Abstract: A method and apparatus of reducing interference in space frequency block coding (SFBC) communication are disclosed. SFBC encoding is performed on at least one pair of symbols. The symbols are assigned to subcarriers in accordance with a frequency assignment pattern assigned to a cell. Different frequency assignment patterns are assigned to neighboring cells. Cells in the network may be divided into a plurality of groups and a different frequency assignment pattern may be assigned to each group of cells. The frequency assignment pattern may be defined such that subcarriers mapped to a pair of symbols in one cell are interlaced to subcarriers mapped to a pair of symbols in a neighbor cell. Alternatively, the frequency assignment pattern may be defined such that subcarriers mapped to a pair of symbols in one cell are shifted in a neighbor cell.

Abstract: A method and system for dynamic configuring of one or both of a transmitter pulse-shaping filter and a receiver pulse-shaping filter to generate a total partial response that incorporates a predetermined amount of inter-symbol interference (ISI). The predetermined amount of ISI is determined based on an estimation process during extraction of data from an output of the receiver pulse-shaping filter, such that performance of total partial-response-based communication matches or surpasses performance of communication incorporating filtering based on no or near-zero ISI. The reconfiguring may comprise obtaining data relating to changes affecting one or more of: the pulse-shaping filtering, and a channel and/or an interface used in the communication of data based on the total partial response, and adjusting the filter configuration, such as by determining a new optimized filtering configuration or changes to existing configurations (e.g., by applying a filtering optimization process).

Abstract: A delay quantity estimation apparatus comprises a first correlation value arithmetic unit to calculate a first correlation value as a correlation value between a first input signal and a feedback signal delayed with a first delay value; a second correlation value arithmetic unit to calculate a second correlation value as a correlation value between the first input signal and a feedback signal delayed with a second delay value; and a delay quantity estimation unit to estimate a delay quantity of the feedback signal with respect to the input signal on the basis of the first difference value as a difference between the first correlation value and the second correlation value, wherein the second delay value is a value given by adding a certain value to the first delay value.

Abstract: An orthogonal frequency division multiplex (OFDM) transmitter may adaptively load each sub-carrier, buffering less than an OFDM frame in order to reduce hardware requirements and latency. The transmitter may use feedback information from the receiver regarding the quality of the sub-carriers. In addition, combining repetition and puncturing to achieve a desired date rate per class further reduces hardware by simplifying or even eliminating an interleaver. Additional mitigation and even performance enhancement techniques are incorporated to address inter-class boundaries within an OFDM frame, such as introducing transition classes. Channel state information may be reported in various formats including full bitmap, changed subchannels, and reported bad subchannels.

Abstract: A method in a receiver includes receiving from a transmitter an instruction to check for messages from the transmitter at intervals having a specified time period. A frequency error of the receiver relative to the transmitter is estimated at the receiver, and an actual time period that does not exceed the specified time period is selected based on the estimated frequency error. The receiver is activated periodically according to the selected actual time period so as to reset the frequency error.

Abstract: Method and apparatus for decoding a transmitted signal by a receiver in a MIMO system into a first estimate component for estimating a first signal, a first interference component indicating interference resulting from a correlation relationship among a set of signals to be transmitted, and a first noise component. A base station generates the transmitted signal from the set of signals through a coding process, the coding process defining a correlation relationship amongst the set of signals. The correlation information about the correlation relationship is transmitted to the receiver directly or by a dedicated reference symbol. The decoding is performed by determining a linear receiver filter for the first signal in accordance with the correlation information, and de-correlating the first signal and interferences.

Abstract: A filter includes, in at least one aspect, one or more differential inputs to receive one or more differential input signals, a first filter stage to provide one or more primary poles corresponding to a first frequency associated with the one or more differential input signals, a second filter stage coupled with the first filter stage to provide one or more secondary poles corresponding to a second frequency associated with the one or more differential input signals, the second frequency and the first frequency having a predefined relationship, and one or more differential outputs coupled with the second filter stage to provide one or more differential output signals.

