rotation around the transmit axis from the first data signal.

Abstract: A method for transmitting a sounding reference signal from a user equipment in a MIMO antenna wireless communication system. The method includes receiving sounding reference signal setup information from a base station, the sounding reference signal setup information including an initial cyclic shift value nSRScs and an initial transmissionComb parameter value kTC; setting an interval between cyclic shift values corresponding to each antenna port based on the initial cyclic shift value, to reach a maximum interval; setting a transmissionComb parameter value corresponding to a specific one of the antenna ports to a value different from the initial transmissionComb parameter value if the initial cyclic shift value is a previously set value and the number of antenna ports is 4; and transmitting the sounding reference signal to the base station through each antenna port by using the set cyclic shift value and transmissionComb parameter value.

Abstract: A transmission method simultaneously transmitting a first modulated signal and a second modulated signal at a common frequency performs precoding on both signals using a fixed precoding matrix and regularly changes the phase of at least one of the signals, thereby improving received data signal quality for a reception device.

Abstract: 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.

Abstract: A method of data transmission includes determining the number of layers, generating mapping symbols by mapping modulation symbols for a first codeword and modulation symbols for a second codeword to each layer, and transmitting the mapping symbols through a plurality of antennas. At least one of the first codeword and the second codeword is mapped to at least 3 layers and the number of layers is larger than 3.

Abstract: A system employing vector signal generator (VSG) and vector signal analyzer (VSA) modules or cards that are configured to test multiple devices under test simultaneously. Each VSG is configured to generate multiple RF test signals and send them to multiple devices under test simultaneously. Similarly, each VSA is configured with multiple signal receiving modules connected to a single controller or memory. Each signal receiving module receives an RF signal from a device under test, converts it to a baseband digital signal, and transmits this digital signal to the VSA's memory. A single RF testing system can employ multiple such VSGs and VSAs, each capable of evaluating multiple devices under test. Each VSG/VSA can further be tuned for operation in discrete or defined frequency bands, which are narrower than those for conventional RF testers, and which can correspond to various wireless standards.

Abstract: Various embodiments provide for systems and methods for wireless communications that implement transmitter protection schemes using spatial combining. The protection scheme implemented by some embodiments provides for a number of benefits, including without limitation: hitless protection; constant power monitoring for each wireless channel being utilized; extra gain to wireless signals transmitted; beam steering, beam hopping, and beam alignment capabilities; and varying levels of transmission path protection (e.g., 1+1 protection, or 1+N protection). Additionally, the features of some embodiments may be applied to a variety of wireless communications systems including, for example, microwave wireless systems, cellular phone systems and WiFi systems.

Abstract: Methods and systems for antenna switching for mitigating leakage of a 60 GHz transmitted signal back into an RF input of a 60 GHz device are disclosed and may include configuring one or more antennas in the plurality of remote RF modules based on a measured signal characteristic, wherein the RF modules receive IF signals via coaxial lines. In-phase (I) and quadrature phase (Q) signals may be generated from the received IF signals. The generated I and Q signals may be summed before being transmitted via the antennas. The received IF signals may be up-converted into first I and Q signals, filtered, and up-converted a second time into the generated I and Q signals. Control signals for the RF modules may be communicated utilizing the coaxial lines. A local oscillator frequency may be configured for the up-conversion of signals via the communicated control signals.

Abstract: A sounding reference signal transmission method which is efficient in an uplink wireless telecommunications system using a multiple antenna technique and sounding reference signal hopping. A terminal using the multiple antenna technique is equipped with a plurality of antennas, and a base station receives the sounding reference signal transmitted from these antennas and estimates the uplink channel state of each antenna. Moreover, the sounding reference signal performs frequency hopping so that the base station determines the channel condition for the entire bandwidth to which data is transmitted in the uplink system. The sounding reference signal is transmitted through an antenna pattern in which the sounding reference signal can be transmitted through the entire data transmission bandwidth of the uplink system for each antenna of the terminal without additional overhead in this environment.

Abstract: A method and apparatus for dynamic acknowledgement repetition for a downlink medium access control packet data unit transmission ‘MAC PDU’ requiring multiple acknowledgements, the method having the steps of: receiving the downlink MAC PDU requiring multiple acknowledgements; and utilizing a differentiating factor and acknowledgement scheme, sending the multiple acknowledgements.

Abstract: Methods and apparatus are provided for transmitting/receiving data in consideration of carrier frequency in the mobile communication system using multiple transmission antennas for increasing data rate and system throughput. A number of antennas and a plurality of symbols are determined via an in-phase domain and a quadrature-phase domain. The symbols are mapped according to the number of antennas and the in-phase domain and the quadrature-phase domain. The mapped symbols are transmitted through corresponding antennas.

