Abstract: A modulator generates a modulation signal from an input signal. A serial-parallel converter generates a subcarrier modulation signal from the modulation signal. A first operator generates first data by multiplying a predetermined non-singular matrix by the subcarrier modulation signal. A second operator generates second data by multiplying a matrix calculated by multiplying a predetermined transformation matrix by the predetermined non-singular matrix by the subcarrier modulation signal, or multiplying the predetermined transformation matrix by the first data. A synthesizer generates a baseband signal from data obtained by adding the second data to the first data, or data obtained by subtracting the second data from the first data. A transmitter generates a transmission signal from the baseband signal, and transmits the transmission signal to another apparatus via an antenna.

Abstract: A Log-Likelihood Ratio (LLR) combining method and apparatus for Hybrid Automatic Repeat Request (HARQ) in a wireless communication system for reducing a number of the LLR bits of previous packet stored for LLR combining are provided. The LLR combining apparatus includes an LLR combiner for combining a first LLR of a currently received packet and a second LLR of a previously received packet, an LLR buffer for storing the second LLR and a first packet exponent for recovering the second LLR in the same size as the first LLR, and an HARQ controller for determining whether the currently received packet is a retransmission packet or an initial transmission packet, and for controlling the LLR combiner to generate a third LLR by combining the first and second LLRs for the retransmission packet and to bypass the initial transmission packet.

Abstract: A constant amplitude decoding apparatus and method for multiplexed direct-sequence spread spectrum communication system are provided. The constant amplitude decoding apparatus includes: a despreading and demultiplexing module receiving a data stream of a constant amplitude and despreading and demultiplexing the received data stream to restore it to a 2D signal; a decoding module first performing a vertical decoding on the 2D signal and then performing horizontal decoding thereon; a control module determining whether to repeatedly perform vertical decoding and horizontal decoding; and a bit stream information output module outputting the decoding results from the decoding module as a bit stream.

Abstract: A sampling rate converter that converts an incoming stream of data, clocked at a first frequency, to an output stream of data that can be clocked at a second frequency is described. The sampling rate converter up-samples an incoming data stream, filters the up-sampled incoming data stream, interpolates the filtered up-sampled data stream, and then stores the interpolated filtered up-sampled incoming data stream in a FIFO at the first frequency. The interpolated filtered up-sampled data can then be read from the FIFO at the second frequency. A control block that includes a numerically controlled oscillator (NCO) that generated the first frequency is provided. Control of the NCO's production of the first frequency is based on the status of the FIFO, how the data stream is modulated, and the sampling rate ratio of the incoming data stream with respect to the output or read rate of data stream.

Abstract: The present invention relates to a method and a device for decoding precoded signals in a wireless communication system and network node or terminal associated therewith. The wireless communication system comprises a sender and a receiver that share a codebook containing a plurality of precoding matrices. The sender precodes at least a data signal to be transmitted with one of the plurality of precoding matrices. Said method comprising receiving signals from the sender, estimating a channel between the sender and the receiver based on a part of received signals that is known a priori, evaluating relevancies of precoding matrices in said codebook to a precoded signal in the received signals based on at least the estimated channel and the codebook according to a predetermined criterion, and selecting a precoding matrix with maximum relevancy by comparing the evaluated relevancies, and applying the selected precoding matrix for decoding the received precoded signal.

Abstract: Provided is a method of generating an adaptive codebook and a multiple input multiple output (MIMO) communication system using the adaptive codebook. A transmitter and a receiver may generate, from a base codebook based on a matrix associated with statistics of a channel matrix, the adaptive codebook maintaining a unitary characteristic. The transmitter may perform scheduling, transmit filter design, and precoding using adaptive codebook based feedback information.

Abstract: A method and apparatus for decoding of tailbiting convolutional codes (TBCC) are disclosed. The proposed modified maximum-likelihood TBCC decoding technique preserves error correction performance of optimal maximum-likelihood based TBCC decoding, while the computational complexity is substantially decreased since a reduced number of decoding states has been evaluated. Compare to other sub-optimal TBCC decoding algorithms, modified maximum-likelihood TBCC decoding achieves improved packet error rate performance with similar computational complexity.