Abstract: A remote radio head unit (RRU) system for multiple operating frequency bands, multi-channels, driven by a single or more wide band power amplifiers. More specifically, the present invention enables multiple-bands RRU to use fewer power amplifiers in order to reduce size and cost of the multi-band RRU. The present invention is based on the method of using duplexers and/or interference cancellation system technique to increase the isolation between the transmitter signal and receiver signal of the RRU.

Abstract: A method and apparatus for modeling distortion of a non-linear device are disclosed. A pre-distorter model has a plurality of branches. Each branch receives a different output basis function signal. At least one branch includes a down-sampler, a memory structure and an up-sampler. The down-sampler down-samples the received output basis function signal received by the branch by a factor of 1/Mk, where Mk is different for each of the at least one branches. The memory structure includes at least one delay element to delay the output of the down-sampler according to a predetermined delay. The memory structure has an output based on an output of the at least one delay element. The up-sampler up-samples the output of the memory structure by the up-sampling factor, Mk.

Abstract: An apparatus for estimating far-end crosstalk RDS-FEXT, i (fd) or an end (C1-2) of a communication line (C1) furthest from a transceiver (10-1) to which the communication line (C1) is connected. The apparatus is configured to: measure upstream noise RUS-Noise(fu) at an upstream frequency (fu), the upstream noise RUS-Noise(fu) induced in the communication line (C1) due to the crosstalk; select a downstream frequency (fd) for which the far-end crosstalk RDS-FEXT, i (fd) is to determined; and estimate the far-end crosstalk RDS-FEXT, i (fd)? as a function of the upstream Noise RUS-Noise(fu), the upstream frequency (fu) and the downstream frequency (fd). An apparatus reversing upstream and downstream features, a system, a computer readable medium and related methods are also described.

Abstract: The present invention provides a radio communication system which includes a plurality of radio base station apparatuses that transmit reference signals orthogonal to each other among a plurality of transmitting antennas and a mobile terminal apparatus that performs channel estimation based on the reference signals transmitted from the plurality of radio base station apparatuses, sets priority among a plurality of neighboring radio base station apparatuses and introduces a bias in the number of reference signals that can be allocated to each radio base station apparatus according to the priority from the radio resources shared among the plurality of neighboring radio base station apparatuses.

Abstract: A mobile station receiving a signal from a base station experiences time/frequency varying channel conditions. In order to get the maximum throughput from a base-station, it is necessary to adjust the modulation and coding schemes to the actual channel quality. To do so, mobile receivers are required to probe the radio channel condition and feedback a limited set of estimated channel state information parameters such as CQI, RI, and PMI. The invention uses modulation-specific mutual information as a basic metric for CQI-PMI-RI computation to yield high bandwidth efficiency under both flat fading and interference conditions as well as time and frequency selective fading and interference conditions, at reasonable complexity.

Abstract: The present invention provides a data transmission method, a transmitter, and a receiver in a coordinated communication system, including: precoding, by a first transmitter, its payload data by using a first precoding matrix to obtain first precoded data; precoding, by the first transmitter, coordinated data by using a second precoding matrix to obtain second precoded data to cancel interference with the first precoded data at a receiver caused by data transmitted by another transmitter; and transmitting the first precoded data and the second precoded data after the precoding to the receiver. According to the method, the first transmitter codes its payload data by using the first precoding matrix; and codes the coordinated data by using the second precoding matrix to cancel, by using different precoding matrices, the interference with the first precoded data at the receiver caused by the data transmitted by another transmitter.

Abstract: In a method for generating a physical layer (PHY) data unit for transmission via a communication channel, a first set of modulation coding schemes (MCSs) and a second set of MCSs that correspond to a number of spatial streams and a number of encoders are provided. The first set of MCSs correspond to a first channel bandwidth and the second set of MCSs correspond to a second channel bandwidth, and the first set of MCSs is different than the second set of MCSs. An MCS is selected from the first set of MCSs when the PHY data unit is to be transmitted using a channel having the first channel bandwidth, and the MCS is selected from the second set of MCSs when the PHY data unit is to be transmitted using a channel having the second channel bandwidth. Information bits are encoded using the number of encoders and according to the selected MCS, and the encoded information bits are parsed into the number of spatial streams.