Abstract: Method, receiver and computer program product for processing a signal, wherein the signal is received over a wireless network from a transmitter, the signal comprising a plurality of data streams. A selected one of the data streams is preferentially treated by reporting an adjusted value of a characteristic of the selected data stream to the transmitter and the received signal is decoded using a technique of successively decoding data streams in which the selected data stream is the first data stream to be decoded, a signal corresponding to the selected data stream being removed from the received signal prior to decoding at least one of the unselected data streams in the received signal.

Abstract: A configurable network adapter has N analog front ends, each generating a receiver output and a transmitter input. In a first mode of operation, the analog front end receiver outputs are coupled to a MIMO equalizer, which is coupled to an outer receiver and to a first MAC input, with the first MAC having an output coupled to an outer transmitter, a MIMO modulator, and to the analog front end transmitter inputs. In a second mode of operation, one or more of the analog front ends is directed to a SISO modulator fed by a second outer transmitter coupled to a second MAC transmitter output. An associated one or more of the analog front end receivers is coupled to a SISO equalizer, and thereafter to an outer receiver and to the second lower MAC, thereby providing a first mode for a single MIMO adapter and a second mode for a MIMO plus independent PAN interface.

Abstract: Disclosed is a precoding method for generating, from a plurality of baseband signals, a plurality of precoded signals that are transmitted in the same frequency bandwidth at the same time. According to the precoding method, one matrix is selected from among matrices defining a precoding process that is performed on the plurality of baseband signals by hopping between the matrices. A first baseband signal and a second baseband signal relating to a first coded block and a second coded block generated by using a predetermined error correction block coding scheme satisfy a given condition.

Abstract: A transmission method for transmitting a first modulated signal and a second modulated signal in the same frequency at the same time. Each signal has been modulated according to a different modulation scheme. The transmission method applies precoding on both signals using a fixed precoding matrix, applies different power change to each signal, and regularly changes the phase of at least one of the signals, thereby improving received data signal quality for a reception device.

Abstract: The invention relates to a technical field of multiple-antenna transmission in a wireless communication system. Communication of feedback representation of and generating a codebook suitable for precoding of multiple-antenna transmission is disclosed. An example matrix representation of precoding of a first number of antenna ports comprises precoding sub-matrices of less antenna ports.

Abstract: Systems and methods for suppressing interference from a data signal received at a receiving device, where the receiving device has two or more receive antennas, are provided. Characteristics of a channel are estimated, the channel being a channel through which the data signal was transmitted by a transmitting device to the receiving device. A spatial correlation of interference and noise received at the two or more receive antennas of the receiving device is determined based on the estimated characteristics of the channel. The spatial correlation indicates how the interference and noise received at a particular one of the receive antennas is related to the interference and noise received at another one of the receive antennas. The spatial correlation of the interference and noise is used to suppress interference and noise from the data signal received at the receiving device.

Abstract: The present invention relates to a wireless communication system, and more particularly, to a method and apparatus for transmitting signals using codebooks in a wireless communication system that supports multiple antennas. A method in which a base station transmits downlink signals according to one embodiment of the present invention comprises the following steps: receiving a first precoding matrix indicator (PMI) and a second precoding matrix indicator from a terminal; determining a first matrix (W1) from a first codebook including precoding matrixes indicated by the first PMI, determining a second matrix (W2) from a second codebook, including precoding matrices indicated by the second PMI, and determining a precoding matrix (W) based on the first matrix (W1) and second matrix (W2); performing precoding on one or more layers, to which the downlink signals are mapped, using the determined precoding matrix (W); and transmitting the precoded signals to the terminal.

Abstract: Uplink transmission from a mobile device having multiple antennas to a base station having multiple antennas includes transmitting in an open-loop single-user MIMO mode when the mobile device is at high speed, transmitting in a closed-loop single-user MIMO mode when the mobile device is at low speed, and, upon request, transmitting in a multi-user collaborative MIMO mode. The method also includes controlling uplink transmissions in a selected one of the open-loop single-user MIMO, the closed-loop single-user MIMO and the multiuser collaborative MIMO modes. Uplink transmissions from the mobile device may be transmitted using multiple antennas of the mobile device. Upon request, the mobile device may switch to transmitting in multi-user collaborative MIMO mode with a subset of the multiple antennas.

