Abstract: Techniques to control shared antenna architectures for multiple co-located radio modules are disclosed. The shared antenna architecture may include a combiner and at least one bypass switch for enabling simultaneous operations or mutually-exclusive operations of multiple transceivers. Dynamic gain control is employed to accommodate different front-end losses associated with a variety of signal paths that are achievable using the switch and combiner. Such dynamic gain control can include selecting from multiple sets of amplifier gain values that are tailored to meet the needs of the particular applications that are active at a particular time. Gain values can be chosen based upon received gain information including characteristics including a desired path loss, an application demand, a radio module type, a path configuration, and a mode of operation. By providing dynamic selection of gain values based on application demands, range and throughput of the transceivers can be attained.

Abstract: A MIMO wireless communications device supports a dual polarized mode of antenna operation and a single polarized mode of antenna operation. Antenna mode selection is performed as a function of signal to noise ration information and/or rank information corresponding to a communications channel matrix. One of a communications device's processing chains is switched between first and second polarization orientation antennas, e.g., vertical and horizontally polarized antennas, as a function of the antenna mode selection. In various embodiments, the dual polarized mode is advantageously used for high SNR users, while in the low SNR regime, where the capacity is limited by received power, the single polarized antenna configuration, sometimes referred to as the spatial MIMO configuration, is used.

Abstract: A method and apparatus are provided for feedback for closed-loop transmitting with multiple transmit antenna elements and multiple receive antenna elements. A base station includes a codebook containing sets of weightings for the multiple transmit antenna elements, with each set of weightings identified by an index and the codebook known to the base station and a served mobile station (MS). The base station pre-codes pilot signals using a precoding matrix, preferably a unitary matrix, to produce pre-coded pilot signals, which precoding matrix may or may not be known to the MS and which precoding matrix may or may not be included in the codebook. The base station then transmits the pre-coded pilot signals to the MS via the multiple transmit antenna elements and, in response, receives an index to a set of weightings in the codebook for use in a subsequent transmission of a data stream.

Abstract: A method for improving multiple-input multiple-output MIMO downlink transmissions includes obtaining a channel state information CSI report including preferred matrix index PMI for precoding, channel quality index CQI and rank index RI at a base station from user terminals through a channel feedback; applying selectively a signal-to-interference-plus-noise-ratio SINR offset to a SINR of said CSI report; applying selectively a rate matching responsive to SINR offset or the CSI report; and controlling or adjusting the SINR offset.

Abstract: A method and apparatus for using an antenna selection signal for selecting a transmit diversity parameter, including phase difference and/or power ratio between concurrently transmitting antennas.

Abstract: Embodiments of the present invention are directed to methods, apparatuses, and systems for implementing a point-to-point radio architecture in which the isolation needed between the transmitter and receiver may be achieved through the use of separate antennas. One embodiment is directed at a radio head comprising a transmitter configured to operate at a first frequency, a receiver configured to operate at a second frequency, and a processor coupled to both the transmitter and the receiver. The transmitter is further coupled to a first antenna interface coupled to a first antenna configured to transmit signals at the first frequency. The receiver is further coupled to a second antenna interface coupled to a second antenna configured to receive signals at the second frequency.

Abstract: A multi-antenna codebook selection modulation method for solving weak scattering is provided by the present invention. The method obtains higher diversity gain from a combination of multi-antenna codebook pre-coding and a rotation modulation solution by designing a new codebook selection rule. The present invention employs a design solution of designing a higher-order modulation diversity and space interleaver to obtain the higher diversity gain. In addition, the number of transmission antennas and the number of rotation modulation dimension can be set arbitrarily. However, the present invention takes the number Nt of transmission antennas to be equal to the number D of rotation modulation dimension in order to obtain higher diversity gain. In this way, the method evenly disperses signals of each dimension after D-dimensional rotation to each antenna through space interleaving technique, so that the signals of each dimension suffer different fading, thus enabling space diversity gain.

