Abstract: A digital subscriber line XDSL communication system for optimizing dynamic range in digital multi-tone modulated (DMT) modems. The system comprises a digital subscriber line access multiplexer (DSLAM) and at least one modem. The DSLAM distributes a near end crosstalk (NEXT) model of anticipated disturbance from neighboring disturber subscriber lines. The at least one modem has a transmit path and a receive path. The at least one modem couples to the DSLAM and is responsive to the distributed NEXT model to adjust a dynamic range of an analog portion of the receive path to accommodate the anticipated disturbance modeled in the distributed NEXT model.

Abstract: A method for generating an amplified radio frequency (RF) signal is provided. In-phase (I) and quadrature (Q) signals are received and interleaved so as to generate a time-interleaved signal. Delayed time-interleaved signals are then generated from the time interleaved signal, and each of the delayed time-interleaved signals is amplified so as to generate a plurality of amplified signals. The amplified signals are then combined with a transformer, where the delayed time-interleaved signals are arranged to generate a filter response with the transformer.

Abstract: Processing may be performed by a first device on behalf of a second device to offload processing from the second device. In some aspects a device from which processing has been offloaded may be advantageously adapted to consume less power, have a smaller size, and have less complexity. Offloaded processing may be employed to enable a first device to process data for transmission and then send the data to another device for processing. Offloaded processing may be employed to enable a first device to process data on behalf of a second device and then send the processed data to the second device. In some aspects the data may be waveform encoded for wireless transmission between the devices. Offloaded processing may be implemented in a static manner or in a dynamic manner.

Abstract: Devices, networks, systems and methods for coordinating communications on multi-path radio transmission mesh networks include evaluating available path metrics to ensure the best available connection routes through the network can be understood and utilized. The evaluation of the path metric may include comparing an xth percentile signal strength indication (RSSI) value with a predetermined RSSI threshold level, wherein x is strategically selected to address multi-path signal fading issues.

Abstract: A communication system for performing serial communication using a first level, a second level and a middle level includes a first device; a second device; and a signal line, wherein the serial communication is performed by a first communication format signal sent together with a clock from the first device to the second device under a first mode, and a second communication format signal sent from the second device to the first device under a second mode, wherein the first communication format signal includes a first start bit, a plurality of first data bits, a plurality of first inverted data bits, a first check bit generated from the first data bits and a first inversion check bit, and the second communication format signal includes a second start bit, a plurality of second data bits, and a second check bit generated from the second data bits.

Abstract: A multicarrier transmitter and a multicarrier receiver improve the reception characteristic of hierarchical modulation multiplex communication. A base station transmits a multicarrier superposition signal of a modulated signal addressed to a far user (a far-user addressed signal) and a modulated signal addressed to a near user (a near-user addressed signal) and modulated with a modulation multivalued number different from that of the far-user addressed signal. The base station separates the far-user addressed signal into frequency range signals, serial/parallel-transforms the near-user addressed signal to generate N1 parallel signals, and combines the generated N1 frequency components and the N1 parallel signals. Since the far-user receiver changes the near-user addressed signal into white noise by inverse discrete Fourier transform, the far-user receiver can demodulate the far-user addressed signal with high accuracy.

Abstract: Methods for transmission and detection, as well as a transmitter and a receiver for performing the methods are disclosed. An example transmission method according to an aspect of the invention includes determining of a modulation vector for an information symbol vector and modulating subcarriers with elements of the modulation vector. Example resulting out-of-band signal power emission improvements over prior art are demonstrated.

Abstract: In one embodiment, a Television (TV) receiver to perform a method of synchronizing a demodulator at a Viterbi decode input in the TV receiver using one or more bit de-interleaved even and odd Orthogonal Frequency Division Multiplexing (OFDM) symbols is provided. The method includes (i) performing a Viterbi decoding on the bit de-interleaved even and odd OFDM symbols when a frame boundary does not exist for the bit de-interleaved even and odd OFDM symbols, (ii) performing a convolutional encoding on an decoded data output of the Viterbi decoding, (iii) determining whether an output of the convolutional encoding of the bit de-interleaved OFDM symbols matches an input at a Viterbi decode, and (iv) determining whether the output of the convolutional encoding of the bit de-interleaved even and odd OFDM symbols matches with a SYNC pattern or a SYNC? pattern to obtain a RS packet align boundary.