Abstract: An electronic device includes a main antenna and a diversity antenna. The diversity antenna includes a first portion configured to enable a transceiver to receive a signal in a first low-band frequency of four frequency bands. A second portion enables the transceiver to receive a signal in first and second high-band frequencies. A third portion is RF coupled to the first portion when the third portion is connected to ground. The third portion tunes the first portion such that the transceiver receives a signal in a second low-band frequency. A switch is connected between the third portion and the ground. When the switch is open, the first portion enables the transceiver to receive the signal in the first low-band frequency. When the switch is closed, the third portion tunes the first portion to enable the transceiver to receive the signal in the second low-band frequency.

Abstract: The signaling amount in selecting a plurality of beams is reduced in pre-coding to enhance throughput. When notification of a beam number is provided in a feedback signal from an user equipment to a radio base station, a superior beam number, having a high quality rank with small time variation, is bound up and fixed for a predetermined time period and notification of only a inferior beam number is provided within the predetermined time period. For example, to select three beams among six beams, first, notification of the superior two beam numbers (beam numbers ‘b’ and ‘c’) is provided. These beam numbers are fixed for a predetermined time period and then notification of only the inferior one beam number (beam number ‘e’) is provided within the predetermined time period. Thus, the signaling amount for providing beam number notification is reduced.

Abstract: Electronic devices may have multiple wireless integrated circuits such as a pair of baseband processor integrated circuits and may have multiple antennas such as a pair of antennas. An electronic device may be operated in different modes depending on the operating environment of the electronic device. When both antennas are unblocked, both baseband processors and both antennas may be used in transmitting signals. When one antenna is not available, the device may be operated in a mode in which the available antenna is used and both baseband processors are used or in a mode in which the available antenna is used and only one of the baseband processors is used. Operating mode decisions may be made so as to minimize the potential for intermodulation distortion and absorbed radiation.

Abstract: A mobile communication device and a method of controlling same, in which the mobile communication device transmits a plurality of transmit diversity signals comprising a first transmit signal and a second transmit signal differing at least by values of a transmit diversity parameter, receives a plurality of feedback signals from at least one base station in response to the plurality of transmit diversity signals; and determines a system delay based on detecting that a number of expected feedback signal patterns among the received plurality of feedback signals exceeds a system delay threshold.

Abstract: The present invention relates to a transmitter in a transmission system operable to optimize estimates of a quantity at a receiver for improved operation. The transmission system includes a transmitting unit connected to a number of antennas (Txm), and to control unit. The control unit controls the transmitting unit to initially transmit an initial training/quantity estimation sequence during an initial training/quantity estimation phase and subsequently transmit a sequence of data symbols such that the information rate of the data symbols is progressively increased.

Abstract: A method for transmitting a Channel State Information (CSI) reporting at a user equipment (UE) in a wireless communication system is disclosed. The method includes transmitting a rank indicator (RI) and a first type precoding matrix indicator (PMI) to a base station (BS) according to a first CSI feedback type; transmitting a second type PMI to the BS according to a second CSI feedback type, wherein the RI and the first type PMI are jointly coded, and transmitted through a physical uplink control channel (PUCCH), wherein the RI and the second type PMI are not jointly coded, and transmitted through the PUCCH, wherein a transmission period of the first type PMI is different than a transmission period of the second type PMI, and wherein the transmission period of the first type PMI is longer than the transmission period of the second type PMI.

Abstract: Methods in a wireless terminal are described for supporting co-ordinated multipoint transmissions including joint transmissions from two or more transmission points, specifically the method of receiving indication of two or more CSI reference signal configurations, each CSI reference signal configuration representing one or more antenna ports comprising a set of antenna ports; determining a first set of transmission parameters corresponding to a first set of antenna ports corresponding to a first CSI reference signal configuration and a second set of transmission parameters corresponding to a second set of antenna ports corresponding to a second CSI reference signal configuration; the first set and second set of transmission parameters determined to maximize the sum data rate for simultaneous transmission from the first set and the second set of antenna ports; conveying, to the base station, information pertaining to the first set of transmission parameters and the second set of transmission parameters.

Abstract: A process selects a Precoding Matrix Index (PMI) in a Multiple In Multiple Out (MIMO) receiver used in a wireless communications system including a base station communicating with User Equipments (UE) through a downlink and uplink channel. The base station applies a precoding on the transmit symbol vector based on a matrix selected from a set of predefined matrices and identified by a PMI index computed by the UE and forwarded to the base station via the uplink. The process includes estimating the MIMO channel matrix H of a given set of resources blocks comprising received symbol vectors, estimating the variance ?2 of the additive noise (AWGN), and computing for each particular matrix comprised within the set of predefined matrices a cost function representative of the orthogonality of the matrix MIMO channel matrix H.