Abstract: Techniques to calibrate downlink and uplink channels to account for differences in the frequency responses of transmit and receive chains are described. In one embodiment, pilots are transmitted on downlink and uplink channels and used to derive estimates of the downlink and uplink channel responses, respectively. Sets of correction factors are then determined based on estimates of downlink and uplink channel responses. A calibrated downlink channel is formed using a first set of correction factors for the downlink channel, and a calibrated uplink channel is formed using a second set of correction factors for the uplink channel. The first and second sets of correction factors may be determined using a matrix-ratio computation or a minimum mean square error computation. The calibration may be performed in real-time based on over-the-air transmission. Other aspects, embodiments, and features are also claimed and described.

Abstract: Various arrangements for mapping antennas to transceivers are presented. A plurality of antennas may be present. Each antenna of the plurality of antennas may be configured to communicate using different radio technologies. A plurality of transceivers may be present. At least some of the transceivers of the plurality of transceivers may be configured to utilize different radio technologies. A selector circuit may be present that is configured, based on input from a processor, to map each antenna of the plurality of antennas with each transceiver of the plurality of transceivers. The processor may be configured to control which antennas of the plurality of antennas are mapped to which transceiver of the plurality of transceivers. Touch sensors may be used to determine which antenna or antennas are likely to serve as effective electromagnetic transducers. Signal-to-noise measurements may be used to determine when to modify an antenna mapping.

Abstract: Methods and apparatus are disclosed for applying successive multi-rank beamforming strategies (e.g., successive precoding strategies) for the design of precoders over a set of parallel channels. Successive beamforming is applied to a narrow band channel model and is also applied for finer quantization of a single beamforming vector (e.g., recursive beamforming). A first embodiment provides the optimal approach with high complexity. An alternative embodiment provides successive beamforming for near optimal precoding selection with medium complexity. A low complexity method for precoder selection is also provided wherein a channel representative matrix for the set of parallel channels is determined and successive beamforming on the calculated channel representative is applied.

Abstract: The invention provides an antenna system for wireless communications and in particular to a multiple antenna system for operation in conjunction with a radio frequency (RF) front end for wireless communication. The antenna system comprises one or more antennas configurable for transmission and reception in a first set of configurations and configured for transmission in a second set of configurations. The antenna system further comprises two or more antennas configurable for MIMO-diversity reception for the second set of configurations. The antennas that are configured for MIMO-diversity reception may be tunable, and may have similar characteristics to enhance MIMO reception. Mobile communications terminals utilizing the antenna system, and radio-frequency (RF) front ends for operation in conjunction with the antenna system are also provided. The antenna system may support communications in multiple frequency bands and/or multiple communication standards of operation.

Abstract: Methods and apparatus for uplink data transmission in a Long Term Evolution (LTE) compliant communication system use beam-forming in the uplink to increase the range of LTE compliant wireless communication terminals. Methods are provided for steering the beam in an optimal direction towards the base station, both for time division duplex (TDD) and frequency division duplex (FDD) communication schemes.

Abstract: Provided is a radio communication method employed in a base station having plural antenna elements. The method includes the steps of: setting an inner zone and an outer zone by dividing a cell formed by the base station into two; determining whether a mobile station is located in the inner zone or the outer zone on the basis of a predetermined criterion; notifying the mobile station located in the inner zone of control information, including information on channel allocation and a communication method, through a broadcast channel; and notifying the mobile station located in the outer zone of control information through a dedicated channel by beamforming using the plural antenna elements.

Abstract: Methods and apparatus are disclosed for applying successive multi-rank beamforming strategies (e.g., successive precoding strategies) for the design of precoders over a set of parallel channels. Successive beamforming is applied to a narrow band channel model and is also applied for finer quantization of a single beamforming vector (e.g., recursive beamforming). A first embodiment provides the optimal approach with high complexity. An alternative embodiment provides successive beamforming for near optimal precoding selection with medium complexity. A low complexity method for precoder selection is also provided wherein a channel representative matrix for the set of parallel channels is determined and successive beamforming on the calculated channel representative is applied.

