Abstract: A method for transmitting/receiving data in a Multiple Input Multiple Output (MIMO) communication system is disclosed. The data transmission method includes determining a precoding matrix to be a part of a phase-shift-based precoding matrix, determining a first diagonal matrix for phase shift to be a part of the phase-shift-based precoding matrix, determining a unitary matrix to be a part of the phase-shift-based precoding matrix, precoding a transmission symbol for each resource using the phase-shift-based precoding matrix to produce precoded data, and transmitting the precoded data, wherein the phase-shift-based precoding matrix is determined by the product of the precoding matrix, a Hermitian matrix of the unitary matrix, the first diagonal matrix, and the unitary matrix.

Abstract: A system and method for packet communication is disclosed. Echo in a received symbol stream may be reduced to produce an echo-reduced symbol stream. The echo-reduced symbol stream may be buffered and aligned according to a deskew signal to produce a deskewed symbol stream. The deskewed symbol stream may be decoded to produce a decoded packet.

Abstract: A minimum mean square error (MMSE) equalizer corresponding to a plurality of receive antennas is generated using (i) channel information for a first plurality of users including a desired user, (ii) a ratio of white noise power to noise power due to code division multiple access (CDMA) signals corresponding to the first plurality of users, (iii) channel information for a second plurality of users served by another base station, and (iv) a ratio of noise power due to CDMA signals corresponding to the second plurality of users to noise power due to CDMA signals corresponding to the first plurality of users. CDMA signals received by a plurality of antennas are filtered using the MMSE equalizer. The CDMA signals are despread using a spread code corresponding to the desired user.

Abstract: Techniques for transmitting data using channel information for a subset of all subcarriers used for data transmission are described. A transmitter station receives channel information for at least one subcarrier that is a subset of multiple subcarriers used for data transmission. The channel information may include at least one transmit steering matrix, at least one set of eigenvectors, at least one channel response matrix, at least one channel covariance matrix, an unsteered pilot, or a steered pilot for the at least one subcarrier. The transmitter station obtains at least one transmit steering matrix for the at least one subcarrier from the channel information and determines a transmit steering matrix for each of the multiple subcarriers. The transmitter station performs transmit steering or beam-steering for each of the multiple subcarriers with the transmit steering matrix for that subcarrier.

Abstract: A receiving apparatus for receiving a signal from a transmitting includes a receiving unit configured to receive the signal from the transmitting apparatus; a selecting unit configured to select whether to consider channel information in estimating an offset value between the transmitting apparatus and the receiving apparatus; an offset value estimating apparatus configured to estimate the offset value between the transmitting apparatus and the receiving apparatus either considering the channel information or without considering the channel information based on a selection made by the selecting unit; a synchronization performing unit configured to perform synchronization based on the estimated offset value; and a demodulation unit configured to perform demodulation of the received signal based on a result of performing the synchronization.

Abstract: Methods and systems that enable the determination of accurate channel estimates by measuring only power values of pilot signal transmissions at a receiver are described. Various measurement procedures that are based on average power measurements or short term, per-symbol measurements can be employed. Furthermore, procedures utilizing adaptive pilots generated with receiver feedback and deterministic pilots generated without receiver feedback are also described.

Abstract: The disclosed embodiments provide a system that facilitates transmission of a serial data stream. The system may include, in a receiver of the serial data stream, a first mechanism for converting from single-ended signaling to differential signaling, wherein the first mechanism facilitates rejection of common mode noise in the serial data stream. For example, the first mechanism may be a balun and/or a common-mode choke.

Abstract: The present invention relates to an apparatus and a method for selection of a precoding matrix. In the present invention, a precoding matrix to enable an effective signal-to-noise ratio (ESNR) to have a maximum value with respect to a signal vector that requires retransmission is selected in a codebook and fed back to a transmitter. Accordingly, since the effective signal-to-noise ratio has the maximum value after the signal vector is retransmitted, it is possible to minimize a reception error probability of retransmission.