Abstract: Systems and methods are provided for decoding signal vectors in multiple-input multiple-output (MIMO) systems, where the receiver has received one or more signal vectors based on the same transmitted vector. The receiver linearizes each received signal vector using one or more zero-forcing, MMSE, or other suitable linear equalizers. The components of the equalized signal vectors may be combined using maximum-ratio combining to form the components of a combined equalized signal vector. The components of the combined equalized signal vector may then be decoded individually using a linear decoder.

Abstract: Codebook based communication of precoding data between two stations involves determining a ‘best fit’ precoding at a receiving station, on the basis of channel state measurements taken therein. The best fit precoding is compared with pre-agreed entries in a codebook, and an indicator is sent back to the terminal emitting the analysed signal. The determination is separated into two elements, one being sufficient for use with SU-MIMO, and another being provided, with a second codebook indicator, if MU-MIMO is to be employed. This second codebook indicator points to a codebook of eigenvector representations for the multi-user space in which the channel is persisting.

Abstract: Multi-antenna transmission control presented herein involves generating a set of virtual channel realizations at the transmitter that shares the same second-order statistics as the actual channel realizations observed for a targeted receiver. By making the control-related quantities of interest at the transmitter depend on the long-term statistics of the channel, the actual channel realizations are not needed for transmission control, e.g., for accurate Multiple-Input-Multiple-Output (MIMO) preceding. As such, the use of virtual channel realizations enables transmission control that approaches the “closed-loop” channel capacity that would be provided by full feedback of the (instantaneous) actual channel realizations, without requiring the overhead signaling burden that attends full feedback.

Abstract: A method for accessing extrinsic information in a turbo decoder is disclosed. Operation phases for Forward State Metric Calculators (FSMCs) and Reverse State Metric Calculators (RSMCs) in multiple maximum a posteriori probability (MAP) decoders are misaligned differently based on whether a current half iteration is even or odd. First extrinsic information is read from a memory into the FSMCs and RSMCs using the misaligned operation phases. Second extrinsic information is determined using the MAP decoders. Each row of the second extrinsic information is stored to a different bank in the memory using the misaligned operation phases.

Abstract: Systems and methods are provided for decoding signal vectors in multiple-input multiple-output (MIMO) systems, where the receiver has received one or more signal vectors based on the same transmitted vector. The symbols of the received signal vectors are combined, forming a combined received signal vector that may be treated as a single received signal vector. The combined received signal vector may be equalized by, for example, a zero-forcing or minimum-mean-squared error equalizer or another suitable linear equalizer. Following equalization, the equalized signal vector may be decoded using a simple, linear decoder.

Abstract: A communications system includes a source, a destination, and multiple relays. In a first time period, the source emits a first transmission and a first relay retransmits a prior source transmission. Then, in a second, subsequent time period, the source node emits a second transmission and a second relay transmits the source transmission from the first time period. Optionally, the transmission from the second relay also includes the message from the first relay during the first time period. Similarly, in a third time period, the first relay transmits a message that includes the second relay's transmission and the second source transmission from the second time period. Alternatively, the source node transmit in a first frequency band, the first and second relays receive only in the first frequency band, and retransmit in a second frequency band, and the destination receives in both the first and second frequency bands.

Abstract: Briefly, in accordance with one or more embodiments, in response to receiving a single carrier signal that is not phase locked, channel equalization may be applied to the signal via a channel equalizer. The equalized signal may be phase averaged to provide a signal that is at least partially phase stabilized. The channel equalizer may then be trained by feeding back the at least partially phase stabilized phase reference to the channel equalizer. The resulting signal may then be decoded via coherent or quasi-coherent detection.

Abstract: One of a plurality of candidate data symbols is selected. All possible values of the selected one candidate data symbol are grouped into two or more bit groups. A bit group is selected from the two or more bit groups. A local optimum candidate value from values in the selected bit group is determined for the selected one candidate data symbol for a given set of values corresponding to all of the plurality of candidate data symbols but the selected one candidate data symbol, the local optimum candidate value minimizing a distance value corresponding to a distance between the received data symbol vector and a channel matrix multiplied with the candidate vector, without calculating the distance value. A likelihood value is calculated for a bit in the selected one candidate data symbol based at least in part on the determined local optimum candidate value.