Abstract: A formatted data unit that was transmitted by a transmitter is received at a receiver. Received signal points are determined based on the received formatted data unit. Actual transmitted signal points corresponding to the received formatted data unit is determined at the receiver based on information known a priori by the receiver. An error is determined between the received signal points and the actual transmitted signal points determined at the receiver. An indicator of impulse noise is generated based on the error.

Abstract: The teachings herein provide a method and apparatus for partitioning sets of MIMO streams, for joint processing. In particular, there is an optimum or otherwise best partitioning of a set of MIMO streams into a first subset to be jointly processed and a second subset to be suppressed as interference with respect to that joint processing. Of course, more than one partitioning may be used, e.g., across different joint processing stages and/or at different times, such that all streams of interest are processed. Correspondingly, the present invention provides a method and apparatus for selecting an optimum or otherwise relative “best” subset of MIMO streams for processing together in a joint process, from among a larger set of MIMO streams. The method and apparatus may, for example, be employed in a multi-stage joint processing receiver, where subset selections are performed on a per-stage basis.

Abstract: Provided are a transmitting apparatus and a transmitting method in a multiple input multiple output system. A power allocation controller includes a block Tomlinson-Harashima precoder (BTHP) that precodes and outputs data to be transmitted to each user in a nonlinear scheme. The BTHP removes and outputs inference signals from data for each user based on the channel information that is fed back from the users. The data for each user output from the BTHP are allocated with power by the power allocation controller. The power allocation controller calculates power allocation parameters so that receiving minimum distances at receiving ends for each user that receive data through the MIMO antennas are the same, and allocates the calculated parameters to data for each user.

Abstract: This disclosure concerns beam-forming vectors and beam-forming matrices for multiple-input, multiple-output (MIMO) communications systems. These systems, from the method perspective, provide, according to one embodiment, a method of feeding back, to a transmitter from a receiver in a MIMO communications system, at least part of a beam-forming vector of a beam-forming matrix, wherein: the vector relates to a spatial stream of the MIMO system; the vector comprises a series of elements; each element specifies a beam-forming weight for a respective transmit antenna of the transmitter; and the method comprises: calculating a scaling factor that would scale a first element of the vector to a value of one; scaling the other element or elements of the vector with the scaling factor; and feeding back the scaled other element or elements to the transmitter to inform a beam-forming process.

Abstract: A transmitter and a receiver of a multiple input multiple output (MIMO) communication system may use two codebooks to share channel information. When the transmitter uses eight transmit antennas, two codebooks may be defined. When the receiver generates two precoding matrix indicators from two codebooks, a combination of the two precoding matrix indicators may indicate a single precoding matrix. Precoding matrix candidates may also be defined.

Abstract: A multi-antenna channel estimation method based on polyphase decomposition includes: receiving frequency domain received signals transformed using discrete fourier transformation (DFT) in pilot symbols; performing phase correction on the frequency domain received signals; performing polyphase decomposition on the frequency domain received signals which are corrected using phase correction and acquiring polyphase signals; performing interpolation on the polyphase signals and acquiring the estimation values of the multi-antenna channel parameters with various linear combinations on each frequency; acquiring decorrelation array based on the pilot structure of the transmission antenna and decorrelating the estimation values of the multi-antenna channel parameters with various linear combination on each frequency using the decorrelation array and acquiring channel parameters of the pilot symbols on each frequency; acquiring channel parameters of data symbols based on the channel parameters of the pilot symbols.

Abstract: Modern coding and modulation techniques have greatly improved the transmission of signals. A method is described including receiving a stream of data bits, demultiplexing the stream into a first and second substream, encoding the first and second substream using a low density parity check coding process, and mapping the first substream to a first region of a symbol constellation map and the second substream to a second region. Also, an apparatus is described including a demultiplexer that produces a first and second bitstream, a first encoder that encodes the first substream using a low density parity check coding process at a first encoding rate, a second encoder that encodes the second substream at a second rate, and a symbol mapper that maps bits from the first substream to a first region of a symbol constellation map and maps bits from the second substream to a second region.