Abstract: The present invention relates to a method and a user equipment for use in a wireless communication system that allow for improved uplink transmit diversity performance by using downlink measurements for making informed decisions on whether or not to change precoding vector for uplink transmission. The user equipment measures (32) downlink characteristics, such as received power, on a plurality of antennas of the user equipment. Based on the measured downlink characteristics a precoding vector for unlink transmission is determined (38). The determined precoding vector is then used to perform uplink transmission (31).

Abstract: A wireless device may comprise a plurality of antennas that may be utilized during communications via various wireless interfaces. The wireless interfaces may comprise mobile interfaces, wireless personal area network (WPAN) interfaces, and/or wireless local area network (WLAN). The plurality of antennas may be utilized during a communication via a wireless interface in the mobile device. The mobile device may switch among antennas in the plurality of antennas utilizing one or more RF switches to enable utilizing best path for transmitted and/or received RF signals during the wireless communication. The mobile device may also perform signal combining of RF signals received via the plurality of antenna, and to enable a receiving end to perform signal combining of RF signals transmitted via the mobile device. A multiple-input-multiple-output (MIMO) combiner may be utilized to perform signal combing; the MIMO combiner may utilize maximal ratio combining to perform signal combining and equalization.

Abstract: A first precoding matrix W1 is selected from a first codebook comprising sets of rank specific precoding matrices. The first codebook is characterized by there being fewer precoding matrices associated with higher ranks than associated with lower ranks, and characterized by precoding matrices associated with ranks above a certain rank all being diagonal matrices. The selected first precoding matrix W1 is used to select a rank-specific second precoding matrix W2 from a second codebook, such that the selected first and second precoding matrices form a joint precoder specific to a desired rank. The second codebook is characterized by differently sized precoding matrices associated with each of N total ranks, in which N is an integer greater than one. Information on the joint precoder is reported to a network node over an uplink transmission channel.

Abstract: Methods and apparatus are disclosed for applying successive multi-rank beamforming strategies (e.g., successive precoding strategies) for the design of precoders over a set of parallel channels. Successive beamforming is applied to a narrow band channel model and is also applied for finer quantization of a single beamforming vector (e.g., recursive beamforming). A first embodiment provides the optimal approach with high complexity. An alternative embodiment provides successive beamforming for near optimal precoding selection with medium complexity. A low complexity method for precoder selection is also provided wherein a channel representative matrix for the set of parallel channels is determined and successive beamforming on the calculated channel representative is applied.

Abstract: A method of generating modulation signals is disclosed including generally three steps. A plurality of modulation signals are generated, each of which is to be transmitted from a different one of a plurality of antennas in an identical frequency band, wherein each modulation signal includes a pilot symbol sequence including a plurality of pilot symbols used for demodulation. Each of the pilot symbol sequences is inserted at the same temporal point in each modulation signal, wherein the pilot symbol sequences are orthogonal to each other with zero mutual correlation among the plurality of modulation signals, each pilot symbol having a non-zero amplitude, the quantity of the plurality of pilot symbols in each sequence being greater than the quantity of the plurality of modulation signals to be transmitted. The plurality of modulation signals each including different transmission data and one of the pilot symbol sequences are output to the antennas.

Abstract: One embodiment of the present invention provides a multi-band RF transmitter. The RF transmitter includes an RF integrated circuit (IC) chip that includes a plurality of identical wideband ports for outputting modulated RF signals, a plurality of narrowband power amplifiers (PAs), and a plurality of matching networks. A respective narrowband power amplifier (PA) is coupled to a wideband port of the RF IC chip via a respective matching network.

Abstract: A base station is provided. The base station includes a transmit path circuitry configured to transmit downlink control information in a downlink control information (DCI) format to a subscriber station, and a receive path circuitry configured to receive multiple-input multiple-output (MIMO) feedback from the subscriber station in response to the downlink control information. The MIMO feedback from the subscriber station is determined by two or more codepoints in the DCI format. One of the two or more codepoints indicates a rank-limited single user multiple-input multiple-output (SU-MIMO) feedback corresponding to a rank up to a maximum rank.