Abstract: A system and method of construction of unique word sets together with an efficient method of implementing correlation with the members of the set is presented. The set of UWs is constructed by breaking a UW sequence in to equal length segments, and then multiplying this vector by an orthogonal matrix. First an arbitrary vector U is chosen of length K for a set of N UWs. Then a matrix H of size N×N is chosen. The columns of H are then repeated L times to form a matrix H?. The set of N UW consists of the rows of H?UT. N sub-correlations of the N segments of the vector U with the segments of the (suitably delayed) received signal is performed at the receiver. Then the N different outputs are obtained as Z=HCT, where C=[C0 . . . CN-1] is the vector of correlated outputs. The receiver only requires N correlators, each of length L, instead of length K, which provides a less complex and more efficient solution for detection of UW sets.

Abstract: Beamforming systems and methods are disclosed. In accordance with one method, indications of channel matrices for a plurality of receivers are obtained. Further, a beamformer matrix is formulated as a linear combination of columns of hermitians of the channel matrices. In addition, coefficients of the hermitians in the linear combination are determined to compute the beamformer matrix such that a lowest reception rate among reception rates of each of the receivers is maximized. Data signals are transmitted to the receivers by applying the computed beamformer matrix to data symbols to maximize the lowest reception rate.

Abstract: This disclosure relates a method and apparatus for generating pre-coding matrix codebook. The method for generating pre-coding matrix codebook, comprising: acquiring a universal set of pre-coding matrixes in a first format; acquiring a universal set of pre-coding matrixes in a second format; selecting a first predetermined number of pre-coding matrixes in the first format from the universal set of pre-coding matrixes in the first format; and selecting a second predetermined number of pre-coding matrixes in the second format from the universal set of pre-coding matrixes in the second format, according to the selected first predetermined number of pre-coding matrixes in the first format.

Abstract: Provided is a transmitter which is small in size and operates with high efficiency and compensates a delay error with high accuracy. A signal generation section 11 outputs a PM test signal and an AM test signal. The AM test signal is inputted to a multiplier 16 via a delay adjustment section 12 and a regulator 14. The PM test signal is inputted to the multiplier 16 via the delay adjustment section 12. A power measurement section 17 measures an average power of a multiplication signal which is outputted from the multiplier 16 and outputs a measured value to a control section 18. The control section 18 determines an amplitude delay time and a phase delay time on the basis of the inputted measured value and sets the determined delay times in the delay adjustment section 12.

Abstract: A mechanism for jointly correcting carrier phase and carrier frequency errors in a demodulated signal. A computer system may receive samples of a baseband input signal (resulting from QAM demodulation). The computer system may compute values of a cost function J over a grid in a 2D angle-frequency space. A cost function value J(?,?) is computed for each point (?,?) in the grid by (a) applying a phase adjustment of angle ? and a frequency adjustment of frequency ? to the input signal; (b) performing one or more iterations of the K-means algorithm on the samples of the adjusted signal; (c) generated a sum on each K-means cluster; and (d) adding the sums. The point (?e, ?e) in the 2D angle-frequency space that minimizes the cost function J serves an estimate for the carrier phase error and carrier frequency error. The estimated errors may be used to correct the input signal.

Abstract: In a method of digital communication where the transmitter includes a pulse-shaping filter and the receiver includes a plurality of corresponding matched filters, the pulse shaping filter is approximated to match a plurality of filters of the receiver for reducing the number of transmit shaping filters. The filter comprises a square-root raised cosine (SRRC) filter where the SRRC filter amplitude/phase response is approximated using a typical Parks-McClellan (remez) algorithm for designing linear phase FIR filters which, for a given set of input parameters, outputs a transmit filter coefficient set for the SRRC filter. The input parameters to the Parks-McClellan algorithm are chosen by iteration such that pass-band ripple, 3-dB point, and stop-band attenuation of the transmit filter meet or exceed specification requirements while the resulting transmit-receive filter pair ISI is minimized across a plurality of matched filter specifications.