Abstract: The present invention relates to a method and apparatus for transmitting and receiving data. A data transmission method from a sender terminal to a receiver terminal in a MIMO system using a variable frequency band according to one embodiment of the present invention comprises: repeatedly generating a signal field depending on a frequency band that is applied to the transmission of a data frame; generating a data field including the data; generating a data frame including the signal field and the data field; and transmitting the data frame to the receiver terminal. The present invention is advantageous in that a signal field which is transmitted together with the data being transmitted from the sender terminal to the receiver terminal in the MIMO system can be sent more efficiently.

Abstract: A receiver in a multiple-input multiple-output (MIMO) system is provided. The receiver includes a channel estimator estimating a channel based on a receiving signal, a minimum mean square error (MMSE) based reciprocal log likelihood ratio (R-LLR) calculator connected with the channel estimator and calculating an R-LLR based on the receiving signal and the estimated channel, and a channel decoder connected with the MMSE based R-LLR calculator and decoding the channel and the receiving signal based on the calculated R-LLR, wherein the R-LLR is calculated based on the reciprocity.

Abstract: A system for enhancing performance of a multiple-input-multiple-output (MIMO) receiving system is provided. The performance enhancement system includes a MIMO receiving system having N branches and is configured to operate in accordance with one or more legacy MIMO receiving classes, types and schemes; a radio distribution network (RDN) connected to the MIMO receiving system and including one or more beamformers, wherein at least one of the beamformers is being fed by two or more antennas so that a total number of the antennas in the system is M which is larger than N; and a control module configured to tune the one or more beamformers based on legacy MIMO signals derived from the MIMO receiving system in various methods depending on the MIMO class/type, so that the RDN adds gain and antenna directivity to the MIMO receiving system.

Abstract: A method and circuit for performing channel equalization in a high speed transmission system comprising a transmitter and receiver. An application specific digital signal processor, ASDSP, performs channel equalization and compensation on digital data received from an analogue-to digital converter of the receiver. The ASDSP is operable to execute an application specific set of op-codes needed for performing channel equalization and compensation. An ASDSP register is coupled between the ASDSP and a system CPU in a feedback loop for performing channel equalization at the receiver. The ASDSP stores equalizer parameters and bit error rate measurements used by the ASDSP for performing channel equalization and compensation. An ASDSP program storage memory, coupled to and accessible by the ASDSP, stores an ASDSP micro-sequence program for controlling the processing steps for channel equalization and dataflow through the ASDSP.

Abstract: An embodiment of the present invention includes a technique to calibrate receiver and transmitter in a communication system. N digitized samples I(n) and Q(n) are stored. The N digitized samples represent in-phase and quadrature (I-Q) components, respectively, of a down-converted signal from a receiver. The I-Q components are generated from a quadrature demodulator or modulator having I-Q imbalance. Phase and gain adjustment constants are computed from the N digitized samples to compensate for the I-Q imbalance using a closed form solution. Another embodiment of the present invention includes a technique to calibrate a transceiver in a communication system without using a calibrated reference receiver. A first test signal at a first frequency is injected to a transmitter having a quadrature modulator with I-Q imbalance. The quadrature modulator has a carrier frequency. The transmitter generates a transmitter signal.

Abstract: An apparatus for transmitting and receiving broadcasting-communication data, the apparatus including an original signal generator configured to receive the original data and generate baseband original signals, a first modulator configured to receive the baseband additional signals and generate original signals of a predetermined band, an additional signal generator configured to receive the additional data and generate baseband additional signals, a second modulator configured to receive the baseband additional signals and generate additional signals of a predetermined band, an average power controller configured to control an average power of the additional signals of the predetermined band, an inserter configured to insert the additional signals of the predetermined band with a controlled average power to the original signals of the predetermined band to thereby generate mixed signals of a predetermined band, and a transmitter configured to transmit the mixed signals of the predetermined band.