Abstract: The present invention relates to a system and to a method for the cooperation among base stations, in which a communication service is provided to a plurality of communication terminals through the plurality of base stations. When channel state information of a communication terminal is acquired, a serving base station selects a serving channel code matching the channel state information from a codebook, calculates linear transform information using the serving channel code and the channel state information, and transmits the serving channel code to a cooperative base station. When the cooperative base station receives a cooperation channel code, the serving base station calculates serving weight information of the serving base station and cooperation weight information of the cooperative base station using the serving channel code and the cooperation channel code, and determines a beam forming vector by applying the linear transform information to the serving weight information.

Abstract: Signals propagating from an aggressor communication channel can cause detrimental interference in a victim communication channel. One or more noise cancellers can generate an interference compensation signal to suppress or cancel the interference based on one or more settings. A controller can execute algorithms to find preferred settings for the noise canceller(s). The controller can use a feedback signal (e.g., receive signal quality indicator) received from a victim receiver during the execution of the algorithm(s) to find the preferred settings. One exemplary algorithm includes sequentially evaluating the feedback resulting from a predetermined list of settings. Another algorithm includes determining whether to move from one setting to the next based on the feedback values for both settings. Yet another algorithm includes evaluating a number of sample settings to determine which of the sample settings result in a better feedback value and searching around that sample setting for a preferred setting.

Abstract: Certain aspects of the present disclosure relate to a method for equalizing a pulse signal corrupted by a noise and by various channel effects for obtaining a signal based on the periodic-sinc pulse, which is suitable for Finite Rate of Innovation (FRI) processing applied at a receiver of a pulse-based communication system (e.g., an Ultra-Wideband receiver).

Abstract: A communication system is described that includes a transmitter to transmit data using one or more drivers. The drivers may drive the data in a manner that accords with pre-emphasis being selectively enabled or disabled for each driver. The pre-emphasis, when enabled, is applied by corresponding driver. The drivers may also be programmably selected and enabled or disabled. The transmitter also includes one or more driver selection circuits. The driver selection circuits may be configured to select one or more of the drivers to transmit the data, to selectively enable or disable pre-emphasis to be applied by each of the selected drivers, and to provide the data, or representations thereof, to the selected drivers.

Abstract: A method for processing a signal with a corresponding noise profile includes analyzing spectral content of the noise profile, filtering at least one noise harmonic within the signal based on the analyzed spectral content, and limiting the filtered signal. The noise profile may include a phase noise profile. The signal may include a sinusoidal signal and/or a noise signal. At least one filter coefficient that is used to filter the at least one noise harmonic may be determined. The filtering may include low pass filtering. The limiting may include hard-limiting of the filtered signal. A phase difference between the limited signal and a reference signal may be detected.

Abstract: Precoding information prior to MIMO transmission is described, comprising determining a suitable preceding perturbation. The perturbation is determined by assembling a list of candidate perturbations in reduced lattice space, transforming these back into information lattice space and determining which candidate precoder perturbation is most suitable given a performance criterion.

Abstract: A receiving device which receives a signal transmitted from a transmitting device by using a power amplifier, the receiving device includes a calculating unit which performs distortion compensation on a symbol included in a reception signal, a delay unit which holds a signal for a result from the distortion compensation, and the calculating unit performing the distortion compensation on a second symbol at a timing later than a first symbol based on a coefficient corresponding to an amplification characteristic of the power amplifier and on the signal for the result from the distortion compensation with respect to the first symbol held by the delay unit.

Abstract: Techniques for transmitting pilot and for processing received pilot to obtain channel and interference estimates are described. A terminal may generate pilot symbols for a first cluster in a time frequency block based on a first sequence and may generate pilot symbols for a second cluster in the time frequency block based on a second sequence. The first and second sequences may include common elements arranged in different orders and may be considered as different versions of a single sequence. The terminal may transmit the pilot symbols in their respective clusters. A base station may obtain received pilot symbols from multiple clusters in the time frequency block. The base station may form each of multiple basis vectors with multiple versions of the sequence assigned to the terminal and may process the received pilot symbols with the multiple basis vectors to obtain a channel estimate for the terminal.