Abstract: Aspects of the present disclosure describe an efficient channel estimation algorithm for high-speed processing of dedicated reference signals. The channel estimation algorithm may utilize one or more compressed interpolation matrices. The compressed interpolation matrices may be selected based on the Doppler value and signal to noise ratio (SNR) of the channel.

Abstract: The disclosure relates to a method for decoding a received signal in a MIMO communication system and in at least one layer, each layer carrying at least one data symbol belonging to a signal constellation. The method includes, for one of the at least one layer, a maximum likelihood detection step. This step includes: selecting one candidate value for the data symbol of the layer, and determining the Euclidian distance between the received signal Y and the data signal transmitted using said candidate value multiplied by said channel matrix H, weighted by the inverse of a noise covariance matrix C such as ?Y??iHixi?C?12, expressed as: ?i?n?Hi?C?12|xi|2?2(HiHC?1Y?0.5?j?i,nHiHC?1Hjxj)x*i+?Hn?C?12|xn|2?2(HnHC?1Y??j?nHnHC?1Hjxj)x*n=?i?n?iR(xi)2?2?iRxi+?nR(xn)2?2?nRxn+?i?n?iI(?xi)2?2?iI?xi+?nI(?xn)2?2?nI?xn. The terms depending on ?k are computed by adding to each of them a predetermined constant depending on the size of the constellation of the layer k, called a constellation dependent constant.

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: The present invention relates to a method in a receiver for decoding at least two received communication signals, wherein the communication signals are modulated, pre-coded by a discrete Fourier transform and transmitted by means of single-carrier frequency division multiple access scheme (SC-FDMA). The method comprises the steps of: performing an antenna combining and equalization on a signal observed at the receiver; performing inverse discrete Fourier transform on a model of the observed signal; whitening a time domain model of the observed signal; and jointly detecting the received at least two communication signals by performing soft value calculations based on maximum likelihood detection of a whitened time domain model using a whitened time domain channel estimate.

Abstract: In various aspects, the disclosure describes systems and methods for decoding of convolutionally encoded signals representing, for example, telecommunications signals such as command or content signals used in digital telecommunications. In various embodiments such aspects of the disclosure provide systems and methods for improving the efficiency, speed, and power consumption of such processes by providing architectures and methods for processing various parts of the encoded data records in parallel, using multiple and optionally specially-designed, dedicated memory registers and multiplexers.

Abstract: In one aspect there is provided a method. The method may include receiving a signal transmitted through a channel; receiving an estimate of the channel; determining from the estimate of the channel at least one statistic representative of a variability of the estimate of the channel; decoding the received signal by at least searching for an output using a plurality of cost metrics determined based on at least the estimate of the channel and the at least one statistic; and providing, based on at least one of the plurality of cost metrics, the output. Related apparatus, systems, methods, and articles are also described.

Abstract: A demodulation reference signal generator includes a non-correlation sequence generator to generate a non-correlation sequence for RS of a first resource block; a first spectrum spreading unit to spread spectrums of elements in the non-correlation sequence for RS to be mapped to a first frequency resource of the first resource block, by using a first group of codes; a second spectrum spreading unit to spread spectrums of elements in the non-correlation sequence for RS to be mapped to a second frequency resource of the first resource block, using a second group of Codes; the first and second frequency resources are adjacent frequency resources used for RS transmission in the first resource block, and the first and second groups of Codes are mirrors in column to each other; and a mapping unit to map the spectrum-spread elements to the first and second frequency resources.

Abstract: A forward error correction encoding method includes: separating a first header section from an inputted packet stream; generating a second payload section by encoding a first payload section of the packet stream, from which the first header section is separated, according to a preset code rate; generating a second header section according to the code rate; and combining the first header section, the second header section, and the second payload section.

Abstract: A method is disclosed for avoiding inter-cell interference in a closed-loop multiple-input multiple-output (MIMO) system using a plurality of codebooks. A base station of a serving cell transmits information about codebooks used in an interfering cell among the plurality of codebooks to a mobile station. The transmission of the information may be made at the request of the mobile station. Alternatively, the mobile station may directly measure information about codebooks used in the interfering cell among the plurality of codebooks. The mobile station measures restricted precoding matrix indexes (PMIs) or requested PMIs based on the codebook information. The measured PMIs are transmitted to the interfering cell and are used to restrict the use of a PMI in the interfering cell.