Abstract: A transmitter for performing multicarrier modulation comprising a processing unit configured to generate a multicarrier data signal comprising a plurality of subcarriers, wherein each of the plurality of subcarriers represents at least one data bit of a plurality of data bits, select a subset of the subcarriers based on signal quality information about one or more of the subcarriers, construct a kernel signal comprising the subset of subcarriers, and create a digital signal comprising combining the multicarrier data signal and a peak-to-average ratio (PAR) reduction signal based on the kernel signal, wherein a PAR of the digital signal is less than a PAR of the multicarrier data signal.

Abstract: A disclosed precoder circuit is used for differential phase shift keying and includes multiple levels of parallel precoder units, each of which is configured to perform a precoding operation using a data signal having multiple symbols and one of a fixed value and a one-symbol preceding modulated signal output from a preceding-level parallel precoder unit so as to obtain a modulated signal, precoding operations of the parallel precoder units being simultaneously performed in a parallel fashion; multiple levels of re-timing units configured to synchronize modulated signals output from the parallel precoder units; and multiple levels of offset units, each of which is configured to add a phase difference between the fixed value and the one-symbol preceding modulated signal to the modulated signals output from the corresponding re-timing units.

Abstract: A method for pre-processing a signal prior to receipt of the signal by a non-linear device (NLD) to compensate for AM-AM distortion and AM-PM distortion of the signal by the NLD. The method includes generating a modified amplitude rk based on an amplitude xk derived from a digitized envelope Ri,k of the signal, generating a scale factor ck based on the modified amplitude rk and the amplitude xk, generating an AM-AM compensated signal based on the scale factor ck, generating a first AM-PM phase compensation value based on the modified amplitude rk, and generating an AM-AM and AM-PM compensated signal by modifying a phase of the AM-AM compensated signal based on the first AM-PM phase compensation value.

Abstract: An apparatus comprises a differential equalizer having: a) a first differential input, b) a second differential input, c) a first differential output, and d) a second differential output; a frequency detector coupled to the first and second differential inputs; an amplifier coupled to a first differential output and a second differential output of the differential equalizer; and a logical combiner having a first input coupled to an output of the frequency detector and an output coupled to a control input of the amplifier, wherein the logical combiner can mask at least one received de-emphasis parameter.

Abstract: A peak suppressing apparatus includes a pre-emphasis section that performs a pre-emphasis process on a signal, which is to be wirelessly transmitted and a peak of which is to be suppressed, the pre-emphasis process emphasizing a given frequency range component of the signal, a clipping section that limits, to a given threshold value, an amplitude of the signal that has been subjected to the pre-emphasis process, a de-emphasis section that performs a de-emphasis process on the signal, whose amplitude has been limited, the de-emphasis process suppressing the given frequency range component of the signal, and a frequency converter that converts, to allow wireless transmission, a frequency of the signal that has been subjected to the de-emphasis process.

Abstract: An arrangement of interleavers allocates bits from an input symbol across sub-symbols transmitted via sub-carriers of multiple orthogonal frequency division multiplex (OFDM) carriers. The input bits are allocated in a fashion to provide separation across subcarriers, and rotation of sub-symbols across the OFDM carriers provides additional robustness in the present of signal path impairments.

Abstract: A communication apparatus and a channel estimating method for performing channel estimations with high precision. The communication apparatus, which receives multicarrier signals comprising a plurality of subcarriers, has a first estimating unit that generates temporary channel estimation values from pilot signals located in any ones of a plurality of received subcarriers; a second estimating unit that generates a virtual channel estimation value sequence related to the frequency bands other than the frequency bands of the plurality of subcarriers and that combines the generated virtual channel estimation value sequence with the plurality of temporary channel estimation values to generate a channel estimation value sequence corresponding to a predetermined frequency bandwidth; and a generating unit that uses this generated channel estimation value sequence to generate channel estimation values related to any ones of the plurality of subcarriers.

Abstract: Disclosed herein are methods of processing transmissions in a wireless communication system to detect whether a transmission unit contains transmitted data, systems for processing transmissions in a digital communications system to detect the same, receivers for processing transmissions in a wireless communications system and computer readable media implementing a method for processing the same. In one embodiment, a method of processing transmissions in a wireless communication system to detect whether a transmission unit contains transmitted data includes: generating an averaged function of bit reliability indicators from a plurality of received samples and applying a test to compare an average of ln cosh(·) (natural logarithm of the hyperbolic cosine) values for the reliability indicators, with a factor proportional to an average signal-to-disturbance ratio of the plurality of samples to determine if the transmission unit contains transmitted data.