Abstract: Self-jamming interference associated with a transmitted signal of an aggressor transmitter may affect a received signal of a victim receiver in a communication device. An aggressor transmitter may provide two or more non-linear interference cancelation (NLIC) signals, including a first NLIC signal and a second NLIC signal. A NLIC unit may reconstruct an interference signal based on a selected one of the first NLIC signal or second NLIC signal. Power of the transmitted signal at the aggressor transmitter may be used to select either the first interference cancelation signal or the second interference cancelation signal. The first and second NLIC signals may differ by the use of digital pre-distortion (DPD) at the aggressor transmitter.

Abstract: The invention provides a receiver associated with a body, e.g., located inside or within close proximity to a body, configured to receive and decode a signal from an in vivo transmitter which located inside the body. Signal receivers of the invention provide for accurate signal decoding of a low-level signal, even in the presence of significant noise, using a small-scale chip, e.g., where the chip consumes very low power. Also provided are systems that include the receivers, as well as methods of using the same.

Abstract: Estimating a channel impulse response (CIR) for a wireless transmission, for example a multimedia broadcast multicast services single frequency network (MBSFN) transmission, may be performed by a receiver of an wireless subframe, without requiring operational memory in excess of what is needed for CIR estimation of unicast signaling, while providing enhanced delay spread coverage. The wireless subframe may be a MBSFN subframe. The receiver may form an aggregate vector of pilot tones extracted from an OFDM reference symbol of an wireless subframe. The receiver may subsample the aggregate vector to obtain a plurality of sub-vectors each comprising a distinct subsampling phase. The receiver may process the plurality of sub-vectors using an inverse fast Fourier transform to obtain time domain representations of each of the sub-vectors. The receiver may combine the time domain representations in various ways to obtain a CIR estimate for the wireless subframe.

Abstract: For voltage values (observed noise sequence) in an electronic power line (communication medium) which are obtained at a predetermined interval, initial values of noise characteristics based on a statistic of the observed noise sequence itself are decided by a moment method (S301 to S307), the noise characteristics (state transition probabilities and state noise power) for maximization of the likelihood of the observed noise sequence are obtained from the initial values by MAP (Maximum A Posteriori) estimation using a Baum-Welch algorithm (S309 to S312), a state sequence is estimated from the obtained noise characteristics, and an impulsive noise at each time point is detected.

Abstract: The present invention provides an apparatus and method for estimating a frequency offset which are robust against non-Gaussian noise. In a frequency offset estimation method of an Orthogonal Frequency Division Multiplexing (OFDM) system using a training symbol, the method includes receiving a reception signal, setting a specific initial frequency offset corresponding to the reception signal, and calculating a log-likelihood function based on a Complex Isotropic Symmetric ? Stable (CIS?S) probability density function obtained by modeling non-Gaussian noise included in the reception signal and estimating an optimum frequency offset based on the log-likelihood function and the initial frequency offset through a Maximum Likelihood Estimator (MLE). Accordingly, in a non-Gaussian noise environment, frequency offset estimated performance can be improved as compared with a conventional method in which noise is assumed to be a normal distribution.

Abstract: A channel estimating method and device are provided. The method includes: performing multi-path searching on a pilot channel, and performing interpolation on a channel estimation value at a radial position of the multi-path searching (101); performing raised cosine de-convolution on the channel estimation value that undergoes the interpolation (102); acquiring the channel estimation value at each radial position in the pilot channel according to the channel estimation value that undergoes the raised cosine de-convolution and a sample deviation acquired by performing the multi-path searching (103). The channel estimating method and device eliminate the sample deviation of the channel estimation value, improve the demodulation performance, and evidently reduce the operation workload.