Abstract: A method for communication includes modulating data to produce a series of symbols defined in a signal space. The symbols are pulse-shaped using a given pulse shape. A signal, which includes a sequence of the pulse-shaped symbols (104A . . . 104C) transmitted at a symbol rate that is higher than a Nyquist rate defined for the given pulse shape, is transmitted to a receiver (40). Prior to pulse-shaping the symbols, Inter-Symbol Interference (ISI) in the signal is pre-compensated for by applying a lattice precoding operation to the symbols. The lattice precoding operation confines the symbols to a predefined volume (110) in the signal space and is computed independently of any feedback from the receiver.

Abstract: A wireless communication system includes a) a first device having a transmitter part with a Tx-antenna for transmitting an electrical signal having a signal bandwidth BWsig and b) a second device having a receiver part with an Rx-antenna for receiving the transmitted electromagnetic signal. At least one of the Tx- and Rx- antennas is a narrowband antenna having an antenna bandwidth BWant, wherein the Tx- and/or Rx-antenna bandwidths fulfil the relation BWant=k·BWsig. The system is adapted to provide that k is smaller than 1.25, and the antenna bandwidth BWant is defined as the ?3dB bandwidth of the loaded antenna when it is connected to the communication system, and the signal bandwidth BWsig is defined as the bandwidth within which 99% of the desired signal power is located.

Abstract: A base station apparatus used in a mobile communication system where user terminals with various numbers of reception antennas may be situated includes a providing unit configured to provide plural reference signals according to the number of transmission antennas; a precoding unit configured to replicate each of a predetermined number of input signal sequences according to the number of transmission antennas, apply a predetermined precoding vector to each of the replicated sequences, and generate output signal sequences corresponding to the number of transmission antennas; and a transmitting unit configured to transmit transmission signals including the output signal sequences from plural transmission antennas; wherein at least one of the input signal sequences includes a control signal and one of the plural reference signals.

Abstract: Provided are an apparatus and method for compensating for a delay mismatch between an amplitude component signal and a phase component signal. The apparatus includes an amplitude path delay obtainer configured to obtain amplitude-delay information on a delay occurring in a propagation path of an amplitude component signal, a phase path delay obtainer configured to obtain phase-delay information on a delay occurring in a propagation path of a phase component signal, a delay controller configured to calculate and output a difference between the obtained amplitude path delay and the obtained phase path delay, and a variable delayer configured to compensate for a delay by changing a delay value on the basis of the delay difference output from the delay controller.

Abstract: A method for estimating timing in a wireless communication comprises the steps of receiving a plurality of symbol bursts corresponding to a plurality of time slots and selecting a subset of symbols from a first symbol burst of the plurality of symbol bursts. The subset comprises a first midamble symbol. The method further comprises the steps of calculating, for each symbol in the subset, a corresponding midamble estimation error, and determining the lowest calculated midamble estimation error to determine a timing for the first symbol burst. The method further comprises the steps of processing the first symbol burst utilizing the timing determined for the first symbol burst, and processing a second symbol burst of the plurality of symbol bursts utilizing the timing determined for the first symbol burst.

Abstract: An I/Q imbalance compensation block of a RF receiver for compensating an imbalance between an in-phase component and a quadrature component of an RF signal is disclosed. The compensation block includes a conjugation block; an adaptive finite impulse response (FIR) filter; and an adder. The filter use filter coefficients iteratively updated at least partly in response to a compensated digital signal. The filter can have a complex number for at least one, but not all of filter taps, and real numbers for other filter taps. The filter can be provided with adaptation step sizes different from filter tap to filter tap. The filter can also be provided with an adaptation step size(s) varying over time. The filter can also be provided with an adaptation step size(s) divided by the square norm of the compensated signal.