Abstract: A process for computing Log-Likelihood-ratios (LLRs) in a detector of a wireless communication receiver is disclosed, with the, LLRs being used by a channel decoder. A signal is received from a telecom front end, the signal corresponding to data belonging to a finite set of constellation symbols, each constellation symbol being arranged in a lattice constellation impaired by additive noise and a multiplicative channel. A limited set of distances representative of Euclidian distances between the received signal and a finite set of predetermined constellation symbols are computed, possibly multiplied by the channel. A set of soft decision LLRs are derived from the computed set of distances under the constraint of a limited length of the list of distances. The derived LLRs are completed by clipping values read from a look-up table which is simultaneously addressed by the values of the SNR and a bit index.

Abstract: The present invention relates to a Multi-Input Multi-Output (MIMO) communication system and more particularly, to a method for precoding matrix index (PMI) restriction/recommendation in a multi-cell wireless communication system.

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: Systems and methods are provided for decoding signal vectors in multiple-input multiple-output (MIMO) systems, where the receiver has received one or more signal vectors from the same transmitted vector. For each received signal vector, the receiver evaluates a decoding metric using each possible value of the transmitted signal vector to produce a set of distances. The receiver then combines distances from across the received signal vectors to produce a combined distance associated with each possible value of the transmitted signal vector. Using the combined distances, the receiver may choose among the possible values of the transmit signal vector to determine the actual transmit signal vector.

Abstract: Techniques are described herein that receive communications transmitted according to different operation modes at a multi-mode, programmable receiver system. The multi-mode, programmable receiver system may receive communication signals from transmit antennas in “cells” (e.g., base station transceivers and/or the like) according to one or more operation modes, using receive antennas. The received signals may be converted and processed by various modules of the multi-mode, programmable receiver system to produce an output signal. The multi-mode, programmable receiver system includes modules that are programmable to be selectively enabled or disabled according to an operation mode in accordance with which the multi-mode, programmable receiver system operates.

Abstract: A modified soft output Viterbi algorithm (SOVA) detector receives a sequence of soft information values and determines a best path and an alternate path for each soft information value and further determines, when the best and alternate paths lead to the same value for a given soft information value, whether there is a third path departing from the alternate path that leads to an opposite decision with respect to the best path for a given soft information value. The SOVA detector then considers this third path when updating the reliability of the best path. The modified SOVA detector achieves max-log-map equivalence effectively through the Fossorier approach and includes modified reliability metric units for the first N stages of the SOVA detector, where N is the memory depth of a given path, and includes conventional reliability metric units for the remaining stages of the detector.

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: A communication terminal is provided with: first and second transmission units transmitting signals on a communication line, first and second receiving units receiving signals from another communication terminal; and a communication method switching unit switching the signal communication method. The first transmission unit transmits an electrical current signal to the communication line. The first receiving unit receives a voltage signal obtained by converting, by means of a current/voltage conversion unit, the electrical current signal transmitted from the first transmission unit. The second transmission unit transmits a communication signal to the communication line as a voltage signal. The second receiving unit receives the voltage signal transmitted from the second transmission unit.

Abstract: A system including a first receiver module and a first interference canceller module. The first receiver module generates a first set of decoded codewords by decoding codewords in a received signal and determines if any of the first set of decoded codewords fails cyclic redundancy check (CRC). The first interference canceller module generates a second signal based on a first decoded codeword from the first set of decoded codewords when (i) any of the first set of decoded codewords fails CRC and (ii) the first decoded codeword passes CRC. By subtracting the second signal from the first signal, the first interference canceller module (i) cancels interference of a first codeword, which corresponds to the first decoded codeword, on a second set of codewords, which includes the plurality of codewords and excludes the first codeword and (ii) generates a third signal, which includes the second set of codewords.

Abstract: A receiver for receiving a layer-modulated signal includes: a base layer decoding unit configured to calculate a bit metric including code bit information of a base layer based on the reception signal and decode an information bit of the base layer; and at least one enhancement layer decoding unit configured to decode an information bit of an upper layer of a lower layer based on the decoding results of the lower layer, wherein the base layer decoding unit and the at least one enhancement layer decoding unit are sequentially connected according to the order of the corresponding layers.