Abstract: A system and method for realizing virtual interference alignment. The system comprises a retrieving module, a determination module and a precoding module. The retrieving module retrieves source data. The determination module receives shared data and transmission information. The shared data and transmission information are generated from a shared signal received from one or more participating communication systems associated with a first virtual transmitting group. The precoding module calculates a precoding vector describing one or more requirements of interference alignment based at least in part on the transmission information. The precoding module generates a first transmission signal based at least in part on the precoding vector, the source data and the shared data.

Abstract: Multi-band single-carrier modulation. A novel approach is presented by which interference compensation may be performed for signals received by a piconet operable device. The piconet operable device may be implemented within a region that includes two or more SOPs (Simultaneously Operating Piconets). Estimation of the level and location of interference is performed and the input to a decoder (within the piconet operable device) is selectively weighted to ensure that the effect of any existent interference within the signal received by the piconet operable device is minimized. Different interference levels are dealt with differently. For one example, portions of the received signal having undergone a large amount of interference may be simply treated as erasures with respect to the input the decoder. For another example, portions of the received signal having undergone some smaller degree of interference, but some interference nonetheless, may be de-weighted before being provided to the decoder.

Abstract: An evaluation device is configured to provide a transceiver system with performance information thereof. The transceiver system models a channel between a transmitter and a receiver thereof using Nakagami distribution with a fading parameter. The evaluation device includes a setting module operable to set an average signal-to-noise rate (SNR) for the channel between the transmitter and the receiver, a computing module operable to estimate a symbol error rate related to a signal received by the receiver from the transmitter based upon the fading parameter and the average SNR, and an output module operable to provide the average SNR and the symbol error rate as the performance information of the transceiver system.

Abstract: The method for mitigating interference in Orthogonal Frequency Division Multiplexing (OFDM) communications systems uses comb-type pilot signals in a doubly selective channel where the pilot signals are calculated to have zero correlation sequences in order to maintain orthogonality where there is a high Doppler effect to mitigate intercarrier interference. The pilot signals may be precomputed, stored in a look-up table, and selected based upon total power constraints of the pilot signals. The steps of the method may be performed by a Finite Impulse Response (FIR) equalizer.

Abstract: A receiver for receiving signals of a protocol in which traffic data is redundantly modulated onto both of two carriers according to a predetermined decision scheme, the receiver comprising: an input for receiving signals on the two carriers; a demodulator for demodulating the signals received on each of the two carriers to form two respective received data streams; first transformation logic for generating a first candidate set of traffic data by processing the received data streams by the functional inverse of the predetermined decision scheme; second transformation logic for generating a second candidate set of traffic data by aggregating corresponding bits of each of the received data streams; and a traffic data set selector for selecting data from either the first candidate set of traffic data or from the second candidate set of traffic data for further processing, the traffic data set selector being configured to make that selection in dependence on the relative strength with which signals on the two ca

Abstract: An apparatus in a wideband radio transceiver for mitigating interference between a wideband radio operating in a wide frequency band and a narrowband radio operating in a narrow frequency band within the wide frequency band. The effects of transmissions by the wideband radio on the narrowband radio are reduced by creating by the wideband radio, a transmitter notch of decreased transmit power centered at a frequency in the wide frequency band that is fixed in relation to the wideband carrier frequency. The wideband carrier frequency is then adjusted so that the transmitter notch is aligned with the second radio's narrow frequency band. The effects of transmissions by the narrowband radio on the wideband radio are reduced by creating by the wideband radio, a fixed receiver notch of decreased receiver gain in the wideband receiver, and aligning the narrowband signal with the fixed receiver notch.

Abstract: There is described the use of Digital Radio Frequency Memory (DRFM) modules to jam certain communication signals while allowing others to be received on a given frequency band. The DRFM modules exploit the multi-path phenomenon by using transmitted signals to cause full band destructive echoes and/or distortions. A set of receivers used in conjunction with the DRFM modules are aware of the exact multi-path induced by the DRFM modules and are therefore able to mitigate or even benefit from the effects of the destructive multi-path and maintain or improve communications.