Abstract: A system is operated to transmit signals from a transmitter to a receiver. The transmitter is muted. A receiver transfer function for the receiver is adjusted so that an output signal of the receiver is minimized. A transmitter transfer function of the transmitter is set to be inverse to the adjusted receiver transfer function.

Abstract: A system and method for estimating a channel in a wireless receiver is disclosed. The method preferably applies to a communication system using the OFDM standard. The method comprises receiving a block of “n” transmitted symbols, the symbols including pilot symbols and “d” data symbols, estimating a channel using the pilot symbols to create a channel estimate, choosing a group of “m” strongest symbols from the “d” received symbols, compensating the “m” strongest symbols using the channel estimate to create a group of “m” compensated symbols, re-estimating the channel using the group of “m” compensated symbols and pilot symbols; and either (1) repeating the steps of choosing a group of “m” strongest symbols, compensating the group of “m” strongest symbols and re-estimating the channel, or (2) using a latest channel estimate to compensate all symbols within the block.

Abstract: Information that includes first information identifying integer quotients obtained by divisions using prediction residuals or integers not smaller than 0 that increase monotonically with increases in the amplitude of the prediction residuals, as dividends, and a separation parameter decided for a time segment corresponding to the prediction residuals or a mapped integer value of the separation parameter, as a modulus, and second information identifying the remainders obtained when the dividends are divided by the modulus is generated as a code corresponding to the prediction residuals, and each piece of side information that includes the separation parameter is subjected to variable length coding.

Abstract: Techniques and devices for antenna selection in a multiple-input-multiple-output (MIMO) system, in which communication is between a transmitter having a first plurality of radio-frequency (RF) chains coupled to a first plurality of antennas and a receiver having a second plurality of RF chains coupled to a second plurality of antennas, are provided. Techniques include receiving consecutive sounding packets each have a training symbol and that collectively sound a full-size channel for the MIMO system. A sub-channel estimate for each sounding packet can then be determined based on various factors, such as a known power level rule and gain factor. Scaling factors may be applied to each of these sub-channel estimates to produce a scaled sub-channel estimates.

Abstract: A multi-tone transceiver with a components forming a transmit path and a receive path configured to couple via a subscriber line to an opposing multi-tone transceiver for frequency division multiplexed multi-tone modulated communications therewith is disclosed. A noise margin channel identifier is configured to identify within a received tone set, discrete tones each associated with a corresponding one of at least two channels differing from one another in a relative noise margin of associated tones. A Viterbi decoder is responsive to the channel identification provided by the noise margin channel identifier to discretely decode each of the at least two channels; thereby improving the fidelity of the error correction provided by the Viterbi decoder by discretely processing the identified channels within the received set of tones.

Abstract: A reception device which receives a signal transmitted by a transmission device which changes at least one of a modulation scheme and a coding rate. The reception device includes an equalization unit which equalizes a received signal in frequency domain, a reliability calculation unit which calculates the reliability of a transmitted bit from the received signal after equalization, a mutual information amount calculation unit which calculates a mutual information amount based on the reliability of the transmitted bit calculated by the reliability calculation unit, and a notification signal generation unit which sets at least one of a modulation scheme and a coding rate based on the mutual information amount calculated by the mutual information amount calculation unit to generate a signal to be reported to the transmission device.

Abstract: Systems and methodologies are described that facilitate signal separation across different carriers within a wireless communications environment. The systems and methods can identify a carrier spacing that can be based upon a tone spacing associated with two or more carriers. Such carrier spacing can be employed within a network in order to mitigate signal separation with multiple carriers. The subject innovation can further evaluate a carrier raster associated with a network in order to identify a carrier spacing to ensure orthogonality between tones from different carriers.

Abstract: Methods and apparatus are provided for performing equalization of communication channels. In an embodiment of the invention, at least one tap can be selected from a set of feedforward taps of feedforward filter circuitry, where each tap of the selected at least one tap has a magnitude that is greater than or substantially equal to a magnitude of any tap of the set of feedforward taps that is not in the selected at least one tap. In addition, at least one tap can be added to a set of taps of feedback filter circuitry in communication with the feedforward filter circuitry. The invention advantageously allows for more efficient and reliable equalization of communication channels.