Abstract: A testing system comprises a noise source coupled to at least two antenna elements. The noise source forms a total noise power on the basis of a total signal power received by the emulator, a gain of at least one antenna-specific channel between the emulator and the antenna elements, and a desired signal-to-noise ratio. The noise source transmits noise at the total noise power from the at least two antenna elements to the device under test wirelessly.

Abstract: The present invention relates to a method and arrangement for symbol mapping in wireless communication systems utilizing OFDM transmission technology in combination with advanced coding schemes. In the method according to the present invention, adapted for use in a wireless communication system utilizing OFDM transmission technology, an OFDM grid is defined by at least a first dimension and a second dimensions from the dimensions time, frequency or space. The advanced coding scheme, for example Alamouti coding, outputs symbols that are related via the coding. At least some of the symbols, defining a code related symbol group should experience identical, or at least very similar, radio channels. According to one embodiment of the present invention, symbols from the same code related symbol group is placed as close together in the OFDM grid as possible.

Abstract: A method of transmitting at least one sub-packet in a wireless communication system is disclosed. More specifically, the method includes transmitting at least one sub-packet based on combination of resources from multiple domains, wherein the combination of resources indicate whether to maintain or change the resource arrangement for subsequent transmission.

Abstract: Apparatus, the apparatus having at least one processor and at least one memory having computer-readable code stored thereon which when executed controls the at least one processor to perform a method comprising: obtaining in-phase and quadrature samples of a received radio signal at least first and second discrete instances in time; processing the samples to provide information relating to the amplitude and/or phase of the received radio signal at the first and second instances in time; using the amplitude and/or phase information of the received radio signal at the first and second instances in time to determine whether interference is present on the received radio signal; forwarding the complex signal parameters for processing if interference is determined not to be present; and discarding the complex signal parameters without forwarding them for processing if interference is determined to be present.

Abstract: Disclosed is a method for selecting a source transmit antenna in a cooperative multiple-input and multiple-output (MIMO) communication system including a source node, a relay node and a destination node. The method includes determining a source transmit antenna selection metric such that a source-destination channel, a source-relay channel and a relay-destination channel are related to one another, and selecting a positive integer number of antennas such that the source transmit antenna selection metric is maximized.

Abstract: A transmission method for transmitting a first modulated signal and a second modulated signal in the same frequency at the same time. Each signal has been modulated according to a different modulation scheme. The transmission method applies precoding on both signals using a fixed precoding matrix, applies different power change to each signal, and regularly changes the phase of at least one of the signals, thereby improving received data signal quality for a reception device.

Abstract: The present invention relates to a data transmission method in a radio communication system, comprising the steps of selecting a first reference transmission antenna of a first base station and a second reference transmission antenna of a second base station from among a plurality of base stations, transmitting a first transmission data stream via the first reference transmission antenna, transmitting a second transmission data stream via the second reference transmission antenna to a terminal, time-delaying the first transmission data stream and retransmitting the delayed first transmission data stream to the terminal via a transmission antenna of a first transmission group, and time-delaying the second transmission data stream and retransmitting the delayed second transmission data stream to the terminal via a transmission antenna of a second transmission group.

Abstract: Methods and systems for antenna switching for 60 GHz distributed communication are disclosed and may include enabling antenna configurations in a plurality of remote RF modules within a computing device to receive RF signals. A signal characteristic may be measured for the configurations receiving an RF signal from a remote device. IF signals may be generated from baseband signals and may be communicated to RF modules based on the signal characteristic via coaxial lines, and may be up-converted to output RF signals utilizing the RF modules. The output RF signals may be transmitted via antennas in the RF modules. The IF signals in the one or more coaxial lines may be tapped via taps coupled to the RF modules. The baseband signals may comprise video data, Internet streamed data, and/or data from a local data source. Control signals for the RF devices may be communicated utilizing the coaxial lines.

Abstract: Methods and systems for communication via subbands in a 60 GHz distributed communication system are disclosed and may include enabling one or more antenna configurations in remote RF modules within a wireless communication device based on a measured signal characteristic. The RF modules may receive IF signals from baseband signals via one or more coaxial lines. Output RF signals may be communicated in frequency subbands via the antenna configurations with external devices. The IF signals in the coaxial lines may be tapped at taps coupled to the RF modules. The baseband signals may include video, Internet streamed, and/or data from a local data source. Frequency division duplexed signals may be communicated to a display device. Control signals may be communicated utilizing the coaxial lines. The signal characteristic may include a received signal strength indicator, and or a bit error rate. The output RF signals may include 60 GHz subband signals.