Abstract: A method for transmitting synchronization messages in a communications network including a plurality of nodes having a first node and at least one second node, wherein in order to take into account differences in a reference clock frequency of a reference clock and an internal clock frequency of an internal clock of the at least one second node, a compensation interval, with which the second clock count state is adjusted on measurement of a delay time, is subdivided into smaller compensation timespans, and the smaller compensation timespans are used to determine a compensated time value for the delay time with a high degree of accuracy, where the compensated time value is then used to update the time information in the synchronization message.

Abstract: Provided is a maximum likelihood decoding method that includes the steps of; firstly arranging channel impulse responses corresponding to the received signals in a plurality of different orders; secondly specifying the same number of parts as the plurality of different orders in which the channel impulse responses are arranged, so that the received signals are placed in each of the parts; thirdly generating channel matrices each having the channel impulse responses as matrix elements, by using the channel impulse responses arranged in the plurality of different orders, obtaining triangular matrices by applying QR decomposition to the generated channel matrices, and determining at least one combination candidate for each of the parts of the plurality of transmission signals by using the obtained triangular matrices; and fourthly selecting the combination candidates so that a Euclidean distance between the combination candidates determined in the third step is shortest.

Abstract: A received signal includes a plurality of user signals, the plurality of user signals including at least a first user signal and a second user signal. The first user signal corresponds to first user data that has been modulated independently of second user data corresponding to the second user signal. At least one of the first user signal or the second user signal is encoded with a finite state machine encoder independently of the other of the first user signal and the second user signal. The received signal is demodulated, wherein demodulating the received signal includes calculating distances between (i) each transmit symbol in the received signal and (ii) expected symbol values, wherein each expected symbol value corresponds to user data for multiple users including the first user and the second user. User data in the received signal including the first user data and the second user data is decoded based on the calculated distances.

Abstract: In general, the subject matter described in this disclosure can be embodied in methods, systems, and program products for adapting data rate. The method includes receiving a data transmission at a data rate, identifying a first quantity of packets that were not adequately received, and using the first quantity to increase a packet loss level. A second quantity of improper bits in those packets that were adequately received at the data rate are identified, and the second quantity is used to increase a bit error level. As a result of having determined that the first value does not satisfy a first criterion for reducing the rate of the data transmission and that the second value does satisfy a second criterion for increasing the rate of the data transmission, an instruction is sent for causing the sending device to increase the rate of the data transmission.

Abstract: A method for identifying a corrupted received signal that includes symbols is described. Each symbol may have a value of a Galois field associated therewith. The receiver may be configured to store a logarithm of normalized probability mass functions and corresponding Galois field values for each of the symbols. The normalized probability mass functions may be normalized with respect to a greatest probability mass function of a given symbol. The method may include comparing, for each symbol, a logarithm of normalized probability of an n-th best probability value with a respective threshold, counting a number of the logarithms that exceed the respective threshold and generating, for each symbol, a score corresponding to the number. The method may also include calculating a moving average of the scores, and comparing the moving average with an output threshold and flagging a just received symbol as corrupted based upon the comparison.

Abstract: The present invention relates to a method and apparatus for deconvolving a noisy measured signal obtained from a sensor device (100), said noisy measured signal (y(t)) being the sum of the convolution product (x(t)N(t)) of an input signal (x(t)) of the sensor device, representative of a feature of physical quantity, by a convolution kernel (N(t)) defined by the response function of the sensor device (100) and a noise which interfere with the measure. The method is characterized in that said method comprises an estimate computation step (400) in the course of which a minimal estimate (xmin(t)N(t)) of the convolution product of the input signal by the convolution kernel of the sensor device is computed in order that said minimal estimate stays below the noisy measured signal (y(t)) and has at least one point in common with the noisy measured signal (y(t)).

Abstract: The present invention relates to method of transmitting and receiving signals and a corresponding apparatus. One aspect of the present invention relates to an efficient layer 1 (L1) processing method for a transmitter and a receiver using data slices.