Abstract: Techniques are provided for computing downlink beamforming weights based on the received data at a base station from a mobile station in a MIMO communication system. An uplink transmission is received at a plurality of antennas at a first communication device from a second communication device, where the uplink transmission comprises a plurality of uplink subbands. The uplink spatial signature is estimated for each of the plurality of uplink subbands. The uplink spatial signature is decomposed into a plurality of direction of arrival (DOA) components for each uplink subband using a transform. Data representing multiple propagation paths between the first communication device and the second communication device is computed for each DOA component. A plurality of direction of departure (DOD) components for each of a plurality of downlink subbands is computed based on the data representing the multiple propagation paths.

Abstract: Data may be transmitted from a first communications device using multiple antennas to a second communications device based on precoder feedback defining a grid of transmission beams. A first precoder index may be received from the second communications device, and a second precoder index may be received from the second communications device. At least one symbol stream may be processed based at least in part on the first and second precoder indices to generate antenna signals for respective antenna elements of the multiple antennas, and the antenna signals may be transmitted over the multiple antennas to the communications device. Related base stations and user equipment are also discussed.

Abstract: The present invention proposes an LTE eNodeB receiver channel estimation technique that is referred to as reduced complexity minimum mean squared error (MMSE) technique for channel estimation. From the invention's assumptions, estimations and modified calculations, the present invention generates precise channel estimates of RS using the reduced complexity MMSE matrix and previously computed LS channel estimates HLS is as follows: (Formula I) which generates precise channel estimates of RS using the reduced complexity MMSE matrix and previously computed LS channel estimates. As a second aspect of the present invention, it is desired that the SNR be estimated within ?3 dB of the actual channel SNR. As a third aspect of the invention, an adaptive method of data channel interpolation from RS channel is being proposed in this invention.

Abstract: A method for air to ground communication interference mitigation within an aircraft equipped with a multi-beam array antenna includes adjusting a modulation symbol interleaving and/or forward error correction of an aircraft receiver interface in response to detected interference from an interferer. The method further includes reducing a data rate of the aircraft receiver interface when the adjusting of the modulation symbol interleaving and/or forward error correction does not mitigate the detected interference. Another method for interference mitigation may include performing antenna beam-steering away from a geographic (GEO) arc during an aircraft turn. This method further includes reducing an aircraft transmitter transmit power when a signal quality of a forward link is within a predetermined range of a signal quality threshold.

Abstract: Provided are a radio transmission device and a radio transmission method capable of improving downlink and uplink throughput even when performing dynamic symbol allocation. In the device and the method, BS and MS share a table correlating a basic TF as a combination of parameters such as TB size used for transmitting only user data, an allocation RB quantity, a modulation method, and an encoding ratio, with a derived TF having user data of different TB size by combining L1/L2 control information. Even when multiplexing L1/L2 control information, Index corresponding to the basic TF is reported from BS to MS.

Abstract: A noise abatement method and system for impulse noise in an RF receiver where the RF analog signal is converted to a digital signal prior to being connected to a demodulator. Two filters are used to detect impulse noise signals even under out-of-band interferer conditions, and prevent the impulse noise from reaching the input to the demodulator. A first of the two filters detects impulse noise using signals lower than the frequency bandwidth of the desired signal, and a second of the two filters detects impulse noise using signals higher the frequency bandwidth of the desired signal. A mean magnitude of the signal is detected over a predetermined time T and is used to select which filter to use for noise abatement.