Abstract: A system for decoding frequency modulated signals includes a glue logic module, a key matrix, and a driver coupled to the key matrix. The glue logic module provides a pre-scaled frequency signal, while the key matrix receives the pre-scaled frequency signal. The driver decodes the pre-scaled frequency signal to generate at least one event update corresponding to a frequency of the pre-scaled frequency signal.

Abstract: A method of recovering a clock signal from a digital signal in a receiver includes generating a representation of an eye diagram from symbols of the digital signal, in which the symbols are sampled at a sample rate such that the representation of the eye diagram is generated by a plurality of samples. The generated representation is converted into an array of data elements having a first set of data corresponding to the plurality of samples, and a second set of data representing a plurality of data bins. A plurality of measurements are performed on the array of data elements and/or the eye diagram to obtain a plurality of measurement outputs corresponding to the plurality of samples, which are combined at each sample. A sample is selected as a clock sample based on results of the combination.

Abstract: A receiving circuit, a transmitting circuit, a micro-controller, and a method for power line carrier communication. The receiving circuit includes: an analog amplifier, a receiving filter, an analog-to-digital converter, a digital mixer, a digital filter, and a digital demodulator connected successively. The transmitting circuit includes: a digital modulator, a gain controller, a digital-to-analog converter, a transmitting filter, and a transmitting amplifier connected successively. The micro-controller includes a central processor and the receiving circuit or the transmitting circuit. The method for power line carrier communication can be implemented based on the receiving circuit or the micro-controller.

Abstract: Incoming data at a high-speed serial receiver is digitized and then digital signal processing (DSP) techniques may be used to perform digital equalization. Such digital techniques may be used to correct various data anomalies. In particular, in a multi-channel system, where crosstalk may be of concern, knowledge of the characteristics of the other channels, or even the data on those channels, may allow crosstalk to be subtracted out. Knowledge of data channel geometries, particularly in the context of backplane transmissions, may allow echoes and reflections caused by connectors to be subtracted out. As data rates increase, fractional rate processing can be employed. For example, the analog-to-digital conversion can be performed at half-rate and then two DSPs can be used in parallel to maintain throughput at the higher initial clock rate. At even higher rates, quadrature techniques can allow analog-to-digital conversion at quarter-rate, with four DSPs used in parallel.

Abstract: Pilot symbol assisted modulation (PSAM) techniques for Rayleigh and Rician fading channels are derived. Previous techniques implement PSAM signal detectors as an ad-hoc design, using pilot symbols to first estimate channel gain, and then using channel gain estimates in a conventional coherent detector to make data decisions. Although this structure may be effective for binary phase shift keying in Rayleigh fading, it is suboptimal for Rician fading and for 16-ary quadrature amplitude modulation in Rayleigh fading. According to techniques disclosed herein, a PSAM signal detector jointly processes pilot symbols and data symbols. The performance of signal detectors according to embodiments of the invention is analyzed and compared with that of conventional detectors. Numerical results are presented to show that the performance gain of a proposed new PSAM signal detector over conventional PSAM detectors can be as much as 2 or 3 dB for Rician fading in some cases.

Abstract: Provided is a wireless communication device which can improve the notification accuracy of the channel state information (CSI) without straining the feedback circuit. In this device, a channel estimator (105) uses a pilot signal input from a wireless receiver (102) to estimate the channel and obtain a plurality of path gains in each of a plurality of delay periods. Then, the channel estimator (105) outputs the plurality of path gains to a quantizer (107). The quantizer (107) quantizes the plurality of path gains in the number of notification bits corresponding to each of the plurality of delay periods based on the correspondence of the delay period and the number of notification bits input from a setting unit (106).

Abstract: Provided are a decoding apparatus and method. The decoding apparatus includes a repository and a configuration unit. The repository stores a plurality of functional units having an input port and an output port which are respectively represented as tokens. The configuration unit receives decoder description which includes an identifier of at least one of the functional units and connection relationship information between the functional units, selects each functional unit corresponding to the received identifier from the repository, and connects the selected functional units by using the token to configure a variable decoder. The decoding apparatus and method defines the connection relationships between a plurality of functional units that configure a decoder, and thus can quickly and dynamically configure a decoder suitable for various encoding schemes.