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: Embodiments for at least one method and apparatus of transmitting a transmission signal through a plurality of antennas are disclosed. One method includes generating at least one dynamically adjustable phase shifted signal from the transmission signal. The transmission signal and the at least one dynamically adjustable phase shifted signal are separately amplified. The amplified transmission signal and the amplified at least one dynamically adjustable phase shifted signal are combined within a multiport network. An output signal for each of the plurality of antennas is generated by the multiport network.

Abstract: A diversity combining receiver may employ a switching architecture that permits multiple receiver chains to be coupled to multiple antennas.

Abstract: Techniques for transmitting data from multiple transmit antennas using space orthogonal resource transmit diversity (SORTD) are described. For the SORTD scheme, a different orthogonal resource may be assigned to each transmit antenna. Data may be sent from the multiple transmit antennas using multiple orthogonal resources. In one design, a UE may process at least one information bit (e.g., with joint or independent coding) to obtain first and second sets of at least one modulation symbol. The UE may process the first set of modulation symbol(s) for transmission from the first transmit antenna using a first orthogonal resource. The UE may process the second set of modulation symbol(s) for transmission from the second transmit antenna using a second orthogonal resource. Each orthogonal resource may include a different reference signal sequence or a different set of reference signal sequence and orthogonal sequence.

Abstract: Methods and systems for mitigating interference or estimating a covariance matrix in a communication system are disclosed. In some embodiments, a method of demodulating a received signal in a communication system includes receiving a first plurality of waveforms, estimating a covariance matrix based on the first plurality of waveforms, determining a spatial filter based on the estimated covariance matrix, receiving a second plurality of waveforms, generating at least one filtered waveform by applying the spatial filter to the second plurality of waveforms, and demodulating the at least one filtered waveform.

Abstract: Tunable radio front end systems and methods are disclosed in which the tunable radio front end includes a first tunable impedance matching network, a second tunable impedance matching network, a transmission signal path, and a reception signal path. The transmission signal path can include a first tunable filter in communication with the first tunable impedance matching network, a tunable power amplifier connected to the first tunable filter, and a radio transmitter connected to the tunable power amplifier. The reception signal path can include a second tunable filter in communication with the second tunable impedance matching network, a tunable low-noise amplifier connected to the second tunable filter, and a radio receiver connected to the tunable low-noise amplifier.

Abstract: In the communications system of the present invention, a communications terminal determines a precoding matrix index in a pilot signal received through a specific downlink channel, examines channel quality information of the downlink channel according to the determined precoding matrix index, and transmits feedback information to a serving base station, which determines a priority factor by using the examined channel quality information, and compares the priority factor with other priority factors. The comparison is used such that a base station having a high priority suggests the use of the precoding matrix to the neighboring base station.

Abstract: A wireless communication system includes an inverse matrix calculating unit which uses an inverse matrix of a channel matrix of a first combination of L antennas (where L is an integer, 1?L?N) selected from the N antennas, so as to calculate an inverse matrix of a channel matrix of a second combination of L antennas selected from the N antennas through an arithmetic operation, and an antenna selecting unit which selects a combination of L antennas from the N antennas as L antennas to be used for communication, the selected combination determining a reference value for antenna selection related to the inverse matrix calculated by the inverse matrix calculating unit so that the reference value for antenna selection fits a successive interference cancellation process carried out for a signal transmitted from the L antennas of the selected combination.

Abstract: An estimate of a multiple input, multiple output (MIMO) channel is computed, and an equalizer to be applied to signals received via the MIMO channel is computed. The equalizer is initialized based on the estimate of the MIMO channel. The equalizer is applied to a received signal, and the received signal is demodulated to generate a demodulated signal. The demodulated signal is decoded according to an error correction code to generate decoded data, and the decoded data is re-encoded according to the error correction code to generate re-encoded data. The re-encoded data is re-modulated to generate a re-modulated signal. The received signal is compared to the re-modulated signal, and the equalizer is updated based on the comparison. After updating the equalizer, the equalizer is applied to the received signal.