Abstract: Techniques to process data for transmission over a set of transmission channels selected from among all available transmission channels. In an aspect, the data processing includes coding data based on a common coding and modulation scheme to provide modulation symbols and pre-weighting the modulation symbols for each selected channel based on the channel's characteristics. The pre-weighting may be achieved by “inverting” the selected channels so that the received SNRs are approximately similar for all selected channels. With selective channel inversion, only channels having SNRs at or above a particular threshold are selected, “bad” channels are not used, and the total available transmit power is distributed across only “good” channels. Improved performance is achieved due to the combined benefits of using only the NS best channels and matching the received SNR of each selected channel to the SNR required by the selected coding and modulation scheme.

Abstract: The invention relates to a weighting circuit for a receiver (1), which is designed to receive a multi-carrier signal consisting of carrier signals. According to the invention, the carrier signals are weighted by the weighting circuit (18) in such a way that the parasitic signal energy has the same intensity in all weighted carrier signals. In a preferred embodiment of the invention, the weighting circuit comprises at least one multiplier that multiplies an assigned a carrier signal by a stored weighting co-efficient. The stored weighting coefficients constitute reliability information for the various carrier signals.

Abstract: According to certain embodiments, a method for removing a peak of an input signal includes forming a peak group including multiple peaks having an amplitude greater than a preset signal threshold value in the input signal, generating a cancellation pulse corresponding to the peak group, and generating a output signal by subtracting the cancellation pulse from the input signal.

Abstract: Common-mode termination within communication systems. Termination is implemented with respect to two respective portions of a system: the intentional signaling within a communication system as well as any unintentional signaling which may be coupled into the system. Such unintentional signaling may be incurred in a variety of ways including via interference which may be generated by the system itself or by other devices or components external to the system. In addition, such unintentional signaling made be characterized as common-mode (CM) signaling, in that, it generally affects different respective portions of the system similarly or in the same manner. Various communication systems may include two or more devices implemented therein, that effectuate signaling via one or more communication links there between. Appropriate termination is made with respect to both the intentional and unintentional signaling portion of the system using any of a variety of impedance types (e.g.

Abstract: The invention relates to a method, an arrangement and a device for transmitting information between a central unit (DSLAM) and at least one decentralised unit (TN1, TN2, TN3) in a communication network. During, for example, the training phase in a decentralised unit (TN1, TN2, TN3), a distance between the at least one decentralised unit (TN1, TN2, TN3) and the central transmission unit (DSLAM) is estimated and a value (kl0) representing said distance is transmitted to the central unit (DSLAM). In the central unit (DSLAM), a value (kl0?) representing a fictional distance is calculated using the transmitted value (kl0) and said value (kl0?) is transmitted to the decentralised unit (TN1, TN2, TN3). Subsequently, information is transmitted in accordance with the value (kl0?) representing the fictional distance.

Abstract: A device (100, 200) and a method is provided for processing a signal. The device comprises a filter unit 5 (101, 201); an FFI unit (102, 202) operatively connected to the filter unit and being located after the filter unit along a signal path for the signal; and a compensation unit (103, 203) operatively connected to the FFI unit and being located after the FFT unit in the signal path. The compensation unit is adapted to compensate for attenuation of the signal, which has been caused by the filter unit.

Abstract: A master device and slave devices are connected with each other through an SDA and an SCL, and at least one of a serial communication data signal communicated through the SDA and a serial communication clock signal communicated through the SCL is latched with use of a noise removal clock signal whose frequency is higher than that of the serial communication clock signal, and is taken in.

Abstract: Communication systems are described that use signal constellations, which have unequally spaced (i.e. ‘geometrically’ shaped) points. In many embodiments, the communication systems use specific geometric constellations that are capacity optimized at a specific SNR. In addition, ranges within which the constellation points of a capacity optimized constellation can be perturbed and are still likely to achieve a given percentage of the optimal capacity increase compared to a constellation that maximizes dmin, are also described. Capacity measures that are used in the selection of the location of constellation points include, but are not limited to, parallel decode (PD) capacity and joint capacity.