Abstract: Systems and methods are provided for computing soft information for digital information based on a received signal, where the received signal suffers from noise and interference. A receiver that decodes the received signal may estimate channel information, such as the channel gain, associated with the interfering source. The receiver may also obtain modulation information through a backbone network or by decoding control information transmitted by the interfering source. Using the modulation information and the channel information, the receiver may estimate the effect that interference has on the received signal, and may compute soft information (e.g., a log-likelihood ratio) for the digital information.

Abstract: A low complexity system and method for operating a receiver in order to estimate an offset between the actual sample clock rate 1/TS? of a receiver and an intended sample clock rate 1/TS. The receiver captures samples of a received baseband signal at the rate 1/TS?, operates on the captured samples to generate an estimate for the clock rate offset, and fractionally resamples the captured samples using the clock rate offset. The resampled data represents an estimate of baseband symbols transmitted by the transmitter. The action of operating on the captured samples involves computing an error vector signal and then estimating the clock rate offset using the error vector signal. The error vector signal may be computed in different ways depending on whether or not carrier frequency offset and carrier phase offset are assumed to be present in the received baseband signal.

Abstract: In one embodiment, a receiver comprises an automatic gain controller (AGC), an equalizer, a controller, and a register interface. The AGC makes gain adjustments to compensate for changes in the average amplitude of a received signal. The equalizer has a coefficient updater that calculates coefficients and a finite impulse response (FIR) filter that applies the coefficients to the received signal to generate an equalized signal. During gain adjustments by the AGC, the register interface provides a weight freeze signal to the coefficient updater, which subsequently freezes the updating of the coefficients for a freeze duration period. Then, register interface provides a scaling factor, generated by the controller based on the size of the gain adjustment, to the coefficient updater. At the end of the freeze period, coefficient updater applies the scaling factor to the coefficients and unfreezes the coefficient updating.

Abstract: An apparatus for canceling interference includes a plurality of converters, a plurality of interference cancellation units, a plurality of variance detectors, and an output selecting unit. The plurality of converters converts a plurality of received signals to a plurality of frequency domain signals, respectively. The plurality of interference cancellation units cancel interference in the plurality of frequency domain signals using a plurality of interference cancellation schemes to generate a plurality of interference-canceled signals corresponding to the plurality of interference cancellation schemes, respectively. The plurality of variance detectors measure a plurality of amounts of residual interference corresponding to the plurality of interference-canceled signals, respectively.

Abstract: A receiving device includes a FFT unit performing FFT on an input signal of a time domain to transform the input signal into a plurality of signals of frequency domains and outputting the plurality of signals of the frequency domains, a signal extracting unit extracting a signal with a power that is greater than a threshold value from among the plurality of signals of the frequency domains output from the first FFT unit and outputting the extracted signal, an IFFT unit performing IFFT on the extracted signal output from the signal extracting unit, a subtracting unit subtracting the extracted signal output from the IFFT unit from the input signal and outputs a subtracted signal, and a second FFT unit transforming the subtracted signal output from the subtracting unit into a signal of the frequency domain by performing the FFT on the subtracted signal output from the subtracting unit.

Abstract: The invention relates to apparatus for the receipt of digital data which is transmitted as a data signal from a remote location and a method by which the receiving apparatus can be designed with a configuration to improve the ability to receive the data signal. The design of the configuration is generated with reference to at least one decision metric which is adapted to suit the known characteristics of the data signal which is being received.

Abstract: A method of reducing signal correlation in a symmetrical adaptive canceller link comprising spectrally inverting one of a first carrier signal and a second carrier signal by causing a spectral inversion of one of the first and second carrier signals using a modulator, transmitting the first and second carrier signals within a bandwidth to a remote receiver using a transmitting device such that a composite carrier signal results, and cancelling at least one of the first carrier signal from the composite carrier signal using a cancellation technique such that the second carrier signal results on one end of the link and the second carrier signal from the composite carrier signal using a cancellation technique such that the first carrier signal results on the opposite end of the link.