Abstract: According to one embodiment, a wireless communication apparatus includes a perturbation vector addition unit, a weight multiplication unit and a normalization coefficient multiplication unit. The perturbation vector addition unit is configured to add a perturbation vector only to a first data signal of a first transmission signal containing a first pilot signal and the first data signal, and obtain a second transmission signal containing a second pilot signal and a second data signal. The weight multiplication unit is configured to multiply each of the second pilot signal and the second data signal by a weight for removing interference on a reception side, and obtain a third transmission signal containing a third pilot signal and a third data signal. The normalization coefficient multiplication unit is configured to multiply each of the third pilot signal and the third data signal by a common normalization coefficient for normalizing a total transmission power.

Abstract: A physical layer module includes a mapping module and a plurality of gain modules. The mapping module maps a plurality of coded data streams to a plurality of transmit antennas, in which each transmit antenna is associated with a respective radio frequency channel of a plurality of radio frequency channels. Each gain module is associated with a respective radio frequency channel of the plurality of radio frequency channels, and is configured to apply a complex gain to the coded data stream mapped to the respective radio frequency channel associated with the gain module. The complex gain applied by the gain module differs relative to that applied by other gain modules, and corresponds to the transmit antenna associated with the respective radio frequency channel.

Abstract: A method of 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 multi-user 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: Systems and methods for transmission power management for a mobile device supporting simultaneous transmission on multiple air interfaces are disclosed. In one embodiment, the method comprises determining a transmission power level for each air interface, comparing the transmission power levels to a threshold power level, and adjusting at least one of the transmission power levels based on said comparison.

Abstract: Embodiments of the present invention may separately utilize transmit paths of a mobile transmit diversity device to initialize communication with a base station over a random access channel, particularly where the transmit paths have power amplifiers with different characteristics, e.g., different power amplification.

Abstract: A transmitter includes multiple transmit antennas, a conversion unit configured to generate multiple signal sequences corresponding to a predefined frequency bandwidth from one or more transmission streams associated with any of the transmit antennas, a precoding unit configured to weight the signal sequences with a precoding matrix selected from a codebook including multiple predefined precoding matrices, and a transmitting unit configured to convert an output signal from the precoding unit into a number of signals corresponding to the number of transmit antennas and transmit the converted signals from the transmit antennas. The precoding unit applies distinct precoding matrices to different signal sequences, and an association between the distinct precoding matrices and the different signal sequences is determined through open-loop control being independent of a feedback from a receiver.

Abstract: A method and apparatus for applications of identification of variations of propagation path to transmit diversity control. Transmit diversity parameters may be modified according to detected dynamics, which may, for example, be related to changes in actual propagation and network conditions. Such dynamics may be referred to as mobility parameters. Mobility parameters may apply to variability in a propagation path due to any conditions. Determination of a mobility parameter may be conducted using one or more of multiple parameters available to the mobile terminal. Such feedback information indication, which is related to the propagation path conditions, may be provided to the apparatus, which would attempt to find a more desired mode of operation, which may lead to reduction in power and the improvement of the quality of transmission.

Abstract: System and method for calculating a transmitter beamforming vector related to a channel vector h under per-antenna power constraints combined with total power constraint, under per-antenna power constraints combined with overall line of site (LOS) effective isotropic radiated power (EIRP) and under all three constraints. Calculating a transmitter beamforming vector may be done in the transmitter, in the receiver and feedback to the transmitter or in both. The method may be adapted to perform with a multi-antenna receiver and with multi-carrier systems.

Abstract: An apparatus for calculating receive parameters for an MIMO system including a plurality of individual transmission sections, a transmission section having a transmit circuit adjustable by a transmit parameter, and a plurality of individual users, a user having a receive circuit being adjustable by a receive parameter, includes a calculator for calculating a receive parameter for a first selected data stream for a first user of the plurality of users using a channel information for a transmission channel between the user and a first individual transmit section, to which the user is associated, and for calculating a receive parameter for a second selected data stream for a second user of the plurality of users associated with a second different individual transmission section using channel information between the first user and the second transmission section the second user is associated with, or using the calculated receive parameter for the first user.