Abstract: There is provided a MIMO wireless communication system, which comprises at least one base station having plural transmitting antennas and at least one user equipment having at least one receiving antennas, the base station being capable of accommodating plural user equipments by precoding based on a codebook, wherein, each of the plural user equipments comprises: a channel estimation unit for conducting a channel estimation based on a pilot signal transmitted from the base station, to obtain a channel information; a codeword determination unit for determining a first codeword that results in the maximum signal-noise-ratio, and at least one second codeword that results in the minimum signal-noise-ratio, based on the channel information; and a transmission unit for feedbacking the first codeword and the second codeword(s) to the base station, the base station is configured to schedule the user equipments based on the first codeword and the second codeword so that a predetermined system performance metric is opt

Abstract: A method for reducing mutual interference of multi-carrier includes: adjusting the phase of at least one modulated signal; modulating all baseband signals onto respective modulated signals; judging whether all baseband signals can be demodulated correctly, and adjusting the phase of at least one modulated signal when there is any modulated signal which cannot be demodulated correctly, until all the baseband signals can be demodulated correctly; and accepting the current phase value as the phase value of the modulated signal of each baseband signal when all can be demodulated correctly. The present disclosure also discloses a device for reducing mutual interference of multi-carrier. The present disclosure can improve performance obviously under the circumstance of arranging the multi-carrier adjacent to each other, and make multiple carriers operate simultaneously in the same radio signal coverage area, therefore the frequency spectrum utilization ratio is greatly improved.

Abstract: A receiver operatively coupled to an antenna structure capable of receiving a first plurality of RF signals is disclosed herein. The receiver includes an RF processing network operative to perform weighting and combining operations within the RF domain using the first plurality of RF signals so as to produce a second plurality of RF signals. Also provided is a downconverter configured to downconvert the second plurality of RF signals into a second plurality of down-converted signals. In alternate implementations certain of the weighting and combining operations are performed at baseband and the remainder effected within the RF domain. A transmitter of corresponding architecture is also disclosed.

Abstract: In one or more embodiments, a circuit is configured to receive a differential signal from a transmitter that is isolated from the receiver circuit and that includes a common-mode suppression circuit and signal combining circuit coupled to the corresponding lines carrying the differential signals. The common-mode suppression and signal combining circuits are configured to suppress common-mode signals of differential signals communicated on the set of differential signal lines and combine to form of differential-mode components of the differential signals.

Abstract: Disclosed is a wireless receiving apparatus, whereby inter-antenna interference can be reduced without inducing an increase of a mounting area due to an increase of the number of antennas, and the number of RFIC input terminals, circuit scale and power consumption can be reduced. In the wireless receiving apparatus (100), when a receiving antenna (110-1) and a down-converter (130) are connected with a multiplexer (120) therebetween, a capacity control unit (190-2) controls the capacity value of the capacity-variable parasitic element (180-2) connected to the receiving antenna (110-2) such that the communication capacity of the receiving antenna (110-1) is maximum.

Abstract: A method for equalizing a received signal is provided. The signal is filtered and transmitted over a channel using an encoding scheme, where the encoding scheme has transmit symbols. This transmitted signal is then shaped such that the filtering and equalization adjust a set of taps in an equalization window so that the taps from the set are substantially equal to one another. Inter-symbol interference is then compensated for in the equalized signal using a speculative DFE with significantly reduced comparator levels.

Abstract: Methods and apparatus for dynamically compensating for the effects of interference between multiple wireless communications apparatus. In one embodiment, the method comprises providing a first wireless communication apparatus operating in a first band and a second wireless communication apparatus operating in the same first band (or proximate to the first band and with a comparatively high transmitter power), where the second wireless communication apparatus operates according to a different communication protocol than the first wireless communication apparatus and further change in physical configuration with respect to one another. Based on the physical configuration, interference is compensated for between the first wireless communication apparatus and the second wireless communication apparatus “on the fly” by selecting and operating according to one of a plurality of operational protocols.