Abstract: According to an embodiment, a semiconductor integrated circuit includes an amplifier, an interference wave suppression unit, a coupler and a filter control circuit. The interference wave suppression unit includes a filter being controlled to be on or off. The filter is configured to suppress an interference wave component of an amplified signal to output the signal as an output signal when the filter is on. The coupler is configured to detect an input signal or the output signal. The filter control circuit controls the filter to be on when a signal level of a detection input signal or a detection output signal detected by the coupler is greater than or equal to a reference value, and controls the filter to be off when the signal level is smaller than the reference value, at arbitrary determination timing in a period of time between a transmission and a reception.

Abstract: Apparatus and methods are provided for computing soft information at a receiver having a plurality of receive antennas. The receiver may be a mobile station or a base station, and can receive a signal vector that includes an intended signal from a first source as well as interfering signals from one or more other, interfering sources. The receiver can determine modulation information, such as the modulation scheme, used by each of the interfering sources. The mobile station can also estimate channel information, such as channel gain information, associated with each interfering source. Using the modulation and channel information, the receiver can compute soft information, such as a log-likelihood ratio. In some embodiments, the receiver can adaptively determine which interference sources and which receive antennas to use when computing the soft information.

Abstract: Systems and/or methods for communications wherein a plurality of spatial streams are received. Each of these spatial streams comprises a symbol having at least one phase shifted pilot signal. The Minimum Mean Square Error (MMSE) estimates of the phase shifted pilot signals are computed and the MMSE estimates are used to estimate phase errors for the symbols.

Abstract: MIMO transmitter with a reconfigurable pooled digital filter is disclosed. A processor uses the output of an envelope detector to set parameters of the filter to minimize the number of instructions per second and the amount of power required by the filter to perform. The processor uses an algorithm or a lookup table stored in memory to select the combination of filter parameters. The parameters may be selected from at least one of: a number of taps, a filter length, a word length, a coefficient quantization, a sampling rate, bits per sample, a sampling bit, a tap delay and a coefficient length. After selecting a combination of filter parameters, the processor sends a control signal to the adaptive filter. The pooled adaptive filter reconfigures itself in accordance with the selected filter parameters.

Abstract: A method and apparatus for processing a signal in a wireless communication system. The method comprises: receiving a signal at a receiver over a wireless channel; sampling the signal to produce a plurality of signal samples; and supplying the samples to an equaliser implemented in software running on a processor of the receiver, the equaliser being configured to process the samples using at least one equaliser time period having a nominal length. The method further comprises dynamically determining one or more characteristics of the channel; in dependence on the determined channel characteristics, dynamically selecting between a first operational state of the equaliser in which the nominal length is used and a second operational state of the equaliser in which an alternative length is used in place of the nominal length; and processing the samples in the equaliser using the determined equaliser time period length.

Abstract: A method of estimating a symbol boundary for adaptive time synchronization in a communication system is presented. An embodiment of the method includes receiving a signal comprising a plurality of OFDM symbols from receiver chains. The OFDM symbols include at least a long training field (LTF) symbol. The method further includes determining a normalized correlation signal based on correlation between the received LTF symbol and a reference symbol for each of the receiver chains for different lags. Also, the method includes estimating an energy window length for the normalized correlation signal. The energy window length includes at least one of channel delay spread and a maximum cyclic shift applied to the signal. The method then includes estimating the symbol boundary associated with the received LTF symbol based on a position of peak energy of the normalized correlation signal using the estimated energy window length.

Abstract: A control signal receiver includes a converting circuit and a synchronization detection circuit. The converting circuit generates a complex control symbol stream including transmission configurations by converting an input signal. The synchronization detection circuit generates a first bit stream by applying a first determination criterion to the complex control symbol stream and generates a first synchronization signal by comparing the first bit stream with a reference synchronization word. The synchronization detection circuit generates a second bit stream by applying the first determination criterion and a second determination criterion to the complex control symbol stream in that order and generates a second synchronization signal by comparing the second bit stream with the reference synchronization word. The synchronization detection circuit outputs one of the first synchronization signal and the second synchronization signal as asynchronization enable signal.