Abstract: Embodiments of the present invention provide an antenna system that includes: at least one antenna unit group, wherein at least two antenna units are arranged in the vertical direction in each antenna unit group, and each antenna unit includes two antennas which are crosswise arranged, where carrier frequency signals transmitted by the at least one antenna unit group are identical, and a gap between adjacent antenna units which transmit any identical carrier frequency signal in each antenna unit group is a half wavelength of a frequency of the transmitted carrier frequency signal; and the number of antenna units which transmit each type of carrier frequency signals is determined by a gap between adjacent antenna units which transmit the type of carrier frequency signals and the coverage radii of at least two types of carrier frequency signals transmitted by the antenna unit group.

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 direction deciding unit calculates a plane the perpendicular of which is a directional vector from the wireless communication apparatus toward a radio station. A group deciding unit decides, as groups, antenna combinations each consisting of some ones but not all of a plurality of antennas. A distance calculating unit calculates the distances each between the coordinates of antennas projected, in parallel with the directional vector, onto the plane, and further calculates, for each group, as a group shortest-distance of the group, the shortest one of the calculation results of the distances each between the coordinates of the antennas constituting the group. An identifying unit identifies a group the group shortest-distance of which is the longest. A plurality of communication units communicate with the radio station by use of respective ones of a plurality of antennas in the group identified by the identifying unit.

Abstract: A method and an apparatus for transmitting and receiving a signal in a communication system are provided. The method includes transmitting a signal to a receiver through one of the antennas, receiving an antenna switching indicator indicating to switch the transmitting antenna from the receiver, and switching the transmitting antenna according to the antenna switching indicator, and transmitting a signal to the receiver through a switched antenna.

Abstract: A mobile terminal having a receive diversity function using a plurality of receive antennas, having a calculation section which combines respective level measurement results of the receive antennas and calculates a level measurement value after being combined as the level measurement result of the mobile terminal.

Abstract: Various embodiments of this disclosure may describe apparatuses, methods, and systems for interpolation of precoding matrixes to increase feedback accuracy of the channel state information (CSI) feedback in a wireless communication network. Other embodiments may also be disclosed or claimed.

Abstract: A method and an apparatus for pre-scheduling in a closed-loop multiple user multiple input multiple output (MU-MIMO) antenna system. A base station receives channel information representing a downlink channel condition of each mobile station from mobile stations in a cell, and determines a candidate user group for each of frequency bands included in an entire frequency band, based on the channel information, the candidate user group including mobile stations to which resources can be simultaneously allocated. The base station also instructs a mobile station included in each candidate user group to transmit a sounding signal through a corresponding frequency band. If the sounding signal is received through the corresponding frequency band, the base station performs a scheduling with regard to the mobile station included in each candidate user group.

Abstract: A data transmission apparatus is provided. A symbol mapper performs symbol mapping on information about an optimum key index that instructs a modified Walsh-Hadamard matrix that causes a minimum peak-to-average power ratio and generates a plurality of key symbols. A modified Walsh-Hadamard transformer generates a plurality of modified Walsh-Hadamard-transformed data symbols by performing modified Walsh-Hadamard transform on a plurality of data symbols according to a modified Walsh-Hadamard matrix that an optimum key index instructs. An inverse Fourier transformer generates a plurality of inverse Fourier-transformed symbols by performing inverse Fourier transform on a plurality of key symbols and a plurality of modified Walsh-Hadamard-transformed data symbols. A transmitter transmits a plurality of inverse Fourier-transformed symbols to a channel through at least one antenna.

Abstract: A wireless communication device, a wireless communication system and a method to adjust transmitted signals constellation in a maximum likelihood multiple-input-multiple-output receiver by transmitting an EVM deviation value. The EVM deviation value may be added to a pre-stored error value at the receiver.

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: Apparatus and methods for providing efficient space-time structures for preambles, pilots and data for multi-input, multi-output (MIMO) communications systems are provided. One such embodiment includes providing a computer program that includes logic configured to provide an initial structure. The computer program further includes logic configured to verify that the rows of the initial structure are linearly independent and logic configured to apply an orthonormalization procedure to the initial structure to obtain a space-time structure. Methods are also provided for providing efficient space-time structures for preambles, pilots and data for MIMO communications systems.