Abstract: A method for Automatic Gain Control (AGC) in a receiver is performed by a circuit having an inner loop and an outer loop. The method includes performing an outer loop energy detection, mitigating interference using the outer loop energy detection, and performing a frequency domain energy measurement in the inner loop. The method also includes adjusting a digital gain component in the inner loop and an analog gain component in the outer loop in response to the frequency domain energy measurement.

Abstract: Techniques to process data for transmission over a set of transmission channels selected from among all available transmission channels. In an aspect, the data processing includes coding data based on a common coding and modulation scheme to provide modulation symbols and pre-weighting the modulation symbols for each selected channel based on the channel's characteristics. The pre-weighting may be achieved by “inverting” the selected channels so that the received SNRs are approximately similar for all selected channels. With selective channel inversion, only channels having SNRs at or above a particular threshold are selected, “bad” channels are not used, and the total available transmit power is distributed across only “good” channels. Improved performance is achieved due to the combined benefits of using only the NS best channels and matching the received SNR of each selected channel to the SNR required by the selected coding and modulation scheme.

Abstract: This invention provides a method for exploiting precoder optimization gains and multi-user diversity gains with interference alignment in general MIMO wireless networks including multiple users. Specifically, two embodiments exploit either a gradient-based search or iteratively orthogonalizing inference. The method can achieve near-optimal performance at a low complexity. Furthermore, a scheduling criterion is provided for wireless networks comprised of a large number of mobile stations in each cell. The criterion can be done independently in each cell to significantly reduce information exchanged between base stations in different cells compared to the methods that perform joint scheduling over all cells. The two embodiments can be utilized in a spectrally efficient communications network equipped with relaying nodes.

Abstract: A method of operating a radio-frequency (RF) circuitry and a signal-processing circuitry in a mobile telephone apparatus includes at least partially disabling the signal-processing circuitry while transmitting or receiving signals. In one example, a processor is efficiently disabled by generating and servicing an interrupt of relatively high priority. One advantage of this example is that preexisting, legacy code can be maintained, while still achieving the desired objectives. The processor can be enabled by generating and servicing a second high priority interrupt.

Abstract: The device, system and method reduce the peak-to-average power ratio (PAPR) of a signal field symbol in a multi-carrier modulation communication signal. The device includes an antenna, a transceiver coupled to the antenna, and a controller to cooperate with the transceiver and being configured to reduce the PAPR of the signal field symbol in the multi-carrier modulation communication signal. The controller is configured to transmit information using a frame format including a header and a data field, the header having a signal field and a service field each having a plurality of bits, the plurality of bits of the signal field defining the signal field symbol. The controller selectively changes at least the header bits to generate the signal field symbol with a reduced or lowest PAPR.

Abstract: A method of controlling interference in a wireless communication system is disclosed. A method for controlling interference by a transmitter of a wireless communication system with multiple antennas comprises generating a base codebook subset including at least one precoding matrix selected from a base codebook; transmitting a base codebook subset indication, which represents the at least one precoding matrix included in the base codebook subset, to a receiver; and precoding data using the base codebook subset or the base codebook.

Abstract: A noise cancellation system has a first transformer with an input side and an output side, the input side having first and second taps coupled to a signal provider, and a center tap providing a first common-mode voltage signal. A first digital subscriber line (xDSL) modem has an input coupled to the output side of the first transformer and an output coupled to customer premises equipment (CPE) for providing an xDSL signal to the CPE. A second transformer has an input side and an output side, the input side having first and second taps coupled to a signal provider, and a center tap providing a second common-mode voltage signal. A second xDSL modem is coupled to the output side of the second transformer. The difference between the first and second common-mode voltage signals is provided to at least one of the first and second xDSL modems to filter out noise from the xDSL signal provided by that modem.

Abstract: A communication device and a mobile station to perform interference alignment, and an interference alignment method are provided. Interference alignment may be performed to enable an interference signal, received in a mobile station, to be removed using channel information fed back from the mobile station.