Abstract: Methods and systems for a 60 GHz communication device comprising multi-location antennas for pseudo-beamforming are disclosed and may include configuring antennas in RF modules for beamforming transmitted signals. Each of the RF modules may receive IF signals via coaxial lines. The beamformed RF signals may be transmitted via the antennas to external devices. The RF signals may be generated from IF signals from baseband signals. The RF modules may be configured utilizing a processor in the wireless communication device. The RF signals may be transmitted to a display device. Control signals for the RF devices may be communicated utilizing the coaxial lines. The RF devices may be selected for the beamforming based on a direction to a receiving device. The beamforming may include adding a phase shift in upconverting the IF signals to the RF signals, which may include 60 GHz signals.

Abstract: A radio communications apparatus transmitting data using multiple antennas is disclosed that includes a data link layer control information generation part configured to generate multiple data link layer control information items from generated data link layer control information; a data unit generation part configured to generate multiple data units to be transmitted through the corresponding antennas, based on the data link layer control information items generated by the data link layer control information generation part, so that the data units include the data link layer control information items; and a physical layer processing part configured to perform adaptive modulation and coding on the data units.

Abstract: The present invention relates to a method and apparatus for transceiving data in a wireless communication system. A method for receiving data in a wireless communication system according to one aspect of the present invention is configured such that a base station receives, from a mobile station, a signal including information and data on the transmission mode which the mobile station has selected in accordance with a channel status, and decodes the data in accordance with the transmission mode.

Abstract: A radio receiver apparatus of a cellular network, wherein the network allocates one or more cells to a particular connection of the radio receiver apparatus based on a feedback signal received from the radio receiver apparatus. The radio receiver apparatus includes a first measurement unit configured to measure at least one cell-specific first quantity indicative of a channel quality of a dedicated downlink channel. Further, the radio receiver apparatus includes a feedback signal generating unit configured to generate the feedback signal on the basis of the first quantity.

Abstract: A method of demodulating a plurality of multiplexed modulation signals is provided, including: i) inputting the plurality of multiplexed modulation signals, each of which being outputted from a plurality of outputs of a communication partner, wherein each modulation signal in the multiplexed modulation signals includes a pilot symbol sequence consisting of a plurality of pilot symbols used for demodulation, ii) estimating respective channels of the multiplexed modulation signals based on one or more of the pilot symbol sequences; and iii) demodulating each modulation signal in the plurality of multiplexed modulation signals based on the channel estimation. Each of the pilot symbol sequences is inserted at a same temporal point in each modulation signal among the multiplexed modulation signals. The pilot symbol sequences are orthogonal to each other with zero cross correlation among the modulation signals in the multiplexed modulation signals, and each pilot symbol has a non-zero amplitude.

Abstract: A wireless communication apparatus is provided that includes a plurality of antennas and at least one receive or transmit circuit. The apparatus further includes a controller configured to: determine one or more performance characteristics associated with a first antenna while the circuit is connected to the first antenna; switch the circuit from the first antenna to a second antenna; determine one or more performance characteristics associated with the second antenna after the switch; compare the performance characteristics associated with the antennas; determine whether to maintain the switch to the second antenna or to switch the circuit back to the first antenna; and determine a duration of time to maintain a connection between the selected antenna and the circuit based, at least, on one or more performance characteristics. Other aspects, embodiments, and features are also claimed and described.

Abstract: A multi-user multiple-input multiple-output (MIMO) downlink beamforming system with limited feed forward is provided to enable precoding matrix information to be efficiently provided to a subset of user equipment devices, where zero-forcing transmit beamformers are computed at the base station and assembled into a precoding matrix. The precoding matrix is encoded using a compact reference signal codebook for forward link signaling, either by sending bits indicating the index of the transmission matrix used, or by transmitting one or more precoded pilots or reference signals wherein the pilot signals are precoded using vectors uniquely representative of the transmission matrix used which includes candidate reference signal matrices which meet a predetermined condition number requirement, such as a condition number threshold. The precoding matrix information is extracted at the user equipment devices using the compact reference signal codebook and used by the MMSE receiver to generate receive beamformers.

Abstract: The present invention relates to user equipment (UE) having at least two transmit antennas that are capable of transmitting RF signals to a base station, which selects either an open-loop mode or a closed-loop mode depending on how the RF signals from the UE are changing. In the closed-loop mode, the base station periodically evaluates the RF signals from the UE and selects which of the UE's transmit antennas are to be used. This information is then sent to the UE. If the base station determines that the RF signals from the UE are changing too rapidly for effective control, then the base station selects the open-loop mode, such that the UE selects which of the UE's transmit antennas are to be used.