Abstract: A configurable decoder within a receiver (for example, within a wireless communication device) includes numerous decoders. In one mode, the multiple decoders are used to decode different sub-packets of a packet. When one decoder completes decoding the last sub-packet assigned to it of the packet, then that decoder generates a packet done indication. A control circuit receives the packet done indications, and when all the decoders have generated packet done indications then the control circuit initiates an action. In one example, the action is the interrupting of a processor. The processor responds by reading status information from the control circuit, thereby resetting the interrupt. End-of-packet markers are usable to generate packet done indications and to generate EOP interrupts. Similarly, end-of-group markers are usable to generate group done indications and to generate EOG interrupts. The decoder block is configurable to process sub-packets of a packet using either one or multiple decoders.

Abstract: A MIMO detection method for a receiver in a MIMO system using N-QAM for modulation, the MIMO detection method including generating a plurality of symbol vector sets and a plurality of search radiuses, selecting a candidate symbol vector set corresponding to a highest level of a multilevel structure of N-QAM constellation, generating a search space corresponding to a lower level of the multilevel structure of N-QAM constellation according to the selected candidate symbol vector set, confirming which level the search space corresponds to, and generating a detection signal according to the search space when the level of the search space is the lowest level of the multilevel structure of the N-QAM constellation.

Abstract: A method of operation of a communication system includes: calculating a shift distance of a received signal having a distortion; calculating an approximate likelihood of the received signal matching a transmitted signal from the shift distance; determining a bias factor from the distortion; and selecting a determined modulation maximizing a combination of the approximate likelihood and the bias factor for communicating with a device.

Abstract: Method and arrangement for use in a receiving node, for determining whether received data is encoded with a certain channel code candidate. The method involves obtaining baseband data encoded with an unknown channel code and calculating the respective posterior probabilities that a set of syndrome checks are satisfied, given the obtained data, which syndrome checks are associated with the channel code candidate. The method further involves combining the posterior probabilities and determining whether the channel code candidate was used for encoding the obtained data, based on the combined posterior probabilities.

Abstract: The invention relates to a method for acquisition of a signal (2) emitted by a satellite, by a receiver in a satellite Positioning System using a multi-code correlation and a multi-frequency correlation, also comprising the step in which if the error induced at the output from a first frequency-augmented correlator (14) at each instant in an integration period is greater than the code space between code correlators (12), the summated results of the first frequency-augmented correlator (14) are transferred to the summated results of a second frequency-augmented correlator (14), the second frequency-augmented correlator (14) using the same frequency-shift as the first frequency-augmented correlator (14) and being associated with a second code correlator (12) that is shifted by the code space from the first code correlator (12) with which said first frequency-augmented correlator (14) is associated.

Abstract: In one embodiment of a communications network, the predetermined encoding scheme and symbol constellation configurations are chosen so that the range in channel qualities that the encoding scheme and symbol constellation configurations are designed to be utilized within overlap with each other. This overlapping provides hysteresis, which reduces the frequency with which a subscriber must alter encoding scheme and symbol constellations. Reducing the frequency of changing encoding scheme and/or symbol constellation eliminates the communication overhead associated with these changes and increases throughput by enabling the subscriber to spend more time transmitting data.

Abstract: A device for decoding code symbols which are interfered with a distortion during a predetermined distortion time interval includes a reliability information generator to provide reliability information based on the code symbols and a decoder to decode the code symbols into code words. The decoder is configured to decode the code symbols based on weighted reliability information, wherein the weighted reliability information is generated from the reliability information by applying a first weight during times not coinciding with the distortion time interval, and by applying a second weight different from the first weight during times coinciding with the distortion time interval.

Abstract: To demodulate a quadrature amplitude modulation (QAM) signal, a reception point is determined corresponding to a symbol in the QAM signal that is received where the symbol is mapped to one reference point of a plurality of reference points in a rotated constellation and the plurality of reference points are represented by an in-phase (I) coordinate and a quadrature-phase (Q) coordinate. A plurality of candidate points corresponding to a portion of the plurality of reference points are selected based on distances between the reception point and the respective reference points. The reception point is demapped by calculating a plurality of log-likelihood ratios based on the plurality of candidate points, the plurality of log-likelihood ratios corresponding to bits of data represented by the reception point.

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.