Abstract: The present invention discloses a method and apparatus for bit and power allocation and a communication system. The method for bit and power allocation comprises: determining a set of candidate modulation modes for sub-channels; constructing an SNR lookup table according to a predetermined target BER, the SNR lookup table containing a relationship of an SNR and the number of bits corresponding to a modulation mode in the set of candidate modulation modes at the target BER; obtaining normalized SNRs on the sub-channels; initializing the numbers of bits for the sub-channels; initializing powers for the sub-channels according to the numbers of bits for the sub-channels, the normalized SNRs on the sub-channels and the SNR lookup table; and adjusting the numbers of bits and the powers for the sub-channels in accordance with a principle of maximizing power utilization rate, to obtain the result of the bit and power allocation for the sub-channels.

Abstract: Varying embodiments of the present invention describe a closed loop system for processing the beamforming information, qualifying the expected performance, activating and deactivating the beamforming system. A first embodiment is a method for closed loop beamforming in a wireless communication system, the system comprising a transmitter and a receiver, the method comprising initiating beamforming on a communication channel between the transmitter and the receiver, monitoring the communication channel, periodically determining a condition of the communication channel and controlling beamforming based on the condition of the communication channel.

Abstract: A radio communication system includes a transmission apparatus configured to transmit data using a radio frame formed in one time block, to which a plurality of continuous or discontinuous frequency areas are assigned, and a reception apparatus configured to receive the data transmitted from the transmission apparatus by using the radio frame. The transmission apparatus transmits to the reception apparatus a radio frame provided in the beginning of the radio frame with a pilot which is a known signal used for measurement of reception quality and a control signal used for the control of demodulation at the reception apparatus. The reception apparatus transmits reception quality information concerning reception quality measured by the pilot, and the transmission apparatus performs a transmission process by using a radio frame format which does not include control information for the reception apparatus which has transmitted the reception quality information.

Abstract: A calibration technique to compensate for the phase error between the in-phase and quadrature sampling clocks controlling the quadrature bandpass sampling delta-sigma analog-to-digital demodulator (QBS-ADD) is provided. A low-frequency test tone is injected, up-converted to the RF frequency, and added to an input of the QBS-ADD. The test tone is demodulated by the QBS-ADD into an in-phase signal and a quadrature signal. The in-phase and quadrature signals are filtered and multiplied together to generate a phase error signal, which is subsequently integrated to generate a phase shift control signal being used to correct the phase error between the in-phase and quadrature sampling clocks.

Abstract: A system and method for reducing interference in a wireless communication system may include sending by a transmitter to a receiver a signal sequence s=(s1, s2, . . . , sL) of length L and information bit m, the signal sequence s having an interference signal sequence j=(j1, j2, . . . , jL). The system and method may also include identifying by the receiver an optimal lag ?° of the signal sequence s in relation to the interference signal sequence j, determining an estimate of the information bit m from the optimal lag ?° by the transmitter and calculating the signal to interference plus noise ratio by the receiver.

Abstract: A wireless device comprises a plurality of diverse antennas, an accelerometer configured to determine an orientation of the wireless device, and a processor. The processor is configured to initially select a primary link configuration based on the determined orientation of the wireless device. The primary link configuration designates one or more of the plurality of diverse antennas and one or more diverse antennas of another wireless device configured to transmit the payload messages. The processor is further configured to receive payload messages using the primary link configuration, record a received signal strength indication (RSSI) value for the received payload messages, and periodically test RSSI for alternative link configurations. The processor compares RSSI between the primary link configuration and the alternative link configuration, and revises the primary link configuration if the comparison indicates that the alternative link configuration RSSI is greater than primary link configuration RSSI.

Abstract: A system and method for estimating a channel in a wireless receiver is disclosed. 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. The system comprises a wireless receiver having an estimator programmed according to the method.

Abstract: A wireless communication method by which unnecessary retransmission request is suppressed and feedback information is reduced at the same time in a MIMO communication system. The wireless communication method is provided for transmitting signals by using a plurality of antennas, and has a step of applicably selecting the group configuration of the antennas, and a step of adding data to be used for error detection to a signal to be transmitted by using the antennas, by following the results of the selection.